Method and apparatus for reporting sounding reference signal power in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A control signal processing method carried out by a user equipment in a wireless communication system, according to an embodiment of the present disclosure, comprises the steps of: triggering power headroom reporting (PHR); configuring a medium access control (MAC) control element (CE) for the PHR; and transmitting the configured MAC CE to a base station, wherein the MAC CE includes power imbalance information.

Description

Method and device for reporting sounding reference signal 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 reports power headroom and additional information to a base station to improve the channel estimation accuracy of the base station during enhanced downlink channel estimation based on SRS antenna switching, and to an apparatus capable of performing the same.

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

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

[0004] Currently, discussions are underway to improve and enhance the performance of the initial 5G mobile communication technology, taking into account the services that the 5G mobile communication technology was intended to support. Additionally, physical layer standardization 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 that meets 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 due to the advancement of wireless communication systems as described above, measures to smoothly provide these services are required, and in particular, a method for a terminal to report power headroom and additional information to a base station is required to improve the accuracy of the base station's channel estimation.

[0009] The disclosed embodiments aim to provide an apparatus and method capable of effectively providing services in a mobile communication system.

[0010] In order to solve the above problems, in one embodiment of the present disclosure, a control signal processing method performed by a terminal in a wireless communication system comprises: a step of triggering a power headroom reporting (PHR); a step of setting a medium access control (MAC) control element for the PHR; and a step of transmitting the set MAC CE to a base station, wherein the MAC CE includes power imbalance information.

[0011] In one embodiment of the present disclosure, a control signal processing method performed by a base station in a wireless communication system comprises: receiving a medium access control (MAC) control element for power headroom reporting (PHR) from a terminal; obtaining power imbalance information included in the MAC CE; and performing downlink channel estimation based on the power imbalance information.

[0012] In one embodiment of the present disclosure, a terminal performing control signal processing in a wireless communication system comprises: a transceiver; and at least one processor, wherein the at least one processor is configured to trigger a power headroom reporting (PHR), set a medium access control (MAC) control element for the PHR, and transmit the set MAC CE to a base station, wherein the MAC CE includes power imbalance information.

[0013] In one embodiment of the present disclosure, a base station performing control signal processing in a wireless communication system comprises: a transceiver; and at least one processor, wherein the at least one processor is configured to receive a medium access control (MAC) control element for power headroom reporting (PHR) from a terminal, obtain power imbalance information included in the MAC CE, and perform downlink channel estimation based on the power imbalance information.

[0014] The disclosed embodiments provide an apparatus and a method capable of effectively providing services in a mobile communication system. 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 pertains from the description below.

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

[0016] FIGS. 2a and 2b are drawings 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 a channel state information-reference signal (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.

[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] FIGS. 7a and 7b illustrate examples of single-entry and multiple-entry power headroom MAC CE formats containing [DSRS], which is the maximum imbalance value between powers for each SRS resource of an SRS AS in a wireless communication system according to an embodiment of the present disclosure.

[0022] FIG. 8 illustrates an example of a flowchart in which the [DSRS] field is set in the MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 9 illustrates an example of a flowchart in which the [DSRS] field is set using the P field in the MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0024] FIG. 10 illustrates an example of a flowchart in which the [DSRS] field is set in a single-entry MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0025] FIG. 11 illustrates an example of a flowchart in which the [DSRS] field is set in a multi-entry MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 12 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0027] FIG. 13 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] Hereinafter, a 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. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. In this disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted by a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted by a terminal to a base station. Furthermore, while LTE or LTE-A systems may be described as examples below, embodiments of this disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, 5th generation mobile communication technologies (5G, new radio, NR) developed after LTE-A may be included therein, and the 5G below may be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications made at the discretion of a person with skilled technical knowledge, without significantly departing from the scope of the present disclosure. The contents of the present disclosure are applicable to FDD and TDD systems.

[0033] 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).

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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).

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] Hereinafter, 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.

[0045] [Uplink: PUSCH]

[0046] [PUSCH: Regarding transmission method]

[0047] Next, the scheduling method for PUSCH transfers can be described. PUSCH transfers can be dynamically scheduled by UL grants within the DCI, or operated by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transfers can be in DCI format 0_0 or 0_1.

[0048] A terminal's Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving a configuredGrantConfig containing rrc-ConfiguredUplinkGrant of [Table 1] through a higher-level signaling, without receiving a UL grant within the DCI. A terminal's Configured grant Type 2 PUSCH transmission can be semi-continuously scheduled by a UL grant within the DCI after receiving a configuredGrantConfig that does not contain rrc-ConfiguredUplinkGrant of [Table 1] through a higher-level signaling. When a PUSCH transmission is operated by a configured grant, the parameters applied to the PUSCH transmission can be applied through the higher-level signaling configuredGrantConfig of [Table 1], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided by the higher-level signaling pusch-Config of [Table 2]. 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 the configured grant.

[0049] ConfiguredGrantConfig ::= SEQUENCE {frequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need S,cg-DMRS-Configuration DMRS-UplinkConfig,mcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { CG-UCI-OnPUSCH} OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},rbg-Size ENUMERATED {config2} OPTIONAL, -- Need SpowerControlLoopToUse ENUMERATED {n0, n1},p0-PUSCH-Alpha P0-PUSCH-AlphaSetId,transformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need SnrofHARQ-Processes INTEGER(1..16),repK ENUMERATED {n1, n2, n4, n8},repK-RV ENUMERATED {s1-0231, s2-0303, s3-0000} OPTIONAL, -- Need Rperiodicity ENUMERATED {sym2, sym7, sym1x14, sym2x14, sym4x14, sym5x14, sym8x14, sym10x14, sym16x14, sym20x14,sym32x14, sym40x14, sym64x14, sym80x14, sym128x14, sym160x14, sym256x14, sym320x14, sym512x14,sym640x14, sym1024x14, sym1280x14, sym2560x14, sym5120x14,sym6, sym1x12, sym2x12, sym4x12, sym5x12, sym8x12, sym10x12, sym16x12, sym20x12, sym32x12,sym40x12, sym64x12, sym80x12, sym128x12, sym160x12, sym256x12, sym320x12, sym512x12, sym640x12,sym1280x12, sym2560x12},configuredGrantTimer INTEGER (1..64) OPTIONAL, -- Need Rrrc-ConfiguredUplinkGrant SEQUENCE {timeDomainOffset INTEGER (0..5119),timeDomainAllocation INTEGER (0..15),frequencyDomainAllocation BIT STRING (SIZE(18)),antennaPort INTEGER (0..31),dmrs-SeqInitialization INTEGER (0..1) OPTIONAL, -- Need RprecodingAndNumberOfLayers INTEGER (0..63),srs-ResourceIndicator INTEGER (0..15) OPTIONAL, -- Need RmcsAndTBS INTEGER (0..31),frequencyHoppingOffset INTEGER (1.. maxNrofPhysicalResourceBlocks-1) OPTIONAL, -- Need RpathlossReferenceIndex INTEGER (0..maxNrofPUSCH-PathlossReferenceRSs-1),...} OPTIONAL, -- Need R...}.

[0050] 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'.

[0051] 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.

