Method and apparatus for switching uplink transmission antenna in communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to operations of a terminal and a base station in a wireless communication system and, more specifically, to a method performed by a terminal, the method comprising the steps of: receiving, from a base station, a radio resource control (RRC) message including configuration information related to antenna switching, the configuration information related to antenna switching including information indicating switching of three or more antennas; receiving downlink control information (DCI) from the base station; performing antenna switching if the number of antenna ports indicated by the DCI is different from the number of antenna ports used for previous transmission; and transmitting an uplink signal on the basis of the DCI. The terminal is not expected to transmit an uplink signal during an antenna switching period.

Description

Method and device for uplink transmission antenna switching in a communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for uplink transmission antenna switching in a communication system and a device capable of performing the same.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

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

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

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

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

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

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

[0009] According to one embodiment of the present disclosure, a method performed by a terminal in a wireless communication system comprises the steps of: receiving an RRC (radio resource control) message including configuration information related to antenna switching from a base station, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas; receiving DCI (downlink control information) from the base station; and performing antenna switching when the number of antenna ports indicated by the DCI is different from the number of antenna ports used in a previous transmission; and transmitting an uplink signal based on the DCI, characterized in that the terminal does not expect to transmit an uplink signal during an antenna switching period.

[0010] According to one embodiment of the present disclosure, a method performed by a base station in a wireless communication system comprises the steps of: transmitting an RRC (radio resource control) message including configuration information related to antenna switching to a terminal, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas; transmitting DCI (downlink control information) to the terminal; and receiving an uplink signal based on the DCI, wherein when the number of antenna ports indicated by the DCI is different from the number of antenna ports used for previous transmission, the terminal is scheduled not to transmit an uplink signal during an antenna switching period.

[0011] According to one embodiment of the present disclosure, a terminal in a wireless communication system comprises: at least one transceiver; at least one processor communicatively connected to the at least one transceiver; and a memory communicatively connected to the at least one processor and executable individually or in any combination of the at least one processor, wherein the terminal receives an RRC (radio resource control) message including configuration information related to antenna switching from a base station, the configuration information related to antenna switching including information indicating switching of three or more antennas, receives DCI (downlink control information) from the base station, and, when the number of antenna ports indicated by the DCI is different from the number of antenna ports used in a previous transmission, performs antenna switching, transmits an uplink signal based on the DCI, and stores a command so that the terminal does not expect to transmit an uplink signal during an antenna switching period.

[0012] According to one embodiment of the present disclosure, a base station in a wireless communication system comprises: at least one transceiver; at least one processor communicatively connected to the at least one transceiver; and a memory communicatively connected to the at least one processor and executable individually or in any combination of the at least one processor, wherein the base station transmits to a terminal an RRC (radio resource control) message including configuration information related to antenna switching, the configuration information related to antenna switching including information indicating switching of three or more antennas, transmits to the terminal downlink control information (DCI), receives an uplink signal based on the DCI, and schedules the terminal not to transmit an uplink signal during an antenna switching period when the number of antenna ports indicated by the DCI is different from the number of antenna ports used for a previous transmission.

[0013] The disclosed embodiment provides a device and method capable of effectively providing a service in a mobile communication system.

[0014] FIG. 1 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to one embodiment of the present disclosure.

[0015] FIG. 2A illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band and performs UL transmission using port 3 through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0016] FIG. 2B illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band and performs UL transmission using port 3 through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0017] FIG. 2C illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band and performs UL transmission using port 3 through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0018] FIG. 3A illustrates an example of Tx switching in a case where a terminal has performed preceding UL transmission using 3 ports through a first UL carrier of a first band and the current terminal is performing UL transmission using 3 ports through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0019] FIG. 3B illustrates an example of Tx switching in a case where a terminal has performed preceding UL transmission using 3 ports through a first UL carrier of a first band and the current terminal is performing UL transmission using 3 ports through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0020] FIG. 4A illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using 3 ports through a first UL carrier of a first band and performs UL transmission using 1 port or 2 ports through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0021] FIG. 4B illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using 3 ports through a first UL carrier of a first band and performs UL transmission using 1 port or 2 ports through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0022] FIG. 4C illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using 3 ports through a first UL carrier of a first band and performs UL transmission using 1 port or 2 ports through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0023] FIG. 5A illustrates an example of Tx switching in a case where a terminal has performed preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band but cannot perform UL transmission using port 3, and the terminal currently performs UL transmission using port 3 through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0024] FIG. 5B illustrates an example of Tx switching in a case where a terminal has performed preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band but cannot perform UL transmission using port 3, and the terminal currently performs UL transmission using port 3 through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0025] FIG. 5C illustrates an example of Tx switching in a case where a terminal has performed preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band but cannot perform UL transmission using port 3, and the terminal currently performs UL transmission using port 3 through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0026] FIG. 6A illustrates an example of Tx switching in a state in which a terminal has performed preceding UL transmission using 1 port or 2 ports through a first UL carrier of a first band and can perform UL transmission using 3 ports on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs UL transmission using 2 ports or 1 port through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0027] FIG. 6B illustrates an example of Tx switching in a state in which a terminal has performed preceding UL transmission using 1 port or 2 ports through a first UL carrier of a first band and can perform UL transmission using 3 ports on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs UL transmission using 2 ports or 1 port through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0028] FIG. 7A illustrates an example of Tx switching in a case where a terminal has performed a preceding UL transmission using 1 port or 2 ports through a first UL carrier of a first band and cannot perform a UL transmission using 3 ports on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs a UL transmission using 2 ports or 1 port through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0029] FIG. 7B illustrates an example of Tx switching in a case where a terminal has performed a preceding UL transmission using 1 port or 2 ports through a first UL carrier of a first band and cannot perform a UL transmission using 3 ports on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs a UL transmission using 2 ports or 1 port through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0030] FIG. 8A illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using 1 port through a first UL carrier of a first band and performs 2 Tx full coherent-based 2-port transmission through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0031] FIG. 8B illustrates an example of Tx switching in a case where a terminal performs preceding UL transmission using 1 port through a first UL carrier of a first band and performs 2 Tx full coherent-based 2-port transmission through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0032] FIG. 9A illustrates an example of a state of a Tx chain of a terminal when a base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' or 'threeT' according to one embodiment of the present disclosure.

[0033] FIG. 9B illustrates an example of a state of a Tx chain of a terminal when a base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' or 'threeT' according to one embodiment of the present disclosure.

[0034] FIG. 9C illustrates an example of a state of a Tx chain of a terminal when a base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' or 'threeT' according to one embodiment of the present disclosure.

[0035] FIG. 10A illustrates an example of a case where a 3Tx-supporting terminal supports three UL carriers according to one embodiment of the present disclosure, and the carrier of the first UL band does not affect the carrier of the second UL band and the carrier of the third UL band, and the carrier of the second UL band and the carrier of the third UL band are a band pair that affect each other.

[0036] FIG. 10B illustrates an example of a case where a 3Tx-supporting terminal supports three UL carriers according to one embodiment of the present disclosure, and the carrier of the first UL band does not affect the carrier of the second UL band and the carrier of the third UL band, and the carrier of the second UL band and the carrier of the third UL band are a band pair that affect each other.

[0037] FIG. 11 illustrates an implementation example of a terminal supporting 3Tx according to one embodiment of the present disclosure.

[0038] FIG. 12 illustrates an implementation example of a terminal capable of supporting 3Tx UL switching using SRS support method 1 according to one embodiment of the present disclosure.

[0039] FIG. 13 illustrates an implementation example of a terminal capable of supporting 3Tx UL switching using SRS support method 2 according to one embodiment of the present disclosure.

[0040] FIG. 14 is a diagram illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0041] FIG. 15 is a diagram illustrating the operation of a base station according to an embodiment of the present disclosure.

[0042] FIG. 16 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0043] FIG. 17 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0044] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0045] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0046] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0047] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, their definitions should be made based on the contents throughout the specification.

[0048] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0049] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0050] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0051] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0052] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0053] As a representative example of the above broadband wireless communication system, the LTE system adopts the OFDM (Orthogonal Frequency Division Multiplexing) method in the downlink (DL) and the SC-FDMA (Single Carrier Frequency Division Multiple Access) method in the uplink (UL). The uplink refers to a wireless link in which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B or base station (BS)), and the downlink refers to a wireless link in which a base station transmits data or control signals to a terminal. The above multiple access method can distinguish the data or control information of each user by allocating and operating the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality.

[0054] As a future communications system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0055] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must simultaneously provide the peak data rate and an increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0056] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the IoT, mMTC requires supporting large-scale terminal connections within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. The IoT requires the ability to support a large number of terminals (e.g., 1,000,000 terminals / km2) within a cell, as it provides communication capabilities through the attachment of various sensors and devices. Furthermore, due to the nature of the service, terminals supporting mMTC are likely to be located in shadow areas, such as basements, beyond cell coverage. This may require broader coverage compared to other services provided by 5G communication systems. Terminals supporting mMTC must be inexpensive, and since frequent battery replacement is unlikely, they may require extremely long battery lifespans, such as 10 to 15 years.

[0057] Finally, URLLC refers to a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services such as remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and, at the same time, must have a 10 -5The following packet error rate (PER) requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller Transmit Time Interval (TTI) than other services. Simultaneously, design considerations may require the allocation of extensive resources in the frequency band to ensure communication link reliability.

[0058] The three 5G services—eMBB, URLLC, and mMTC—can be multiplexed and transmitted within a single system. To meet the differing requirements of each service, different transmission and reception techniques and parameters can be used. Of course, 5G is not limited to the three services described above.

[0059] Hereinafter, a / b can be understood as at least one of a or b.

[0060] [CA / DC related]

[0061] FIG. 1 is a diagram illustrating a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation according to an embodiment of the present disclosure.

[0062] Referring to Fig. 1, the wireless protocol of the next-generation mobile communication system consists of NR SDAP (Service Data Adaptation Protocol 125, 170), NR PDCP (Packet Data Convergence Protocol 130, 165), NR RLC (Radio Link Control 135, 160), and NR MAC (Medium Access Control 140, 155) in the terminal and NR base station, respectively.

[0063] The main functions of NR SDAP (125, 170) may include some of the following functions:

[0064] - Transfer of user plane data

[0065] - Mapping function between QoS flow and data bearer for both DL and UL

[0066] - Marking function of QoS flow ID for both uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0067] - Ability to map reflective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0068] For the above SDAP layer device, the terminal can be configured by an RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can instruct the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0069] The main functions of NR PDCP (130, 165) may include some of the following functions:

[0070] - Header compression and decompression (ROHC only)

[0071] - User data transfer function

[0072] - In-sequence delivery of upper layer PDUs

[0073] - Out-of-sequence delivery of upper layer PDUs

[0074] - PDCP PDU reordering for reception

[0075] - Duplicate detection of lower layer SDUs

[0076] - Retransmission function (Retransmission of PDCP SDUs)

[0077] - Encryption and decryption functions (Ciphering and deciphering)

[0078] - Timer-based SDU discard in uplink.

