Method and apparatus for controlling transmission power of sounding reference signals in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to operations of a terminal and a base station in a wireless communication system, and relates to a method by which the terminal controls transmission power of sounding reference signals and reports sounding reference signal power headrooms to the base station, in order to ensure signal quality during transmission of the sounding reference signals and improve channel estimation accuracy of the base station, and to an apparatus capable of performing same.

Description

Method and device for controlling sounding reference signal transmission power in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method in which a terminal controls the transmission power of a sounding reference signal and reports sounding reference signal power headroom and additional information to a base station in order to ensure signal quality when the terminal transmits a sounding reference signal and to improve the channel estimation accuracy of the base station, and an apparatus capable of performing the same.

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

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

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

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

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

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

[0008] As various services can be provided following the development of wireless communication systems as described above, measures to smoothly provide these services are required. In particular, to improve the channel estimation accuracy of a base station based on a sounding reference signal, a method is required for a terminal to control the power of the sounding reference signal and to report the sounding reference signal power headroom and additional information to the base station.

[0009] The technical problem of the present disclosure is to provide a method and an apparatus for improving the channel estimation accuracy of a base station by ensuring the quality of the signal when a terminal transmits a sounding reference signal.

[0010] As one aspect of the present disclosure, a method performed by a terminal in a wireless communication system is provided, the method comprising: determining a maximum output power for a sounding reference signal (SRS) within a range of maximum output power for the SRS; and determining a transmission power for the SRS based on the determined maximum output power, wherein the lower limit of the range of maximum output power for the SRS is (P PowerClass - ΔP PowerClass - ΔT RxSRS Established based on ), and the above P PowerClass represents the maximum terminal power defined for each band, and the above ΔP PowerClass is set to 3dB or 0dB, and the above ΔT RxSRS can represent a value applied during SRS transmission in an SRS resource set configured for antenna switching.

[0011] In one aspect of the present disclosure, a terminal of a wireless communication system is provided, the terminal comprises: at least one transceiver; at least one processor connected to communicate with the at least one transceiver; and at least one memory connected to communicate with the at least one processor and comprising instructions executable individually or in any combination by the at least one processor, wherein the instructions cause the terminal to perform a method, the method comprises: determining a maximum output power for a sounding reference signal (SRS) within a range of maximum output power for the SRS; and determining a transmission power for the SRS based on the determined maximum output power, wherein the lower limit of the range of maximum output power for the SRS is (P PowerClass - ΔP PowerClass - ΔT RxSRS Established based on ), and the above P PowerClassrepresents the maximum terminal power defined for each band, and the above ΔP PowerClass is set to 3dB or 0dB, and the above ΔT RxSRS can represent a value applied during SRS transmission in an SRS resource set configured for antenna switching.

[0012] As one aspect of the present disclosure, a non-transient computer-readable storage medium is provided that comprises instructions that cause the terminal to perform a method when executed individually or in any combination by at least one processor of the terminal, wherein the method comprises: determining a maximum output power for a sounding reference signal (SRS) within a range of maximum output power for the SRS; and determining a transmission power for the SRS based on the determined maximum output power, wherein the lower limit of the range of maximum output power for the SRS is (P PowerClass - ΔP PowerClass - ΔT RxSRS Established based on ), and the above P PowerClass represents the maximum terminal power defined for each band, and the above ΔP PowerClass is set to 3dB or 0dB, and the above ΔT RxSRS can represent a value applied during SRS transmission in an SRS resource set configured for antenna switching.

[0013] According to the present disclosure, a terminal can improve the accuracy of channel estimation of a base station by ensuring the quality of the signal when transmitting a sounding reference signal.

[0014] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0015] FIG. 1 is a diagram showing a MAC (medium access control) CE (control element) structure containing single PHR (power headroom) information in a wireless communication system according to one embodiment of the present disclosure.

[0016] FIG. 2 is a diagram showing a MAC CE structure including a plurality of PHR information in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 3 is a diagram showing the sounding reference signal (SRS) antenna switching operation in a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 4 illustrates an example comparing a method for estimating a downlink channel based on CSI-RS (channel state information-reference signal) and a method for estimating a downlink channel based on SRS and reciprocity in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 5 illustrates an example of a case in which, in a wireless communication system according to one embodiment of the present disclosure, when a terminal supports 1T4R, the terminal performs SRS antenna switching so that the base station acquires a downlink channel.

[0020] FIG. 6 is a diagram showing an example of a terminal structure supporting four receiving antennas in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 7 illustrates an example of a case depending on the distance between the terminal and the base station or the transmission power of the terminal when the terminal transmits SRS in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 8 illustrates an example in which two power headroom prohibition timers operate independently in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 9 illustrates an example in a wireless communication system according to one embodiment of the present disclosure in which an existing power headroom prohibition timer operates depending on whether a new power headroom prohibition timer has expired.

[0024] FIG. 10 illustrates an example in a wireless communication system according to one embodiment of the present disclosure in which a new power headroom prohibition timer operates depending on whether an existing power headroom prohibition timer has expired.

[0025] FIG. 11 shows examples of single-entry and multiple-entry power headroom MAC CE formats that add power headroom information for SRS along with power headroom information for PUSCH in a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 12 shows examples of single-entry and multiple-entry power headroom MAC CE formats for power headroom information for SRS in a wireless communication system according to one embodiment of the present disclosure.

[0027] FIGS. 13a and FIGS. 13b show examples of single-entry and multiple-entry power headroom MAC CE formats in which power headroom information for PUSCH is added along with multiple power headroom information for each SRS resource in a wireless communication system according to one embodiment of the present disclosure.

[0028] FIGS. 14a and FIGS. 14b show examples of single-entry and multiple-entry power headroom MAC CE formats for power headroom information of each SRS resource in a wireless communication system according to one embodiment of the present disclosure.

[0029] FIG. 15 illustrates a method performed by a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0030] FIG. 16 illustrates a method performed by a base station in a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 17 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0032] FIG. 18 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0034] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0035] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the dimensions of each component do not entirely reflect their actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference numbers.

[0036] The advantages and features of the present disclosure, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration might unnecessarily obscure the essence of the present disclosure, such detailed description is omitted. Additionally, the terms described below are defined considering their functions in the present disclosure, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout the specification.

[0037] In the present disclosure, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In the present disclosure, the downlink (DL) refers to the wireless transmission path of a signal transmitted by the base station to the terminal, and the uplink (UL) refers to the wireless transmission path of a signal transmitted by the terminal to the base station. Furthermore, although the embodiments of the present disclosure are described using a 5G system as an example, the embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and 6G mobile communication technology developed after 5G may be included therein. Furthermore, the present disclosure may be applied to other communication systems with some modifications made in the judgment of a person skilled in the art, without significantly departing from the scope of the present disclosure. The contents of the present disclosure are applicable to FDD and TDD systems.

[0038] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing instruction means to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that perform a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer can also provide steps for executing the functions described in the flowchart block(s).

[0039] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For example, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order according to their corresponding functions.

[0040] In this embodiment, the term "part" refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or configured to run one or more processors. Thus, as an example, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, in the embodiments, 'parts' may include one or more processors.

[0041] In describing the present disclosure below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the present disclosure, such detailed description will be omitted. Embodiments of the present disclosure may be described below with reference to the attached drawings.

[0042] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0043] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above-mentioned multiple access method can distinguish the data or control information of each user by allocating and operating time-frequency resources to be sent for each user so that they do not overlap, that is, so that orthogonality is established.

[0044] As a future communication system following LTE, for example, a 5G communication system must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy various requirements simultaneously must be supported. Services being considered for a 5G communication system include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0045] eMBB aims to provide data transmission speeds that are superior to those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and 10 Gbps in the uplink from the perspective of a single base station. Furthermore, while providing these peak data rates, the 5G communication system must also provide an increased user-perceived data rate. To satisfy these requirements, it necessitates improvements in various transmission and reception technologies, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, while LTE transmits signals using a maximum bandwidth of 20 MHz in the 2 GHz band, the 5G communication system can meet the data transmission speeds required by using a frequency bandwidth wider than 20 MHz in frequency bands of 3–6 GHz or above 6 GHz.

[0046] Simultaneously, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC requires support for a large number of terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT devices are attached to various sensors and equipment to provide communication functions, the system must be able to support a large number of terminals within a cell (e.g., 1,000,000 terminals / km²). Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones not covered by cells, such as building basements; therefore, they may require wider coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace terminal batteries, a very long battery life of 10 to 15 years may be required.

[0047] Finally, URLLC is a mission-critical cellular-based wireless communication service. For example, consider services used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts. Therefore, the communication provided by URLLC must offer very low latency and very high reliability. For instance, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds, and simultaneously 10 -5The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and at the same time, design considerations may be required to allocate a wide resource in the frequency band to ensure the reliability of the communication link.

[0048] The three 5G services (e.g., eMBB, URLLC, mMTC) can be multiplexed and transmitted within a single system. In this case, different transmission and reception techniques and parameters may be used between the services to satisfy the different requirements of each service. Of course, 5G is not limited to the three services mentioned above.

[0049] In the present disclosure, a / b may be understood as at least one of a or b. Additionally, upper signaling may be understood as upper layer signaling or upper layer signal. In the present disclosure, upper signaling (or upper layer signaling) is a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel, and may be referred to as any one of RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE). Alternatively, in the present disclosure, upper layer signaling (or upper layer signaling) may be a signaling corresponding to at least one or a combination of one or more of the following signalings.

[0050] - MIB (Master Information Block)

[0051] - SIB (System Information Block) or SIB X (X=1, 2, ...)

[0052] - RRC (Radio Resource Control)

[0053] - MAC (Medium Access Control) CE (Control Element)

[0054] In addition, L1 signaling may be a signaling corresponding to at least one or a combination of at least one of a signaling method using a physical layer channel or signaling.

[0055] - PDCCH (Physical Downlink Control Channel)

[0056] - DCI (Downlink Control Information)

[0057] - Terminal-specific (UE-specific) DCI

[0058] - Group common DCI

[0059] - Common DCI

[0060] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0061] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0062] - PUCCH (Physical Uplink Control Channel)

[0063] - UCI (Uplink Control Information)

[0064] The term "slot" as used in the present disclosure is a general term that may refer to a specific time unit corresponding to the Transmit Time Interval (TTI), and specifically, it may mean a slot used in a 5G system, or a slot or subframe used in a 4G LTE system.

[0065] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with lower priority.

[0066] In this disclosure, the examples are described through a plurality of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0067] For convenience in this disclosure, cells, transmission points, panels, beams, and / or transmission directions that can be distinguished through upper-level / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be described uniformly as TRP (transmission reception point), beam, or TCI state. Therefore, in actual application, TRP, beam, or TCI state can be appropriately replaced with one of the above terms.

[0068] [Time-Frequency Resources]

[0069] In the time and frequency domains, the basic unit of a resource is the Resource Element (RE), which can be defined as one OFDM symbol on the time axis and one subcarrier on the frequency axis. In the frequency domain, a specific number (e.g., 12) of consecutive REs can constitute a Resource Block (RB). In the time axis, one subframe can contain multiple OFDM symbols. For example, the length of one subframe can be 1 ms.

[0070] One frame can be defined as 10 ms. One subframe can be defined as 1 ms, and thus one frame can be composed of a total of 10 subframes. One slot can be defined as 14 OFDM symbols. One subframe can be composed of one or more slots, and the number of slots per subframe may vary depending on the setting value μ for the subcarrier spacing.

[0071] The base station may configure one or more Bandwidth Parts (BWPs) for the terminal, and for each Bandwidth Part, various parameters such as a Bandwidth Part identifier, Bandwidth Part location, subcarrier spacing, and cyclic preposition may be configured for the terminal. Configuration information regarding the Bandwidth Part may be transmitted from the base station to the terminal via higher-layer signaling, for example, Radio Resource Control (RRC) signaling. At least one of the configured Bandwidth Parts may be activated. Whether a configured Bandwidth Part is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling or dynamically via DCI.

[0072] [Uplink: PUSCH]

[0073] [PUSCH: Regarding transmission method]

[0074] Next, the scheduling method for PUSCH (physical uplink shared channel) transmissions is described. PUSCH transmissions can be dynamically scheduled by UL grants within the DCI, or operated by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transmissions can be provided in DCI format 0_0 or 0_1.

[0075] The terminal's Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig, which includes rrc-ConfiguredUplinkGrant of [Table 1], through the upper signaling, without receiving UL grants within the DCI. The terminal's Configured grant Type 2 PUSCH transmission can be semi-continuously scheduled by UL grants within the DCI after receiving configuredGrantConfig, which does not include rrc-ConfiguredUplinkGrant of [Table 1], through the upper signaling. When the PUSCH transmission is operated by the configured grant, the parameters applied to the PUSCH transmission can be applied through configuredGrantConfig, the upper signaling of [Table 1], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH, which are provided by pusch-Config of [Table 2], the upper signaling. If the terminal is provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 1], the terminal can apply tp-pi2BPSK in pusch-Config of [Table 2] to PUSCH transmissions operated by configured grant.

[0076] [Table 1]

[0077]

[0078] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission may be the same as the antenna port for SRS transmission. PUSCH transmission may follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in pusch-Config in [Table 2], the upper signaling, is 'codebook' or 'nonCodebook'.

[0079] As described above, PUSCH transmissions can be dynamically scheduled via DCI format 0_0 or 0_1 and semi-statically configured by a configured grant. If a terminal is instructed to schedule a PUSCH transmission via DCI format 0_0, the terminal may perform beam configuration for the PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the terminal-specific PUCCH resource corresponding to the minimum ID within an active uplink BWP in the serving cell, whereby the PUSCH transmission may be based on a single antenna port. Within a BWP where a PUCCH resource containing pucch-spatialRelationInfo is not configured, the terminal may not expect scheduling a PUSCH transmission via DCI format 0_0. If the terminal has not been configured with txConfig within pusch-Config of [Table 2], the terminal may not expect to be scheduled via DCI format 0_1.

[0080] [Table 2]

[0081]

[0082] Next, codebook-based PUSCH transmission can be described. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the terminal can determine a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and the transmission rank (number of PUSCH transmission layers).

[0083] In this case, the SRI can be provided through the SRS resource indicator field within the DCI or configured through the higher-level signaling srs-ResourceIndicator. When transmitting a codebook-based PUSCH to the terminal, at least one SRS resource may be configured, and up to two may be configured. When the terminal receives an SRI through the DCI, the SRS resource indicated by the SRI received through the DCI may refer to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI received through the DCI. Additionally, the TPMI and transmission rank may be provided through the precoding information and number of layers field within the DCI or configured through the higher-level signaling precodingAndNumberOfLayers. The TPMI may be used to indicate the precoder applied to the PUSCH transmission. If one SRS resource is configured to the terminal, the TPMI may be used to indicate the precoder to be applied to that configured SRS resource. If multiple SRS resources are configured on the terminal, TPMI can be used to specify the precoder to be applied to the SRS resource indicated by SRI.

[0084] The precoder to be used for PUSCH transmission may be selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper signaling SRS-Config. In codebook-based PUSCH transmission, the terminal may determine the codebook subset based on TPMI and the codebookSubset in the upper signaling pusch-Config. The codebookSubset in the upper signaling pusch-Config may be set to 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the terminal capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' as its terminal capability, the terminal may not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the terminal reports 'nonCoherent' as a terminal capability, the terminal may not expect the value of the upper-level signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper-level signaling SRS-ResourceSet points to two SRS antenna ports, the terminal may not expect the value of the upper-level signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0085] One SRS resource set may be configured in the terminal with the usage value in the upper signaling SRS-ResourceSet set set to 'codebook', and one SRS resource within the configured SRS resource set may be indicated via SRI. If multiple SRS resources are configured within the SRS resource set in which the usage value in the upper signaling SRS-ResourceSet set to 'codebook', the terminal can expect the value of nrofSRS-Ports in the upper signaling SRS-Resource to be set to the same value for all SRS resources.

[0086] A terminal may transmit one or more SRS resources included in an SRS resource set in which the value of usage is set to 'codebook' according to the upper signaling, to a base station, and the base station may select one of the SRS resources transmitted by the terminal and instruct the terminal to perform PUSCH transmission using the transmit beam information of the selected SRS resource. In this case, in codebook-based PUSCH transmission, SRI is used as information to select the index of one SRS resource and may be included in the DCI. Additionally, the base station may include information in the DCI that instructs the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal may perform PUSCH transmission by using the SRS resource instructed by the SRI, applying the instructed rank based on the transmit beam of the SRS resource instructed by the SRI and the precoder instructed by the TPMI.

[0087] Next, non-codebook-based PUSCH transmission is described. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1 and can operate semi-statically via configured grant. If at least one SRS resource is configured within an SRS resource set in which the value of usage within the upper signaling SRS-ResourceSet is set to 'nonCodebook', non-codebook-based PUSCH transmission can be scheduled to the terminal via DCI format 0_1.