[0052] PUSCH-Config ::= SEQUENCE {dataScramblingIdentityPUSCH INTEGER (0..1023) OPTIONAL, -- Need StxConfig ENUMERATED {codebook, nonCodebook} OPTIONAL, -- Need Sdmrs-UplinkForPUSCH-MappingTypeA SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mdmrs-UplinkForPUSCH-MappingTypeB SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mpusch-PowerControl PUSCH-PowerControl OPTIONAL, -- Need MfrequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need SfrequencyHoppingOffsetLists SEQUENCE (SIZE (1..4)) OF INTEGER (1..maxNrofPhysicalResourceBlocks-1)OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},pusch-TimeDomainAllocationList SetupRelease { PUSCH-TimeDomainResourceAllocationList} OPTIONAL, -- Need Mpusch-AggregationFactor ENUMERATED { n2, n4, n8} OPTIONAL, -- Need Smcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need StransformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need ScodebookSubset ENUMERATED {fullyAndPartialAndNonCoherent, partialAndNonCoherent,nonCoherent}OPTIONAL, -- Cond codebookBasedmaxRank INTEGER (1..4) OPTIONAL, -- Cond codebookBasedrbg-Size ENUMERATED { config2} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { UCI-OnPUSCH} OPTIONAL, -- Need Mtp-pi2BPSK ENUMERATED {enabled} OPTIONAL, -- Need S...}.

[0053] 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).

[0054] 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.

[0055] 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 UE capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' as the UE 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 UE 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'.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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 UE 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.

[0063] 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.

[0064] [PUSCH: Regarding transmission power]

[0065] The following describes in detail how to determine the transmission power of an uplink data channel in a 5G system.

[0066] In a 5G system, the transmission power of the uplink data channel can be determined through the following [Equation 1].

[0067] [Mathematical Formula 1]

[0068]

[0069] 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, j {2, 3, ..., J-1} represents a 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 layer 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 for 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 upper layer settings and SRI (in the case of dynamic grant PUSCH or ConfiguredGrantConfig-based configured grant PUSCH (type 2 configured grant PUSCH) that does not include upper layer settings rrc-ConfiguredUplinkGrant) or through upper layer settings. 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 method. 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.

[0070] TPC command field Accumulated [dB]Absolute [dB]0-1-410-1211334

[0071] [PHR Related]

[0072] 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 (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 standards), 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:

[0073] - [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.

[0074] - [Trigger Event 2] The upper layer parameter phr-PeriodicTimer may expire.

[0075] - [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.

[0076] - [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).

[0077] - [Trigger Event 5] PSCell added. (e.g., PSCell newly added or changed)

[0078] - [Trigger Event 6] When the upper layer parameter phr-PhrobitTimer 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):

[0079] a) There are uplink resources allocated for transmission, or PUCCH can be transmitted to the cell.

[0080] b) When a MAC entity has uplink resources for transmission or PUCCH transmission to the cell, the power backoff 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.

[0081] - [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.

[0082] - [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 meet the maximum permissible exposure (MPE) in FR2, and the mpe-ProhibitTimer may not operate. In this case, if the power headroom report is referred to as 'MPE P-MPR report', the measured P-MPR applied to meet 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.

[0083] 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.

[0084] - [Additional Conditions for Temporary Power Requirement Backoff] When power requirement backoff 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 power requirement backoff is temporarily reduced and a power headroom report is triggered by other trigger events, this results in P, which represents the ratio between maximum power and residual (available) power. CMAX,f,cIt may be necessary to ensure that the value of / PH is not temporarily reduced. For example, the PHR should 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 periodictimer), a condition may have been added so that the PH reflecting the temporary power reduction caused by the power backoff is not reported, and instead, the PH excluding the effect of the power backoff is reported.

[0085] - [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.

[0086] 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.

[0087] 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 transmit 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 transmit power parameters set at the upper layer, even though there is no actual uplink signal (e.g., PUSCH) 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.

[0088] 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].

[0089] [Mathematical Formula 2]

[0090]

[0091] 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].

[0092] [Mathematical Formula 3]

[0093]

[0094] According to the above [Equation 2], power headroom information can be calculated using the difference in transmission power with respect to the PUSCH transmission occasion i with respect to the maximum output power. 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 and the NR freq. 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.

[0095] 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.

[0096] FIG. 1 is a diagram showing a medium access control (MAC) control element (CE) structure containing single power headroom (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 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.

[0097] - P: In one embodiment, P, which consists of 1 bit, is configured with mpe-Reporting-FR2, and when the serving cell operates in FR2, it may be set to 0 if the P-MPR applied according to TS38.133 is less than P-MPR_00, and otherwise set to 1. In one embodiment, in either case where mpe-Reporting-FR2 is not configured or the serving cell operates in FR1, P may indicate whether or not power backoff has been applied for transmit power regulation. If power backoff is not applied due to power management and the corresponding P_cmax,c field has a different value, the P region may be set to 1; - P CMAX,f,c :P CMAX,f,cThe field may indicate the maximum transmit power value used to calculate the power headroom when reporting power headroom. With 6 bits of information, any one of a total of 64 nominal UE transmit power levels can be selected; - MPE: In one embodiment, if mpe-Reporting-FR2 is set, the serving cell is operating at FR2, and the P field is set to 1, the MPE area may indicate the power backoff value applied to satisfy the MPE (maximum permissible exposure) requirement. The MPE area is a 2-bit field that may indicate any one of a total of 4 measured P-MPR value levels. In one embodiment, if mpe-Reporting-FR2 is not set, if the serving cell operates in FR1, or if the P field is set to 0, the MPE region may exist as a reversed bit such as R; - DPC: In one embodiment, if dpc-Reporting-FR1 is set and the serving cell operates in FR1, the DPC region is It can instruct. The above may mean a power class change value to indicate the maximum amount of transmission power that the terminal reduces to satisfy the duty cycle, as specified in technical specifications TS 38.101-1 and TS 38.101-3. The DPC area is composed of 2 bits and can indicate one of 4 indices. In one embodiment, if the terminal does not perform DPC reporting, the terminal may set the DPC area to 0. If the DPC area is set to a value of 1, 2, or 3, the DPC area may indicate DPC_00, DPC_03, or DPC_06, which respectively represent DPC level measurement values ​​in dB scale. - R (111): The R field is a spare bit and can be set to 0; - PH: The PH field may indicate the power headroom level. It is composed of 6 bits and can be selected as any one of 64 power headroom levels.

[0098] 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.

[0099] FIGS. 2A and 2B are drawings illustrating a MAC CE structure containing multiple PHR information in a wireless communication system according to an embodiment of the present disclosure. Referring to FIGS. 2A and 2B, setting '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 FIGS. 2A and 2B.

[0100] The first format (200) of FIG. 2a 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. 2b 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. 2a and FIG. 2b 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 at 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. 2a and 2b 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].

[0101] - C i : This area may indicate the existence of a power headroom area for the support cell with ServCellIndex i. If power headroom for support cell i is reported, the corresponding C i You can set the area to 1. If power headroom for support cell i is not reported, the corresponding C i The area can be set to 0; - V: This area may indicate whether the power headroom value was calculated based on actual transmission or a reference format. For Type 1 power headroom information, if PUSCH is actually transmitted, V can be set to 0, and if the reference format for PUSCH is used, it can be set to 1. For Type 2 PH information, if PUCCH is actually transmitted, V can be set to 0, and if the reference format for PUCCH is used, it can be set to 1. For Type 3 PH information, if SRS is actually transmitted, V can be set to 0, and if the reference format for SRS is used, it can be set to 1. Additionally, for Type 1, Type 2, and Type 3 power headroom information, if the V value is 0, the P corresponding thereto cmax,f,c and if the MPE field exists and the V value is 1, then P for this cmax,f,c and the MPE field may be omitted.