[0079] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of transmitting data directly without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0080] The main functions of NR RLC (135, 160) may include some of the following functions:

[0081] - Data transfer function (Transfer of upper layer PDUs)

[0082] - In-sequence delivery of upper layer PDUs

[0083] - Out-of-sequence delivery of upper layer PDUs

[0084] - ARQ function (Error Correction through ARQ)

[0085] - Concatenation, segmentation and reassembly of RLC SDUs

[0086] - Re-segmentation of RLC data PDUs

[0087] - Reordering of RLC data PDUs

[0088] - Duplicate detection function

[0089] - Protocol error detection

[0090] - RLC SDU discard function

[0091] - RLC re-establishment function

[0092] In the above, the in-sequence delivery function of the NR RLC device refers to the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering a single RLC SDU when it is received divided into multiple RLC SDUs, a function of rearranging received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU when there is a lost RLC SDU, or may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs may be processed in the order in which they are received (in the order of arrival, regardless of the order of the sequence number) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0093] The out-of-sequence delivery function of the NR RLC device above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when one RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing and arranging the RLC SN or PDCP SN of received RLC PDUs to record lost RLC PDUs.

[0094] NR MAC (140, 155) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0095] - Mapping function (Mapping between logical channels and transport channels)

[0096] - Multiplexing / demultiplexing of MAC SDUs

[0097] - Scheduling information reporting function

[0098] - HARQ function (Error correction through HARQ)

[0099] - Priority handling between logical channels of one UE

[0100] - Priority handling between UEs by means of dynamic scheduling

[0101] - MBMS service identification function

[0102] - Transport format selection function

[0103] - Padding function

[0104] The NR PHY layer (145, 150) can perform an operation of channel coding and modulating upper layer data, converting it into an OFDM symbol and transmitting it through a wireless channel, or demodulating and channel decoding an OFDM symbol received through a wireless channel and transmitting it to a higher layer.

[0105] The above wireless protocol structure can have various detailed structures depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure that has a single structure for each layer, as in 100. On the other hand, when a base station transmits data to a terminal based on CA (carrier aggregation) that uses multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to RLC, as in 110, but multiplexes the PHY layer through the MAC layer. As another example, when a base station transmits data to a terminal based on DC (dual connectivity) that uses multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to RLC, as in 120, but multiplexes the PHY layer through the MAC layer.

[0106] [PUSCH: Transmission Method Related]

[0107] Next, we describe the scheduling method for PUSCH transmission. PUSCH transmission can be dynamically scheduled by the UL grant within the DCI or can operate by configured grant Type 1 or Type 2. Dynamic scheduling instructions for PUSCH transmission are possible in DCI format 0_0 or 0_1.

[0108] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig containing rrc-ConfiguredUplinkGrant of [Table 1] through higher-level signaling, without receiving UL grant in DCI. Configured grant Type 2 PUSCH transmission can be semi-persistently scheduled by UL grant in DCI after receiving configuredGrantConfig not containing rrc-ConfiguredUplinkGrant of [Table 1] through higher-level signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied through configuredGrantConfig of higher-level signaling of [Table 1], except dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH provided by pusch-Config of [Table 2]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 1], the terminal applies tp-pi2BPSK in pusch-Config of [Table 2] to PUSCH transmission operated by the configured grant.

[0109] [Table 1]

[0110]

[0111]

[0112] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based or non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the upper signaling, pusch-Config in [Table 2], is 'codebook' or 'nonCodebook'.

[0113] As described above, PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can be semi-statically configured by configured grant. If the UE is instructed to schedule PUSCH transmission via DCI format 0_0, the UE performs beam configuration for PUSCH transmission using pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the activated uplink BWP within the serving cell, and the PUSCH transmission is based on a single antenna port. The UE does not expect scheduling for PUSCH transmission via DCI format 0_0 within a BWP where a PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE does not configure txConfig in pusch-Config of [Table 2], the UE does not expect to be scheduled with DCI format 0_1.

[0114] [Table 2]

[0115]

[0116] Next, we describe codebook-based PUSCH transmission. Codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, or can operate semi-statically based on a configured grant. When codebook-based PUSCH is dynamically scheduled via DCI format 0_1 ​​or semi-statically configured via a configured grant, the UE determines a precoder for PUSCH transmission based on the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (the number of PUSCH transmission layers). At this time, the SRI can be provided via the SRS resource indicator field in the DCI or configured via the srs-ResourceIndicator higher-level signaling. When performing codebook-based PUSCH transmission, the UE is configured with at least one SRS resource, and can be configured with up to two. When a UE receives an SRI through DCI, the SRS resource indicated by the SRI refers to an SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. In addition, the TPMI and transmission rank can be provided through the precoding information and number of layers fields in the DCI, or can be configured through the higher-level signaling precodingAndNumberOfLayers. The TPMI is used to indicate the precoder applied to PUSCH transmission. If the UE is configured with one SRS resource, the TPMI is used to indicate the precoder to be applied to the configured SRS resource.When a terminal is configured with multiple SRS resources, TPMI is used to indicate the precoder to be applied in the SRS resource indicated through SRI.

[0117] The precoder to be used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the nrofSRS-Ports value in the upper layer signaling, SRS-Config. In codebook-based PUSCH transmission, the UE determines the codebook subset based on the TPMI and codebookSubset in the upper layer signaling, pusch-Config. The codebookSubset in the upper layer signaling, pusch-Config, can be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the UE to the base station. If the UE reported 'partialAndNonCoherent' as the UE capability, the UE does not expect the value of codebookSubset in the upper layer signaling to be set to 'fullyAndPartialAndNonCoherent'. Additionally, if the UE reports 'nonCoherent' as the UE capability, the UE does not expect the value of the upper signaling codebookSubset to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. If nrofSRS-Ports in the upper signaling SRS-ResourceSet points to two SRS antenna ports, the UE does not expect the value of the upper signaling codebookSubset to be set to 'partialAndNonCoherent'.

[0118] The terminal can be configured with one SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', and one SRS resource in the SRS resource set can be indicated via SRI. If multiple SRS resources are configured in the SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the terminal expects that the value of nrofSRS-Ports in the upper signaling SRS-Resource is set to the same value for all SRS resources.

[0119] The terminal transmits to the base station one or more SRS resources included in the SRS resource set in which the usage value is set to 'codebook' according to upper signaling, and the base station selects one of the SRS resources transmitted by the terminal and instructs the terminal to perform PUSCH transmission using transmission beam information of the corresponding SRS resource. At this time, in codebook-based PUSCH transmission, the SRI is used as information for selecting an index of one SRS resource and is included in the DCI. Additionally, the base station includes in the DCI information indicating the TPMI and rank to be used by the terminal for PUSCH transmission. The terminal performs PUSCH transmission by applying the indicated rank and the precoder indicated by the TPMI based on the transmission beam of the corresponding SRS resource using the SRS resource indicated by the SRI.

[0120] Next, we describe non-codebook-based PUSCH transmission. Non-codebook-based PUSCH transmission can be dynamically scheduled via DCI format 0_0 or 0_1, and can operate semi-statically based on a configured grant. If at least one SRS resource is configured within an SRS resource set in which the usage value in the upper signaling, SRS-ResourceSet, is set to 'nonCodebook', the UE can be scheduled for non-codebook-based PUSCH transmission via DCI format 0_1.

[0121] For an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'nonCodebook', the UE can be configured with one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE can perform calculations for a precoder for SRS transmission by measuring the NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource connected to the SRS resource set and the first symbol of the aperiodic SRS transmission at the UE is less than 42 symbols, the UE does not expect information about the precoder for SRS transmission to be updated.

[0122] If the value of resourceType in the upper signaling SRS-ResourceSet is set to 'aperiodic', the connected NZP CSI-RS is indicated by the SRS request field in DCI format 0_1 ​​or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the presence of the connected NZP CSI-RS is indicated when the value of the SRS request field in DCI format 0_1 ​​or 1_1 is not '00'. At this time, the DCI must not indicate cross-carrier or cross BWP scheduling. In addition, if the value of the SRS request indicates the presence of an NZP CSI-RS, the NZP CSI-RS is located in the slot in which the PDCCH including the SRS request field is transmitted. At this time, the TCI states set for the scheduled subcarriers are not set to QCL-TypeD.

[0123] If a periodic or semi-persistent SRS resource set is configured, the associated NZP CSI-RS can be indicated through the associatedCSI-RS within the upper-level signaling SRS-ResourceSet. For non-codebook-based transmission, the UE does not expect the upper-level signaling spatialRelationInfo for the SRS resource and the associatedCSI-RS within the upper-level signaling SRS-ResourceSet to be configured together.

[0124] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI can be indicated through the SRS resource indicator field in the DCI or set through the srs-ResourceIndicator, which is a higher-order signaling. Similar to the codebook-based PUSCH transmission described above, when the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. At this time, the SRS resources that the UE simultaneously transmits occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

[0125] The base station transmits one NZP-CSI-RS associated with an SRS resource set to the terminal, and the terminal calculates a precoder to be used when transmitting one or more SRS resources within the SRS resource set based on the result measured upon reception of the NZP-CSI-RS. When the terminal transmits one or more SRS resources within the SRS resource set with usage set to 'nonCodebook' to the base station, the terminal applies the calculated precoder, and the base station selects one or more SRS resources from the received one or more SRS resources. At this time, in non-codebook based PUSCH transmission, the SRI represents an index that can express a combination of one or more SRS resources, and the SRI is included in the DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station can be the number of transmission layers of the PUSCH, and the terminal transmits the PUSCH by applying the precoder applied to SRS resource transmission to each layer.

[0126] [PUSCH: Transmission Power Related]

[0127] As an example of the present disclosure, when uplink data is transmitted through an uplink data channel (PUSCH; Physical Uplink Shared Channel) in response to a power control command received from a base station, a method for transmitting by setting the transmission power of the uplink data channel by a terminal is described. The uplink data channel transmission power of the terminal can be determined as shown in [Mathematical Formula 1] below, expressed in units of dBm, together with the i-th transmission unit, the parameter set configuration index j, and the PUSCH power control adjustment state corresponding to the closed loop index l. In [Mathematical Formula 1] below, when the terminal supports multiple carrier frequencies in multiple cells, each parameter can be set for each cell c, each carrier frequency f, and each bandwidth part b, and can be distinguished by indices b, f, and c.

[0128] [Mathematical Formula 1]

[0129]

[0130] - : The maximum transmission power available to the terminal in the i-th transmission unit is determined by the power class of the terminal, parameters activated from the base station, and various parameters built into the terminal.

[0131] - : Is and It consists of the sum of . is set to cell-specific upper layer signaling to the terminal, is a value set by terminal-specific upper layer signaling. Here, when j=0, it means PUSCH for transmitting msg3, when j=1, it means configured grant PUSCH, and when j={2,...,J-1} is one of the values, it means grant PUSCH.

[0132] - : Subcarrier spacing configuration value

[0133] - : It may mean the amount of resources used in the i-th PUSCH transmission unit (e.g., the number of Resource Blocks (RBs) used for PUSCH transmission on the frequency axis).