[0088] For an SRS resource set in which the value of usage within the upper signaling SRS-ResourceSet is set to 'nonCodebook', one NZP CSI-RS resource (non-zero power CSI-RS) connected to the terminal may be configured. The terminal can perform calculations for a precoder for SRS transmission by measuring the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the terminal is less than 42 symbols, the terminal may not expect the information for the precoder for SRS transmission to be updated.

[0089] If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS may be indicated by the SRS request field in DCI format 0_1 ​​or 1_1. In this case, if the connected NZP CSI-RS resource is a non-periodic NZP CSI-RS resource, the existence of the connected NZP CSI-RS may be indicated if the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. In this case, the DCI may not indicate cross-carrier or cross-BWP scheduling. Additionally, if the value of the SRS request indicates the existence of the NZP CSI-RS, the NZP CSI-RS may be located in the slot where the PDCCH containing the SRS request field was transmitted. In this case, the TCI states set on the scheduled subcarrier may not be set to QCL-TypeD.

[0090] If a periodic or semi-persistent SRS resource set is established, the associated NZP CSI-RS can be indicated via the associated CSI-RS within the higher-level signaling, SRS-ResourceSet. For non-codebook-based transmissions, the terminal may not expect the spatialRelationInfo, the higher-level signaling for the SRS resource, and the associated CSI-RS within the higher-level signaling, SRS-ResourceSet, to be established together.

[0091] When multiple SRS resources are configured in a terminal, the terminal can determine the precoder and transmission rank to be applied for PUSCH transmission based on the SRI indicated by the base station. In this case, the SRI may be indicated via the field SRS resource indicator within the DCI or configured via the higher-level signaling srs-ResourceIndicator. Similar to the codebook-based PUSCH transmission described above, when the terminal receives the SRI via the DCI, the SRS resource indicated by the SRI received via the DCI may refer to the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH containing the SRI received via the DCI. The terminal may use one or multiple SRS resources for SRS transmission, and the maximum number of SRS resources that can be transmitted simultaneously in the same symbol within a single SRS resource set and the maximum number of SRS resources may be determined by the terminal capability reported by the terminal to the base station. In this case, the SRS resources transmitted simultaneously by the terminal may occupy the same RB. The terminal can configure one SRS port for each SRS resource. Only one SRS resource set can be configured where the value of usage in the upper signaling SRS-ResourceSet is set to 'nonCodebook', and up to four SRS resources can be configured for non-codebook based PUSCH transmission.

[0092] A base station can transmit one NZP-CSI-RS connected to an SRS resource set to a terminal, and the terminal can calculate a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the results measured upon receiving the NZP-CSI-RS. The terminal can apply the calculated precoder described above when transmitting one or more SRS resources within an SRS resource set where usage is set to 'nonCodebook' to the base station, and the base station can select one or more SRS resources from among the received one or more SRS resources. In this case, in non-codebook-based PUSCH transmission, the SRI may represent an index capable of expressing a combination of one or more SRS resources, and the SRI may be included within the DCI. In this case, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH, and the terminal can transmit the PUSCH by applying the precoder applied for SRS resource transmission to each layer.

[0093] [PUSCH: Regarding transmission power]

[0094] The following describes in detail how to determine the transmission power of an uplink data channel in a 5G system.

[0095] In a 5G system, the transmission power of the uplink data channel can be determined through the following [Equation 1].

[0096] [Mathematical Formula 1]

[0097]

[0098] In [Equation 1], j represents the PUSCH grant type; specifically, j=0 is a PUSCH grant for random access response, j=1 is a configured grant, means dynamic grant. represents the maximum output power set at the terminal for the carrier f of the supporting cell c for the PUSCH transmission occasion i. is set as a higher-level parameter and can be determined through upper-level settings and SRI (in the case of dynamic grant PUSCH) It is a parameter composed of the sum of represents the bandwidth for resource allocation expressed as the number of resource blocks (RB) for a PUSCH transmission occasion i, and represents a value determined by the type of information transmitted via MCS (Modulation Coding Scheme) and PUSCH (e.g., whether UL-SCH is included or CSI is included, etc.). is a value for compensating for path loss, which can be determined through upper layer settings and SRI (SRS Resource Indicator) (in the case of dynamic grant PUSCH). The reference signal index is q d It refers to the downlink path loss estimate calculated by the terminal using the reference signal, and the reference signal index q dThe terminal can determine this through the upper layer configuration and SRI (in the case of dynamic grant PUSCH or ConfiguredGrantConfig-based configured grant PUSCH (type 2 configured grant PUSCH) that does not include the upper layer configuration rrc-ConfiguredUplinkGrant) or through the upper layer configuration. is a closed-loop power adjustment value that can be supported in accumulation and absolute modes. If the upper-layer parameter tpc-Accumulation is not set on the terminal, the closed-loop power adjustment value can be determined using the accumulation mode. In this case, is to transmit PUSCH transmission occasion i-i0 to the closed-loop power adjustment value for the previous PUSCH transmission occasion i-i0 K PUSCH Transmitting PUSCH transmission occasion i from (i-i0)-1 symbols K PUSCH (i) Between symbols, the sum of TPC command values ​​for closed-loop index l received via DCI It is determined as follows. If the upper layer parameter tpc-Accumulation is set on the terminal, is the TPC command value for closed-loop index l received via DCI It is determined as follows. The closed-loop index l can be set to 0 or 1 if the upper-layer parameter twoPUSCH-PC-AdjustmentStates is configured on the terminal, and its value can be determined through the upper-layer configuration and SRI (in the case of dynamic grant PUSCH). The TPC command field and TPC value within the DCI according to the accumulation method and the absolute method. The mapping relationship can be defined as shown in [Table 3] below.

[0099] [Table 3]

[0100]

[0101] [PHR Related]

[0102] The above power headroom report may mean that the terminal measures the difference between the terminal's nominal UE maximum transmit power and the estimated power for uplink transmission (e.g., representing the terminal's available transmit power) and transmits it to the base station. The above power headroom report may be used to support power-aware packet scheduling. The estimated power for uplink transmission may be the estimated power for UL-SCH (or PUSCH) transmission per active serving cell, the estimated power for UL-SCH and PUCCH transmission in SpCells of other MAC entities (e.g., E-UTRA MAC entities in EN-DC, NE-DC, and NGEN-DC cases in 3GPP specifications), the estimated power for SRS transmission per active serving cell, etc. The terminal may trigger the power headroom report if any of the following trigger events are satisfied:

[0103] - [Trigger Event 1] When the upper layer parameter phr-ProhibitTimer expires and the MAC entity has uplink resources for a new transmission, the path loss for at least one active support cell may change more than the upper layer parameter phr-Tx-PowerFactorChange dB since the most recent PHR transmission. Here, the active downlink bandwidth part for the at least one active support cell may not be a dormant bandwidth part. In this case, the change in path loss for a cell may be determined by the difference between the currently measured path loss with respect to the current path loss reference and the path loss measured at that time with respect to the path loss reference at the time of the most recent PHR transmission.

[0104] - [Trigger Event 2] The upper layer parameter phr-PeriodicTimer may expire.

[0105] - [Trigger Event 3] A setting or reset of the power headroom reporting function by a higher layer may be performed, rather than a setting or reset that disables power headroom reporting.

[0106] - [Trigger Event 4] SCell may be activated for any MAC entity having an uplink where firstActiveDownlinkBWP-Id is not set to dormant bandwidth part. The firstActiveDownlinkBWP-Id may represent the identifier of the DL BWP to be activated when performing RRC (re)configuration (if configured for SpCell) or the identifier of the DL BWP to be used when activating SCell (if configured for SCell).

[0107] - [Trigger Event 5] PSCell added (e.g., PSCell newly added or changed).

[0108] - [Trigger Event 6] When the upper layer parameter phr-ProhibitTimer has expired and the MAC entity has uplink resources for a new transmission, any active support cells of any MAC entity with an established uplink may satisfy both of the following a) and b):

[0109] a) There are uplink resources allocated for transmission, or PUCCH can be transmitted to the cell.

[0110] b) When a MAC entity has uplink resources for transmission or PUCCH transmission to the cell, the power back-off required due to power management for the cell may be greater than the upper layer parameter phr-Tx-PowerFactorChange dB since the most recent PHR transmission.

[0111] - [Trigger Event 7] For any MAC entity with a configured uplink, the active bandwidth part of SCell can be changed from a dormant bandwidth part to a non-dormant downlink bandwidth part.

[0112] - [Trigger Event 8] If the upper-level parameter mpe-Reporting-FR2 is set on the terminal to indicate whether to report the MPE P-MPR (Maximum allowed UE output power reduction) to satisfy the maximum permissible exposure (MPE) in FR2, and mpe-ProhibitTimer may not operate. In this case, if power headroom reporting is referred to as 'MPE P-MPR reporting', the measured P-MPR applied to satisfy the FR2 MPE requirements for at least one active FR2-enabled cell after the most recent power headroom report may be greater than or equal to the upper-level parameter mpe-Threshold.

[0113] Power headroom reporting may be triggered according to the above trigger events, and the terminal may decide to report power headroom according to the additional conditions below.

[0114] - [Additional Conditions for Temporary Required Power Back-Off] When the required power back-off is temporarily reduced due to power management (e.g., up to tens of milliseconds), the MAC entity may not trigger a power headroom report. If the required power back-off is temporarily reduced and the power headroom report is triggered by other trigger events, this results in P, which represents the ratio between maximum power and remaining (available) power. CMAX,f,c It may be necessary to ensure that the value of / PH is not temporarily reduced. For example, the PHR may not be triggered due to a temporary power backoff. For instance, if the PHR is triggered by another PHR trigger event (such as the expiration of a periodic timer), a condition may have been added so that the PH reflecting the temporary power reduction due to the required power backoff is not reported, and the PH excluding the effect of the required power backoff is reported.

[0115] - [Power Headroom Reporting Conditions Based on Terminal Implementation] If a HARQ process is configured with cg-RetransmissionTimer and a power headroom report has already been included in the MAC PDU for a transmission by the corresponding HARQ process but transmission through the lower layer has not yet been performed, the method of processing the corresponding power headroom report may be determined based on the terminal implementation.

[0116] If one or more of the above trigger events occur to trigger a power headroom report, and an uplink transmission resource allocated via downlink control information can accommodate a MAC entity for the power headroom report and a subheader therefor, the terminal can perform a power headroom report through the said uplink resource. In this case, the corresponding uplink resource may refer to a resource for an uplink transmission scheduled by the first DCI format or the first uplink grant that schedules the initial transmission of a transport block (TB) after the power headroom trigger. For example, after the power headroom trigger occurs, the terminal can perform a power headroom report through an uplink transmission scheduled by the first DCI format or the first uplink grant among the uplink resources capable of accommodating a MAC entity for the power headroom and a subheader therefor. Alternatively, after a power headroom trigger occurs, the terminal may perform power headroom reporting by sending a configured grant PUSCH that can accommodate a MAC entity for power headroom and a subheader therefor.

[0117] When reporting power headroom for a specific cell, the terminal may select, calculate, and report one of two types of power headroom information. The first type is actual PHR, which may be power headroom information calculated based on the transmission power of the uplink signal (e.g., PUSCH) actually being transmitted. The second type is virtual PHR (or reference format), which may be power headroom information calculated based on transmission power parameters set at the upper layer, even though there is no uplink signal (e.g., PUSCH) actually being transmitted. After the power headroom report is triggered, the terminal may calculate the actual PHR based on downlink control information received up to the point including the PDCCH monitoring period, which includes receiving the first DCI format for scheduling the PUSCH to transmit the MAC CE containing the power headroom report as described above, and upper layer information for periodic / semi-persistent SRS transmission and configured grant transmission. If, after the PDCCH monitoring period in which the first DCI format is received, the terminal receives downlink control information or decides to transmit periodic / semi-persistent SRS or a configured grant, the terminal can calculate a virtual PHR for the corresponding cell. Alternatively, after a power headroom report is triggered, the terminal can calculate T' corresponding to the PUSCH preparation time described above, based on the very first uplink symbol of the configured grant PUSCH in which the power headroom information can be transmitted. proc,2 =T proc,2The actual PHR can be calculated based on downlink control information received up to the previous point in time and upper-layer information for periodic / semi-persistent SRS transmission and configured grant transmission. If T' based on the very first uplink symbol of the configured grant PUSCH proc,2 If, after the previous point in time, the terminal receives downlink control information or decides to transmit periodic / semi-persistent SRS or configured grant, the terminal can calculate a virtual PHR for the corresponding cell.

[0118] If the terminal calculates the actual PHR based on the actual PUSCH transmission, the power headroom report information for the support cell c, carrier f, bandwidth part b, and PUSCH transmission time i can be expressed as follows [Equation 2].

[0119] [Mathematical Formula 2]

[0120]

[0121] As another example, if the terminal calculates a virtual PHR based on transmission power parameters set in the upper layer, the power headroom report information for support cell c, carrier f, bandwidth part b, and PUSCH transmission time i can be expressed as follows [Equation 3].

[0122] [Mathematical Formula 3]

[0123]

[0124] According to the above [Equation 2], power headroom information can be calculated using the difference between the maximum output power and the transmission power for the PUSCH transmission occasion i. According to [Equation 3], parameters related to MPR (Maximum Power Reduction) (e.g., MPR, A-MPR (Additional MPR), P-MPR (Power Management MPR), etc.) and △T c The maximum output power when assuming is 0 and default transmission power parameters (e.g., , p0 and alpha of P0-PUSCH-AlphaSetId=0, and pusch-PathlossReferenceRS-Id=0 corresponding to Power headroom information can be calculated using the difference in reference PUSCH transmission power using the closed-loop index l=0 (closed-loop power adjustment value). For the explanation of each variable in [Equation 2] and [Equation 3] above, refer to the variable explanation in [Equation 1] above. The above A-MPR may be an MPR that satisfies the additional emission requirement indicated by the base station by upper-layer signaling (e.g., by combining additionalSpectrumEmission indicated by RRC with the NR frequency band (Table 6.2.3.1-1A in TS 38.101-1), the network signaling label is identified, and the corresponding A-MPR value is defined in Table 6.2.3.1-1 in TS 38.101-1). The above P-MPR is the Maximum allowed UE output power reduction for serving cell c, and the purpose may be an MPR capable of satisfying applicable electromagnetic energy absorption requirements. The above A-MPR and P-MPR may refer to 3GPP standard TS 38.101-1 section 6.2. In a communication system to which the present disclosure may be applied, the first type of power headroom information may mean power headroom information for PUSCH transmit power. Additionally, the second type of power headroom information may mean power headroom information for PUCCH transmit power. Additionally, the third type of power headroom information may mean power headroom information for SRS transmit power. Meanwhile, the present disclosure is not limited thereto.

[0125] If MR-DC or UL-CA is not supported, the base station may set the upper layer parameter 'multiplePHR' to 'false' for the corresponding terminal.

[0126] FIG. 1 is a diagram showing the structure of a medium access control (MAC) control element (CE) containing single power headroom report (PHR) information in a wireless communication system according to one embodiment of the present disclosure. Referring to FIG. 1, setting 'multiplePHR' to 'false' may mean that the terminal supports power headroom reporting for a PCell (primary cell) with a MAC CE having a single entry as in (110) of FIG. 1. Each field of FIG. 1 may be defined as shown in the following [Table 4]. Meanwhile, this is merely an example and the present disclosure is not limited thereto.

[0127] [Table 4]

[0128]

[0129] If the terminal supports MR-DC (multi-RAT dual connectivity) or UL-CA (uplink carrier aggregation), the base station may set the upper layer parameter 'multiplePHR' to 'trUE' for the corresponding terminal to perform power headroom reporting for each supported cell.

[0130] FIG. 2 is a diagram showing a MAC CE structure containing multiple PHR information in a wireless communication system according to one embodiment of the present disclosure. Referring to FIG. 2, the setting of 'multiplePHR' to 'trUE' may mean that the terminal supports power headroom reporting for multiple support cells with a MAC CE having multiple entries, such as the first format (200) or the second format (202) shown in FIG. 2.