[0102] [Uplink: RS]

[0103] [Regarding SRS]

[0104] 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.

[0105] - srs-ResourceSetId: SRS resource set index

[0106] - srs-ResourceIdList: A set of SRS resource indices referenced by the SRS resource set

[0107] - 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.

[0108] - 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'.

[0109] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for controlling the transmit power of the SRS resource referenced in the SRS resource set.

[0110] 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.

[0111] 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.

[0112] 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 active uplink BWP for a periodic SRS resource activated through upper layer signaling.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] SRS-Resource ::= SEQUENCE {srs-ResourceId SRS-ResourceId,nrofSRS-Ports ENUMERATED {port1, ports2, ports4},ptrs-PortIndex ENUMERATED {n0, n1} OPTIONAL, -- Need RtransmissionComb CHOICE {n2 SEQUENCE {combOffset-n2 INTEGER (0..1),cyclicShift-n2 INTEGER (0..7)},n4 SEQUENCE {combOffset-n4 INTEGER (0..3),cyclicShift-n4 INTEGER (0..11)}},resourceMapping SEQUENCE {startPosition INTEGER (0..5),nrofSymbols ENUMERATED {n1, n2, n4},repetitionFactor ENUMERATED {n1, n2, n4}},freqDomainPosition INTEGER (0..67),freqDomainShift INTEGER (0..268),freqHopping SEQUENCE {c-SRS INTEGER (0..63),b-SRS INTEGER (0..3),b-hop INTEGER (0..3)},groupOrSequenceHopping ENUMERATED { neither, groupHopping, sequenceHopping},resourceType CHOICE {aperiodic SEQUENCE {...},semi-persistent SEQUENCE {periodicityAndOffset-sp SRS-PeriodicityAndOffset,...},periodic SEQUENCE {periodicityAndOffset-p SRS-PeriodicityAndOffset,...}},sequenceId INTEGER (0..1023),spatialRelationInfo SRS-SpatialRelationInfo OPTIONAL, -- Need R...}

[0117] 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.

[0118] SRS-SpatialRelationInfo ::= SEQUENCE {servingCellId ServCellIndex OPTIONAL, -- Need SreferenceSignal CHOICE {ssb-Index SSB-Index,csi-RS-Index NZP-CSI-RS-ResourceId,srs SEQUENCE {resourceId SRS-ResourceId,uplinkBWP BWP-Id}}}

[0119] 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.

[0120] [SRS: Antenna switching]

[0121] The following describes the SRS for antenna switching.

[0122] 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 UE after scheduling the transmission of the SRS to the User Equipment (UE). In this case, the base station can assume reciprocity between the DL (downlink) and UL (uplink) 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 can receive a setting from the base station for the use of the SRS for acquiring downlink channel information as antenna switching.

[0123] 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.

[0124] 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.

[0125] - 't1r2': A terminal capability report value indicating that the terminal is capable of 1T2R operation

[0126] - 't1r1-t1r2': A terminal capability report value indicating that the terminal is capable of 1T1R or 1T2R operation

[0127] - 't2r4': A terminal capability report value indicating that the terminal is capable of 2T4R operation.

[0128] - 't1r4': A terminal capability report value indicating that the terminal is capable of 1T4R operation

[0129] - 't1r6': A terminal capability report value indicating that the terminal is capable of 1T6R operation

[0130] - 't1r8': A terminal capability report value indicating that the terminal is capable of 1T8R operation

[0131] - 't2r6': A terminal capability report value indicating that the terminal is capable of 2T6R operation

[0132] - 't2r8': A terminal capability report value indicating that the terminal is capable of 2T8R operation

[0133] - 't4r8': A terminal capability report value indicating that the terminal is capable of 4T8R operation.

[0134] - 't1r1-t1r2-t1r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, or 1T4R operation.

[0135] - 't1r4-t2r4': A terminal capability report value indicating that the terminal is capable of 1T4R or 2T4R operation.

[0136] - 't1r1-t1r2-t2r2-t2r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, or 2T4R operations.

[0137] - 't1r1-t1r2-t2r2-t1r4-t2r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, 1T4R, or 2T4R operations.

[0138] - 't1r1': A terminal capability report value indicating that the terminal is capable of 1T1R operation

[0139] - 't2r2': A terminal capability report value indicating that the terminal is capable of 2T2R operation.

[0140] - 't1r1-t2r2': A terminal capability report value indicating that the terminal is capable of 1T1R or 2T2R operation.

[0141] - 't4r4': A terminal capability report value indicating that the terminal is capable of 4T4R operation.

[0142] - 't1r1-t2r2-t4r4': A terminal capability report value indicating that the terminal is capable of 1T1R, 2T2R, or 4T4R operation.

[0143] FIG. 3 is a diagram showing the SRS antenna switching operation in a wireless communication system according to one embodiment of the present disclosure.

[0144] 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).

[0145] 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).

[0146] 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).

[0147] 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.

[0148] [UE capability]

[0149] [Regarding Terminal Capability Reporting]

[0150] 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.

[0151] A base station may transmit a UE capability enquiry message requesting capability reporting to a connected terminal. The UE capability enquiry message may include a request for terminal capability specific to the base station's RAT (radio access technology) type. The request for terminal capability 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 UE capabilities for each RAT type 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 the request for terminal capability for each RAT type, to the terminal multiple times. That is, the UE 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, a UE capability request 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.

[0152] According to one embodiment, a terminal that receives a request to report UE capability from a base station can configure terminal capability according to the RAT type and band information requested from the base station. The method by which a terminal configures UE capability in an NR system may be as follows.

[0153] 1. If the terminal receives a list of LTE and / or NR bands from the base station via a UE capability request, the terminal can configure a band combination (BC) for EN-DC and NR stand alone (SA). That is, it can configure a candidate list of BCs for EN-DC and NR SA based on the bands requested from the base station via FreqBandList. Additionally, the bands may have priority in the order listed in FreqBandList.

[0154] 2. If the base station requests a UE 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.

[0155] 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."

[0156] 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 configure the supportedBandCombinationList in a predetermined order. That is, the terminal can configure the BCs and UE capabilities to report according to the pre-configured rat-Type order (nr -> eutra-nr -> eutra). Additionally, it can configure a featureSetCombination for the configured 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.

[0157] 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.

[0158] 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.

[0159] Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The contents of the present disclosure may be applicable to FDD and TDD systems. In the present disclosure, upper signaling (or upper layer signaling) is a signal transmission method transmitted from a base station to a terminal using a physical layer downlink data channel, or from a terminal to a base station using a physical layer uplink data channel, and may be referred to as any one of RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE).

[0160] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use at least one of the following methods: a method in which PDCCH(s) that allocate the PDSCH to which cooperative communication is applied have a specific format; a method in which PDCCH(s) that allocate the PDSCH to which cooperative communication is applied include a specific indicator that indicates whether cooperative communication is applied; a method in which PDCCH(s) that allocate the PDSCH to which cooperative communication is applied are scrambled with a specific RNTI; or a method in which cooperative communication is assumed to be applied in a specific section indicated to an upper layer. Hereinafter, the reception of a PDSCH to which cooperative communication is applied by the terminal based on conditions similar to those above may be referred to as an NC-JT case.