[0134] - : It refers to a value that can be determined (in case of dynamic grant PUSCH) through upper layer settings and SRI (SRS Resource Indicator) as a value to compensate for path loss.

[0135] - : Pathloss is the path loss between the base station and the terminal, and the terminal uses the reference signal (RS) resource signaled by the base station. The path loss is calculated from the difference between the transmission power and the terminal reception signal level of the reference signal. The reference signal index is It refers to the downlink path loss estimate estimated by the terminal through the reference signal and the reference signal index. The UE can decide this via upper layer configuration and SRI (in case of dynamic grant PUSCH or configured grant PUSCH based on ConfiguredGrantConfig that does not include upper layer configuration rrc-ConfiguredUplinkGrant (type 2 configured grant PUSCH)) or via upper layer configuration.

[0136] - : It refers to a value determined according to the MCS (Modulation Coding Scheme) and the format of information transmitted via PUSCH (TF: transport format, e.g., whether UL-SCH is included or CSI is included, etc.).

[0137] - : Refers to a value for a closed loop index that can be determined by a higher layer setting and SRI for PUSCH as a closed loop power control adjustment value. Here, the closed loop power adjustment for PUSCH transmission can be supported by dividing into an accumulation method that accumulates and applies a value indicated by a TPC command and an absolute method that directly applies the value indicated by the TPC command, and this can be determined depending on whether the higher layer parameter tpc-Accumulation is set. If the higher layer parameter tpc-Accumulation is set to disabled, the closed loop power adjustment for PUSCH transmission is performed by the absolute method, and if tpc-Accumulation is not set, the closed loop power adjustment for PUSCH transmission is performed by the accumulation method.

[0138] PUSCH power control adjustment status can be determined through the bandwidth part b, carrier frequency f, cell c, i-th transmission unit, and closed loop index l.

[0139] - : A value indicated by a TPC command field included in DCI format 0_0, 0_1, or 0_2 that schedules the i-th PUSCH transmission unit corresponding to the closed loop index l within the bandwidth part b, carrier frequency f, and cell c, or a value indicated by a TPC command field included in DCI format 2_2 transmitted together with a CRC scrambled with TPC-PUSCH-RNTI.

[0140] ○ If the terminal has received the upper layer signaling twoPUSCH-PC-AdjustmentStates, the closed loop index l can have a value of 0 or 1.

[0141] ○ If the terminal has not received the upper layer signaling twoPUSCH-PC-AdjustmentStates or has been scheduled for PUSCH transmission based on RAR UL grant, the closed loop index l may have a value of 0.

[0142] ◎ If the terminal has set ConfiguredGrantConfig, which is a higher layer signaling, and performs PUSCH transmission or retransmission, the closed loop index l may follow the powerControlLoopToUse value, which is a higher layer signaling.

[0143] ◎ If the terminal has been configured with the upper layer signaling SRI-PUSCH-PowerControl, the terminal can obtain a connection relationship between the value indicated by the SRI (SRS resource indicator) field in the DCI format that schedules PUSCH transmission and the closed loop index l configured through the upper layer signaling sri-PUSCH-ClosedLoopIndex, and can determine the closed loop index l based on the value indicated by the SRI field in the DCI format based on the connection relationship.

[0144] ◎ If the terminal is scheduled for PUSCH transmission based on a DCI format that does not include an SRI field, or if the upper layer signaling SRI-PUSCH-PowerControl is not set, the terminal may regard the closed loop index as 0.

[0145] ◎ If the terminal is indicated with a TPC command value through a TPC command field included in DCI format 2_2 transmitted with a CRC scrambled with TPC-PUSCH-RNTI, the closed loop index l can be indicated through the closed loop index field included in DCI format 2_2.

[0146] - If the terminal has not been set up with the upper layer signaling tpc-Accumulation, i.e., if the TPC command accumulation operation is possible for the terminal, the PUSCH power control adjustment state for the i-th PUSCH transmission unit corresponding to the closed loop index l within the bandwidth part b, carrier frequency f, and cell c. can be calculated as in [Mathematical Formula 2].

[0147] [Equation 2]

[0148]

[0149] ○ As described above, the TPC command field included in DCI format 0_0, 0_1, or 0_2 that schedules the m-th PUSCH transmission unit corresponding to the closed loop index l within the bandwidth part b, carrier frequency f, and cell c may be a value indicated by the TPC command field included in DCI format 2_2 transmitted together with the CRC scrambled with TPC-PUSCH-RNTI. If the TPC command accumulation operation is possible, The value may have a corresponding value in [dB] units depending on which value the TPC command field included in the DCI format 0_0, 0_1, 0_2, or 2_2 is indicated as in [Table 3] below. For example, if the value of the TPC command field is 0, can have a value of -1 dB.

[0150] ○ is a specific set of the TPC command values ​​described above. For all transmission units corresponding to mine can mean the sum of . At this time is a set It can mean the number of all elements belonging to me. may mean a set of DCIs including all TPC command values ​​for which a TPC command accumulation operation is to be performed for the i-th PUSCH transmission unit. To determine the starting point and the ending point in the time dimension, all DCIs received by the terminal within the two points are defined. can be included as an element of .

[0151] ● The end point for determining is from the start symbol of the i-th PUSCH transmission unit. It could be as far back as the symbol.

[0152] ● The starting point for deciding is From the start symbol of the th PUSCH transmission unit It can be a point as far back as the symbol. In this case, a positive integer is above The end point for determining (from the start symbol of the i-th PUSCH transmission unit) (as much as the previous point) than the symbol, From the start symbol of the th PUSCH transmission unit It can be determined as the smallest value that satisfies that the previous time point becomes an earlier time point in time by a symbol.

[0153] For example, The end point for determining can be defined as sym(i), From the start symbol of the th PUSCH transmission unit The time point before the symbol is sym( ), if sym(i) = sym(i-1) > sym(i- 2) > sym(i-3) holds, then i0 can be determined as 2.

[0154] - If the terminal has been set to the upper layer signaling tpc-Accumulation, i.e., if the TPC command accumulation operation is not possible for the terminal, the PUSCH power control adjustment state for the i-th PUSCH transmission unit corresponding to the closed loop index l within the bandwidth part b, carrier frequency f, and cell c. can be calculated as in [Mathematical Formula 3].

[0155] [Equation 3]

[0156]

[0157] o As described above, the TPC command field included in DCI format 0_0, 0_1, or 0_2 that schedules the i-th PUSCH transmission unit corresponding to the closed loop index l within the bandwidth part b, carrier frequency f, and cell c may be a value indicated by the TPC command field included in DCI format 2_2 transmitted together with the CRC scrambled with TPC-PUSCH-RNTI. If the TPC command accumulation operation is impossible, The value may have a corresponding value in [dB] units depending on which value the TPC command field included in the DCI format 0_0, 0_1, 0_2, or 2_2 is indicated as in [Table 3] below. For example, if the value of the TPC command field is 0, can have a value of -4 dB.

[0158] TPC command fieldAccumulated [dB]Absolute [dB]0-1-410-1211334

[0159] [PUSCH: TPMI Related]

[0160] Next, we describe the TPMI (Transmit Precoding Matrix Indicator) indicated by the base station through DCI during codebook-based PUSCH transmission.

[0161] If the terminal is scheduled for 1-layer transmission using a single PUSCH antenna port by the base station via DCI or higher layer signaling, the TPMI can be defined as W=1. Otherwise, that is, if the terminal is scheduled for 1-layer or higher PUSCH scheduling using multiple PUSCH antenna ports by the base station via DCI or higher layer signaling, the TPMI W can be defined through [Table 4] to [Table 10] below.

[0162] [Table 4]

[0163]

[0164] The above [Table 4] shows the TPMI of 1 layer when the terminal has two PUSCH antenna ports. In the above [Table 4], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select one of TPMI index 0 and 1, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select one of TPMI index 0 to 5.

[0165] [Table 5]

[0166]

[0167] The above [Table 5] shows the TPMI for a 1-layer case where the terminal has 4 PUSCH antenna ports, transform precoding is used (i.e., DFTS-OFDM waveform is used). In the above [Table 5], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 3, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 11, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 27.

[0168] [Table 6]

[0169]

[0170] The above [Table 6] shows the TPMI for a 1-layer case where the terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., CP-OFDM waveform is used). In the above [Table 6], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 3, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 11, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indexes 0 to 27.

[0171] [Table 7]

[0172]

[0173] The above [Table 7] shows a 2-layer TPMI when the terminal has two PUSCH antenna ports, no transform precoding is used (i.e., CP-OFDM waveform is used). In the above [Table 7], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select TPMI index 0, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal to select one of TPMI index 0 to 2.

[0174] [Table 8]

[0175]

[0176] The above [Table 8] shows a 2-layer TPMI when a terminal has 4 PUSCH antenna ports, no transform precoding is used (i.e., a CP-OFDM waveform is used). In the above [Table 8], if a terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indices 0 to 5, if a terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indices 0 to 13, and if a terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by one of TPMI indices 0 to 21.

[0177] [Table 9]

[0178]

[0179] The above [Table 9] shows the TPMI for a 3-layer case where the terminal has 4 PUSCH antenna ports and no transform precoding is used (i.e., CP-OFDM waveform is used). In the above [Table 9], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by TPMI index 0, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 2, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station may select and instruct the terminal by one of TPMI indexes 0 to 6.

[0180] [Table 10]

[0181]

[0182] The above [Table 10] shows a 4-layer TPMI when a terminal has 4 PUSCH antenna ports and transform precoding is not used (i.e., CP-OFDM waveform is used). In the above [Table 10], if the terminal has a non-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct the terminal by TPMI index 0, if the terminal has a partial-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct one of TPMI index 0 to 2 to the terminal, and if the terminal has a full-coherent antenna structure and has reported the corresponding terminal capability to the base station, the base station can select and instruct one of TPMI index 0 to 4 to the terminal.

[0183] [Regarding terminal capability reporting]

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

[0185] A base station can transmit a UE capability inquiry message requesting a capability report to a connected terminal. The message can include a UE capability request for each RAT (radio access technology) type of the base station. The RAT type-specific request can include information on a combination of supported frequency bands, etc. In addition, in the case of the UE capability inquiry message, UE capabilities for multiple RAT types can be requested through a single RRC message container transmitted by the base station, or the base station can include multiple UE capability inquiry messages including UE capability requests for each RAT type and transmit them to the terminal. That is, the UE capability inquiry can be repeated multiple times in one message, and the terminal can compose a corresponding UE capability information message and report it multiple times. In the next-generation mobile communication system, a UE capability request can be made for MR-DC (Multi-RAT dual connectivity), including NR, LTE, and EN-DC (E-UTRA - NR dual connectivity). Additionally, the terminal capability inquiry message is typically transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

[0186] In the above step, the terminal that receives the UE capability report request from the base station configures the terminal capability based on the RAT type and band information requested from the base station. Below is a summary of how the terminal configures the UE capability in the NR system.