[0131] The first format (200) of FIG. 2 may be a PHR MAC CE format that can be used when multiple serving cells are configured and the largest index value among the serving cells is less than 8. The second format (202) of FIG. 2 may be a PHR MAC CE format that can be used when multiple serving cells are configured and the largest index value among the serving cells is greater than or equal to 8. Unlike the PHR MAC CE format shown in FIG. 1, the first format (200) or the second format (202) illustrated in FIG. 2 may have a variable size depending on the set or number of serving cells configured. The information may include second type PH information for SpCell (special cell) of another MAC entity (e.g., LTE) and first type PH information for PCell. When the largest index value among the serving cells is less than 8, the field indicating serving cell information may be composed of a single octet. If the largest index value among the corresponding serving cells is greater than or equal to 8, the field indicating serving cell information may consist of 4 octets. Power headroom information may be included within the PHR MAC CE according to the order of the serving cell index. When a power headroom report is triggered, the MAC entity may transmit the PHR MAC CE containing power headroom information via a transmittable PUSCH. At this time, whether the power headroom information is calculated based on actual transmission (e.g., actual PHR) or based on transmission power parameters set in the upper layer (e.g., virtual PHR) is determined as described above at a specific point in time (e.g., a point in time including the PDCCH monitoring interval where the first DCI format was detected, or at the first symbol of the initial PUSCH T' proc,2It can be determined based on the upper signal and downlink control information received up to the previous point in time. Meanwhile, the fields of the PHR MAC CE format shown in FIG. 2 may have the same meaning (definition) as most of the fields of the PHR MAC CE format shown in FIG. 1, and C i and V can have the same meaning as described in the following [Table 5].

[0132] [Table 5]

[0133]

[0134] [Uplink: RS]

[0135] [Regarding SRS]

[0136] Next, a method for estimating the uplink channel using the transmission of the terminal's Sounding Reference Signal (SRS) is described. To transmit configuration information for SRS transmission to the terminal, the base station may set at least one SRS configuration for each uplink BWP, and may also set at least one SRS resource set for each SRS configuration. For example, the base station and the terminal may exchange upper-level signaling information as follows to transmit information regarding the SRS resource set.

[0137] - srs-ResourceSetId: SRS resource set index

[0138] - srs-ResourceIdList: A set of SRS resource indices referenced by the SRS resource set

[0139] - resourceType: This is the time-axis transmission setting for the SRS resource referenced in the SRS resource set, and can be set to one of 'periodic', 'semi-persistent', or 'aperiodic'. If set to 'periodic' or 'semi-persistent', associated CSI-RS information may be provided depending on the usage of the SRS resource set. If set to 'aperiodic', a non-periodic SRS resource trigger list and slot offset information may be provided, and associated CSI-RS information may be provided depending on the usage of the SRS resource set.

[0140] - usage: A setting regarding the usage of the SRS resource referenced in the SRS resource set, which can be set to one of 'beamManagement', 'codebook', 'nonCodebook', or 'antennaSwitching'.

[0141] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for controlling the transmit power of the SRS resource referenced in the SRS resource set.

[0142] The terminal can understand that the SRS resources included in the set of SRS resource indices referenced in the SRS resource set follow the information set in the SRS resource set.

[0143] Additionally, the base station and the terminal may transmit and / or receive upper-layer signaling information to convey individual configuration information for the SRS resource. For example, the individual configuration information for the SRS resource may include time-frequency axis mapping information within the slot of the SRS resource, which may include information regarding frequency hopping within or between slots of the SRS resource. Additionally, the individual configuration information for the SRS resource may include the time-axis transmission setting of the SRS resource, which may be set to one of 'periodic', 'semi-persistent', or 'aperiodic'. This may be restricted to having the same time-axis transmission setting as the SRS resource set containing the SRS resource. If the time-axis transmission setting of the SRS resource is set to 'periodic' or 'semi-persistent', the SRS resource transmission period and slot offset (e.g., periodicityAndOffset) may additionally be included in the time-axis transmission setting.

[0144] A base station may enable, deactivate, or trigger SRS transmission to a terminal via upper-layer signaling, including RRC signaling or MAC CE signaling, or L1 signaling (e.g., DCI). For example, a base station may enable or deactivate periodic SRS transmission to a terminal via upper-layer signaling. A base station may instruct an SRS resource set with resourceType set to periodic to be enabled via upper-layer signaling, and the terminal may transmit an SRS resource referenced in the enabled SRS resource set. The time-frequency axis resource mapping within the slot of the transmitted SRS resource may follow the resource mapping information set in the SRS resource, and the slot mapping, including the transmission period and slot offset, may follow the periodicityAndOffset set in the SRS resource. Additionally, a spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource, or may refer to associated CSI-RS information set in the SRS resource set containing the SRS resource. The terminal can transmit an SRS resource within an uplink BWP that is active for a periodic SRS resource activated through upper layer signaling.

[0145] For example, a base station can enable or disable semi-persistent SRS transmission to a terminal via upper-layer signaling. The base station can instruct the terminal to enable an SRS resource set via MAC CE signaling, and the terminal can transmit an SRS resource referenced in the enabled SRS resource set. The SRS resource set enabled via MAC CE signaling may be limited to an SRS resource set where the resourceType is set to semi-persistent. The time-frequency axis resource mapping within the slot of the transmitted SRS resource may follow the resource mapping information set in the SRS resource, and the slot mapping, including the transmission period and slot offset, may follow the periodicityAndOffset set in the SRS resource. Additionally, the spatial domain transmission filter applied to the transmitted SRS resource may refer to the spatial relation info set in the SRS resource, or may refer to the associated CSI-RS information set in the SRS resource set containing the SRS resource. If spatial relation info is configured in the SRS resource, the spatial domain transmission filter can be determined by referring to the configuration information regarding the spatial relation info transmitted via MAC CE signaling that enables semi-persistent SRS transmission without following it. The terminal can transmit the SRS resource within the uplink BWP enabled for the semi-persistent SRS resource activated via upper-layer signaling.

[0146] For example, a base station can trigger an aperiodic SRS transmission to a terminal via the DCI. The base station can specify one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTrigger) through the SRS request field of the DCI. The terminal can understand that among the configuration information of the SRS resource set, an SRS resource set containing the aperiodic SRS resource trigger specified via the DCI from the list of aperiodic SRS resource triggers has been triggered. The terminal can transmit the SRS resource referenced in the triggered SRS resource set. The time-frequency axis resource mapping within the slot of the transmitted SRS resource may follow the resource mapping information set in the SRS resource. Additionally, the slot mapping of the transmitted SRS resource may be determined through the slot offset between the PDCCH containing the DCI and the SRS resource, which may refer to the value(s) included in the set of slot offsets set in the SRS resource set. Specifically, the slot offset between the PDCCH containing the DCI and the SRS resource may be the value specified in the time domain resource assignment field of the DCI among the offset value(s) included in the slot offset set configured in the SRS resource set. Additionally, the spatial domain transmission filter applied to the transmitted SRS resource may refer to the spatial relation info configured in the SRS resource, or may refer to the associated CSI-RS information configured in the SRS resource set containing the SRS resource. The terminal may transmit the SRS resource within an uplink BWP that is enabled for a non-periodic SRS resource triggered via the DCI.

[0147] When a base station triggers aperiodic SRS transmission to a terminal via DCI, a minimum time interval may be required between the PDCCH containing the DCI triggering the aperiodic SRS transmission and the transmitted SRS so that the terminal can apply configuration information for the SRS resource and transmit the SRS. The time interval for the terminal's SRS transmission can be defined as the number of symbols between the last symbol of the PDCCH containing the DCI triggering the aperiodic SRS transmission and the first symbol mapped to the first transmitted SRS resource(s). The minimum time interval can be determined by referencing the PUSCH preparation procedure time required for the terminal to prepare for PUSCH transmission. Additionally, the minimum time interval may have different values ​​depending on the usage of the SRS resource set containing the transmitted SRS resource. For example, the minimum time interval can be determined by N2 symbols defined by considering the terminal's processing capability based on the terminal's capability, referencing the terminal's PUSCH preparation procedure time. Additionally, considering the usage of the SRS resource set including the transmitted SRS resource, if the usage of the SRS resource set is set to 'codebook' or 'antennaSwitching', the minimum time interval can be set to N2 symbols, and if the usage of the SRS resource set is set to 'nonCodebook' or 'beamManagement', the minimum time interval can be set to N2+14 symbols.The terminal transmits an aperiodic SRS when the time interval for the aperiodic SRS transmission is greater than or equal to the minimum time interval, and can ignore the DCI that triggers the aperiodic SRS when the time interval for the aperiodic SRS transmission is less than the minimum time interval.

[0148] [Table 6]

[0149]

[0150] The spatialRelationInfo setting information in [Table 6] above can be applied to the beam used for SRS transmission by referencing a single reference signal and the beam information of that reference signal. For example, the spatialRelationInfo setting may include information such as that shown in [Table 7] below. Of course, it is not limited to the following examples.

[0151] [Table 7]

[0152]

[0153] Referring to the spatialRelationInfo setting above, the terminal can receive from the base station an index of the reference signal to be referenced in order to use beam information of a specific reference signal, namely an SS / PBCH block index, a CSI-RS index, or an SRS index. The upper signaling referenceSignal is setting information indicating which reference signal beam information to reference for the corresponding SRS transmission, and ssb-Index may mean the SS / PBCH block index, csi-RS-Index may mean the CSI-RS index, and srs may mean the SRS index. If the value of the upper signaling referenceSignal is set to 'ssb-Index', the terminal can apply the receiving beam used when receiving the SS / PBCH block corresponding to ssb-Index as the transmitting beam for the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'csi-RS-Index', the terminal can apply the receiving beam used when receiving the CSI-RS corresponding to csi-RS-Index as the transmitting beam for the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used during the transmission of the SRS corresponding to srs as the transmission beam for the transmission of the SRS.

[0154] [SRS: Antenna switching]

[0155] The following describes the SRS for antenna switching.

[0156] The SRS transmitted from the terminal can be used by the base station to acquire Channel State Information (DL CSI) information (e.g., DL CSI acquisition). As a specific example, in a single-cell or multi-cell (e.g., carrier aggregation (CA)) situation based on Time Division Duplex (TDD), the base station (BS) can measure the SRS transmitted from the terminal after scheduling the transmission of the SRS to the terminal. In this case, the base station can assume reciprocity between the downlink (DL) and uplink (UL) channels and consider the uplink channel information estimated based on the SRS transmitted from the terminal as downlink channel information, and use this to perform scheduling of downlink signals / channels for the terminal. At this time, the terminal may receive a setting from the base station for the use of the SRS for acquiring downlink channel information as antenna switching.

[0157] For example, according to the standard (e.g., 3gpp TS38.214), the use of the SRS can be configured for the base station and / or terminal using a higher layer parameter (e.g., the usage of the RRC parameter SRS-ResourceSet). Here, the use of the SRS can be configured for beam management, codebook transmission, non-codebook transmission, antenna switching, etc.

[0158] As described above, if the terminal receives the parameter 'usage' within the upper layer signaling SRS-ResourceSet from the base station as 'antennaSwitching', the terminal may receive at least one upper layer signaling setting from the base station according to the reported terminal capability. In this case, the terminal may report 'supportedSRS-TxPortSwitch' as ​​the terminal capability, and the value may be as follows. In the following, 'mTnR' may refer to the terminal capability to support transmission through m antennas and reception through n antennas.

[0159] - 't1r2': A terminal capability report value indicating that the terminal is capable of 1T2R operation

[0160] - 't1r1-t1r2': A terminal capability report value indicating that the terminal is capable of 1T1R or 1T2R operation

[0161] - 't2r4': A terminal capability report value indicating that the terminal is capable of 2T4R operation.

[0162] - 't1r4': A terminal capability report value indicating that the terminal is capable of 1T4R operation

[0163] - 't1r6': A terminal capability report value indicating that the terminal is capable of 1T6R operation

[0164] - 't1r8': A terminal capability report value indicating that the terminal is capable of 1T8R operation

[0165] - 't2r6': A terminal capability report value indicating that the terminal is capable of 2T6R operation

[0166] - 't2r8': A terminal capability report value indicating that the terminal is capable of 2T8R operation

[0167] - 't4r8': A terminal capability report value indicating that the terminal is capable of 4T8R operation.

[0168] - 't1r1-t1r2-t1r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, or 1T4R operation.

[0169] - 't1r4-t2r4': A terminal capability report value indicating that the terminal is capable of 1T4R or 2T4R operation.

[0170] - 't1r1-t1r2-t2r2-t2r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, or 2T4R operations.

[0171] - 't1r1-t1r2-t2r2-t1r4-t2r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, 1T4R, or 2T4R operations.

[0172] - 't1r1': A terminal capability report value indicating that the terminal is capable of 1T1R operation

[0173] - 't2r2': A terminal capability report value indicating that the terminal is capable of 2T2R operation.

[0174] - 't1r1-t2r2': A terminal capability report value indicating that the terminal is capable of 1T1R or 2T2R operation.

[0175] - 't4r4': A terminal capability report value indicating that the terminal is capable of 4T4R operation.

[0176] - 't1r1-t2r2-t4r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 2T2R, or 4T4R operation.

[0177] FIG. 3 is a diagram showing the SRS antenna switching operation in a wireless communication system according to one embodiment of the present disclosure.

[0178] Referring to FIG. 3, the terminal may be in a situation where it operates in 1T4R and has received two non-periodic SRS resource sets (e.g., SRS resource set #0 and #1). The terminal receives a PDCCH from a base station (300) and may be instructed to trigger a non-periodic SRS for SRS resource set #0 (310) and SRS resource set #1 (320) through the PDCCH. At this time, the slot offset value for SRS resource set #0 (310) may be set to slotOffset, which is an upper layer signaling, and the value may be 1. Additionally, the terminal may perform a non-periodic SRS transmission for SRS resource set #0 at a position one slot after the slot in which the PDCCH was received (e.g., at slot #1). Additionally, the slot offset value for SRS resource set #1 (320) may be set to slotOffset, which is an upper layer signaling, and the value may be 2. In addition, the terminal can perform a non-periodic SRS transmission for SRS resource set #1 at a position two slots after the slot in which the PDCCH was received (e.g., at slot #2).

[0179] SRS resource #0 (311) and SRS resource #1 (312) included in SRS resource set #0 (310) can be transmitted at different OFDM symbol locations within slot #1, and there may be Y number of OFDM symbols as a guard interval between SRS resource #0 and #1 (313). Additionally, when transmitting for SRS resource #0 (330), the terminal can perform SRS transmission by connecting one SRS port to the terminal's first receiving antenna port (335). When transmitting for SRS resource #1 (340), the terminal can perform SRS transmission by connecting one SRS port to the terminal's second receiving antenna port (345).

[0180] SRS resource #2 (321) and SRS resource #3 (322) included in SRS resource set #1 (320) are transmitted at different OFDM symbol locations within slot #1, and there may be Y number of OFDM symbols as a guard interval between SRS resource #2 and #3 (323). Additionally, when transmitting for SRS resource #2 (350), the terminal can perform SRS transmission by connecting one SRS port to the terminal's third receiving antenna port (355). When transmitting for SRS resource #3 (360), the terminal can perform SRS transmission by connecting one SRS port to the terminal's fourth receiving antenna port (365).

[0181] By connecting the four SRS resources #0 to #3 described above to the receiving antenna ports of different terminals and transmitting SRS, the terminal can transmit SRS from all different receiving antenna ports so that it can acquire channel information connected to all receiving antennas of the terminal. Additionally, by the terminal transmitting SRS from all different receiving antenna ports, the base station can acquire channel information between the base station and the terminal and utilize it for uplink or downlink scheduling.

[0182] [Terminal capability]

[0183] [Regarding Terminal Capability Reporting]

[0184] In LTE and NR, a terminal can perform a procedure to report the capabilities supported by the terminal to the base station while connected to the serving base station. In the description below, this is referred to as a UE capability report.

[0185] A base station may transmit a UE capability enquiry message requesting a capability report to a connected terminal. The UE capability enquiry message may include a terminal capability request specific to the base station's RAT (radio access technology) type. The terminal capability request specific to the RAT type may include information such as supported frequency band combinations. Furthermore, in the case of the UE capability enquiry message, multiple terminal capabilities specific to RAT types may be requested through a single RRC message container transmitted by the base station, or the base station may transmit the UE capability enquiry message, which includes a terminal capability request specific to each RAT type, to the terminal multiple times. That is, the terminal capability inquiry may be repeated multiple times within a single message, and the terminal may construct a corresponding UE capability information message and report it multiple times. In next-generation mobile communication systems, terminal capability requests can be made for NR, LTE, EN-DC (E-UTRA - NR dual connectivity), and MR-DC (Multi-RAT dual connectivity). In addition, the above terminal capability inquiry message can generally be transmitted initially after the terminal is connected to the base station, but the base station may also request it under any conditions when necessary.

[0186] According to one embodiment, a terminal that receives a request for a terminal capability report from a base station can configure the terminal capability according to the RAT type and band information requested from the base station. The method by which a terminal configures the terminal capability in an NR system may be as follows.

[0187] 1. If a terminal receives a list of LTE and / or NR bands from a base station via a terminal capability request, the terminal can configure a band combination (BC) for EN-DC and NR stand alone (SA). That is, based on the bands requested from the base station via FreqBandList, a candidate list of BCs for EN-DC and NR SA can be configured. Additionally, the bands may have priority in the order listed in FreqBandList.