[0161] In the following disclosure, determining the priority between A and B may be referred to in various ways, such as selecting the one with the higher priority according to a predetermined priority rule and performing the corresponding action, or omitting or dropping the action for the one with the lower priority.

[0162] In the following 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.

[0163] For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, and / or transmission directions that can be distinguished through upper layer / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be 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.

[0164] Hereinafter, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, LTE or LTE-A mobile communication and mobile communication technologies developed after 5G may be included therein. Accordingly, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure, as judged by a person skilled in the art. The contents of the present disclosure are applicable to FDD and TDD systems.

[0165] In describing the present disclosure below, the term "upper layer signaling" may refer to a signaling corresponding to at least one or a combination of one or more of the signalings.

[0166] - MIB (Master Information Block)

[0167] - SIB (System Information Block) or SIB

[0168] - RRC (Radio Resource Control)

[0169] - MAC (Medium Access Control) CE (Control Element)

[0170] 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.

[0171] - PDCCH (Physical Downlink Control Channel)

[0172] - DCI (Downlink Control Information)

[0173] - Terminal-specific (UE-specific) DCI

[0174] - Group common DCI

[0175] - Common DCI

[0176] - Scheduling DCI (e.g., DCI used for the purpose of scheduling downlink or uplink data)

[0177] - Non-scheduling DCI (e.g., DCI not intended for scheduling downlink or uplink data)

[0178] - PUCCH (Physical Uplink Control Channel)

[0179] - UCI (Uplink Control Information)

[0180] The term "slot" used in the present disclosure below is a general term that may refer to a specific time unit corresponding to TTI (Transmit Time Interval), and specifically, it may mean a slot used in a 5G system, or a slot or subframe used in a 4G LTE system.

[0181] [Start of Example]

[0182] As explained earlier regarding antenna switching, since reciprocity exists between the uplink and downlink channels in a TDD system, if channel information for one of the two channels can be obtained, information for the other channel can also be estimated. Because 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.

[0183] 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.

[0184] 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 (hereinafter 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 due to 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.

[0185] 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.

[0186] 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 chain modules such as transmitting filters, as well as LNAs (low noise amplifiers) and PAs (power amplifiers), 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.

[0187] 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.

[0188] 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. The LPAF may be composed of an LNA, a PA, and a 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 (510) 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 level 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 shown in the example illustrated in FIG. 5, the magnitude of the SRS transmission power (512, 513, 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.

[0189] 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.

[0190] Referring to FIG. 6, unlike FIG. 5 described above, an example of a terminal supporting four receiving antennas (601, 602, 603, 604) can be illustrated. Unlike the transmitting module, the receiving module (DRX-M, diversity Rx module) (611, 612, 613, 614) for diversity support can be implemented with a simpler structure and 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, 602, 603, 604) and the receiving module (611, 612, 613, 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.

[0191] 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.

[0192] As shown in Figures 5 and 6, depending on the occurrence of 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 downlink throughput.

[0193] <1st Embodiment: Method for reporting power imbalance information to a base station using existing indicators>

[0194] In the first embodiment, the terminal may use a power headroom-based report to convey to the base station information regarding power imbalances that occur when transmitting SRS resources for antenna switching purposes to the base station. When using the power headroom-based report, methods are described in detail for the terminal to reuse the existing MAC CE format for power headroom reporting as much as possible to additionally include new information regarding power imbalances in the base station.

[0195] As described above, when transmitting SRS resources for antenna switching purposes, the terminal may transmit the actual SRS resources at a lower power than the SRS transmission power calculated using schedule information and RRC settings, due to factors such as power back-off considering the characteristics of the terminal implementation or the impact on other elements. For example, assume that four SRS resources within a set of SRS resources for 1T4R antenna switching are transmitted. The terminal can transmit each SRS resource by connecting to four different antennas using a single UL RF chain for uplink transmission. Such SRS for antenna switching purposes can be used to estimate the downlink channel received through the four antennas by utilizing the uplink channel estimated from the SRS transmitted by the terminal in a TDD system and the channel reciprocity characteristics. As described above, in order to accurately estimate the downlink channel transmitted by the downlink channel received through the four terminal antennas via SRS, the transceiver of the base station and the transceiver of the terminal may need to be identical (or similar). If a base station can transmit a downlink signal to a base station transmitting antenna by applying the same power and a terminal can receive the downlink signal transmitted by the base station using a terminal receiving antenna of the same gain (or similar gain), then in order to estimate the downlink channel using the SRS, the terminal can transmit the SRS to the base station by applying similarly the same (or similar) power and the base station can receive the SRS transmitted by the terminal using a base station receiving antenna of the same (or similar) gain.Although a base station can receive SRS using a base station receiving antenna with the same (or similar) gain, the terminal may not be able to transmit SRS at the same (or similar) power due to terminal implementation characteristics such as power back-off considering terminal circuit configuration and interference as described above. If the SRS resource used for antenna switching by the terminal is transmitted at a power different from the transmission power calculated according to scheduling information (e.g., power transmission parameters indicated by TCI, etc.) and RRC parameters (e.g., values ​​indicated by indicated transmission power parameters), the base station can estimate an uplink channel received with an SRS resource that has a different actual transmission power. Since the base station estimates the uplink channel with an SRS resource transmitted at a different actual power rather than an SRS resource transmitted at the same power, the accuracy of the estimated uplink channel may decrease, and the accuracy of the downlink channel estimated based on channel reciprocity may also decrease. Equation 4 below can represent an uplink channel estimated with an SRS resource transmitted by the terminal at a non-identical transmission power.

[0196] [Mathematical Formula 4]

[0197]

[0198] Here, y represents the SRS received by the base station, and refers to the four SRS resource signals transmitted by the terminal, and can refer to the uplink channel. The four SRS resources transmitted by the terminal are transmitted via different time symbols, and the above Equation 4 can refer to the signal received by the base station through all SRS resources transmitted by the terminal. Since the base station and the terminal know s from each other, the base station obtains channel information from the received signal y. It can be estimated. Ideally, the base station is Although it must be estimated, it implies power imbalance because s is transmitted with unequal transmission power. a may be included in the uplink channel information estimated by the base station. For example, meaning power imbalance between SRS resources transmitted by the terminal Uplink channel estimated by the base station due to The accuracy of and the downlink channel estimated by the base station based on channel reciprocity The accuracy may decrease. If the base station experiences power imbalance when the terminal transmits multiple SRS resources for antenna switching purposes. If information about it is available, the estimated downlink channel by correcting for or considering power imbalance The accuracy can be improved. As a method to be considered for reporting power imbalance, in one embodiment, the terminal may report to the base station the difference in transmission power between each SRS resource when transmitting SRS resources within the SRS resource set for antenna switching. In one embodiment, when the terminal transmits SRS resources within the SRS resource set for antenna switching, the terminal may determine a maximum transmission power for each SRS resource by taking into account all power back-offs caused by the influence of the transmitting RF chain and other factors, and may report the determined maximum transmission power to the base station. For example, the terminal may transmit an SRS resource transmitted through the first antenna at a maximum of 23 dBm, but an SRS resource transmitted through the fourth antenna may be transmitted at a maximum of 20 dBm due to insertion loss caused by the path between the antenna and the RF chain. At this time, if the terminal can report to the base station the maximum transmission power of the SRS resource transmitted to the first antenna, 23 dBm, the maximum transmission power of the SRS resource transmitted to the fourth antenna, 20 dBm, and the power actually transmitted for each SRS resource, the base station can improve the estimation accuracy of the downlink channel by taking this into account.