[0187] 1. If the UE receives a list of LTE and / or NR bands through a UE capability request from the base station, the UE configures a band combination (BC) for EN-DC and NR stand-alone (SA). That is, it configures a candidate list of BCs for EN-DC and NR SA based on the bands requested to the base station via FreqBandList. Furthermore, the bands are prioritized in the order listed in FreqBandList.

[0188] 2. If the base station requests UE capability reporting by setting the "eutra-nr-only" flag or the "eutra" flag, the UE completely removes NR SA BCs from the list of configured BC candidates. This operation can only occur when the LTE base station (eNB) requests the "eutra" capability.

[0189] 3. The terminal then removes fallback BCs from the BC candidate list constructed in the above step. Here, a fallback BC is a BC obtained by removing at least one band corresponding to an SCell from a random BC. This step can be omitted because the BC before removing the band corresponding to at least one SCell can already cover the fallback BC. This step also applies to MR-DC, i.e., to LTE bands. The BCs remaining after this step are the final "candidate BC list."

[0190] 4. The terminal selects BCs to report by selecting BCs that match the requested RAT type from the final "candidate BC list" above. In this step, the terminal constructs the supportedBandCombinationList in a set order. That is, the terminal constructs BCs and UE capabilities to report according to the preset rat-Type order (nr -> eutra-nr -> eutra). In addition, it constructs a featureSetCombination for the constructed supportedBandCombinationList, and constructs a list of "candidate feature set combinations" from the candidate BC list after removing the list for the fallback BC (which contains capabilities of the same or lower level). The "candidate feature set combinations" above include feature set combinations for both NR and EUTRA-NR BCs, and can be obtained from the feature set combinations in the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0191] 5. Also, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations are included in both containers: UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set is included only in UE-NR-Capabilities.

[0192] After the terminal capability is configured, the terminal transmits a terminal capability information message including the terminal capability to the base station. The base station then performs appropriate scheduling and transmission / reception management for the terminal based on the terminal capability received from the terminal. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. The contents of the present disclosure can be applied to FDD and TDD systems. In the present disclosure below, upper signaling (or upper layer signaling) refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC control element; MAC CE).

[0193] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as having the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied have a specific format, or including a specific indicator that indicates whether cooperative communication is applied, or scrambled with a specific RNTI by the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied, or assuming cooperative communication is applied in a specific section indicated by a higher layer. For the convenience of the following description, the case where the terminal receives the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case.

[0194] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0195] In the following disclosure, the above examples are described through a number of embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0196] For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, and / or transmission directions, which can be distinguished through upper layer / L1 parameters such as TCI state or spatial relation information, or indicators such as cell ID, TRP ID, and panel ID, may be uniformly described as TRP (transmission reception point), beam, or TCI state. Therefore, in actual application, TRP, beam, or TCI state can be appropriately replaced with one of the above terms.

[0197] In the present disclosure, when determining whether cooperative communication is applied, the terminal may use various methods, such as having the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied have a specific format, or including a specific indicator that indicates whether cooperative communication is applied, or scrambled with a specific RNTI by the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied, or assuming cooperative communication is applied in a specific section indicated by a higher layer. For the convenience of the following description, the case where the terminal receives the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as the NC-JT case.

[0198] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. Hereinafter, a base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Although embodiments of the present disclosure are described below using a 5G system as an example, embodiments of the present disclosure may be applied to other communication systems having a similar technical background or channel type. For example, this may include LTE or LTE-A mobile communication and mobile communication technologies developed after 5G. Therefore, embodiments of the present disclosure may be applied to other communication systems with some modifications without significantly departing from the scope of the present disclosure as determined by a person skilled in the art. The contents of the present disclosure are applicable to FDD and TDD systems.

[0199] Additionally, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents throughout this specification.

[0200] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0201] - PDCCH (Physical Downlink Control Channel)

[0202] - DCI (Downlink Control Information)

[0203] - UE-specific DCI

[0204] - Group common DCI

[0205] - Common DCI

[0206] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0207] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0208] - PUCCH (Physical Uplink Control Channel)

[0209] - UCI (Uplink Control Information)

[0210] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0211] The term “slot” used in the present disclosure below is a general term that may refer to a specific time unit corresponding to a TTI (Transmit Time Interval), and may specifically mean a slot used in a 5G NR system, or a slot or subframe used in a 4G LTE system.

[0212] In the following disclosure, the above examples are described through a number of embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0213] An uplink RF chain within a terminal may be implemented to enable the terminal to simultaneously transmit an uplink signal over multiple frequency bands (e.g., two bands). For example, the terminal may transmit an uplink signal (e.g., a PUSCH) over a first band (e.g., band 1) using two transmit antennas (hereinafter referred to as 2Tx), while simultaneously transmitting an uplink signal (e.g., a PUSCH) over a second band (e.g., band 2) different from the first band using one transmit antenna (hereinafter referred to as 1Tx). If a base station can schedule PUSCHs to transmit different TBs (transport blocks) to the terminal over multiple different bands in this way, the uplink data throughput of the terminal can be increased.

[0214] On the other hand, if multi-user uplink MIMO (UL MIMO) is not supported, only a single terminal can transmit an uplink signal through specific time and frequency resources of multiple bands. That is, if the number of terminals that a base station needs to support is very large, it may be difficult for the base station to allocate multiple bands to a single terminal to support a large number of terminals. In this case, the terminal may be scheduled to transmit an uplink signal through only one band. If a terminal transmits an uplink signal using only a fixed number of transmit antennas (e.g., 2Tx) through a specific band (e.g., band 1) and is not scheduled to transmit an uplink signal through another band (e.g., band 2), the terminal may not be able to use the transmit antennas (e.g., 1Tx) to support the other bands. If a terminal transmits an uplink signal over a first band (e.g., band 1, which may be a single band) and does not transmit an uplink signal over a second band (e.g., band 2), and if the terminal can use an antenna for transmitting an uplink signal over the second band (e.g., band 2) on the first band, the terminal can transmit the uplink signal using more transmit antennas (e.g., 3Tx) on the first band, thereby obtaining reliability gains due to diversity or obtaining uplink throughput gains by transmitting signals over more layers. However, since a transmit antenna for supporting a specific band is tuned to a frequency band for supporting the band, a Tx switching operation must be performed first to tune the antenna to an appropriate frequency band in order to use the antenna for another frequency band.While a terminal performs Tx switching, the terminal cannot use the transmit antenna performing the Tx switching, as well as other transmit antennas that may be affected during the Tx switching. The base station should determine the time required for the terminal to perform Tx switching and schedule uplink signals to the terminal so that the terminal does not transmit uplink signals using antennas that are inoperable while performing Tx switching.

[0215] In another support scenario, if the terminal transmits an uplink signal using the 3Tx antennas through the first band, but the base station supports uplink CA considering the supported terminal situation, some of the 3Tx antennas of the first band can be tuned to the second band to support transmission of another uplink signal (PUSCH) that overlaps with the uplink signal (PUSCH) transmitted through the first band. In this case as well, a Tx switching operation should be performed in advance, and the base station may have to schedule not to transmit an uplink signal to the Tx antenna affected by the Tx switching while the terminal performs Tx switching.

[0216] In this disclosure, in order to efficiently operate a 3Tx transmit antenna implemented in a terminal supporting uplink CA, a terminal capability report, RRC parameter setting, and base station operation and terminal operation are specifically described to support 3Tx-based Tx switching. Meanwhile, for convenience of explanation, this disclosure uses three transmit antennas as an example, but the scope of the present disclosure is not limited thereto. In other words, this disclosure can also be applied to four or more transmit antennas.

[0217] <First embodiment: A method for a terminal supporting uplink CA to support 3Tx-based single uplink transmission using Tx switching>

[0218] In the first embodiment, a specific method is described in which a terminal supporting uplink carrier aggregation (CA) for multiple bands or multiple carriers performs Tx switching to transmit an uplink channel using up to three Txs.

[0219] If a terminal reports to the base station a terminal capability (e.g., an RRC parameter such as band combination information related to uplink transmit antenna switching (BandCombination-UplinkTxSwitch)) that it can support an uplink transmit antenna switching method (which can be used interchangeably with UL Tx switching) for a certain band combination, the base station can transmit to the terminal an RRC parameter (e.g., any parameter that can indicate uplink UL Tx switching, such as uplinkTxSwitching or uplinkTxSwitchingMoreBands) to configure UL Tx switching for the band combination reported by the terminal. The terminal can switch a number of transmit antennas greater than 2, and can support, for example, uplink 3Tx switching (UL 3Tx switching) and 3Tx uplink transmission. To support enhanced UL Tx switching, the terminal may report terminal capabilities to the base station, indicating that it can support enhanced UL Tx switching (e.g., performing UL transmission by switching a number of transmit antennas greater than 2, such as UL 3Tx switching) for a certain band combination. For example, if the terminal supports switching for three antennas, the terminal may transmit UL 3Tx switching to the base station by including it in the terminal capabilities or by setting UL 3Tx switching to True. Similarly, if the terminal supports switching for four antennas, the terminal may transmit UL 4Tx switching to the base station by including it in the terminal capabilities or by setting UL 4Tx switching to True. In addition, the above-described method may be equally applied to three or more antennas. Alternatively, the terminal may transmit information indicating the number of antennas for which switching is supported to the base station.Additionally, if the terminal supports enhanced UL Tx switching (e.g., UL 3Tx switching) for more than two uplink bands, the base station can transmit to the terminal an RRC parameter (e.g., uplinkTxSwitching3TMoreBands, etc.) to configure enhanced UL Tx switching for more than two bands. For a terminal that reports support for enhanced UL Tx switching (switching a number of transmit antennas greater than two) through the terminal capability, the base station can configure an RRC parameter to support uplink 3Tx switching, and the RRC parameter to support uplink 3Tx switching can be defined as a new RRC parameter (e.g., uplinkTxSwitching3Tx, etc., which can additionally add support for 3Tx to the RRC parameter name).

[0220] The terminal can report the Tx switching period that it can support as a terminal capability based on the number of Tx antennas for UL Tx switching that the terminal can support. If the terminal can support UL 3Tx switching, the terminal can use a new BandCombination-UplinkTxSwitch (e.g., BandCombination-UplinkTxSwitch-vxx00, where xx in vxx00 can mean release xx of a wireless communication standard) to report the terminal capability for UL 3Tx switching to the base station. The UE may report the new BandCombination-UplinkTxSwitch to the base station by setting a new RRC parameter (e.g., uplinkTxSwitchingPeriodfor3T, uplinkTxSwitchingPeriod3T3T, or uplinkTxSwitchingPeriod3T) within the new BandCombination-UplinkTxSwitch to any time value (e.g., n35us, n140us, 210us, 420us, etc.) to inform the base station of the Tx switching period required for the UE to switch 3Tx. The UE may report the Tx switching period required to switch different numbers of Tx chains to the base station, respectively, in the new BandCombination-UplinkTxSwitch. To report this, the UE may set multiple RRC parameters to the times required to switch RF chains of each Tx number and report them to the base station. Depending on the number of Txs that the terminal switches, the base station can schedule not to transmit an uplink signal during the Tx switching time period according to the number of Txs that the terminal switches.