[0188] 2. If the base station requests a terminal capability report by setting the "eutra-nr-only" flag or the "eutra" flag, the terminal may completely remove NR SA BCs from the list of candidate BCs configured. This action may occur only when the LTE base station (eNB) requests the "eutra" capability.

[0189] 3. Subsequently, the terminal may remove fallback BCs from the candidate list of BCs configured in the above step. Here, a fallback BC refers to a BC that can be obtained by removing a band corresponding to at least one SCell from any BC; this step may be omitted because the BC before removing the band corresponding to at least one SCell already covers the fallback BC. This step applies to MR-DC as well, meaning it can also be applied to LTE bands. The BCs remaining after this step may be the final "candidate BC list."

[0190] 4. The terminal can select BCs to report by selecting BCs that match the requested RAT type from the final "Candidate BC List" above. In this step, the terminal can construct the supportedBandCombinationList in a predetermined order. That is, the terminal can construct the BCs to report and terminal capabilities according to the pre-set order of rat-Type (nr -> eutra-nr -> eutra). Additionally, it can construct a featureSetCombination for the constructed supportedBandCombinationList and construct a list of "Candidate Feature Set Combinations" from the Candidate BC List from which the list of fallback BCs (containing capabilities of the same or lower level) has been removed. The above "Candidate Feature Set Combinations" include feature set combinations for both NR and EUTRA-NR BCs and can be obtained from feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0191] 5. Additionally, if the requested rat Type is eutra-nr and has an influence, featureSetCombinations can be included in both the UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, the NR feature set can only be included in UE-NR-Capabilities.

[0192] After terminal capability is configured, the terminal can transmit a terminal capability information message containing the terminal capability to the base station. Based on the terminal capability received from the terminal, the base station can subsequently perform appropriate scheduling and transmission and / or reception management for the terminal.

[0193] [Regarding Terminal Maximum Output Power Setting]

[0194] As previously described in the method for determining the transmission power of the uplink data channel of a 5G system, the terminal has a maximum output power P for the carrier f of the serving cell c in each slot. CMAX,f,c You can set the maximum output power P CMAX,f,c It can be set within the following range.

[0195] [Mathematical Formula 4]

[0196]

[0197] [Mathematical Formula 5]

[0198]

[0199] [Mathematical Formula 6]

[0200]

[0201] P in [Equation 5] and [Equation 6] EMAX,c is a value given in one of the additionalPmax fields of p-Max IE or NR-NS-PmaxList IE, if applicable according to TS 38.331.

[0202] P in [Equation 5] and [Equation 6] PowerClass is the maximum terminal power defined for each band, and the tolerance defined as such is not taken into account.

[0203] If IE powerBoostPi2BPSK is set to 1, for Power Class 3 terminals operating on TDD bands n40, n41, n77, n78, and n79 using PI / 2 BPSK modulation, P EMAX,c α increases by +3 dB, and if the terminal supports the terminal capability powerBoosting-pi2BPSK and 40% or fewer symbols are used for uplink transmission during a specific evaluation period, P EMAX,c It is >= 20 dBm (the exact evaluation period is at least one radio frame).

[0204] If IE powerBoostPi2BPSK is set to 1, △P PowerClass = -3 dB, and for a Power Class 3 terminal operating in TDD bands n40, n41, n77, n78 and n79 using PI / 2 BPSK modulation, the terminal supports the powerBoosting-pi2BPSK terminal capability, and less than 40% of the slots in the radio frame are used for uplink transmission.

[0205] △P in [Equation 5] and [Equation 6] PowerClass It can be determined as follows.

[0206] - If P-max is indicated as 23 dBm or less, which is 3 dB for a Power Class 2 terminal or 6 dB for a Power Class 1.5 terminal, and the terminal capability maxUplinkDutyCycle-PC2-FR1 field is absent and the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is absent and the ratio of uplink symbols transmitted during a specific evaluation period is greater than 50%; or if the terminal capability maxUplinkDutyCycle-PC2-FR1 field is absent and the ratio of uplink symbols transmitted during a specific evaluation period is greater than maxUplinkDutyCycle-PC2-FR1 as defined in TS 38.306; Or, if the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is missing and the ratio of half of the uplink symbols transmitted during a specific evaluation period is greater than maxUplinkDutyCycle-PC1dot5-MPE-FR1 as defined in TS 38.306 (the exact evaluation period is at least one radio frame).

[0207] - When P-max is between 23 dBm and 26 dBm, it is 3 dB for a Power Class 1.5 terminal, and the terminal capability maxUplinkDutyCycle-PC2-FR1 field is absent and the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is absent, and the ratio of uplink symbols transmitted during a specific evaluation period is between 25% and 50%; or when the terminal capability maxUplinkDutyCycle-PC2-FR1 field is absent and the ratio of uplink symbols transmitted during a specific evaluation period is between maxUplinkDutyCycle-PC2-FR1 and maxUplinkDutyCycle-PC2-FR1 / 2 as defined in TS 38.306; Or, when the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is missing and the ratio of uplink symbols transmitted during a specific evaluation period is greater than maxUplinkDutyCycle-PC1dot5-MPE-FR1 as defined in TS 38.306 (the exact evaluation period is at least one radio frame).

[0208] - When the terminal is configured in supplementary uplink (SUL) configuration and the basic power class requirements apply in the band where the terminal indicates power class 2, it is 3dB.

[0209] - When a Power Class 2 terminal has txDiversity-r16 or txDiversity2Tx-r18 capabilities or a Power Class 1.5 terminal has SRS-TxSwitch capabilities 't1r2', 't1r4', 't1r1-t1r2', 't1r1-t1r2-t1r4' or srs-AntennaSwitchingBeyond4RX-r17 't1r8', it applies with SRS transmission timing where SRS-ResourceSet is set to 'antennaSwitching' using one SRS port configured with the SRS resource configured in each SRS resource set.

[0210] - 0 dB in cases other than the above

[0211] △T in [Equation 5] IB,c is an additional tolerance for serving cell c for NR CA (new radio carrier aggregation), SUL, or EN-DC, and △T unless specifically defined. IB,c = 0 dB. If the terminal supports one or more band combinations for the V2X operating band for simultaneous operation, and the operating band belongs to two or more band combinations

[0212] a) If the operating band frequency range is 1 GHz or less, additional △T applied to the said operating band IB,c is the average value of all band combinations, and is the value applied to the corresponding operating band among the supported band combinations, rounded to the first decimal place. If there is a harmonic relationship between the low-band UL and high-band DL, △T among the different supported band combinations including these bands IB,c The maximum value of is applied.

[0213] b) If the operating band frequency range exceeds 1 GHz, additional △T applied to the said operating band IB,c is the maximum value of all defined band combinations.

[0214] △P in [Equation 5] and [Equation 6] PowerBoost It is defined as 1 dB for power class 3 and 0.5 dB for power class 2 if all of the following conditions are met.

[0215] - If the terminal supports Power Class 2 or Power Class 3 in the TDD band

[0216] - △P PowerClass When is 0dB

[0217] - If, according to the schedule, uplink transmission is DFT-s-OFDM using PI / 2 BPSK modulation or QPSK modulation

[0218] - When the RB allocation belongs to the internal area

[0219] - If the terminal displays Power Class 3 and the ratio of uplink symbols transmitted during a specific evaluation period is less than 80%

[0220] - If the terminal indicates Power Class 2, the terminal capability maxUplinkDutyCycle-PC2-FR1 field is missing and the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is missing and the ratio of uplink symbols transmitted during a specific evaluation period is less than 0.9*50%; or the terminal capability maxUplinkDutyCycle-PC2-FR1 field is missing and the ratio of uplink symbols transmitted during a specific evaluation period is less than 0.9*maxUplinkDutyCycle-PC2-FR1 as defined in TS 38.306; or the terminal capability maxUplinkDutyCycle-PC1dot5-MPE-FR1 field is missing and the ratio of half of the uplink symbols transmitted during a specific evaluation period is less than 0.9*maxUplinkDutyCycle-PC1dot5-MPE-FR1 as defined in TS 38.306 (the exact evaluation period is at least one radio frame).

[0221] - 0 dB in cases other than the above

[0222] △T in [Equation 5] RxSRS This may apply when SRS-ResourceSet is set to 'antennaSwitching' during SRS transmission, depending on the following conditions:

[0223] a) When the terminal's SRS-TxSwitch function is set to 't1r2' or 't1r1-t1r2', when transmitting SRS to the second SRS resource in all configured SRS resource sets

[0224] b) If the terminal's SRS-TxSwitch function is set to 't1r4', 't1r4-t2r4', 't1r1-t1r2-t1r4', or 't1r1-t1r2-t2r2-t1r4-t2r4', when transmitting SRS to the second, third, and fourth SRS resources among a total of four SRS resources containing one SRS port in each configured SRS resource set

[0225] c) If the terminal's SRS-TxSwitch function is set to 't2r4', 't1r4-t2r4', 't1r1-t1r2-t2r2-t2r4', or 't1r1-t1r2-t2r2-t1r4-t2r4', when transmitting SRS to the second SRS resource containing two SRS ports in each configured SRS resource set

[0226] d) When the terminal transmits SRS to a DL-only carrier

[0227] e) When the terminal's srs-AntennaSwitchingBeyond4RX-r17 function is set to at least 't1r8', when transmitting SRS to the second, third, fourth, fifth, sixth, seventh, and eighth SRS resources among a total of eight SRS resources containing one SRS port in each configured SRS resource set

[0228] f) When the terminal's srs-AntennaSwitchingBeyond4RX-r17 function is set to at least 't2r8', when transmitting SRS to the second, third, and fourth SRS resources containing two SRS ports in each configured set of SRS resources

[0229] g) When the terminal's srs-AntennaSwitchingBeyond4RX-r17 function is set to at least 't4r8', when transmitting SRS to the second SRS resource containing four SRS ports in each configured set of SRS resources

[0230] Next △T RxSRS It can be applied according to the indicated SRS-TxSwitch or srs-AntennaSwitchingBeyond4RX-r17 functions:

[0231] If 't1r8' and 't4r8' are displayed:

[0232] - The terminal is Power Class 3, Power Class 5, or Power Class 1.5 in any band, or Power Class 2 in any band and △P PowerClass = 3 dB, or if the terminal supports Tx diversity, the upper limit of the corresponding uplink band (F UL_high ) is the lower bound of n79(F UL_low △T in the band higher than ) RxSRS The value of is 7.3 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 5.8 dB.

[0233] - The terminal is Power Class 2 in the relevant band and △P PowerClass If = 0 dB and Tx diversity is not supported, when transmitting SRS to a configured SRS resource containing a single SRS port, F UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 10.3 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 8.8 dB.

[0234] If 't1r8' and 't2r8' are displayed:

[0235] - The terminal is Power Class 3, Power Class 5, or Power Class 1.5 in the relevant band, or Power Class 2 in the relevant band and △P PowerClass If = 3 dB, or if the terminal supports txDiversity-r16, F UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 6.0 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 4.5 dB.

[0236] - The terminal is Power Class 2 in the relevant band and △P PowerClass If = 0 dB and Tx diversity is not supported, when transmitting SRS to a configured SRS resource containing a single SRS port, F UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 9.0 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 7.5 dB.

[0237] If 't1r8' or 't2r8' is displayed but neither is displayed:

[0238] - The terminal is Power Class 3, Power Class 5, or Power Class 1.5 in the relevant band, or Power Class 2 in the relevant band and △P PowerClass If = 3 dB, or if the terminal supports the Tx diversity function, F UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 5.5 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 4.0 dB.

[0239] - The terminal is Power Class 2 in the relevant band and △P PowerClass If = 0 dB and Tx diversity function is not supported, F along with the SRS transmission timing with the configured SRS resource containing a single SRS port UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 8.5 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 7.0 dB.

[0240] If 't1r2', 't1r1-t1r2', 't1r4', 't1r4-t2r4', 't1r1-t1r2-t1r4', 't2r4', 't1r1-t1r2-t2r2-t2r4', 't1r1-t1r2-t2r2-t1r4-t2r4' or 't4r8' is displayed:

[0241] - The terminal is Power Class 3, Power Class 5, or Power Class 1.5 in the relevant band, or Power Class 2 in the relevant band and △P PowerClass If = 3 dB, or if the terminal supports the Tx diversity function, F UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 4.5 dB, and F UL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 3 dB.

[0242] - The terminal is Power Class 2 in the relevant band and △P PowerClass If = 0 dB and Tx diversity function is not supported, F along with the SRS transmission timing with the configured SRS resource containing a single SRS port UL_high F of n79 UL_low △T in a higher band RxSRS The value of is 7.5 dB, and FUL_high F of n79 UL_low △T in the lower band RxSRS The value of can be set to 6 dB.

[0243] For other SRS transmissions, △T RxSRS is set to 0.

[0244] In [Equation 5], P-MPRc is the maximum power reduction amount for the following power management.

[0245] a) Comply with applicable electromagnetic energy absorption requirements and address unwanted emission / self-defense requirements for simultaneous transmission of multiple RAT(s) in scenarios not covered by the scope of 3GPP RAN specifications.

[0246] b) When used to address requirements such as the need to reduce maximum output power, comply with applicable electromagnetic energy absorption requirements.

[0247] The terminal must apply P-MPRc to serving cell c only in the above cases. For terminal performance conformance tests, P-MPRc must be 0 dB.

[0248] The terminal uses [Equation 5] and [Equation 6] to P CMAX,f,c After calculating the maximum and minimum values ​​of, P that satisfies the various requirements at the corresponding time point between the two values. CMAX,f,c Select .

[0249] [Proposed Method of the Present Disclosure]

[0250] As explained earlier regarding antenna switching, reciprocity exists between the uplink and downlink channels in a time division duplex (TDD) system; therefore, if channel information for one of the two channels can be obtained, information regarding the other channel can also be estimated. Since base stations consist of a larger number of transmitting antennas than terminals, the base station can transmit a greater number of reference signal ports to the terminal to estimate the downlink channel between the base station and the terminal compared to estimating the uplink channel. This means that to orthogonally estimate the downlink channel between each transmitting antenna port of the base station and all terminal antenna ports, a number of CSI-RS (channel state information - reference signals) equal to the number of base station transmitting antennas may be required. On the other hand, to estimate the downlink channel based on reciprocity with the uplink channel, the terminal can transmit only a number of SRS (sounding reference signals) equal to the number of terminal receiving antennas.

[0251] FIG. 4 illustrates an example comparing a method for estimating a downlink channel based on CSI-RS and a method for estimating a downlink channel based on SRS and reciprocity in a wireless communication system according to one embodiment of the present disclosure.

[0252] Referring to FIG. 4, examples of a method for estimating a downlink channel based on CSI-RS and a method for estimating a downlink channel based on SRS and reciprocity are described. In FIG. 4, it can be assumed that a terminal (400) receives a downlink channel with two receiving antennas and a base station (410) transmits a downlink channel with four transmitting antennas. If the base station (410) transmits CSI-RS (421, 422, 423, 424) for each transmitting antenna port to the terminal (400), the terminal (400) can measure the downlink channel. Subsequently, the terminal (400) can report the channel state information (CSI) of the downlink channel estimated from the received CSI-RS (421, 422, 423, 424) to the base station (410). On the other hand, if the terminal (400) transmits SRS (431, 432) for each receiving antenna port to the base station (410), the base station (410) can measure the uplink channel. In this way, if the base station measures the uplink channel based on the SRS and estimates the downlink channel through it, the base station can obtain downlink channel information without quantization error of the downlink channel caused by CSI feedback. In addition, considering the number of antenna ports of the base station and the terminal, the base station can estimate the downlink channel through a small number of SRS ports compared to the total number of CSI-RS ports. If a high-performance base station with a very large number of transmitting antenna ports is considered (for example, a base station composed of 32 transmitting antenna ports), the advantages of SRS-based downlink channel estimation can be further enhanced. On the other hand, since the transmission power of the SRS transmitted by the terminal is very small compared to the transmission power of the CSI-RS transmitted by the base station, it may be difficult for the base station to successfully receive the SRS if the distance between the base station and the terminal is very large or if sufficient uplink coverage is not secured.Alternatively, because the estimation error of the uplink channel becomes very large, it may be difficult for the base station to estimate the downlink channel based on the reciprocity of the uplink channel. Despite these disadvantages, if sufficient coverage of the uplink channel between the base station and the terminal can be secured, using a method to acquire SRS-based downlink channel information may have advantages in that it enables efficient use of RS resources from a system perspective and allows for the acquisition of the downlink channel without quantization error.