[0199] 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. The terminal may trigger a power headroom report when certain conditions are met as described above, and the terminal may include a MAC CE for the power headroom report in a PUSCH and transmit it to the base station. In one embodiment, when the terminal reports the power headroom, the maximum transmission power P that the terminal can transmit at either the time of transmitting the PUSCH or SRS, or at the time of reporting the power headroom CMAX,f,cThe terminal may 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 if no uplink signal is actually transmitted). In one embodiment, in a serving cell supporting FR2, the terminal may additionally report to the base station power back-off values, etc., to satisfy the MPE (maximum permissible emission) requirements in FR2. In one embodiment, if FR2 supports multiple beams, the terminal may additionally report to the base station power back-off values ​​to satisfy the MPE requirements for each candidate beam. In one embodiment, if the terminal operates in a serving cell supporting FR1, as a method to avoid human impact regulations such as SAR (specific absorption rate), the terminal may report power back-off values ​​according to the uplink duty cycle (UL duty cycle) in the cell via DPC (delta power class). In one embodiment, if a terminal transmits multiple SRS resources within an SRS resource set for antenna switching to a base station and applies power back-off considering the terminal's implementation or interference from other factors, and an imbalance in transmission power occurs between the multiple SRS resources transmitted by the terminal, the terminal may report additional information to the base station using power headroom reporting.

[0200] There are two main methods for reporting additional information to a base station using such power headroom reports. The first method involves reusing the existing MAC CE format for power headroom reporting as much as possible to instruct the base station on power imbalance information. The second method involves configuring a new MAC CE format for SRS-specific power headroom and PCMAX reporting, separate from the existing Type 3 power headroom reporting, and including SRS power imbalance information in this format to report to the base station. In this invention, the first method, which involves reusing the existing MAC CE format for power headroom reporting as much as possible to instruct the base station on power imbalance information, is described in detail.

[0201] As described above, in order for a terminal to report power imbalance information to a base station, the terminal can transmit a MAC CE for SRS power headroom reporting to the base station using PUSCH. Since power imbalance information is a new type of information, it may be difficult for the terminal to report power imbalance information to the base station when using the MAC CE format illustrated in FIG. 1, FIG. 2a, or FIG. 2b. Therefore, if the terminal wishes to reuse the existing MAC CE format for power headroom reporting as much as possible, it may report to the base station by adding new information to the parameters included in the existing MAC CE format or by changing the parameters. Thus, as described below, the existing MAC CE format for power headroom reporting can be redefined by applying new parameters containing power imbalance information.

[0202] In one embodiment, the terminal may redefine the DPC information included in existing single-entry and multi-entry power headroom reports to include SRS power imbalance information. In one embodiment, the terminal may report the amount of PUSCH power back-off to the base station through the DPC field within the existing power headroom MAC CE format. Specifically, if the terminal can determine the degree of power imbalance between SRS resources transmitted through multiple antennas through hardware configuration or arrangement within the terminal, the terminal may additionally define a DPC field consisting only of the amount of existing PUSCH power back-off and [DSRS (delta SRS)], which is the maximum degree of power imbalance between antennas that may occur when transmitting multiple SRS resources through antenna switching, and report this by including it in the [DPC] value according to [Table 8] and [Table 9]. The range of DPC+[DSRS] values ​​included in [Table 9] is merely an example, and the reported values ​​DPC_00 to DPC_03 may be replaced with other values ​​or ranges. In one embodiment, the terminal may first report to the base station a value including SRS power imbalance information [DSRS] in the DPC information included in the existing single entry power headroom report described in FIG. 1 and the existing multi-entry power headroom report described in FIG. 2a and 2b.

[0203] DPCMeasured DPC value0DPC_001DPC_012DPC_023DPC_03

[0204] Reported valueReported quantity valueUnitDPC_00DPC+[DSRS] < 5dBDPC_015 DPC+[DSRS] < 10dBDPC_0210 DPC+[DSRS] < 15dBDPC_0315 DPC+[DSRS]dB

[0205] According to the above embodiment, the terminal can report to the base station, through fields included in the existing power headroom report, the degree of maximum power imbalance between antennas that may occur during the transmission of multiple SRS resources via antenna switching, while minimizing changes to the MAC CE format for additional terminal capability or power headroom reporting. Additionally, the base station can utilize the information in the reported fields to recognize the overall degree of power back-off applied at the terminal's transmit output including SRS, and can rapidly perform DL precoding by performing downlink channel estimation and channel estimation correction based on this. In this case, the main fields of FIGS. 1, 2a, and 2b described above may be redefined as shown in the following [Table 10]. Meanwhile, this corresponds to only one embodiment and the present disclosure is not limited thereto.

[0206] - P: In one embodiment, P, which consists of 1 bit, is configured with mpe-Reporting-FR2, and when the serving cell operates in FR2, it may be set to 0 if the P-MPR applied according to TS38.133 is less than P-MPR_00, and otherwise set to 1. In one embodiment, in either case where mpe-Reporting-FR2 is not configured or the serving cell operates in FR1, P may indicate whether or not power backoff has been applied for transmit power regulation. If power backoff is not applied due to power management and the corresponding P_cmax,c field has a different value, the P region may be set to 1; - P CMAX,f,c :P CMAX,f,cThe field may indicate the maximum transmit power value used to calculate the power headroom when reporting power headroom. With 6 bits of information, any one of a total of 64 nominal UE transmit power levels can be selected; - MPE: In one embodiment, if mpe-Reporting-FR2 is set, the serving cell is operating at FR2, and the P field is set to 1, the MPE area may indicate the power backoff value applied to satisfy the MPE (maximum permissible exposure) requirement. The MPE area is a 2-bit field that may indicate any one of a total of 4 measured P-MPR value levels. In one embodiment, if mpe-Reporting-FR2 is not set, if the serving cell operates in FR1, or if the P field is set to 0, the MPE region may exist as a reversed bit such as R; - DPC: In one embodiment, if dpc-Reporting-FR1 is set and the serving cell operates in FR1, the DPC region is and T RxSRS It may be directed within the scope of the agreement. The above may mean a power class change value for indicating the maximum transmission power that the terminal reduces to satisfy the duty cycle, as specified in technical standards TS 38.101-1 and TS 38.101-3. T RxSRSmay represent the maximum power imbalance value between SRS resources according to SRS AS as specified in technical specifications TS 38.101-1 and TS 38.101-3. The DPC area is composed of 2 bits and can indicate one of 4 indices. If the terminal does not perform DPC reporting, the DPC area may exist as a reversed bit, such as R; - R: The R field is a reversed bit and can be set to 0; - PH: The PH field may indicate the power headroom level. It is composed of 6 bits and can be selected as any one of 64 power headroom levels.

[0207] <Second Embodiment: Method for reporting power imbalance information to a base station by adding a new indicator>

[0208] In the second embodiment, a method for reporting to a base station by adding a new indicator or field containing power imbalance information to the MAC CE format for power headroom reporting is specifically described.

[0209] As described above, when a terminal triggers a power headroom report to report power imbalance information to a base station, the terminal can transmit a MAC CE for the power headroom report to the base station using PUSCH. Since power imbalance information is a new type of information, it may be difficult for the terminal to report power imbalance information to the base station if the MAC CE format shown in FIG. 1, FIG. 2a, or FIG. 2b is used. A new MAC CE format may be required for the terminal to report power imbalance information to the base station through a power headroom report. Therefore, as described below, a MAC CE format may be defined that adds an indicator for a new power headroom report containing power imbalance information.