[0221] If the terminal can transmit an uplink channel using 2Tx or more antennas as described below, and can transmit 2Tx PUSCH in a full coherent manner or 3Tx PUSCH in a full coherent manner or 3Tx PUSCH in a partial coherent manner, the terminal can report to the base station a new parameter for terminal capability reporting (e.g., uplinkTxSwitching3T3T-PUSCH-TransCoherence or an RRC parameter of any name for indicating a coherent transmission type of the terminal capable of transmitting up to 3Tx) set to one of fullCoherent, partialCoherent, or nonCoherent values. Alternatively, the terminal may report to the base station the coherent transmission type that can be supported during 2Tx PUSCH transmission in addition to the coherent transmission type that can be supported during 3Tx PUSCH transmission using a separate RRC parameter, and the RRC parameter may be configured as a lower RRC parameter in a new BandCombination-UplinkTxSwitch as described above.

[0222] Whether or not to perform UL Tx switching can be determined based on the number of transmission ports of the terminal used to perform preceding uplink transmission (hereinafter referred to as preceding UL transmission or preceding UL transmission) and the number of transmission ports to be used by the terminal to perform uplink transmission. The operation of the terminal according to the combination of the number of terminal transmission ports used for various preceding UL transmissions and the number of terminal transmission ports to be used for the current uplink transmission can be considered by dividing them into the following cases. In each case, if the terminal has the above-described uplinkTxSwitching or uplinkTxSwitching3Tx set, the terminal Assume that an uplink signal scheduled with previously received DCI(s) or an uplink signal scheduled based on RRC parameters is transmitted. Here, is the start time of transmission of the scheduled uplink signal, refers to a UE processing procedure defined to transmit a scheduled uplink signal.

[0223] - Case 1) If a terminal performs 3-port transmission (current UL transmission) through one UL carrier (hereinafter, the first UL carrier) of one band (hereinafter, the first band), and if the terminal performs preceding UL transmission as 1-port transmission or 2-port transmission through another UL carrier (hereinafter, the second UL carrier) of another band (hereinafter, the second band), the terminal may perform the 3-port transmission on any of the carriers (any of the carriers, which may include the first UL carrier or the second UL carrier or the first and second UL carriers, and may be applied to the entire disclosure). UL transmission may not be expected during the period determined based on the terminal capabilities reported by the terminal. This may mean that UL Tx switching has been completed and the UL signal is ready to be transmitted. may mean different switching periods depending on the terminal capability reported by the terminal and the number of ports (1 port or 2 ports) used in the preceding UL transmission.

[0224] For example, if the terminal performs a preceding UL transmission as a 1-port transmission through the 2nd UL carrier of the 2nd band and the terminal performs a 3-port transmission through the 1st UL carrier of the 1st band (current UL transmission), the base station shall perform a period of at least greater than or equal to uplinkTxSwitchingPeriod for any carrier. The terminal can be scheduled not to perform UL transmission during the period. As another example, if the terminal has performed a preceding UL transmission via the second UL carrier of the second band as a two-port transmission and the terminal performs a three-port transmission via the first UL carrier of the first band (current UL transmission), the base station can schedule a period of at least uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) for any carrier. The terminal should be scheduled not to perform UL transmission during the period. Alternatively, the terminal may report to the base station a terminal capability reporting parameter to inform the base station of the UL switching period for 3 Tx ports, such as uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) or uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) described later, regardless of the number of Tx ports used by the terminal for the preceding UL transmission, and the base station may report to the base station the terminal capability reporting parameter to inform the base station of the UL switching period for 3 Tx ports, such as uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) described later, and the base station may report to the base station the terminal capability reporting parameter to the base station to inform the base station of the UL switching period for 3 Tx ports, regardless of the number of ports used by the terminal for the preceding UL transmission. Terminals can be scheduled not to perform UL transmission during this period.

[0225] FIGS. 2A to 2C illustrate Tx switching examples in which a terminal performs preceding UL transmission (200, 210) using port 1 or port 2 through a first UL carrier of a first band and performs UL transmission (220) using port 3 through a second UL carrier of a second band (current UL transmission) according to one embodiment of the present disclosure.

[0226] It can be assumed that the terminal performs preceding transmission (200, 210) using 1 port or 2 ports (a combination of 2 ports other than the two PAs and two antenna modules represented by the bold solid arrows in preceding transmission (210)) through UL carrier 1 (201) based on the uplink scheduling information received from the base station. Here, a combination of PAs and antenna modules can be represented as an antenna port. In this case, it can be assumed that the terminal performs preceding UL transmission using the first antenna port (preceding transmission (200)) or the first and second antenna ports (preceding transmission (210)) for data transmitted from the baseband module of UL carrier 1, as represented by the bold solid arrows. In Fig. 2, a bold solid arrow indicates a path along which data transmitted to a corresponding UL carrier is transmitted and a connection status between an antenna port where UL transmission is performed. A solid arrow indicates that data is not transmitted, but the UL carrier and the antenna port are connected. A dotted arrow indicates that the UL carrier and the antenna port are not connected. The connection by a solid arrow and a dotted arrow is only an example, and a UL carrier and an antenna port may be connected in other ways. It is assumed that the meanings of bold solid arrows, solid arrows, and dotted arrows are the same in other drawings described below.

[0227] Thereafter, the terminal may prepare to perform UL transmission using 3 ports through UL carrier 2 (202) based on scheduling information of the current uplink signal to be transmitted received from the base station. As described above, the terminal may perform Tx switching to connect at least one or two antenna ports connected to UL carrier 1 (201) to UL carrier 2 (202) for performing preceding transmission (200 or 210) (or, if three antenna ports are connected to UL carrier 1 (201), Tx switching may be performed to connect three antenna ports to UL carrier 2 (202)). The base station shall set the period for Tx switching reported by the terminal as described above to be greater than or equal to (uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) or uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) etc.) The terminal can be scheduled not to perform UL transmission during uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod2T can mean a period for two Tx switching, and uplinkTxSwitchingPeriod3T3T or uplinkTxSwitchingPeriod3T can mean a period for three Tx switching. In addition, the definitions of the above terms can be used identically herein. Therefore, the terminal During this time, it is not expected to transmit UL signals over either carrier (UL carrier 1 (201) and UL carrier 2 (202)).

[0228] - Case 2) If the terminal performs 3-port transmission through the 1st UL carrier of the 1st band (current UL transmission) and the terminal performs preceding UL transmission using the 3rd port through the 2nd UL carrier of the 2nd band, for which carrier does the terminal It may not be expected to transmit during the period of . For Case 2, in order to support switching between 3Tx, the terminal capability report of the terminal may have to be made in advance, and the base station may set the RRC parameter (e.g., uplinkTxSwitching-3T-Mode) based on the terminal capability reported by the terminal. As described above, the terminal capability reported by the terminal is determined based on the terminal capability. This may mean that all 3 ports have completed Tx switching, and are ready to transmit UL signals to the 3 ports. is defined as a value greater than or equal to uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) reported to the base station through the terminal capability, or may mean uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) which may be newly defined to support 3Tx switching. As a specific example, if the terminal has performed preceding UL transmission using 3 ports through the 2nd UL carrier of the 2nd band and the terminal is performing 3 port transmission through the 1st UL carrier of the 1st band (current UL transmission), the base station shall define at least uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) for any carrier. Terminals can be scheduled not to perform UL transmission during this period.

[0229] FIGS. 3A to 3B illustrate Tx switching examples in which a terminal has performed preceding UL transmission using 3 ports through a first UL carrier of a first band and the terminal currently performs UL transmission using 3 ports through a second UL carrier of a second band (current UL transmission) according to one embodiment of the present disclosure.

[0230] It can be assumed that the terminal performed preceding transmission (300) using port 3 through UL carrier 1 (301) based on uplink transmission scheduling information received from the base station.

[0231] Afterwards, the terminal can prepare to perform UL transmission using 3 ports through UL carrier 2 (302) based on the scheduling information of the current uplink signal to be transmitted received from the base station. As described above, the terminal can perform Tx switching to connect the three antenna ports connected to UL carrier 1 (301) for performing the preceding transmission (300) to UL carrier 2 (302). As described above, the base station can perform Tx switching for a period greater than or equal to the period for Tx switching reported by the terminal (uplinkTxSwitchingPeriod3T3T or uplinkTxSwitchingPeriod3T, etc.). A terminal can be scheduled not to perform UL transmission during the During this time, it is not expected to transmit UL signals over either carrier (UL carrier 1 (201) and UL carrier 2 (202)).

[0232] - Case 3) If the terminal performs 1-port transmission or 2-port transmission through the 1st UL carrier of the 1st band (current UL transmission) and the terminal performs preceding UL transmission using 3 ports through the 2nd UL carrier of the 2nd band, for which carrier does the terminal perform the transmission? UL transmission may not be expected during the period determined based on the terminal capabilities reported by the terminal. This may mean that UL Tx switching has been completed and the UL signal is ready to be transmitted. may mean different switching periods depending on the terminal capability reported by the terminal and the number of ports (1 port or 2 ports) currently being used for UL transmission.

[0233] For example, if a terminal performs 1-port transmission through the 1st UL carrier of the 1st band (current UL transmission) and performs preceding UL transmission using 3 ports through the 2nd UL carrier of the 2nd band, the base station shall perform at least uplinkTxSwitchingPeriod for any carrier. The terminal can be scheduled not to perform UL transmission during the period. As another example, if the terminal performs 2-port transmission through the first UL carrier of the first band (current UL transmission) and performs preceding UL transmission using the third port through the second UL carrier of the second band, the base station can schedule at least uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) for any carrier. The terminal may be scheduled not to perform UL transmission during the period. Alternatively, the terminal may report parameters such as uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) or uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) to the base station regardless of the number of Tx ports currently used for UL transmission, and the base station may schedule the terminal to perform UL transmission during the period. Terminals can be scheduled not to perform UL transmission during this period.

[0234] FIGS. 4A to 4C illustrate Tx switching examples in which a terminal performs preceding UL transmission using 3 ports through a first UL carrier of a first band and performs UL transmission (current UL transmission) using 1 port or 2 ports through a second UL carrier of a second band, according to one embodiment of the present disclosure.

[0235] It can be assumed that the terminal performed preceding transmission (400) using port 3 through UL carrier 1 (401) based on uplink transmission scheduling information received from the base station.

[0236] Afterwards, the terminal may prepare to perform UL transmission (410) using one port or UL transmission (420) using two ports through UL carrier 2 (402) based on scheduling information of the current uplink signal to be transmitted received from the base station. The terminal may perform Tx switching to connect at least one (410) or two (420) antenna ports among three antenna ports connected to UL carrier 1 (401) for performing preceding transmission (400) to UL carrier 2 (402). The base station may perform Tx switching for a period (uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod3T3T, etc.) greater than or equal to the period for Tx switching reported by the terminal as described above. A terminal can be scheduled not to perform UL transmission during the During this time, it is not expected to transmit UL signals through either of the two carriers (UL carrier 1 (201) and UL carrier 2 (202)). Fig. 4 is only an example, and the terminal may perform the current UL transmission by Tx switching all three antennas from UL carrier 1 instead of Tx switching one or two antennas from UL carrier 1.