[0253] The terminal can support transmission through m antennas and reception through n antennas, such as 'mTnR'. Considering the complexity and cost of the transmitting antennas, the number of transmitting antennas m of the terminal may be less than or equal to the number of receiving antennas n. If the number of transmitting antennas m and the number of receiving antennas n are the same, a separate antenna switching process for acquiring a downlink channel based on SRS may not be required, as described above. The fact that antenna switching is not required can be understood as meaning that an RF chain for uplink transmission is implemented on all receiving antennas. On the other hand, if the number of receiving antennas n is greater than the number of transmitting antennas m, an antenna switching process may be required to transmit SRS through all n receiving antennas, as described above. For example, if the terminal is implemented with 2 transmitting antennas and 4 receiving antennas, the terminal needs to be implemented so that the SRS signal is transmitted through a total of 4 antennas by switching the 2 transmitting antennas once each to transmit SRS for downlink channel estimation to the 4 receiving antennas.

[0254] Considering the cost and complexity of the terminal, the number of transmitting antennas may be smaller than the number of receiving antennas. For example, receiving modules such as receiving filters are connected to all receiving antenna parts of the terminal, so that downlink signals can be received by n receiving antennas. On the other hand, transmitting RF (radio frequency) chain modules such as transmitting filters, low noise amplifiers (LNAs), and power amplifiers (PAs) are connected to only some of the transmitting antenna parts of the total antennas, so that uplink signals can be transmitted by only m transmitting antennas. The above-described implementation method may be one that takes into account the heat generation, cost, and interference between components of the terminal. When the terminal supports mTnR and m is less than n, the base station can schedule antenna switching for the terminal to acquire a downlink channel based on SRS, as described above.

[0255] FIG. 5 illustrates an example of a case in which, in a wireless communication system according to one embodiment of the present disclosure, when a terminal supports 1T4R, the terminal performs SRS antenna switching so that the base station acquires a downlink channel.

[0256] Referring to FIG. 5, an example is described in which, when the terminal supports 1T4R, the terminal performs SRS antenna switching so that the base station acquires a downlink channel. The terminal can perform uplink transmission based on one transmitting antenna port using one transmitting module (e.g., LPAF (LNA, PA, and Filter). LPAF can be composed of LNA, PA, and Filter) (500). If the terminal performs antenna switching for four receiving antennas (501, 502, 503, 504), the terminal can transmit SRS by sequentially switching one transmitting module (500) from the first antenna (501) to the fourth antenna (504) using a switch (505). At this time, due to path loss caused by the form factor of the terminal and the placement location of the receiving antennas, the terminal can transmit SRS with less power than the power applied by the transmitting module. Transmitting SRS with power lower than that applied by the transmitting module can be defined as insertion loss (IL). Additionally, the terminal may intentionally lower the target power value to prevent interference or interference, depending on the operation of other components of the terminal (e.g., camera, Bluetooth, Wi-Fi, etc.), as well as reasons such as terminal shape and path loss. For example, when performing SRS antenna switching, an imbalance may occur in the SRS transmission power (511, 512, 513, 514) transmitted by each antenna due to insertion loss as well as interactions between other components of the terminal. As illustrated in the example in FIG. 5, the magnitude of the SRS transmission power (512 to 514) transmitted to the second to fourth antennas may be relatively smaller than the SRS transmission power (511) transmitted to the first antenna.The relative smaller magnitude of the SRS transmission power transmitted to the second through fourth antennas compared to the SRS transmission power transmitted to the first antenna can be defined as insertion loss imbalance (IL imbalance). For example, due to the terminal's transmitting module, antenna placement, and interactions between other factors, a problem may arise where the SRS transmitted to each receiving antenna cannot be delivered with uniform transmission power.

[0257] FIG. 6 is a diagram showing an example of a terminal structure supporting four receiving antennas in a wireless communication system according to one embodiment of the present disclosure.

[0258] Referring to FIG. 6, unlike FIG. 5 described above, an example of a terminal supporting four receiving antennas (601 to 604) can be illustrated. Unlike the transmitting module, the receiving module (DRX-M, diversity Rx module) (611 to 614) for diversity support can be implemented with a simpler structure and is cheaper than the transmitting module, so it can be deployed and operated on all receiving antennas. Therefore, since there may not be a significant difference in the amount of insertion loss between each receiving antenna (601 to 604) and the receiving module (611 to 614), unlike the case described above (e.g., FIG. 5), the power imbalance between downlink channels or downlink reference signals, such as CSI-RS, received by each antenna may be very small or non-existent.

[0259] In addition to power imbalance (or power imbalance) caused by Tx-Rx mismatch resulting from the difference between the transmitter RF structure and the receiver RF structure of the terminal described above, the difference in transmission power between SRS resources for antenna switching purposes may be greater due to other terminal implementation elements, as illustrated in FIG. 5. For example, elements for non-communication functions, such as a camera, may be implemented in adjacent parts between a specific antenna path (e.g., the second antenna (502) in FIG. 5) and the RF transmitter module (500). If power for uplink transmission is applied to an adjacent transmission RF path, RF interference may occur, which may adversely affect the image quality or operation of the camera. For this reason, if a module such as a camera is turned on (or is in an 'on' state), the terminal may intentionally reduce the amount of power applied to the antenna adjacent to the module such as a camera. For example, the transmission power of uplink signals transmitted to some antennas may be intentionally reduced by considering not only the mismatch between the transmitter and receiver due to the RF structure of the terminal but also the impact on modules of other terminals. As a result, multiple SRS resources intended for antenna switching, which should be transmitted at the same transmission power, may be transmitted at different transmission powers.

[0260] As seen in Figures 5 and 6, depending on the occurrence of insertion loss imbalance (IL imbalance), a difference may arise between the downlink channel estimated based on the SRS transmitted by the terminal and the downlink channel received by the terminal. For example, the base station ideally expects that the downlink channel received by the terminal and the downlink channel obtained through SRS antenna switching are identical; however, due to the occurrence of IL imbalance, an estimation error may occur between the actual downlink channel received by the terminal and the downlink channel estimated by the base station through SRS antenna switching. If the accuracy of the downlink channel estimated by the base station through SRS antenna switching can be improved, the base station can perform accurate precoding on the downlink channel transmitted to the terminal, and through accurate precoding, beamforming gain can be maximized to increase the downlink throughput.

[0261] However, as explained above, in order for a base station to measure the uplink channel based on SRS and estimate the downlink channel through this, the SRS signal transmitted by the terminal must first reach the base station and be received correctly. If the SRS transmitted by the terminal fails to reach the base station due to excessive back-off of SRS power or channel characteristics, or if the base station fails to receive it correctly, it may be difficult to estimate not only the uplink but also the downlink channel through SRS or SRS antenna switching, unlike other uplink channels such as PUSCH (physical uplink shared channel). Furthermore, since the transmission power of the SRS transmitted by the terminal is very small compared to the transmission power of the CSI-RS transmitted by the base station, sufficient uplink coverage must be secured by considering the distance between the base station and the terminal or the signal strength (power) of the SRS itself so that the SRS signal can reach it. When a base station can successfully receive the SRS in this way, the base station can estimate the downlink channel based on the reciprocity of the uplink channel. Since the base station's measurement of the uplink channel via the SRS is an important operation for estimating not only the simple uplink but also the downlink channel, it is important for the terminal to secure uplink coverage above all else when transmitting the SRS.

[0262] FIG. 7 illustrates an example of a case depending on the distance between the terminal and the base station or the transmission power of the terminal when the terminal transmits SRS in a wireless communication system according to one embodiment of the present disclosure.

[0263] Referring to FIG. 7, when a terminal transmits an SRS from a cell to a base station, an example of whether the base station receives the SRS based on the frequency band or transmission power of the SRS transmitted by the terminal is described. If it is assumed that the terminal transmits SRS or other uplink signals in, for example, the 1 GHz band (700), the terminal can assume that the SRS reaches the base station even if the maximum possible output (Pcmax) obtained is insufficient compared to the maximum output (e.g., 23 dBm) (e.g., 15 dBm) (701). However, in the 4 GHz band (710), if the path attenuation characteristics or radio wave diffraction of the frequency band are reduced and the Pcmax of the SRS signal is insufficient compared to the maximum output (e.g., 23 dBm), the SRS may not reach the base station depending on the location of the terminal or the distance from the base station (711). Such problems can occur frequently in 5G systems that primarily utilize higher bands. Given that the use of high frequencies increases as mobile communication generations evolve and that SRS can affect not only uplink but also downlink performance in TDD systems, it is evident that SRS power should be viewed as more important than the power of other uplink channels. However, the current method of setting SRS power is based on the same consideration as parameters that constitute other uplink power, such as adjacent channel leakage or power reduction considering human health regulations.

[0264] In summary, as previously observed in Figures 5 and 6, a difference may occur between the downlink channel estimated based on the SRS transmitted by the terminal and the downlink channel received by the terminal depending on whether an IL imbalance occurs. For example, the base station ideally expects that the downlink channel received by the terminal and the downlink channel obtained through SRS antenna switching are the same, but due to the occurrence of an IL imbalance, an estimation error may occur between the actual downlink channel received by the terminal and the downlink channel estimated by the base station through SRS antenna switching.

[0265] In addition, as seen in Figure 7, due to signal quality issues with the SRS itself, such as high frequency utilization and power settings and control identical to other uplink channels, there may be cases where the SRS signal transmitted by the terminal does not reach the base station regardless of whether the preceding SRS antenna switching is present. For example, the base station ideally expects the terminal to transmit the SRS, but the terminal may be located at the edge of a high-frequency cell and unable to transmit the SRS with enough power for the uplink signal to reach the base station; or back-off settings and control where the SRS power itself is identical to the data signal; or arbitrary back-off by a proximity sensor allowed to the terminal for the purpose of avoiding human impact regulations; there may be cases where the SRS signal transmitted normally by the terminal in the existing settings does not reach the base station due to external factors unrelated to the SRS.

[0266] If the aforementioned problems can be resolved—for example, if a base station can normally receive SRS signals and improve the accuracy of the downlink channel through SRS antenna switching—then the base station can perform accurate precoding on the downlink channel transmitted to the terminal, and through accurate precoding, beamforming gain can be maximized to increase downlink throughput. In this invention, we investigate a method in which the terminal independently sets and manages SRS power, reports the set SRS power to the base station, and enables the base station to acquire a more accurate uplink channel and estimate the downlink channel through independent SRS power control to maximize downlink throughput.

[0267] <1st Embodiment: SRS P CMAX Definition Method>

[0268] In the following, P, which was previously applied to all uplink channels CMAX In the configuration method, based on parameters related to actual SRS signal transmission, the terminal sets the maximum output power (or P) dedicated to SRS. CMAX Explain in detail how to define ).

[0269] As previously mentioned, the existing P CMAXf,c is one P for the carrier f of support cell c. CMAX Only the value is set, and this value applies to all uplink channels such as PUSCH, PUCCH, and SRS. Therefore, when the terminal transmits SRS, the P for the existing uplink power control CMAXAccording to the configuration method, it is possible to apply parameters unrelated to SRS transmission to SRS transmission, such as all parameters primarily required for data channel transmission, for example, maximum power reduction (MPR) based on the location of the RB containing actual data within the transmission bandwidth, or the terminal's proximity sensor-based power back-off (e.g., P-MPR (power management maximum power reduction)) to avoid human impact regulations. More specifically, the SRS transmitted by the terminal to the base station has a primary purpose as a reference signal to help the base station estimate the uplink channel, and additionally, assuming reciprocity between the downlink and uplink, there is also a secondary purpose of enabling downlink channel estimation based on this. Therefore, the proper reception of SRS by the base station is a critical factor for signal quality in both the uplink and downlink. Since the terminal transmits SRS periodically or non-periodically within a fixed slot across the entire channel bandwidth in short bursts, it may be appropriate to use individual power control methods for SRS transmission. Furthermore, constraints on PCMAX values ​​with applied MPR or P-MPR, which are considered in existing uplink data channels, may not be suitable for SRS power control methods. Additionally, because the base station only transmits power headroom information for the PUSCH channel from the terminal and does not know the power or power headroom information for the SRS, it may be unable to provide sufficient appropriate uplink and downlink scheduling to the terminal when the SRS transmitted by the terminal fails to reach the base station or when an imbalance occurs between SRS resources due to antenna switching.

[0270] As a solution to this problem, the terminal is a P designed exclusively for SRS CMAX Based on this, a method to separately set the SRS transmission power can be considered. To do this, a dedicated SRS P CMAX The elements required for configuration can be distinguished from the elements required for existing data channel transmission, and elements irrelevant to SRS transmission can be removed, or new related elements can be added to report accurate SRS or channel status to the base station. For example, the existing P CMAX In the configuration method, parameters such as P-MPR, which are unrelated to SRS transmission but can deeply influence the actual uplink power, are set for SRS P CMAX A method of removing it from and adding a new parameter for SRS might also be considered. That is, P for SRS CMAX One or more of the following methods may be considered as a method to define it.

[0271] - [Method 1-1] (P for SRS CMAX Method for configuring the lower limit level) As described above, the terminal is the existing P CMAX At the lower limit level, a method may be considered to remove parameters such as P-MPR, which are unrelated to SRS transmission but can significantly influence actual uplink power, and instead maintain or add new parameters for SRS. In this case, from the existing lower limit level configuration, MPR-related elements such as modulation scheme and waveform, CA (carrier aggregation)-related elements, and P-MPR—which is a factor allowing arbitrary power back-off by the terminal to avoid human health effects—can be removed; instead, △T, which is the maximum possible power back-off factor related to SRS antenna switching, can be removed. RxSRSMaintaining, or a new tolerance value based on the terminal's SRS design and implementation, e.g., △T related to SRS transmission via DRX for other RF components such as the camera, Bluetooth, Wi-Fi, etc. RxSRS △T that the terminal may intentionally apply for interference or interference prevention, depending on the operation of other terminal components that can be considered in addition. SRS Etc. can be newly added. In this way, the terminal includes only elements directly or indirectly related to the SRS, such as P CMAX Reconfigure the lower limit level, and the P set in this way CMAX By reporting the value to the base station, it can help the base station perform more accurate uplink and downlink channel estimations.

[0272] - [Method 1-2] (P for SRS CMAX Method of constructing as an equality expression) Uplink P defined based on existing inequalities as another method for the terminal to set SRS power to the maximum CMAX One can consider improving the configuration into an equation that includes only the elements necessary for SRS transmission. In this case, △T, the maximum possible power back-off element related to SRS antenna switching—which is an element that must be considered in SRS transmission within the existing upper limit level configuration— RxSRS Or, a new tolerance value based on the terminal's SRS design and implementation, e.g., △T related to SRS transmission via DRX for other RF components such as cameras, Bluetooth, Wi-Fi, etc. RxSRS △T that the terminal may intentionally apply for interference or interference prevention, depending on the operation of other terminal components that can be considered in addition. SRSOnly the following can be newly added. In this way, the terminal includes only elements directly or indirectly related to the SRS, such as P CMAX Reconstructing the equation, and the P thus established CMAX By reporting the value to the base station, it can help the base station perform more accurate uplink and downlink channel estimations.

[0273] Meanwhile, △T mentioned in the preceding methods SRS The maximum or minimum value is not defined as an arbitrary value of the terminal and can be applied without restriction depending on the implementation and design method of the terminal, or a maximum or minimum tolerance value that can be applied by the terminal can be defined assuming one or more implementation and design methods of the terminal.

[0274] In addition, P for SRS, such as the aforementioned [Method 1-1] and [Method 1-2] CMAX In addition to the method of deriving the range or value of, the SRS P derived based on this CMAX Depending on the scope of application, SRS P as follows CMAX It can distinguish.

[0275] - [Example 1-1] (One SRS P per cell CMAX Method for configuring): The terminal has a single SRS P capable of representing the transmission power of multiple SRS resources transmitted to the base station. CMAX You can set it, and at this time, one P for SRS is set. CMAX Based on parameters affecting SRS transmission, for example, based on [Method 1-1] or [Method 1-2] above, parameter values ​​having the maximum, minimum, or average values ​​of the SRS resource power transmitted at each SRS port are set, thereby P for a single SRS CMAX You can set it.

[0276] - [Example 1-2] (One SRS P per SRS resourceCMAX Method for configuring): For the transmission power of multiple SRS resources transmitted to the base station, the terminal has one SRS P for each SRS resource. CMAX You can set it, and at this time, one P for SRS is set. CMAX Based on parameters affecting SRS transmission, for example, based on [Method 1-1] or [Method 1-2] mentioned earlier, parameter values ​​are set differently for each SRS resource transmitted from each SRS port, thereby P for the SRS resource CMAX You can set it.

[0277] That is, SRS P CMAX As a method that can be considered, first, SRS P as in [Method 1-1] and [Method 1-2] CMAX to the existing uplink P CMAX One can consider a method of deriving it by distinguishing it from, and then, as in [Example 1-1] and [Example 1-2], the derived P for SRS CMAX We can also consider how to apply this to SRS. SRS P CMAX As a method for setting , there may be others other than the above methods or examples, and SRS P considering a combination of additional information CMAX It can be configured. Of course, additional information is not limited to the methods and examples above.