[0210] FIGS. 7a and 7b illustrate examples of single-entry and multiple-entry power headroom MAC CE formats containing [DSRS], which is the maximum imbalance value between powers for each SRS resource of an SRS AS in a wireless communication system according to an embodiment of the present disclosure.

[0211] Referring to FIGS. 7a and 7b, if it is assumed that a terminal can be configured to report the maximum power imbalance between SRS resources to a base station through a new terminal capability [dsrs-Reporting-FR1], etc., then [DSRS] information can be reported instead of the existing DPC through new [DSRS] information (single-entry MAC CE format corresponding: 701, multi-entry MAC CE format corresponding: 711) added to the existing MAC CE format for power headroom reporting (single-entry MAC CE format: 700, multi-entry MAC CE format: 710). In one embodiment, if the terminal sets the terminal capability [dsrs-Reporting-FR1] and transmits a MAC CE for power headroom reporting, it may report a [DSRS] value in place of any one of the 2-bit MPE, DPC, or R fields included in the MAC CE format, in which case the [DSRS] value may be defined as the maximum difference in transmission power between each SRS resource, which is determined by taking into account 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.

[0212] 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. The [DSRS] value may be defined as in [Table 11] and [Table 12], and since the value in [Table 12] is an arbitrary value, it may be replaced with another value or range.

[0213] [DSRS]Measured [DSRS] value0DSRS_001DSRS_012DSRS_023DSRS_03

[0214] Reported valueMeasured quantity valueUnitDSRS_00DSRS < 3dBDSRS_013 DSRS < 6dBDSRS_026 DSRS < 9dBDSRS_03DSRS 9dB

[0215] Here, if the terminal operates in an FR1-supported cell and dpc-Reporting-FR1 and dsrs-Reporting-FR1 are set simultaneously, the condition that at least one of the 2-bit fields (701, 711) shared by MPE, DPC, R or the new [DSRS] field included in the MAC CE format for existing power headroom reporting is set can be defined in various ways as follows.

[0216] -[Example 2-1]

[0217] FIG. 8 illustrates an example of a flowchart in which the [DSRS] field is set in the MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0218] Referring to FIG. 8, in one embodiment, if a terminal is configured to report the degree of power imbalance between SRS resources to a base station through a new terminal capability [dsrs-Reporting-FR1] in a cell that supports FR1 (801), [DSRS] has priority, and depending on the presence or absence of [dsrs-Reporting-FR1], the existing 2-bit field may be configured as [DSRS] (if [dsrs-Reporting-FR1] is configured) (811), DPC (if dsrs-Reporting-FR1 is not configured and only dpc-Reporting-FR1 is configured) (821), or R (if neither dpc-Reporting-FR1 nor dsrs-Reporting-FR1 is configured) (831). In one embodiment, if the terminal is configured to report the degree of power imbalance between SRS resources to the base station through a new terminal capability such as [dsrs-Reporting-FR1] in a cell supporting FR2 (803), it may be configured as either MPE (if mpe-Reporting-FR2 is configured) (841) or R (if mpe-Reporting-FR2 is not configured) (831) as before, depending on the presence or absence of mpe-Reporting-FR2 (804). Additionally, the examples included in FIG. 8 (810, 820, 830, 840) may be possible in both single and multiple entries. In this case, the major fields within the MAC CE of 8 described above may be redefined to include DSRS as shown in the following [Table 13]. Meanwhile, this is only one embodiment and the present disclosure is not limited thereto.

[0219] - P: In one embodiment, P, which consists of 1 bit, is configured with mpe-Reporting-FR2, and when the serving cell operates at FR2, it may be set to 0 if the P-MPR applied according to TS38.133 is less than P-MPR_00, and otherwise set to 1. In one embodiment, when mpe-Reporting-FR2 is not configured or when the serving cell operates at FR1, P may indicate whether power backoff has been applied for transmit power regulation. If power backoff is not applied due to power management and the corresponding P_cmax,c field has a different value, the P region may be set to 1; - P CMAX,f,c :P CMAX,f,cThe field may indicate the maximum transmit power value used to calculate the power headroom when reporting power headroom. With 6 bits of information, any one of a total of 64 nominal UE transmit power levels can be selected; - MPE: In one embodiment, if mpe-Reporting-FR2 is set, the serving cell is operating at FR2, and the P field is set to 1, the MPE area may indicate the power backoff value applied to satisfy the MPE (maximum permissible exposure) requirement. The MPE area is a 2-bit field that may indicate any one of a total of 4 measured P-MPR value levels. In one embodiment, if mpe-Reporting-FR2 is not set, if the serving cell is operating in FR1, or if the P field is set to 0, at least one of these cases may exist as a reversed bit such as R;- DPC: In one embodiment, if dpc-Reporting-FR1 is set, if the serving cell is operating in FR1, and if dsrs-Reporting-FR1 is not set, the DPC area is It can instruct. The above may mean a power class change value to indicate the maximum transmission power that the terminal reduces to satisfy the duty cycle, as specified in technical standards TS 38.101-1 and TS 38.101-3. The DPC area is composed of 2 bits and can indicate one of four indices. In one embodiment, if the terminal does not perform DPC reporting, the DPC area may exist as a reversed bit, such as R;- DSRS: In one embodiment, if dsrs-Reporting-FR1 is configured and the serving cell operates on FR1, the DSRS area is specified in technical standards TS 38.101-1 and TS 38.101-3 T RxSRS Based on the value, the maximum power imbalance value between SRS resources according to SRS AS can be indicated. The DSRS area is composed of 2 bits and can indicate one of 4 indices. In one embodiment, the DSRS area can indicate one of 4 indices as shown in [Table 11] and [Table 12]. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is set, the DSRS area can indicate one of the DPC areas. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is not set, the DSRS area may exist as a reversed bit such as R; - R: The R field is a reversed bit and can be set to 0; - PH: The PH field can indicate the power headroom level. It is composed of 6 bits and can be selected as any one of 64 power headroom levels.

[0220] -[Example 2-2]

[0221] FIG. 9 illustrates an example of a flowchart in which the [DSRS] field is set using the P field in the MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0222] Referring to FIG. 9, if the terminal can be configured to report the degree of power imbalance between SRS resources to the base station through a new terminal capability such as [dsrs-Reporting-FR1], the replacement with [DSRS] can be determined based on the existing 1-bit P field. In one embodiment, when the P field is set to 1 (901) and the serving cell is FR1 (902), [DSRS] has priority, and depending on the presence or absence of [dsrs-Reporting-FR1] (903), the existing 2-bit field can be set to [DSRS] (when [dsrs-Reporting-FR1] is set) (911), DPC (when dsrs-Reporting-FR1 is not set and only dpc-Reporting-FR1 is set) (921), or R (when neither dpc-Reporting-FR1 nor dsrs-Reporting-FR1 is set) (931). In one embodiment, when the P field is set to 1 and the serving cell is FR2 (904), depending on whether mpe-Reporting-FR2 is present (905), it can be set to either MPE (when mpe-Reporting-FR2 is set) (941) or R (when mpe-Reporting-FR2 is not set) (931) as before. In one embodiment, when the P field is set to 0 (906) and the serving cell is FR1 (907), DPC has priority and depending on whether dpc-Reporting-FR1 is present (908), it can be set to either DPC (when dpc-Reporting-FR1 is set) (921) or R (when dpc-Reporting-FR1 is not set) (931). In one embodiment, the P field is set to 0 (906), and if the serving cell is FR2, it can be set to R regardless of whether mpe-Reporting-FR2 is present (931).The examples (910, 920, 930, 940) included in FIG. 9 above are provided only for single entries, but may be applicable to both single and multiple entries. In this case, the major fields within the MAC CE format of FIG. 9 described above may be redefined to include DSRS as shown in [Table 14] below. Meanwhile, this is only one embodiment and the present disclosure is not limited thereto.