[0237] - Case 4) If the base station has set the uplinkTxSwitchingOption to the terminal to support multiple UL carriers, such as 'dualUL' (in addition to 'dualUL', a new operation that can indicate multiple UL support, such as 'tripleUL', can be additionally considered), and the terminal is scheduled to perform 3-port transmission through the first UL carrier of the first band, consider a situation in which the terminal has performed the preceding UL transmission through the first UL carrier of the first band as 1-port transmission or 2-port transmission, but the terminal cannot perform 3-port transmission through the first UL carrier, then for which carrier does the terminal UL transmission may not be expected during the period determined based on the terminal capabilities reported by the terminal. This may mean that UL Tx switching has been completed and the UL signal is ready to be transmitted. may mean different switching periods depending on the terminal capability reported by the terminal and the number of ports (1 port or 2 ports) used in the preceding UL transmission.

[0238] For example, if a terminal performs a preceding UL transmission using 1 port through a UL carrier of a band and the terminal performs 3 port transmissions through the same UL carrier of the same band, the base station shall provide a period of time greater than or equal to at least uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) for any carrier. The base station can schedule the terminal not to perform UL transmission during the period. As another example, if the terminal has performed a preceding UL transmission using two ports on one UL carrier of one band and the terminal performs a three-port transmission (current UL transmission) on the same UL carrier of the same band, the base station must schedule the terminal to perform at least one UL transmission period greater than or equal to the uplinkTxSwitchingPeriod for any carrier. The terminal may be scheduled not to perform UL transmission during the period. Alternatively, the terminal may report parameters such as uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T (or uplinkTxSwitchingPeriod2T) or uplinkTxSwitchingPeriod3T3T (or uplinkTxSwitchingPeriod3T) to the base station regardless of the number of Tx ports used to perform preceding UL transmission on the same UL carrier of the same band, and the base station may schedule the terminal to perform preceding UL transmission on the same carrier regardless of the number of ports used by the terminal. Terminals can be scheduled not to perform UL transmission during this period.

[0239] FIGS. 5A to 5C illustrate Tx switching examples in a case where a terminal has performed preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band but cannot perform UL transmission using port 3, and the terminal currently performs UL transmission using port 3 through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0240] A terminal supporting 'dualUL' (or a new operation that can indicate multiple UL support, such as 'tripleUL') can assume that it performed preceding transmission (500 or 510) using port 1 or port 2 over UL carrier 1 (501) based on uplink transmission scheduling information received from the base station.

[0241] Afterwards, the terminal can prepare to perform UL transmission using 3 ports through the same UL carrier 1 (501) based on the scheduling information of the current uplink signal to be transmitted received from the base station. As described above, the terminal can perform Tx switching to connect the antenna port(s) that are not connected to perform the preceding transmission (500 or 510) to UL carrier 1 (501). In addition, the base station can perform Tx switching for a period greater than or equal to the period for Tx switching reported by the terminal (uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod3T3T, etc.) as described above. The terminal can be scheduled not to perform UL transmission during the period. In addition, the terminal During this time, it is not expected to transmit UL signals over either carrier (UL carrier 1 (201) and UL carrier 2 (202)).

[0242] - Case 5) If the base station has set the uplinkTxSwitchingOption to the terminal to support multiple UL carriers, such as 'dualUL' (in addition to 'dualUL', new operations that can indicate multiple UL support, such as 'tripleUL', may be additionally considered), and the terminal is scheduled to perform 1-port transmission or 2-port transmission through one UL carrier of one band, and the terminal performs preceding UL transmission using 2-port or 1-port through another UL carrier of another band, but 3-port transmission is possible through the band that includes the UL carrier on which the terminal performed preceding UL transmission, then for which carrier During the period of UL transmission, UL transmission may not be expected. This means that even if the sum of the number of ports used in the preceding UL transmission and the number of ports to be used for the current UL transmission is less than or equal to 3, if 3Tx ports are available for transmission in the band where the preceding UL was transmitted, the terminal capability is determined before transmitting the current UL signal. This may mean that UL Tx switching is performed within. may mean different switching periods depending on the terminal capability reported by the terminal and the number of ports (1 port or 2 ports) currently being used for UL transmission.

[0243] FIG. 6A and FIG. 6B illustrate Tx switching examples in which a terminal has performed preceding UL transmission using 1 port or 2 ports through a first UL carrier of a first band and can perform UL transmission using 3 ports on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs UL transmission using 2 ports or 1 port through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0244] A terminal supporting 'dualUL' (or a new operation that can indicate multiple UL support, such as 'tripleUL') can assume that it performed preceding transmission (600 or 610) using port 1 or port 2 over UL carrier 1 (601) based on uplink transmission scheduling information received from the base station.

[0245] Thereafter, the terminal can prepare to perform UL transmission (620) using two ports or UL transmission (630) using one port through UL carrier 2 (602) based on scheduling information of the current uplink signal to be transmitted received from the base station. As described above, since the terminal supports three-port based UL transmission as well as one or two antenna ports used when performing preceding transmission (600 or 610) are connected to UL carrier 1 (601), all three antenna ports of the terminal are connected to UL carrier 1 (601). Therefore, the terminal can perform Tx switching to connect at least two (610) or one (620) of the three antenna ports connected to UL carrier 1 (601) to UL carrier 2 (602). The base station shall set a period for Tx switching greater than or equal to the period reported by the terminal (uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod3T3T, etc.) as described above. A terminal can be scheduled not to perform UL transmission during the During this time, it is not expected to transmit UL signals on either carrier (UL carrier 1 (601) and UL carrier 2 (602)).

[0246] - Case 6) If the base station has set the uplinkTxSwitchingOption to the terminal to support multiple UL carriers, such as 'dualUL' (in addition to 'dualUL', a new operation that can indicate multiple UL support, such as 'tripleUL', may be additionally considered), and the terminal is scheduled to perform 1-port transmission or 2-port transmission through one UL carrier of one band, and the terminal performs preceding UL transmission using 2-port or 1-port through another UL carrier of another band, but is not capable of 3-port transmission through the band that includes the UL carrier on which the terminal performed preceding UL transmission, then the terminal shall perform a separate During the period, 1-port transmission can be performed through UL carrier 1 or 2-port transmission can be performed through UL carrier 2 without performing Tx switching. Alternatively, the terminal can perform separate It is possible to perform 2-port transmission over UL carrier 1 or 1-port transmission over UL carrier 2 without performing Tx switching during the period.

[0247] FIG. 7A and FIG. 7B illustrate Tx switching examples in a case where a terminal has performed preceding UL transmission using port 1 or port 2 through a first UL carrier of a first band and cannot perform UL transmission using port 3 on the UL carrier on which the preceding UL transmission was performed, and the terminal currently performs UL transmission (current UL transmission) using port 2 or port 1 through the same UL carrier of the same band, according to one embodiment of the present disclosure.

[0248] A terminal supporting 'dualUL' (or a new operation that can indicate multiple UL support, such as 'tripleUL') can assume that the base station performed preceding transmission (700 or 710) using port 1 or port 2 over UL carrier 1 (701) based on uplink transmission scheduling information.

[0249] Thereafter, the terminal can prepare to perform UL transmission (720) using two ports or UL transmission (730) using one port through UL carrier 2 (702) based on the scheduling information of the current uplink signal to be transmitted received from the base station. At this time, as described above, the terminal can perform UL transmission (720) using two ports or UL transmission (730) using one port by using two antenna ports (720) or one antenna port (730) connected to UL carrier 2 (702) without performing separate Tx switching. In addition, the terminal can simultaneously transmit UL signals by using one antenna port (720) or two antenna ports (730) connected to UL carrier 1 (701) in addition to UL transmission through UL carrier 2.

[0250] - Case 7) If the terminal can transmit in full coherent mode for 2Tx as described above and the terminal is scheduled to perform 2Tx full coherent based 2-port transmission through one UL carrier of one band and is in an operating state where it cannot perform 2Tx full coherent based 2-port transmission through the same UL carrier of the same band, then the terminal may transmit in full coherent mode for any carrier. may not be expected to transmit during the period of time determined based on the terminal capabilities reported by the terminal. This may mean that two ports capable of 2 Tx full coherent transmission are connected to the corresponding carrier through UL Tx switching, thereby completing preparation for transmitting UL signals in a 2 Tx full coherent manner. The method by which the terminal determines whether the UL transmission scheduled for the corresponding UL carrier is a 2 Tx full coherent-based 2-port transmission is specifically described in the second embodiment.

[0251] FIG. 8A and FIG. 8B illustrate Tx switching examples in which a terminal performs preceding UL transmission using one port through a first UL carrier of a first band and performs 2 Tx full coherent-based 2-port transmission (current UL transmission) through a second UL carrier of a second band according to one embodiment of the present disclosure.

[0252] It can be assumed that the terminal performed preceding transmission (800) using port 1 through UL carrier 1 (801) based on uplink transmission scheduling information received from the base station.

[0253] After that, the terminal can prepare to perform 2 Tx full coherent-based 2-port UL transmission through UL carrier 2 (802) based on the current uplink scheduling information to be transmitted received from the base station. As described above, 2-port UL transmission is possible through UL carrier 2 (802), but the two antenna ports may be an antenna port combination that does not allow coherent transmission. If the terminal is not capable of 2 Tx full coherent-based 2-port UL transmission, the base station can perform Tx switching of the antenna port connected to UL carrier 1 (801) to UL carrier 2 (802). As described above, the base station can perform Tx switching for a period greater than or equal to the period for Tx switching reported by the terminal (uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod3T3T, etc.). A terminal can be scheduled not to perform UL transmission during the During this time, it is not expected to transmit UL signals over either carrier (UL carrier 1 (801) and UL carrier 2 (802)).

[0254] - Case 8) A terminal supporting UL transmission using 3 ports can receive RRC parameter settings from the base station to support multiple UL carriers, such as 'dualUL' (in addition to 'dualUL', new operations that can indicate support for multiple ULs, such as 'tripleUL', can also be considered). In addition, a state in which the connection state of the Tx chain of the terminal is not determined to be a single state but can be set to one of several different states can be considered. For example, if the terminal performs UL transmission using 2Tx through the first UL carrier and UL transmission using 1Tx through the second UL carrier, the connection state of the Tx chain of the terminal can be a single state (unique). On the other hand, if the terminal performs UL transmission using 2Tx through the first UL carrier but does not perform transmission through the second UL carrier, the state of the Tx chain can be set to one of several states (not unique). At this time, if the state of the Tx chain of the terminal is not unique, the base station may set a new RRC parameter (e.g., uplinkTxSwitching-TripleUL-TxState or uplinkTxSwitching-DualUL-TxStatefor3Tx, etc.) to the terminal to support the terminal capable of performing uplinkTxSwitching-DualUL-TxState or 3-port transmission. The base station may set a new candidate value other than 'oneT' or 'twoT' as the candidate value of uplinkTxSwitching-DualUL-TxState or uplinkTxSwitching-DualUL-TxStatefor3Tx for the terminal capable of performing 3-port transmission.The above uplinkTxSwitching-DualUL-TxState or uplinkTxSwitching-TripleUL-TxState may mean information indicating the state of the UL Tx chain. For example, 'one-twoT' or 'threeT' may be considered as candidate values ​​for uplinkTxSwitching-DualUL-TxStatefor3Tx, and the base station may set uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' or 'threeT' and transmit it to the terminal.