[0278] <Second Embodiment: Maximum Power Control Method>

[0279] Below, the terminal [specific P] for independent power setting and control dedicated to SRS CMAX Explains the setup methods.

[0280] SRS P for independent power control dedicated to SRS CMAX In order to configure it, as mentioned earlier, the terminal must use the previously mentioned existing P CMAXAt the lower limit level, a typical approach to consider is to remove parameters such as P-MPR, which are unrelated to SRS transmission but can significantly influence actual uplink power, and instead maintain or add new parameters for the SRS. That is, the terminal [uses] SRS P to independently set the SRS power. CMAX You can set it, and in this case, SRS P CMAX The lower limit level is a factor that must be considered in SRS transmission, for example, △T, the maximum possible power back-off factor related to SRS antenna switching. RxSRS , a new tolerance value △T based on the terminal's SRS design and implementation SRS SRS P including only elements directly or indirectly related to SRS, etc. CMAX A lower limit level can be defined.

[0281] As mentioned in the previous embodiment, in addition to the method of adjusting the lower limit level during SRS transmission, the terminal has an SRS-dedicated P CMAX As a method for setting this, one can consider improving the equation by including only the elements necessary for SRS transmission so that the terminal can set the SRS power to the maximum. In addition, the SRS P per serving cell in which the terminal operates CMAX In addition to defining, SRS P for each SRS resource CMAX Methods for configuring can also be considered. Including all these methods, SRS P for each scenario or usability CMAX The method of defining can be defined by distinguishing as follows. However, △T for which detailed conditions are not mentioned in each table below RxSRS The requirements for the above conditions are the same as those previously explained through [Equation 4], [Equation 5], [Equation 6], etc.

[0282] [Table 8] SRS P CMAXMethod for defining a lower bound as a single representative value per cell (combination of [Method 1-1] and [Example 1-1])

[0283]

[0284] [Table 9] SRS P CMAX Method for defining a lower bound as a single value per SRS resource (combination of [Method 1-1] and [Example 1-2])

[0285]

[0286] [Table 10] SRS P CMAX Method to define one representative value per cell (combination of [Method 1-2] and [Example 1-1])

[0287]

[0288] [Table 11] SRS P CMAX Method to define as a single value per SRS resource (combination of [Method 1-2] and [Example 1-2])

[0289]

[0290] <Third Embodiment: Power Headroom Report Trigger Method>

[0291] In the third embodiment, the terminal uses the SRS P set when transmitting SRS resources to the base station. CMAX Power headroom-based reporting can be used to transmit information about to the base station. In this case, SRS P CMAX Power imbalance information △T between SRS resources applied during information and SRS transmission RxSRS Specifically, methods for the terminal to trigger power headroom reporting to perform SRS power headroom reporting that additionally includes are described.

[0292] A terminal may use a power headroom report (PHR) to report information to a base station to improve the estimation accuracy of the downlink channel. As described above, the terminal may trigger a power headroom report when specific conditions are met, and the terminal may include a MAC CE for the power headroom report in a PUSCH and transmit it to the base station. When the terminal reports the power headroom, the maximum transmission power P of the SRS that the terminal can transmit at the time of transmitting the SRS or at the time of reporting the power headroom CMAX,SRS,f,c The terminal can report power headroom to the base station, which is the difference between the maximum power and the current transmission power (or power determined based on reference signal transmission in cases where the uplink signal is not actually transmitted). Additionally, if the terminal transmits multiple SRS resources within an SRS resource set for antenna switching to the base station and applies power back-off considering the terminal's implementation or interference from other factors, causing an imbalance in transmission power between the multiple SRS resources transmitted by the terminal, the terminal can report additional information to the base station using power headroom reporting.

[0293] However, if the trigger conditions for the aforementioned power headroom report are not met, the base station may not receive additional information that could improve estimation accuracy when the terminal transmits an SRS for antenna switching purposes and the base station estimates the channel based on the SRS. The aforementioned power headroom trigger conditions may be cases where the change in transmission power of the current PUSCH compared to the previous PHR report, based on the amount of change in path loss measurable via the downlink reference signal, exceeds a certain threshold, or where events such as SCell (secondary cell) activation or PSCell (primary secondary cell) addition occur. In particular, the terminal's behavior may be defined so that a temporary power back-off does not trigger the power headroom report or does not reflect the power reduction caused by a temporary power back-off. If the terminal reflects the impact of a temporary power back-off in the power headroom report only for PUSCH transmission, a problem may arise in which the base station may have difficulty accurately determining the current transmission power status of the terminal; therefore, the aforementioned constraints on the terminal's behavior may be defined. However, as described above, if the terminal does not report to the base station the effects caused by power back-offs occurring when transmitting SRS or an SRS resource set for antenna switching, problems may arise where the SRS signal does not reach the base station during channel estimation, or the base station cannot detect channel distortion caused by power imbalances between SRS resources. For example, if the terminal transmits multiple SRS resources within an SRS resource set for antenna switching and there is an imbalance in the actual power of the multiple SRS resources, a condition can be added to trigger a separate power headroom report.Therefore, the terminal can support the base station in identifying transmission power imbalances between multiple SRS resources through power headroom reporting, and the base station can improve channel estimation accuracy based on the additional reported information.

[0294] If a terminal transmits an SRS, it may trigger a power headroom report and report power headroom information and additional information per transmitted SRS resource to the base station. For example, a terminal may transmit multiple SRS resources configured in an SRS resource set for 'antenna switching' usage and trigger a power headroom report to report power headroom information and additional information regarding the associated SRS resource set to the base station. An SRS resource set for antenna switching usage may be configured to perform antenna switching for x transmitting antennas and y receiving antennas, where y > x. In this case, a number greater than one SRS resource may be configured in the SRS resource set for 'antenna switching' usage. The trigger for the power headroom report associated with the transmission of the SRS resource set for 'antenna switching' usage may operate independently of the aforementioned trigger event for triggering the power headroom report. Alternatively, some trigger events may be reused to trigger the power headroom report associated with the SRS resource set for 'antenna switching' usage.

[0295] If power headroom reporting is triggered whenever the terminal transmits an SRS or an SRS resource set for 'antenna switching' (for convenience of explanation, an SRS resource set for antenna switching may be briefly referred to as 'SRS AS'), the terminal may frequently report power headroom to the base station, potentially wasting unnecessary uplink resources. Therefore, to limit unnecessary or frequent power headroom reporting, the terminal may check for additional information to trigger power headroom reporting after transmitting an SRS AS. The terminal may determine whether to trigger power headroom reporting by considering each of the additional information described below individually or in combination. Of course, the additional information is not limited to the examples below.

[0296] Additional Information 1) When a terminal transmits an SRS AS, it may determine whether to trigger a power headroom report by considering the type scheduled according to the time domain behavior of the SRS. The time domain behavior of the SRS can be defined as one of 'aperiodic', 'semi-persistent', or 'periodic'. If a terminal transmits an SRS AS scheduled with a specific time domain behavior among the three SRS time domain behaviors, the terminal may trigger a power headroom report associated with the transmitted SRS AS. For example, if a base station schedules an aperiodic SRS AS to the terminal, the terminal can transmit the aperiodic SRS AS and trigger a power headroom report associated with it. If the terminal transmits a periodic SRS AS scheduled based on configured RRC parameters, it may trigger a power headroom report associated with that periodic SRS AS by considering other additional information.

[0297] Additional Information 2) A new timer may be defined for power headroom reporting associated with SRS AS. Power headroom reporting may be triggered by the terminal depending on whether the new timer expires. If the terminal reports to the base station that it can support the power headroom reporting feature associated with SRS AS, and the base station uses a technique to improve channel estimation accuracy using power headroom reporting associated with SRS AS, the base station may set RRC parameters to support such technique on the terminal. In this case, the base station may set a prohibition timer as an RRC parameter to prevent unnecessary triggering of power headroom associated with SRS AS on the terminal. A time value may be set on the terminal for the new prohibition timer associated with SRS AS (e.g., phr-ProhibitTimerforCE) to prohibit the power headroom reporting from being triggered for a certain period after the power headroom report. A value that can be set for a new prohibit timer (in this disclosure, 'new prohibit timer' may mean phr-ProhibitTimerforCE) may be set as a value representing a certain time (e.g., a value in subframe units). Specifically, sf0, sf10, sf20, sf50, sf100, sf500, or sf1000 may be considered as candidate values ​​that can be set for the new prohibit timer (sfN means a time interval corresponding to N subframes). As another example, a value that can be set for the new prohibit timer may be set as a time unit such as ms or a slot unit such as sl. The terminal may start or restart the new prohibit timer after performing a power headroom report associated with the SRS AS. The new prohibit timer operates until the RRC parameter value set by the base station for the terminal, and while the new prohibit timer is operating, the terminal may not trigger a power headroom report associated with the SRS AS.If a new prohibit timer expires after operating for a time set by an RRC parameter value following a power headroom report associated with an SRS AS, the terminal may trigger a power headroom report depending on whether other conditions for triggering a power headroom report associated with an SRS AS are met. The new prohibit timer may operate independently of other PHR prohibit timers (e.g., phr-ProhibitTimer). Alternatively, the new prohibit timer may influence whether phr-ProhibitTimer starts or restarts. The association between the two timers may be determined by the information reported through the power headroom report associated with the SRS AS. For example, if the MAC CE format for the power headroom report associated with the SRS AS reports only the power headroom, maximum transmission power, and additional information to improve channel estimation accuracy for the associated SRS AS, the two timers described above may operate independently. On the other hand, if the MAC CE format for power headroom reporting associated with SRS AS includes power headroom for the associated SRS AS, maximum transmission power for the SRS AS, additional information to improve channel estimation accuracy, power headroom reported through conventional power headroom reporting, maximum transmission power, and MAC CE fields for reporting power back-off values, the two timers described above can operate in association with each other.

[0298] FIG. 8 illustrates an example in which two power headroom prohibition timers operate independently in a wireless communication system according to one embodiment of the present disclosure.

[0299] Referring to FIG. 8, an example is illustrated in which two power headroom prohibit timers (800, 801) operate independently. A terminal may receive an RRC parameter and start a power headroom prohibit timer (800, phr-ProhibitTimer) (802). Independently, the terminal may receive an RRC parameter and start a new power headroom prohibit timer (801, phr-ProhibitTimerforCE) that prohibits power headroom associated with an SRS AS (803). The power headroom prohibit timer (800) expires after a set time set by the RRC (804), and after the timer (800) expires, the terminal may trigger a power headroom report (806). The new prohibit timer (801) expires after a set time set by the RRC (805), and after the timer (801) expires, the terminal may trigger a new power headroom report associated with an SRS AS (807). If a power headroom report is triggered as described above, the terminal can perform a power headroom report (808). At this time, the power headroom report performed by the terminal can be performed independently of the SRS AS transmission. Subsequently, the terminal can restart the prohibition timer (800) for the power headroom report (810), and after a certain period of time has passed and the timer (800) has expired (812), the terminal can trigger another power headroom and perform a power headroom report (814). If a new power headroom report associated with the SRS AS is triggered independently of the existing power headroom report being triggered and reported (808), the terminal can perform the new power headroom report (809). Subsequently, the terminal can restart a new prohibition timer (801) for the new power headroom report (811), and after a certain period of time has passed and the timer (801) has expired (813), the terminal can trigger another new power headroom and perform the new power headroom report (815).

[0300] FIG. 9 illustrates an example in a wireless communication system according to one embodiment of the present disclosure in which an existing power headroom prohibition timer operates depending on whether a new power headroom prohibition timer has expired.

[0301] Referring to FIG. 9, an example is illustrated in which an existing power headroom prohibit timer (900) operates depending on whether a new power headroom prohibit timer (901) has expired. Identical or similar to FIG. 8 described above, the terminal may not be able to trigger power headroom until two prohibit timers (phr-ProhibitTimer, phr-ProhibitTimerforCE) (900, 901) start (902, 903) and expire. If two prohibit timers (900, 901) start (902, 903) and then two timers (900, 901) expire (904, 905) after a certain period of time, the terminal may trigger a power headroom report or a new power headroom report (906, 907). If a new power headroom report is triggered, the terminal can perform the new power headroom report (909), and while the new power headroom report is triggered and performed (909), the terminal cannot trigger the existing power headroom report (908). After the new power headroom report is performed (909), the terminal can restart both prohibit timers (900, 901) (910, 911). When the terminal restarts both prohibit timers (900, 901) (910, 911) and the two timers expire after a certain period of time (912, 913), the terminal can trigger the power headroom report or the new power headroom report (914, 915). If, during the interval (916, 917) in which a power headroom or a new power headroom can be triggered, the existing power headroom prohibition timer (900) is restarted (919) after the existing power headroom report is triggered and executed (918), the new power headroom report can be triggered and executed (917). After the terminal triggers and executes the existing power headroom report (918), the power headroom prohibition timer (900) can be restarted (919).If a new power headroom report associated with the SRS AS is triggered and executed (920), the terminal cannot trigger and execute an existing power headroom report while the new power headroom report is being executed (920) (921). After the terminal executes the new power headroom report (920), both prohibit timers (900, 901) can be restarted (922, 923). When the terminal restarts both prohibit timers (900, 901) (922, 923) and both timers expire after a certain period of time (924, 925), the terminal can trigger an existing power headroom report or a new power headroom report (926, 927).

[0302] FIG. 10 illustrates an example in a wireless communication system according to one embodiment of the present disclosure in which a new power headroom prohibition timer operates depending on whether an existing power headroom prohibition timer has expired.

[0303] Referring to FIG. 10, an example is illustrated in which a new power headroom prohibit timer (1001, phr-ProhibitTimerforCE) operates depending on whether the existing power headroom prohibit timer (1000, phr-ProhibitTimer) has expired. The terminal may not be able to trigger power headroom until both prohibit timers (1000, 1001) start (1002, 1003) and expire. If both prohibit timers (1000, 1001) start (1002, 1003) and the two timers (1000, 1001) expire after a certain period of time (1004, 1005), the terminal may trigger a power headroom report or a new power headroom report (1006, 1007). If an existing power headroom report is triggered, the terminal can perform a power headroom report (1008), and while the power headroom report is triggered and performed (1008), the terminal cannot trigger a new power headroom report (1009). After the existing power headroom report is performed (1008), the terminal can restart both prohibit timers (1000, 1001) (1010, 1011). When the terminal restarts both prohibit timers (1000, 1001) (1010, 1011) and both timers expire after a certain period of time (1012, 1013), the terminal can trigger a power headroom report or a new power headroom report (1014, 1015). If, during the interval (1016, 1017) in which power headroom or new power headroom can be triggered, the new power headroom prohibition timer (1001) is restarted (1019) after the new power headroom report is triggered and executed (1018), the existing power headroom report can be triggered and executed (1020). After the terminal triggers and executes the new power headroom report (1019), the new power headroom prohibition timer (1001) can be restarted (1019).If an existing power headroom report is triggered and executed (1020), the terminal cannot trigger and execute a new power headroom report while the existing power headroom report is being executed (1020) (1021). After the terminal has executed the existing power headroom report (1020), both prohibit timers (1000, 1001) can be restarted (1022, 1023). When the terminal restarts both prohibit timers (1000, 1001) (1022, 1023) and both timers expire after a certain period of time (1024, 1025), the terminal can trigger an existing power headroom report or a new power headroom report (1026, 1027).

[0304] The examples of FIGS. 8 to 10 described above illustrate cases where the time values ​​(e.g., subframe units, ms units, slot units) set in the RRC parameters of two prohibition timers are the same. However, the methods described above can be applied in the same way even when the RRC parameter values ​​set in the two prohibition timers are different.

[0305] Additional Information 3) If certain conditions are met by comparing a power value for the SRS AS at the time of calculating the power headroom associated with a previously reported SRS AS with a power value for the currently transmitting SRS AS, the terminal may trigger and perform a power headroom report associated with the SRS AS. As a specific example, if the difference between the following transmitted power values ​​is greater than a certain threshold, the terminal may trigger a power headroom report associated with the SRS AS. Of course, it is not limited to the following examples.