[0223] - P: In one embodiment, if mpe-Reporting-FR2 is configured in P consisting of 1 bit, and the serving cell operates in FR2, P may be set to 0 if the P-MPR applied according to TS38.133 is less than P-MPR_00, and otherwise set to 1. In one embodiment, if mpe-Reporting-FR2 is not configured or the serving cell operates in FR1, P may indicate whether power backoff has been applied for transmit power regulation. If power backoff is not applied due to power management and the corresponding P_cmax,c field has a different value, the P region may be set to 1. In one embodiment, the P region may also be set to 1 if power imbalance between SRS resources according to SRS AS is applied;- P CMAX,f,c :P CMAX,f,cThe field may indicate the maximum transmit power value used to calculate the power headroom when reporting power headroom. With 6 bits of information, any one of a total of 64 nominal UE transmit power levels can be selected; - MPE: In one embodiment, if mpe-Reporting-FR2 is set, the serving cell is operating at FR2, and the P field is set to 1, the MPE area may indicate the power backoff value applied to satisfy the MPE (maximum permissible exposure) requirement. The MPE area is a 2-bit field that may indicate any one of a total of 4 measured P-MPR value levels. In one embodiment, if mpe-Reporting-FR2 is not set, if the serving cell is operating in FR1, or if the P field is set to 0, at least one of these cases may exist as a reversed bit such as R;- DPC: In one embodiment, if dpc-Reporting-FR1 is set, if the serving cell is operating in FR1, and if the P field is set to 0, the DPC area is It can instruct. The above may mean a power class change value to indicate the maximum transmission power that the terminal reduces to satisfy the duty cycle, as specified in technical standards TS 38.101-1 and TS 38.101-3. The DPC area is composed of 2 bits and can indicate one of four indices. In one embodiment, if the terminal does not perform DPC reporting, the DPC area may exist as a reversed bit, such as R;- DSRS: In one embodiment, if dsrs-Reporting-FR1 is configured, the serving cell operates in FR1, and the P field is set to 1, the DSRS area is specified in technical standards TS 38.101-1 and TS 38.101-3 T RxSRS Based on the value, the maximum power imbalance value between SRS resources according to SRS AS can be indicated. The DSRS area is composed of 2 bits and can indicate one of 4 indices. In one embodiment, the DSRS area can indicate one of 4 indices as shown in [Table 11] and [Table 12]. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is set, the DSRS area can indicate one of the DPC areas. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is not set, the DSRS area may exist as a reversed bit such as R; - R: The R field is a reversed bit and can be set to 0; - PH: The PH field can indicate the power headroom level. It is composed of 6 bits and can be selected as any one of 64 power headroom levels.

[0224] -[Example 2-3]

[0225] FIG. 10 illustrates an example of a flowchart in which the [DSRS] field is set in a single-entry MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0226] Referring to FIG. 10, the MAC CE format for power headroom reporting is divided into single entry and multi-entry, and in single entry, the existing R field can be replaced with the S field (1012, 1022, 1032, 1042). In one embodiment, when the S field is set to 1 (1001) and the serving cell is FR1 (1002), [DSRS] has priority, and depending on the presence or absence of [dsrs-Reporting-FR1] (1003), the existing 2-bit field can be set to [DSRS] (when [dsrs-Reporting-FR1] is set) (1011), DPC (when dsrs-Reporting-FR1 is not set and only dpc-Reporting-FR1 is set) (1021), or R (when neither dpc-Reporting-FR1 nor dsrs-Reporting-FR1 is set) (1031). In one embodiment, when the S field is set to 1 (1001) and the serving cell is FR2 (1004), it can be set to either MPE (when mpe-Reporting-FR2 is set) (1041) or R (when mpe-Reporting-FR2 is not set) (1031) as before, depending on whether mpe-Reporting-FR2 is present (1005). In one embodiment, when the S field is 0 (1006) and the serving cell is FR1 (1007), DPC has priority and can be set to either DPC (when dpc-Reporting-FR1 is set) (1021) or R (when dpc-Reporting-FR1 is not set) (1031) depending on whether dpc-Reporting-FR1 is present (1008). In one embodiment, when the S field is 0 and the serving cell is FR2, it can be set to either MPE (when mpe-Reporting-FR2 is set) (1041) or R (when mpe-Reporting-FR2 is not set) (1031) as before, depending on whether mpe-Reporting-FR2 is present (1005).The examples included in FIG. 10 (1010, 1020, 1030, 1040) may include cases of a single entry.

[0227] FIG. 11 illustrates an example of a flowchart in which the [DSRS] field is set in a multi-entry MAC CE format for power headroom reporting in a wireless communication system according to one embodiment of the present disclosure.

[0228] Referring to FIG. 11, the multiple entries are limited to a 2-bit field within a Type 3 PH representing SRS power headroom (1111, 1121, 1131, 1141). In one embodiment, when the serving cell is FR1 (1101), [DSRS] has priority, and depending on the presence or absence of [dsrs-Reporting-FR1] (1102), the existing 2-bit field can be set to [DSRS] (when [dsrs-Reporting-FR1] is set) (1111), DPC (when dsrs-Reporting-FR1 is not set and only dpc-Reporting-FR1 is set) (1121), or R (when neither dpc-Reporting-FR1 nor dsrs-Reporting-FR1 is set) (1131). In one embodiment, when the serving cell is FR2 (1103), depending on the presence or absence of mpe-Reporting-FR2 (1104), it may be set to either MPE (when mpe-Reporting-FR2 is set) (1141) or R (when mpe-Reporting-FR2 is not set) (1131) as before. The examples included in FIG. 11 (1110, 1120, 1130, 1140) may include cases of multiple entries. In this case, the major fields within the MAC CE format of FIG. 10 and FIG. 11 described above may be redefined to include DSRS as shown in the following [Table 15]. Meanwhile, this is only one embodiment and the present disclosure is not limited thereto.