[0255] If the base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' in the terminal, the terminal is in a state where it can perform 3-port transmission through one UL carrier (e.g., UL carrier1) of a certain band (or all 3 ports are connected to UL carrier 1) and there is no UL transmission following (or not scheduled) through the same UL carrier (e.g., UL carrier1) but is scheduled to perform UL transmission using 1 port or 2 ports through another UL carrier (e.g., UL carrier2) of another band, the terminal can consider that 1-port or 2-port transmission is possible through UL carrier2 and that 2-port or 1-port transmission is possible through UL carrier1.

[0256] If the base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'threeT' in the terminal, the terminal is in a state where it can perform 3-port transmission over one UL carrier (e.g., UL carrier1) of a certain band, and if UL transmission is not followed (or not scheduled) over the same UL carrier (e.g., UL carrier1) but is scheduled to perform UL transmission using port 1 or port 2 over another UL carrier (e.g., UL carrier2) of another band, the terminal can consider that 3-port transmission is possible over UL carrier2. Therefore, the terminal considers that UL transmission is not possible without Tx switching over UL carrier1.

[0257] As another example, the base station may additionally support 'oneT' as a candidate value of uplinkTxSwitching-DualUL-TxState or uplinkTxSwitching-DualUL-TxStatefor3Tx. If the base station configures uplinkTxSwitching-DualUL-TxStatefor3Tx to 'oneT' for the UE, the UE is capable of performing 3-port transmission over one UL carrier (e.g., UL carrier1) of a band, and if no UL transmission is followed (not scheduled) over the same UL carrier (e.g., UL carrier1) but is scheduled to perform UL transmission using one port (or two ports) on another UL carrier (e.g., UL carrier2) of another band, the UE considers that the 1-port transmission is possible over both carriers (UL carrier1 and UL carrier2).

[0258] FIGS. 9A to 9C illustrate examples of states of a Tx chain of a terminal when a base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx to 'one-twoT' or 'threeT' according to one embodiment of the present disclosure.

[0259] It can be assumed that the terminal is currently capable of 3-port UL transmission through UL carrier 1 (801). And the base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx (or uplinkTxSwitching-DualUL-TxState) to 'one-twoT' in the terminal, and the terminal does not perform UL transmission through UL carrier 1 (901) based on the current uplink scheduling information to be transmitted received from the base station and can prepare to perform 1-port UL transmission through UL carrier 2 (902) (910). As in the cases described above, the base station sets the period for Tx switching reported by the terminal to be greater than or equal to uplinkTxSwitchingPeriod or uplinkTxSwitchingPeriod2T2T or uplinkTxSwitchingPeriod3T3T, etc. A terminal can be scheduled not to perform UL transmission during the During this time, the terminal does not expect to transmit UL signals on either of the two carriers (UL carrier 1 (901) and UL carrier 2 (902)). At this time, the terminal can connect one antenna port to UL carrier 2 (902) by Tx switching, and the terminal can perform UL transmission using two ports through UL carrier 1 (901) and UL transmission using one port through UL carrier 2 (902) by Tx switching (910).

[0260] Alternatively, the base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx (or uplinkTxSwitching-DualUL-TxState) to 'one-twoT' in the terminal, and the terminal does not perform UL transmission through UL carrier 1 (901) based on the current uplink scheduling information to be transmitted received from the base station and may prepare to perform two-port UL transmission through UL carrier 2 (902) (920). Similarly, the base station may set the period for Tx switching to be greater than or equal to the period for Tx switching reported by the terminal. A terminal can be scheduled not to perform UL transmission during During this time, the terminal does not expect to transmit UL signals to either of the two carriers (UL carrier 1 (901) and UL carrier 2 (902)). At this time, the terminal can connect to UL carrier 2 (902) by Tx switching the two antenna ports, and the terminal can perform Tx switching (920) such that UL transmission using port 1 is possible through UL carrier 1 (901) and UL transmission using port 2 is possible through UL carrier 2 (902).

[0261] As another example, if the base station sets uplinkTxSwitching-DualUL-TxStatefor3Tx (or uplinkTxSwitching-DualUL-TxState) to 'threeT' in the terminal, the terminal may not perform UL transmission through UL carrier 1 (901) based on the current uplink scheduling information to be transmitted received from the base station and may prepare to perform 1-port UL transmission through UL carrier 2 (902) (930). Similarly, the base station may set the period for Tx switching to be greater than or equal to the period for Tx switching reported by the terminal. A terminal can be scheduled not to perform UL transmission during During this time, the terminal does not expect to transmit UL signals on either of the two carriers (UL carrier 1 (901) and UL carrier 2 (902)). At this time, the terminal can connect to UL carrier 2 (902) by Tx switching all three antenna ports, and the terminal can Tx switch to a state where UL transmission using three ports is possible to UL carrier 2 (902) (930).

[0262] - A terminal may perform 3-port UL transmission on one band and may not expect to simultaneously perform UL transmission over another UL carrier on another band.

[0263] The above cases describe a case where a 3Tx-supporting terminal supports uplink transmission via two different UL carriers within two different bands (or, in the case of intra-band, different UL carriers within the same band). However, depending on the terminal's capabilities, the terminal can support a number of different UL carriers greater than two by Tx-switching three antenna ports. In this case, the following new behavior can be supported for the 3Tx-supporting terminal.

[0264] - Instead of two UL bands (indicated by bandIndexUL1 and bandIndexUL2 in ULTxSwitchingBandPair), three UL bands (indicated by bandIndexUL3 in addition to bandIndexUL1 and bandIndexUL2 in ULTxSwitchingBandPair) may be indicated in ULTxSwitchingBandPair, which means a combination of bands that can be supported simultaneously. However, the present disclosure may also be applied to three or more UL bands, and three or more UL bands may be indicated in information indicating three or more UL bands. In addition, for convenience of explanation, the present disclosure describes three UL bands as an example, but the same may be applied to four or more UL bands.

[0265] - If three UL bands can be supported simultaneously, UL transmission of one port on each UL carrier of each band can be supported simultaneously.

[0266] - or ULTxSwitchingBandPair, which means a combination of bands that can be supported simultaneously, is limited to including two UL bands, but if the base station configures another third UL band (and / or a fourth UL band) that is not affected by the combination of the two UL bands based on the capability report of the terminal via SwitchingPeriodUnaffectedBandDualUL, and maintainedUL-Trans is configured, the terminal can support the following additional operations. At this time, SwitchingPeriodUnaffectedBandDualUL is information indicating a carrier (or band) that can perform dual UL transmission regardless of the carrier (or band) performing Tx switching when two or more UL carrier CAs (or UL band CAs) are supported, and can be indicated via a band index. In addition, maintainedUL-Trans means information indicating that UL transmission can be performed for the band indicated by SwitchingPeriodUnaffectedBandDualUL.

[0267] FIG. 10A and FIG. 10B illustrate an example in which a terminal supporting 3Tx according to one embodiment of the present disclosure supports three UL carriers, and a carrier of a first UL band does not affect a carrier of a second UL band and a carrier of a third UL band, and a carrier of a second UL band and a carrier of a third UL band are band pairs that affect each other (hereinafter, a carrier of the n-th UL band is described as the n-th UL band for convenience of explanation).

[0268] Assume that the terminal performs UL transmission on one port (or two ports as another example with FIGS. 10A and 10B) over the first UL band (1001) and UL transmission on two ports (or one port as another example with FIGS. 10A and 10B) over the second UL band (1002) such that the UL transmissions are scheduled such that the sum of the total ports of the two bands does not exceed three (1020). At this time, 1-port UL transmission was performed for the first UL band (1001) in the preceding UL transmission (1000) and 2-port UL transmission was performed for the third UL band (1003). It can be assumed that the current state of the terminal is such that 1-port UL transmission is possible for the first UL band (1001) and 2-port UL transmission is possible for the third UL band (1003) as in the preceding UL transmission. If the second UL band (1002) and the third UL band (1003) are ULTxSwitchingBandPair, the first UL band (1001) can be set to a band that does not affect the second UL band (1002) and the third UL band (1003) with SwitchingPeriodUnaffectedBandDualUL of the ULTxSwitchingBandPair to which the second UL band (1002) and the third UL band (1003) are set. In addition, maintainedUL-Trans can be set within the SwitchingPeriodUnaffectedBandDualUL to which the first UL band (1001) is set.In this way, if the second UL band (1002) and the third UL band (1003) are ULTxSwitchingBandPair and the first UL band (1001) is configured with maintainedUL-Trans within the configured SwitchingPeriodUnaffectedBandDualUL, the terminal can perform UL transmission without a period for separate Tx switching through the first UL band (1001) that does not affect the second UL band (1002) and the third UL band (1003), and the terminal can perform Tx switching to any UL carrier of the second UL band (1002) and the third UL band (1003) for a period that is greater than or equal to the period. If maintainedUL-Trans is not configured, the terminal may not expect to perform UL transmission during the period that is greater than or equal to the period during which it performs Tx switching to any UL carrier in any band (1001, 1002, 1003). You may not expect to perform UL transmission during this time.

[0269] <Second embodiment: SRS transmission method and UL precoder indication method when supporting 3Tx based on UL Tx switching>

[0270] In the second embodiment, a method for a terminal supporting 3 Tx UL transmission to transmit an SRS to support UL CA and Tx switching and a method for a base station to instruct UL precoding through an SRS transmitted by the terminal are specifically described.

[0271] Depending on the implementation of the terminal, some antenna ports may transmit signals coherently and some antenna ports may not transmit signals coherently. As specified in RAN4 standard specification TS38.101-1 section 6.4D.4, when the terminal can perform transmission such that the phase difference and the relative power difference between UL transmissions transmitted using the two antenna ports of the terminal within a certain time window are within a predefined phase error and relative power error, it can be determined that the UL signal can be coherently transmitted using the two antenna ports. In the example of Fig. 11, for the same terminal as the examples of Figs. 2 to 10, the second antenna port (1102) and the third antenna port (1103) among the three antenna ports (1101, 1102, 1103) are tied together, and the first antenna port (1101) is configured separately. This is an example of a terminal implementation that indicates that the terminal can perform coherent transmission through the second antenna port (1102) and the third antenna port (1103), but cannot perform coherent transmission through the first antenna port (1101) and the second or third antenna port (1102 or 1103).