[0306] - Power Comparison 1) The terminal may compare the transmission power difference between the two SRS resources with the largest transmission power difference among the SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS with the transmission power difference between the two SRS resources with the largest transmission power difference among the SRS resources currently transmitting within the SRS AS. If the difference between the two values ​​is greater than or equal to a certain threshold, the terminal may trigger and perform a power headroom report associated with the SRS AS. For example, four SRS resources may be configured within an SRS resource set for the SRS AS, and the terminal may switch antennas to transmit the four SRS resources to the base station so that the base station can estimate the downlink channel. Assume that the transmission power difference between any two SRS resources (e.g., the first SRS resource and the fourth SRS resource) within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS is greater than the transmission power difference between any other two SRS resources, and that value is 3 dB. Assume that the difference in transmission power between any two SRS resources (e.g., the first SRS resource and the fourth SRS resource) within the SRS AS to be transmitted by the current terminal is greater than the difference in transmission power between any other two SRS resources, and that the value is 9 dB.If a threshold (e.g., phr-Tx-PowerFactorChangeforSRS) is set to 'dB3' (or 3 dB) according to Power Comparison 1, the difference in transmitted power values ​​according to Power Comparison 1 becomes greater than the threshold set at 3 dB because the difference is 6 dB, which is the maximum difference in power values ​​between SRS resources in the current SRS AS to be transmitted, compared to 3 dB, which is the maximum difference in power values ​​between SRS resources at the time of reporting power headroom associated with the previous SRS AS. Therefore, the terminal can trigger and perform power headroom reporting associated with the new SRS AS.

[0307] - Power Comparison 2) The terminal may compare the transmission power value of the SRS resource with the lowest transmission power among the SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS with the transmission power value of the SRS resource with the lowest transmission power among the SRS resources currently transmitting within the SRS AS. If the difference between the two values ​​is greater than or equal to a threshold, the terminal may trigger and perform a power headroom report associated with the SRS AS. For example, assume that at the time of calculating the power headroom associated with the previously reported SRS AS, the transmission power of one of the four SRS resources within the SRS AS (e.g., the fourth SRS resource) is the lowest, and its value is 20 dBm. If the transmission power of one of the four SRS resources within the SRS AS currently being transmitted by the terminal (e.g., the fourth SRS resource) is the lowest, and its value is 16 dBm. If a threshold (e.g., phr-Tx-PowerFactorChangeforSRS) is set to 'dB3' (or 3 dB) according to Power Comparison 2, the difference between the transmission power of the SRS resource with the smallest transmission power at the time of reporting the power headroom associated with the previous SRS AS and the transmission power of the SRS resource with the smallest transmission power in the current SRS AS to be transmitted is 4 dB, which is greater than the 3 dB set as the threshold, so the terminal can trigger and perform a power headroom report associated with the new SRS AS.

[0308] - Power Comparison 3) The terminal may compare the transmission power value of the SRS resource with the highest transmission power among the SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS with the transmission power value of the SRS resource with the highest transmission power among the SRS resources currently transmitting within the SRS AS. If the difference between the two values ​​is greater than or equal to a threshold, the terminal may trigger and perform a power headroom report associated with the SRS AS. For example, assume that at the time of calculating the power headroom associated with the previously reported SRS AS, the transmission power of one of the four SRS resources within the SRS AS (e.g., the first SRS resource) is the highest, and its value is 23 dBm. If it is assumed that the transmission power of one of the SRS resources within the SRS AS currently being transmitted by the terminal (e.g., the first SRS resource) is the highest, and its value is 20 dBm. If a threshold (e.g., phr-Tx-PowerFactorChangeforSRS) is set to 'dB3' (or 3 dB) according to Power Comparison 3, the terminal can trigger and perform a power headroom report associated with the new SRS AS because the difference between the transmission power of the SRS resource with the highest transmission power at the time of reporting the power headroom associated with the previous SRS AS and the transmission power of the SRS resource with the highest transmission power in the current SRS AS is 3 dB, which is the same as the 3 dB set as the threshold.

[0309] In the power comparisons 1 to 3 described above, a power comparison was performed between the SRS AS at the time of calculating the power headroom associated with the SRS AS currently being transmitted and the previously reported SRS AS. However, the method described above may also be applied by extending it to the SRS AS at the time of calculating any reported power headroom prior to the base station reporting additional information that can improve channel estimation accuracy.

[0310] Additional Information 4) If the combination of the two SRS resources with the largest (or smallest) transmission power difference among the SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS changes, and the combination of the two SRS resources with the largest (or smallest) transmission power difference among the SRS resources currently transmitting within the SRS AS changes, the terminal may trigger and perform a new power headroom report associated with the SRS AS. For example, if the combination of any two SRS resources with the largest (or smallest) transmission power difference among the SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS (e.g., the first SRS resource and the fourth SRS resource) is different from the combination of any two SRS resources with the largest (or smallest) transmission power difference among the SRS resources currently transmitting within the SRS AS (e.g., the first SRS resource and the second SRS resource), the terminal may trigger and perform a power headroom report associated with the new SRS AS.

[0311] In Additional Information 4, changes in the two SRS resource combinations with the largest (or smallest) difference in transmission power within the SRS AS at the time of calculating the power headroom associated with the currently transmitted SRS AS and the previously reported SRS AS were compared; however, the trigger for reporting power headroom according to Additional Information 4 may be determined by extending to the SRS AS at the time of calculating any reported power headroom prior to the base station reporting additional information that can improve channel estimation accuracy.

[0312] Additional Information 5) If the relative strength (or order of transmission power) of SRS resources within the currently transmitting SRS AS changes compared to the relative strength (or order of transmission power) of SRS resources within the SRS AS at the time of calculating the power headroom associated with the previously reported SRS AS, the terminal may trigger and perform a new power headroom report associated with the SRS AS. For example, if the transmission power of SRS resources within an SRS AS at the time of calculating the power headroom associated with a previously reported SRS AS has a certain relationship (or order of transmission power magnitude) (e.g., transmission power decreasing in the order of first SRS resource > second SRS resource > third SRS resource > fourth SRS resource), and the transmission power of SRS resources within the SRS AS currently to be transmitted has a different relationship (or order of transmission power magnitude) (e.g., transmission power decreasing in the order of second SRS resource > first SRS resource > fourth SRS resource > third SRS resource), the terminal may determine that the relationship (or order of transmission power magnitude) of the transmission power of SRS resources within the SRS AS at two different time points has changed, and trigger and perform a new power headroom report associated with the SRS AS.

[0313] In Additional Information 5, the relationship between SRS resources at the time of calculating the power headroom associated with the currently transmitted SRS AS and the previously reported SRS AS was compared; however, the trigger for reporting the power headroom according to Additional Information 5 may be determined by extending to the SRS AS at the time of calculating any reported power headroom prior to the base station reporting additional information that can improve channel estimation accuracy.

[0314] Additional Information 6) Among the antenna switching settings that the terminal can support, if the terminal transmits an SRS resource to enable switching for all antennas according to the xTyR setting configured by the base station for the terminal, the terminal may determine whether to trigger a power headroom report. For example, if the terminal supports 1T4R, the terminal may need to transmit a total of four SRS resources using different Rx antennas because it must transmit SRS using 1Tx antenna for up to four Rx antennas. If the terminal has transmitted all four SRS resources to perform antenna switching and determines that a power headroom report should be performed according to the aforementioned additional information(s), the terminal may trigger a power headroom report. On the other hand, if the terminal has transmitted only some of the four SRS resources to perform antenna switching, the terminal may not trigger a power headroom report even if it determines that a power headroom report should be performed according to the aforementioned additional information(s). In this case, the terminal may trigger a power headroom report after transmitting the remaining untransmitted SRS resources.

[0315] <Fourth Embodiment: Method for Configuring MAC CE Format for Power Headroom Reporting>

[0316] In the fourth embodiment, P is the maximum power of the SRS. CMAX,SRS,f,c (or PCMAX,SRS,f,c,p The MAC CE format transmitted by the terminal to the base station to perform reporting of ) and SRS power headroom is described in detail.

[0317] As described above, the P set by the terminal CMAX,SRS,f,c (or P CMAX,SRS,f,c,p If an SRS power headroom report is triggered to report ) and SRS power headroom to the base station, the terminal can transmit a MAC CE for the power headroom report to the base station using PUSCH. SRS-specific power headroom and P CMAX,SRS,f,c (or P CMAX,SRS,f,c,p Since the ) information is a new type of information, if the MAC CE format illustrated in FIG. 1 or FIG. 2 is used, the terminal has power headroom dedicated to SRS and P CMAX,SRS,f,c (or P CMAX,SRS,f,c,p It may be difficult to report ) information to the base station. The terminal has power headroom dedicated to SRS and P CMAX,SRS,f,c (or P CMAX,SRS,f,c,p A new MAC CE format may be required to report ) information to the base station. Therefore, as described below, power headroom dedicated to SRS and P CMAX,SRS,f,c (or P CMAX,SRS,f,c,p A MAC CE format for new power headroom reporting that includes ) information may be defined.

[0318] In addition, for the power headroom report dedicated to SRS, instead of the additional PUSCH transmission-related information included in the existing PUSCH power headroom report—such as P-bit, MPE (maximum permissible exposure), or DPC (delta power class) information—additional SRS-related information—such as power imbalance information between SRS resources based on SRS antenna switching or additional mitigation information applied to SRS transmission, such as △T RxSRS or △T SRSIt may include (referred to as DSRS (delta SRS) in this disclosure). In this case, a new SRS-dedicated MAC CE field may be configured, which includes an S-bit that indicates that DSRS is applied, instead of a P-bit that indicates that P-MPR is applied.

[0319] In one embodiment, assuming that a terminal can be configured to report the degree of maximum power imbalance between SRS resources to a base station through a new terminal capability [dsrs-Reporting-FR1], etc., [DSRS] information can be reported depending on the presence or absence of the terminal capability [dsrs-Reporting-FR1] through new DSRS information added to the MAC CE format. In one embodiment, if the terminal configures the terminal capability [dsrs-Reporting-FR1] and transmits a MAC CE for reporting SRS power headroom, a 2-bit [DSRS] value included in the MAC CE format can be reported, and in this case, the [DSRS] value can be defined as the maximum difference in transmission power between each SRS resource, which is determined by considering all power back-offs caused by the influence of the transmitting RF chain and other factors when the terminal transmits SRS resources within the SRS resource set for antenna switching purposes.

[0320] In one embodiment, referring again to FIG. 5, assuming that the terminal transmits four SRS resources through four antennas, the [DSRS] value may represent the maximum power difference between antenna 1 (511) and antenna 4 (514). In one embodiment, antenna 1 (511) may be capable of transmitting SRS resources at maximum output or without additional power back-off. In one embodiment, antenna 4 (514) may apply the maximum foreseeable power back-off based on an internal design that intentionally reduces the transmission power of uplink signals transmitted to some antennas, taking into account at least one of the effects on transmitting RF chain modules such as LNA, PA, etc., or the terminal's module.

[0321] In this case, a new MAC CE field dedicated to SRS can be configured, which includes an S-bit that indicates that DSRS is applied, instead of the existing P-bit that indicates that P-MPR is applied. The [DSRS] values ​​can be defined as in [Table 12] and [Table 13], and since the values ​​in [Table 13] are arbitrary values, they can be replaced with other values ​​or ranges.

[0322] [Table 12]

[0323]

[0324] [Table 13]

[0325]

[0326] In one embodiment, first, the terminal has a power headroom dedicated to SRS in MAC CE format for single-entry power headroom reporting, P CMAX,SRS,f,c (or P CMAX,SRS,f,c,p MAC CE fields can be additionally configured to report additional information and power imbalance information.

[0327] [Example 4-1-1] Power headroom information for SRS may be added along with power headroom information for PUSCH transmitting MAC CE for single-entry and multiple-entry power headroom reporting.

[0328] FIG. 11 shows examples of single-entry and multiple-entry power headroom MAC CE formats that add power headroom information for SRS along with power headroom information for PUSCH in a wireless communication system according to one embodiment of the present disclosure.

[0329] Referring to FIG. 11, the terminal has a power headroom value for PUSCH and a maximum transmission power P during PUSCH transmission in a single-entry power headroom MAC CE format (1100). CMAX,f,c The first PH field (1101) and the first P CMAX,f,c (1102) can be reported. Additionally, the terminal reports the average power headroom value for SRS transmission (e.g., the average value of the power headroom values ​​of each SRS resource when SRS AS is supported, or the minimum value of the power headroom of the SRS resource, or the maximum value of the power headroom of the SRS resource) as a second PH field (1103), and the P set by the terminal at this time CMAX,SRS,f,c P value CMAX,SRS,f,cIt can be reported via the field (1104). In this case, the P field (1105) within the same octet used for PUSCH power headroom reporting can be replaced with the S field (1106) within the corresponding octet for SRS power headroom reporting. In one embodiment, when the S field is set to 1, the 2-bit MPE or DPC field, which was reported in the same octet as PUSCH depending on whether the terminal [dsrs-Reporting-FR1] is reported, can be set to either DSRS (if [dsrs-Reporting-FR1] is set) or R (if dsrs-Reporting-FR1 is not set) in the field related to SRS power headroom transmission (1107). In this case, the main fields within the MAC CE of FIG. 11 described above are the S bit, DSRS, and P as shown in the following [Table 14]. CMAX,SRS,f,c It may be redefined to include the etc. Meanwhile, this corresponds to only one embodiment and the present disclosure is not limited thereto.

[0330] [Table 14]

[0331]

[0332]

[0333] Referring again to FIG. 11, the MAC CE format (1110) for multi-entry SRS power headroom reporting, like the single-entry MAC CE format in the same figure described earlier, includes PUCCH (Type 2) and PUSCH (Type 1) power headroom reporting and P CMAX,f,c In addition to reports (1111, 1112), SRS-exclusive power headroom reports and P CMAX,SRS,f,c It can be reported (1113, 1114). Also, similar to single-entry SRS power headroom reporting, the P bit used in Type 2 and Type 1 can be changed to an S bit to indicate (1115), and the MPE or DPC field can be replaced with DSRS to indicate (1116).

[0334] [Example 4-1-2] A MAC CE containing only power headroom information for SRS can be configured and reported separately from power headroom information for PUSCH transmitting a MAC CE for single-entry and multiple-entry power headroom reporting.

[0335] FIG. 12 shows examples of single-entry and multiple-entry power headroom MAC CE formats for power headroom information for SRS in a wireless communication system according to one embodiment of the present disclosure.

[0336] Referring to FIG. 12, the terminal reports an average power headroom value for SRS transmission (e.g., the average value of the power headroom values ​​of each SRS resource when SRS AS is supported, or the minimum value of the power headroom of the SRS resource, or the maximum value of the power headroom of the SRS resource) in the first PH field (1201) in a single-entry power headroom MAC CE format (1200), and at this time, the P set by the terminal CMAX,SRS,f,c P value CMAX,SRS,f,c It can be reported as a field (1202). In this case, the P field within the same octet used for PUSCH power headroom reporting can be replaced with the S field (1203) within the corresponding octet for SRS power headroom reporting. In one embodiment, when the S field is set to 1, it can be set to either DSRS (if [dsrs-Reporting-FR1] is set) or R (if dsrs-Reporting-FR1 is not set) depending on whether the terminal reports [dsrs-Reporting-FR1] (1204). In this case, the main fields within the MAC CE of FIG. 12 described above are the S bit, DSRS, and P included in the previous [Table 14]. CMAX,SRS,f,c It may be defined as such. Meanwhile, this corresponds to only one embodiment and the present disclosure is not limited thereto.

[0337] Referring again to FIG. 12, the MAC CE format (1210) for multi-entry SRS power headroom reporting, like the single-entry MAC CE format in the same figure described earlier, replaces the PUSCH (Type 1) power headroom reporting, and includes SRS-specific power headroom reporting and P CMAX,SRS,f,c It can be reported (1211, 1212). Also, similar to single-entry SRS power headroom reporting, the P bit used in Type 2 can be changed to an S bit to indicate (1213), and the MPE or DPC field can be replaced with DSRS to indicate (1214).

[0338] [Example 4-2-1] In addition to power headroom information for PUSCH transmitting MAC CE for single-entry and multiple-entry power headroom reporting, multiple power headroom information for each SRS resource may be added.

[0339] FIGS. 13a and FIGS. 13b show examples of single-entry and multiple-entry power headroom MAC CE formats in which power headroom information for PUSCH is added along with multiple power headroom information for each SRS resource in a wireless communication system according to one embodiment of the present disclosure.

[0340] Referring to FIG. 13a, the terminal, in a single-entry power headroom MAC CE format, has a power headroom value for PUSCH and a maximum transmission power P during PUSCH transmission. CMAX,f,c The first PH field and the first P CMAX,f,c It can be reported as (1301, 1302). In addition, the terminal can report the power headroom value for each SRS resource and the P set by the terminal at this time. CMAX,SRS,f,c,p The value of the second or lower PH p field and P CMAX,SRS,f,c,pIt can be reported as a field (1303, 1304), and assuming the terminal can send N SRS resources, p can have a value from 0 to N-1 (1305, 1306). That is, in the single-entry power headroom MAC CE format of this example, a pair of PUSCH power headroom and PUSCH maximum power P CMAX,f,c and power headroom and SRS maximum power P per SRS resource for N pairs CMAX,SRS,f,c,p Each can be reported using two rows of octets. In this case, the P field (1307) within the same octet used for the PUSCH power headroom report is used for the S within that octet in the power headroom report of each SRS resource. p It can be replaced with a field (1308). In one embodiment, S p When the field is set to 1, the 2-bit MPE or DPC field, which was reported to the same octet as PUSCH depending on whether the terminal [dsrs-Reporting-FR1] reports, is DSRS in the field related to the power headroom transmission of each SRS resource. p It can be set to either (if [dsrs-Reporting-FR1] is set) or R (if dsrs-Reporting-FR1 is not set) (1309). In this case, the major fields within the MAC CE of FIG. 13 described above are S as shown in the following [Table 15]. p Bits, DSRS p , and P CMAX,SRS,f,c,p It may be redefined to include the etc. Meanwhile, this corresponds to only one embodiment and the present disclosure is not limited thereto.