[0229] - P: In one embodiment, P, which consists of 1 bit, is configured with mpe-Reporting-FR2, and when the serving cell operates at FR2, it may be set to 0 if the P-MPR applied according to TS38.133 is less than P-MPR_00, and otherwise set to 1. In one embodiment, when mpe-Reporting-FR2 is not configured or when the serving cell operates at FR1, P may indicate whether power backoff has been applied for transmit power regulation. If power backoff is not applied due to power management and the corresponding P_cmax,c field has a different value, the P region may be set to 1; - P CMAX,f,c :P CMAX,f,c The field may indicate the maximum transmit power value used to calculate the power headroom when reporting power headroom. With 6 bits of information, any one of a total of 64 nominal UE transmit power levels can be selected; - MPE: In one embodiment, if mpe-Reporting-FR2 is set, the serving cell is operating at FR2, and the P field is set to 1, the MPE area may indicate the power backoff value applied to satisfy the MPE (maximum permissible exposure) requirement. The MPE area is a 2-bit field that may indicate any one of a total of 4 measured P-MPR value levels. In one embodiment, if mpe-Reporting-FR2 is not set, if the serving cell is operating in FR1, or if the P field is set to 0, the MPE area may exist as a reversed bit such as R; - DPC: In one embodiment, if dpc-Reporting-FR1 is set, if the serving cell is operating in FR1, and if the S field is set to 0, the DPC area is It can instruct. The above may mean a power class change value to indicate the maximum transmission power that the terminal reduces to satisfy the duty cycle, as specified in technical standards TS 38.101-1 and TS 38.101-3. The DPC area is composed of 2 bits and can indicate one of four indices. In one embodiment, if the terminal does not perform DPC reporting, the DPC area may exist as a reversed bit, such as R;- DSRS: In one embodiment, if dsrs-Reporting-FR1 is configured, the serving cell operates in FR1, and the S field is set to 1, the DSRS area is specified in technical standards TS 38.101-1 and TS 38.101-3. T RxSRS Based on the value, the maximum power imbalance value between SRS resources according to SRS AS can be indicated. The DSRS area is composed of 2 bits and can indicate one of 4 indices. In one embodiment, the DSRS area can indicate one of 4 indices as shown in [Table 11] and [Table 12]. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is set, the DSRS area can indicate one of the DPC areas. In one embodiment, if the terminal does not perform DSRS reporting and dpc-Reporting-FR1 is not set, the DSRS area may exist as a reversed bit such as R; - R: The R field is a reversed bit and can be set to 0; - PH: The PH field can indicate the power headroom level. It is composed of 6 bits and can be selected as any one of 64 power headroom levels.

[0230] In this example, a single entry (replacing the existing R bit) or multiple entries (Type 3 PH target) may each report DSRS values ​​to the base station by including them in the MAC CE, and this may be configured by overlapping with or mixing with other fields in [Example 2-1] and [Example 2-2] discussed earlier.

[0231] 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.

[0232] [Terminal / Base Station]

[0233] FIG. 12 is a drawing illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0234] Referring to FIG. 12, the terminal may include a transceiver (referring to a terminal receiver unit (1200) and a terminal transmitter unit (1210)), a memory (not shown), and a terminal processing unit (1205, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver (1200, 1210), memory, and terminal processing unit (1205) 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 (1200, 1210), memory, and processor (1205) may be implemented in the form of a single chip.

[0235] The transceiver (1200, 1210) can transmit and receive signals with a base station. Here, the signal may include control information and data. To this end, the transceiver (1200, 1210) 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.

[0236] Additionally, the transceiver (1200, 1210) can receive a signal through a wireless channel and output it to a processor (1205), and transmit the signal output from the processor (1205) through a wireless channel.

[0237] 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.

[0238] Additionally, the processor (1205) can control a series of processes to enable the terminal to operate according to the above-described embodiment. For example, the processor (1205) 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 (1205) can perform the control operation of the terminal components by executing a program stored in memory.

[0239] FIG. 13 is a drawing illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0240] Referring to FIG. 13, a base station may include a transceiver unit, which refers to a base station receiver (1300) and a base station transmitter (1310), a memory (not shown), and a base station processing unit (1305, or a base station control unit or processor). According to the communication method of the base station described above, the transceiver unit (1300, 1310), memory, and base station processing unit (1305) 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 (1300, 1310), memory, and processor may be implemented in the form of a single chip.

[0241] The transceiver (1300, 1310) can transmit and receive signals with a terminal. Here, the signal may include control information and data. To this end, the transceiver (1300, 1310) 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 (1300, 1310), and the components of the transceiver are not limited to an RF transmitter and an RF receiver.

[0242] Additionally, the transceiver (1300, 1310) can receive a signal through a wireless channel and output it to a processor (1305), and transmit the signal output from the processor (1305) through a wireless channel.

[0243] 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.

[0244] The processor (1305) 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 (1305) 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 (1305), and the processors can perform control operations on the components of the base station by executing a program stored in memory.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] 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.

[0254] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will understand that modifications can be easily made to other specific forms without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and their equivalents should be interpreted as being included within the scope of the present disclosure.

Claims

1. A method for processing control signals performed by a terminal in a wireless communication system, Steps to trigger power headroom reporting (PHR); A step of setting a medium access control (MAC) control element for PHR; and It includes the step of transmitting the MAC CE set above to a base station, The above MAC CE is a method that includes power imbalance information.

2. A method according to claim 1, wherein the power imbalance information is the difference between the maximum transmission powers of each SRS resource when transmitting multiple SRS resources within a sounding reference signal (SRS) resource set for antenna switching purposes.

3. In paragraph 1, the step of setting the MAC CE for the PHR is: A method for setting a delta power class (DPC) set within the above MAC CE by including a value related to the power imbalance information.

4. In Paragraph 1, The method further includes the step of transmitting terminal capability related to the above power imbalance information to the base station, A method comprising the step of setting a MAC CE for the above PHR, which includes setting a field included in the MAC CE as a field for reporting the power imbalance information.

5. In paragraph 1, the step of setting the MAC CE for the PHR is: A step of setting a field within the MAC CE as a field for the power imbalance information; and A method comprising the step of setting a value related to the power imbalance information in a field for the power imbalance information.

6. In paragraph 1, the step of transmitting the set MAC CE to the base station is: A method for transmitting the above-mentioned MAC CE through a physical uplink shared channel (PUSCH).

7. A method for processing control signals performed by a base station in a wireless communication system, A step of receiving a medium access control (MAC) control element for power headroom reporting (PHR) from a terminal; A step of obtaining power imbalance information included in the above MAC CE; and A method comprising the step of performing downlink channel estimation based on the above power imbalance information.

8. In claim 7, the power imbalance information is the difference between the maximum transmission powers of each SRS resource when transmitting multiple SRS resources within a sounding reference signal (SRS) resource set for antenna switching.

9. In a terminal that performs control signal processing in a wireless communication system, Transmitter / receiver; and It includes at least one processor, and the at least one processor, Trigger power headroom reporting (PHR), set medium access control (MAC) control elements for PHR, and It is configured to transmit the above-set MAC CE to the base station, and The above MAC CE is a terminal containing power imbalance information.

10. In paragraph 9, the power imbalance information is the difference between the maximum transmission powers of each SRS resource when transmitting multiple SRS resources within a sounding reference signal (SRS) resource set for antenna switching.

11. In paragraph 9, the above at least one processor, A terminal further configured to include a value related to the power imbalance information in the delta power class (DPC) set within the above MAC CE.

12. In paragraph 9, the above at least one processor, The terminal capability related to the above power imbalance information is further configured to transmit to the base station, and A terminal configured to set the MAC CE for the above PHR to set the field included within the MAC CE as a field for reporting the power imbalance information.

13. In paragraph 9, the above at least one processor, Set the field within the above MAC CE as the field for the above power imbalance information, and A terminal further configured to include a value related to the power imbalance information in a field for the power imbalance information.

14. In paragraph 9, the above at least one processor, A terminal further configured to transmit the above-mentioned MAC CE through a physical uplink shared channel (PUSCH).

15. In a base station that performs control signal processing in a wireless communication system, Transmitter / receiver; and It includes at least one processor, and the at least one processor, Receive a medium access control (MAC) control element for power headroom reporting (PHR) from a terminal, and Acquire power imbalance information included in the above MAC CE, and A base station configured to perform downlink channel estimation based on the above power imbalance information.

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