[0341] [Table 15]

[0342]

[0343]

[0344] Referring to FIG. 13b, the MAC CE format (1310) for multi-entry SRS power headroom reporting is similar to the single-entry MAC CE format in FIG. 13a described earlier, including PUCCH (Type 2) and PUSCH (Type 1) power headroom reporting and P CMAX,f,c In addition to reports (1311, 1312), the power headroom report and P for each SRS resource CMAX,SRS,f,c,p It can report (1313, 1314, 1315). Also, similar to the power headroom reporting of a single-entry SRS resource, the P bit (1316) used for Type 2 and Type 1 is S p It can be changed to a bit (1317) to indicate, and the MPE or DPC field is DSRS p It can be indicated by replacing it with (1318).

[0345] [Example 4-2-2] A MAC CE containing only the power headroom information of each SRS resource can be configured and reported separately from the power headroom information for the PUSCH transmitting the MAC CE for single-entry and multiple-entry power headroom reporting.

[0346] FIGS. 14a and FIGS. 14b show examples of single-entry and multiple-entry power headroom MAC CE formats for power headroom information of each SRS resource in a wireless communication system according to one embodiment of the present disclosure.

[0347] Referring to FIG. 14a, the terminal, in a single-entry power headroom MAC CE format (1400), has a power headroom value for each SRS resource and P set by the terminal at this time. CMAX,SRS,f,c,p The values ​​are the PH field and P, respectively. CMAX,SRS,f,c,pIt can be reported as a field (1401, 1402), and assuming the terminal can send N SRS resources, p can have a value from 0 to N-1 (1403, 1404). That is, in the single-entry power headroom MAC CE format of this example, the power headroom for each of N pairs of SRS resources and the maximum power P of the SRS resource CMAX,SRS,f,c,p Each can be reported using two rows of octets. In this case, the P field within the same octet used for the PUSCH power headroom report is used for the S within that octet in the SRS resource power headroom report. p It can be replaced with a field (1405). In one embodiment, S p If the field is set to 1, DSRS depends on whether the terminal [dsrs-Reporting-FR1] reports. p It can be set to either (if [dsrs-Reporting-FR1] is set) or R (if dsrs-Reporting-FR1 is not set) (1406). In this case, the major fields within the MAC CE of FIG. 14 described above are S included in the previous [Table 15]. p Bits, DSRS p , and P CMAX,SRS,f,c,p It may be defined as such. Meanwhile, this corresponds to only one embodiment and the present disclosure is not limited thereto.

[0348] Referring to FIG. 14b, the MAC CE format (1410) for multi-entry SRS power headroom reporting also replaces the PUSCH (Type 1) power headroom reporting, just like the single-entry MAC CE format in FIG. 14a described earlier, and the power headroom reporting and P of each SRS resource CMAX,SRS,f,c,p It can report (1411, 1412). Also, similar to the single-entry SRS power headroom report, the P bit (1413) used in Type 2 is S pIt can be changed to bits and indicated (1414), and the MPE or DPC field is DSRS p It can be indicated by replacing it with (1415).

[0349] In this embodiment, the SRS power headroom or the SRS power headroom by resource is each power P CMAX,SRS,f,c or P CMAX,SRS,f,c,p It is characterized by a method of reporting independently to the base station together with. In addition, in power headroom reporting by SRS or SRS resource, it is characterized by the fact that a single entry (replacing the existing R bit) or multiple entries (Type 3 PH target) can have different methods of reporting to the base station by including the DSRS value in the MAC CE, and this can be configured by overlapping with or mixing with other fields in the examples examined above.

[0350] FIG. 15 illustrates a method performed by a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0351] Referring to FIG. 15, in step 1510, the terminal has a maximum output power for the SRS (SRS P CMAX ) can be identified. As described in the first embodiment of the present disclosure, SRS P CMAX is the maximum output power (P) designed exclusively for SRS. CMAX ) may be. For example, the terminal may have an existing uplink P according to at least one of [Method 1-1] or [Method 1-2] of the first embodiment of the present disclosure. CMAX Distinguish from SRS P CMAX It is possible to derive, and according to at least one of [Example 1-1] or [Example 1-2] of the first embodiment of the present disclosure, SRS P CMAX It can be configured per cell or per SRS resource. For example, the terminal has SRS P according to at least one of [Table 8] to [Table 11] of the second embodiment of the present disclosure. CMAXIt can identify. Alternatively, in step 1510, the terminal may identify the maximum output power for the SRS in a manner other than that described in the first and second embodiments of the present disclosure.

[0352] At step 1520, the terminal may obtain power headroom information for the SRS (SRS power headroom) based on the maximum output power for the identified SRS. The SRS power headroom may be obtained when an SRS power headroom report is triggered, for example, the terminal may determine whether an SRS power headroom report is triggered based on additional information 1 or additional information 2 or a combination thereof described in the third embodiment of the present disclosure. Alternatively, the terminal may determine whether an SRS power headroom report is triggered in a manner different from that described in the third embodiment of the present disclosure. If the terminal determines that an SRS power headroom report is triggered, the terminal obtains the maximum output power for the SRS (SRS P CMAX SRS power headroom can be obtained based on the difference between ) and SRS transmission power.

[0353] At step 1530, the terminal may transmit a power headroom report containing power headroom information for the acquired SRS. For example, the terminal may configure a power headroom report MAC CE in the format described in the fourth embodiment of the present disclosure and transmit the configured MAC CE. For example, the power headroom report MAC CE may include the SRS power headroom, P described in the fourth embodiment of the present disclosure. CMAX,SRS,f,c (or P CMAX,SRS,f,c,pIt may include at least one of ) information, DSRS information, S-bit, and power imbalance information. For example, the power headroom report MAC CE may have the format described in [Example 4-1-1], [Example 4-1-2], [Example 4-2-1], and [Example 4-2-2] of the fourth embodiment of the present disclosure. Alternatively, the power headroom report MAC CE transmitted by the terminal in step 1530 may have a format other than the format described in the fourth embodiment of the present disclosure.

[0354] The above-described flowchart illustrates an exemplary method that may be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart in this specification. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0355] FIG. 16 illustrates a method performed by a base station in a wireless communication system according to one embodiment of the present disclosure.

[0356] Referring to FIG. 16, in step 1610, the base station may receive a power headroom report from the terminal containing power headroom information for SRS (SRS power headroom). For example, the power headroom report may include a power headroom report MAC CE in the format described in the fourth embodiment of the present disclosure. For example, the power headroom report MAC CE may include the SRS power headroom, P described in the fourth embodiment of the present disclosure. CMAX,SRS,f,c (or P CMAX,SRS,f,c,pIt may include at least one of ) information, DSRS information, S-bit, and power imbalance information. For example, the power headroom report MAC CE may have the format described in [Example 4-1-1], [Example 4-1-2], [Example 4-2-1], and [Example 4-2-2] of the fourth embodiment of the present disclosure. Alternatively, the power headroom report MAC CE received by the base station in step 1610 may have a format other than the format described in the fourth embodiment of the present disclosure.

[0357] At step 1620, the base station may identify power headroom information for SRS (SRS power headroom) in the received power headroom report. The SRS power headroom may be acquired by the terminal and included in the power headroom report when the SRS power headroom report is triggered at the terminal, for example, whether the SRS power headroom report is triggered may be determined by the terminal based on additional information 1 or additional information 2 or a combination thereof described in the third embodiment of the present disclosure. Alternatively, whether the SRS power headroom report is triggered may be determined by the terminal in a manner different from that described in the third embodiment of the present disclosure.

[0358] SRS power headroom is the maximum output power for SRS (SRS P CMAX It may be obtained at the terminal based on the difference between ) and SRS transmission power. For example, as described in the first embodiment of the present disclosure, SRS P CMAX is the maximum output power (P) designed exclusively for SRS. CMAX It can be. For example, SRS P CMAX is an existing uplink P according to at least one of [Method 1-1] or [Method 1-2] of the first embodiment of the present disclosure. CMAX It can be derived by distinguishing from, and SRS P CMAXSRS P according to at least one of [Example 1-1] or [Example 1-2] of the first embodiment of the present disclosure CMAX It can be set per cell or per SRS resource. For example, SRS P CMAX It may be identified according to at least one of [Table 8] to [Table 11] of the second embodiment of the present disclosure. Alternatively, the maximum output power for the SRS may be identified in a manner other than that described in the first and second embodiments of the present disclosure.

[0359] In step 1630, the base station may schedule and / or configure uplink transmission and / or downlink transmission based on power headroom information (SRS power headroom) for the identified SRS. For example, the uplink transmission may include at least one of an uplink reference signal (e.g., SRS) and a data channel transmission (e.g., PUSCH). For example, the base station may transmit configuration information for the uplink reference signal to the terminal based on the identified SRS power headroom to cause the terminal to transmit the uplink reference signal. For example, the base station may transmit configuration information for the data channel and / or scheduling information for data channel transmission to the terminal based on the identified SRS power headroom to cause the terminal to transmit the data channel.

[0360] The above-described flowchart illustrates an exemplary method that may be implemented in accordance with the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart in this specification. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, each step may be omitted or replaced with another step.

[0361] [Terminal / Base Station]

[0362] FIG. 17 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0363] Referring to FIG. 17, the terminal may include a transceiver (referring to a terminal receiver (1700) and a terminal transmitter (1710)), a memory (not shown), and a terminal processing unit (1705, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver (1700, 1710), memory, and terminal processing unit (1705) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. Furthermore, the transceiver (1700, 1710), memory, and processor (1705) may be implemented in the form of a single chip.

[0364] The transceiver (1700, 1710) can transmit and receive signals with a base station. Here, the signal may include control information and data. To this end, the transceiver (1700, 1710) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver, and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0365] Additionally, the transceiver (1700, 1710) can receive a signal through a wireless channel and output it to a processor (1705), and transmit the signal output from the processor (1705) through a wireless channel.

[0366] Memory can store programs and data necessary for the operation of the terminal. Additionally, memory can store control information or data included in signals transmitted and received by the terminal. Memory may be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0367] Additionally, the processor (1705) can control a series of processes to enable the terminal to operate according to the above-described embodiment. For example, the processor (1705) can control the components of the terminal to receive a DCI composed of two layers and receive a plurality of PDSCHs simultaneously. There may be multiple processors, and the processor (1705) can perform the control operation of the terminal components by executing a program stored in memory.

[0368] FIG. 18 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0369] Referring to FIG. 18, the base station may include a transceiver unit, which refers to a base station receiver (1800) and a base station transmitter (1810), a memory (not shown), and a base station processing unit (1805, or a base station control unit or processor). According to the communication method of the base station described above, the transceiver unit (1800, 1810), memory, and base station processing unit (1805) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the transceiver unit (1800, 1810), memory, and processor may be implemented in the form of a single chip.

[0370] The transceiver (1800, 1810) can transmit and receive signals with a terminal. Here, the signal may include control information and data. To this end, the transceiver (1800, 1810) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver (1800, 1810), and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0371] Additionally, the transceiver (1800, 1810) can receive a signal through a wireless channel and output it to a processor (1805), and transmit the signal output from the processor (1805) through a wireless channel.

[0372] Memory can store programs and data necessary for the operation of the base station. Additionally, memory can store control information or data included in signals transmitted and received by the base station. Memory can be composed of storage media or combinations of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Additionally, there may be multiple memories.

[0373] The processor (1805) can control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. For example, the processor (1805) can control each component of the base station to configure two layers of DCIs containing allocation information for a plurality of PDSCHs and to transmit them. There may be multiple processors (1805), and the processors can perform control operations on the components of the base station by executing a program stored in memory.

[0374] Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0375] When implemented as software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored on the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs may include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of this disclosure.

[0376] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disc storage devices, CD-ROM (Compact Disc-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0377] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to the device performing the embodiment of the present disclosure through an external port. Additionally, a separate storage device on the communication network may be connected to the device performing the embodiment of the present disclosure.

[0378] In the specific embodiments of the present disclosure described above, the components included in the invention are expressed in a singular or plural form according to the specific embodiments presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed of a singular form, or even if a component is expressed in the singular form, it may be composed of a plural form.

[0379] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure may be combined to operate a base station and a terminal. In addition, although the above embodiments are presented based on an FDD LTE system, other variations based on the technical concept of the above embodiments may be implemented in other systems such as a TDD LTE system, 5G, or NR system.

[0380] Meanwhile, the order of description in the drawings illustrating the method of the present invention does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0381] Alternatively, drawings describing the method of the present invention may omit some components and include only some components to the extent that the essence of the present invention is not impaired.

[0382] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not impair the essence of the invention.

[0383] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and is not limited to the embodiments disclosed. Those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of determining the maximum output power for the SRS (sounding reference signal) within the range of the maximum output power for the SRS; and The method includes the step of determining the transmission power for the SRS based on the maximum output power determined above, The lower limit of the range of maximum output power for the above SRS is (P PowerClass - ΔP PowerClass - ΔT RxSRS It is set based on ), and The above P PowerClass represents the maximum terminal power defined for each band, and the above ΔP PowerClass is set to 3dB or 0dB, and the above ΔT RxSRS A method representing a value applied during SRS transmission in an SRS resource set configured for antenna switching.

2. In Claim 1, The upper limit of the range of maximum output power for the above SRS is (P PowerClass - ΔP PowerClass A method established based on ).

3. In claim 1 or 2, The step of determining the maximum output power for the above SRS is, A method comprising determining the maximum output power for the SRS for each antenna port.

4. In any one of claims 1 to 3, A method in which MPR (maximum power reduction), A-MPR (additional MPR), and P-MPR (power management MPR) are not applied to the maximum output power for the above SRS.

5. In any one of claims 1 to 4, A method in which the maximum output power for the above SRS is determined as one of the maximum, minimum, or average values ​​of the maximum output power for each SRS resource.

6. In Claim 5, A step of determining power headroom per SRS resource based on the maximum output power for the above SRS; and A method comprising the step of transmitting a power headroom report including information indicating the maximum output power for the SRS and information indicating one of the maximum, minimum, or average values ​​of the power headroom for each SRS resource.

7. In any one of claims 1 to 4, A method in which the maximum output power for the above SRS is determined per SRS resource.

8. In Claim 7, A step of determining power headroom for each SRS resource based on the maximum output power for each SRS resource; and The method includes the step of transmitting a power headroom report comprising at least one piece of information indicating the maximum output power for each SRS resource and at least one piece of information indicating the power headroom for each SRS resource, wherein A method in which the above power headroom report further includes information indicating the maximum output power for a PUSCH (physical uplink shared channel) and information indicating the power headroom for the PUSCH.

9. In Claim 7, A step of determining power headroom for each SRS resource based on the maximum output power for each SRS resource; and A method comprising the step of transmitting a power headroom report including at least one piece of information indicating the maximum output power for each SRS resource and at least one piece of information indicating the power headroom for each SRS resource.

10. In any one of claims 6, 8, and 9, The above power headroom report is the above ΔT RxSRS A method that includes additional information indicating a value.

11. In Claim 10, The above power headroom report is the above ΔT RxSRS A method that further includes information indicating that is applied.

12. In any one of claims 6, 8, and 9, The above power headroom report is related to the time domain behavior of the SRS, and A method in which the time domain operation of the above SRS is one of aperioditic, semi-persistent, or periodic.

13. In any one of claims 6, 8, and 9, The method further includes the step of receiving radio resource control (RRC) parameters regarding a power headroom reporting prohibition timer that prohibits power headroom related to SRS antenna switching, The above power headroom report is triggered when the above power headroom report prohibition timer expires, a method.

14. In a terminal of a wireless communication system, the terminal, At least one transmitting and receiving unit; At least one processor connected to communicate with the above-mentioned at least one transmitting and receiving unit; and A terminal comprising at least one memory connected to communicate with at least one processor and comprising instructions executable individually or in any combination by the at least one processor, wherein the instructions cause the terminal to perform any one of the methods of claims 1 to 13.

15. A non-transient computer-readable storage medium comprising instructions that cause the terminal to perform any one of the methods of claims 1 to 13 when executed individually or in any combination by at least one processor of the terminal.

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