[0272] In the example of FIG. 11 described above, if the terminal performs 3Tx transmission using all three antenna ports (1101, 1102, 1103), the terminal is capable of 3Tx partial coherent transmission. If the terminal performs 2Tx transmission using the second antenna port (1102) and the third antenna port (1103) in the example described above, the terminal is capable of 2Tx full coherent transmission. If the terminal performs 2Tx transmission using the first antenna port (1101) and the second antenna port (1102) in the example described above, the terminal is capable of 2Tx non-coherent transmission. If the terminal performs 2Tx transmission using the first antenna port (1101) and the third antenna port (1103) in the example described above, the terminal is capable of 2Tx non-coherent transmission.

[0273] In order to support 3Tx-based Tx switching for terminals capable of supporting 3Tx transmission, the base station can set and operate SRS on the UL carrier of each band as follows.

[0274] - SRS support method for supporting 3Tx 1) If it is assumed that the terminal does not support full power mode (especially, full power mode 2), an SRS resource (in case of codebook) supporting the same number of SRS ports can be configured in an SRS resource set, and the number of SRS ports in the SRS resource can be four or three. If the terminal transmits an SRS resource configured with four SRS ports, the terminal does not transmit any one of the four SRS ports (for example, the last SRS port among the four SRS ports), and the base station can confirm that any one of the SRS ports (the last SRS port) is not transmitted. If the terminal supports a noncodebook-based PUSCH transmission technique, the terminal can transmit three SRS resources, each of which has 1 SRS port in the SRS resource set, to the base station. Such configuration of SRS resources and SRS resource sets can be configured for each UL BWP of each UL carrier in each band.

[0275] - SRS support method for supporting 3Tx 2) SRS resources (in case of codebook) supporting different numbers of SRS ports can be set in an SRS resource set, and the number of SRS ports of the SRS resource can be one, two, four (or three). The terminal can transmit SRS resources each having a different number of SRS ports depending on the implementation of the terminal. For example, the base station can set three SRS resources in an SRS resource set whose usage is codebook for a terminal that supports Tx switching to support 3Tx UL transmission and UL CA-based 3Tx. The number of SRS ports of the first SRS resource can be 1, and a terminal such as FIG. 11 can transmit an SRS resource having an SRS port number of 1 through one antenna port (e.g., 1101) among multiple antennas. The number of SRS ports of the second SRS resource may be 2, and a terminal such as FIG. 11 may transmit an SRS resource having the number of SRS ports 2 through two antenna ports (e.g., 1102 and 1103) among multiple antennas. In this case, the terminal may perform full coherent UL transmission using the two antenna ports (1102 and 1103), and the base station may also configure a 2-port SRS resource based on the terminal capability for coherent transmission reported by the terminal (e.g., an RRC parameter such as uplinkTxSwitching3T3T-PUSCH-TransCoherence as described above), and expect that the terminal will transmit the two SRS ports in full coherence.The number of SRS ports of the third SRS resource may be 4 or 3, and if the number of SRS ports of the SRS resource is 4, as described above, the terminal may not transmit any one of the four SRS ports (e.g., the last SRS port). In this case, the terminal as in FIG. 11 may transmit the SRS resource having the number of SRS ports 3 or 4 through all three antenna ports (1101, 1102, and 1103). In this case, the terminal may perform partial coherent UL transmission using the three antenna ports (1101, 1102, and 1103), and the base station may also configure a 3-port SRS resource based on the terminal capability for coherent transmission reported by the terminal (e.g., an RRC parameter such as uplinkTxSwitching3T3T-PUSCH-TransCoherence as described above), and expect that the terminal will transmit the three SRS ports in a partial coherent manner. This operation of configuring multiple SRS resources with different numbers of SRS ports in a single SRS resource set can be supported through additional terminal capabilities and RRC parameters set by the base station, regardless of full power mode (especially full power mode2). In order for the terminal to transmit three SRS resources supporting different numbers of SRS ports included in the same SRS resource set, the transmission interval between each SRS resource must be at least a value greater than or equal to the period during which Tx switching is performed. It must be greater than or equal to . This is because, in order to transmit SRS resources supporting different numbers of SRS ports, the antenna port connected to another UL carrier of a different band from the UL carrier transmitting the SRS resource must be switched to the UL carrier transmitting the SRS resource. Or, a value greater than or equal to the period during which the UE performs at least Tx switching before transmitting SRS resources in the SRS resource set. Tx switching can be performed for a time period greater than or equal to that of the SRS resource, and then SRS resources can be transmitted without a separate time interval. In this case, the base station should not schedule other UL transmissions to prevent the UE from Tx switching to another UL carrier in a different band while transmitting SRS resources in order to receive the SRS resources. Alternatively, the base station can schedule the UE to transmit a UL signal with a higher priority than the SRS transmission, and the UE can transmit the UL signal with the higher priority and skip or cancel the SRS transmission.

[0276] In this way, the base station can configure the SRS resource set and SRS resource(s) for the terminal that the terminal can support when transmitting 3Tx, and based on this, can receive the SRS from the terminal and estimate the UL channel. Based on the estimated UL channel, the base station can instruct the terminal to use an uplink precoder and / or an SRS resource to refer to when transmitting a PUSCH. However, in order for the base station to determine a combination of antenna ports that can transmit coherently among the multiple antennas of the terminal or to perform a precoder instruction to instruct coherent transmission, a rule may be required between the base station and the terminal. That is, the base station can determine an antenna port that the terminal can transmit coherently or schedule coherent transmission to instruct the terminal to transmit a UL signal coherently through one or a combination of the following methods.

[0277] - Method for determining terminal antenna 1) The base station can schedule the terminal to report the combination of antenna ports that can transmit coherently. For example, the terminal can configure an additional RRC parameter to report the combination of antenna ports that can transmit coherently in the RRC parameter for reporting the coherent transmission method that can be supported in 3Tx transmission, such as the above-described uplinkTxSwitching3T3T-PUSCH-TransCoherence. For example, the base station can request the terminal to report the RRC parameter such as 'coherentAntennaPort' by selecting one of the candidate values ​​such as 'port1-port2' or 'port1-port3' or 'port2-port3'.

[0278] - Method for identifying terminal antennas 2) The base station can request a terminal capability report to define subgroup(s) of the coherent UL codebook for the terminal and report a subgroup of codebooks that the terminal can support among the subgroups of the coherent UL codebook. The subgroup(s) of the coherent UL codebook can be composed of 1 layer or 2 layers. The subgroup(s) of the coherent UL codebook can include two non-coefficient layers transmitted to two antenna ports capable of coherent transmission. The subgroup(s) of the coherent UL codebook composed of 1 layer can be composed as follows.

[0279] [Equation 4]

[0280]

[0281] Referring to [Equation 4], the two non-zero coefficients are and 1-layer precoders composed of can be configured as subgroup(s) of the coherent UL codebook. For example, , , , A precoder group such as can be defined as a subgroup G1 of a coherent UL codebook. Similarly, subgroup(s) of a two-layer coherent UL codebook can be configured as follows.

[0282] [Equation 5]

[0283]

[0284] Referring to [Equation 5], the two non-zero coefficients are and A precoder can be composed of a first layer consisting of a zero coefficient and a second layer consisting of a non-zero coefficient, and these precoders can be composed of subgroup(s) of a coherent UL codebook. Here, can be defined as 0. Or if If this is a non-zero coefficient, then the terminal is You can ignore it and configure it to 0 so that no UL signal is transmitted using that antenna port. For example, A group of precoders such as can be defined as subgroup G2 of the coherent UL codebook. Or By defining it as 0 A precoder group such as may be defined as a subgroup G2 of the coherent UL codebook. If a base station requests a terminal to report the terminal capability for a subgroup of the coherent UL codebook that the terminal can support, the terminal may report to the base station whether it can support G1, G2, both G1 and G2, or one or more subgroups among other subgroups determined according to Equation 4 or Equation 5. The terminal may configure a bitmap to indicate whether the base station and the predefined limited number of subgroups are supported in order to indicate the subgroups of the coherent UL codebook that the terminal can support, and if a bit of the bitmap is indicated as 0, it means that the terminal cannot support the subgroup of the coherent UL codebook corresponding to the bit, and if a bit of the bitmap is indicated as 1, it means that the terminal can support the subgroup of the coherent UL codebook corresponding to the bit. Alternatively, one of the candidate values ​​may be reported as a combination of supportable subgroups, or a list of supportable subgroups may be reported as a terminal capability, unlike the bitmap configuration method.

[0285] - Method for identifying terminal antennas 3) The base station and the terminal can define in advance the antenna ports of the terminal that are capable of coherent transmission. The antenna ports of the terminal are digital ports, and the mapping between the actually implemented physical antenna ports can be determined according to the rules defined by the base station and the terminal. That is, the terminal can allocate physical antenna ports to correspond to the digital ports defined by the base station and the terminal, and the terminal can map the digital ports and coherent physical antennas so that coherent UL transmission is possible through the defined digital ports. For example, the base station and the terminal can define the first antenna port (e.g., antenna port 1000) and the third antenna port (e.g., antenna port 1002) as digital ports that are capable of coherent UL transmission, and the terminal can map the physical antenna ports and the first and third antenna ports so that coherent UL transmission can be performed using the first and third antenna ports. Alternatively, the first and second antenna ports, rather than the first and third antenna ports, may be combined as digital ports capable of coherent UL transmission, or may be defined as combinations between other antenna ports.

[0286] The terminal transmits an SRS for supporting 3Tx using one or a combination of the above-described methods, and the base station can indicate the SRS resource and UL precoder through the SRI (SRS resource indicator) and TPMI (transmit precoding matrix indicator, Precoding information and number of layers field in DCI format 0_1 / 0_2) considering the coherent transmission type that the terminal can support. The terminal can determine the SRS resource and precoder to refer to and the coherent transmission type to use when transmitting a scheduled UL signal based on the SRI and TPMI indicated by the base station.

[0287] If the terminal supports UL 3Tx switching, Tx switching can be performed based on the coherent transmission type of the preceding UL transmission performed through a UL carrier of a band and the coherent transmission type of the UL transmission to be performed through the UL carrier. That is, the terminal can determine whether to perform Tx switching by additionally considering the coherent transmission type determined by the precoder scheduled by the base station as well as the number of Tx antenna ports available for the UL carrier.

[0288] It is assumed that the terminal supports codebook-based PUSCH and can support full coherent and non-coherent transmission schemes for 2Tx as described above and partial coherent and non-coherent transmission schemes for 3Tx. In addition, it is assumed that the terminal transmits SRS for supporting 3Tx using SRS support method 1 for supporting 3Tx and that the base station and the terminal identify antenna port combinations that can support coherent transmission types using one or a combination of the terminal antenna identification methods 1 to 3 described above. If the terminal is scheduled to perform 2Tx coherent-based 2-port transmission through one UL carrier of one band (i.e., it means that the terminal is scheduled to transmit a UL signal through a precoder with a non-zero coefficient of 2 in one layer) and cannot perform 2Tx coherent-based 2-port transmission through the same UL carrier of the same band, the terminal determines which carrier to use for You may not expect to transmit during that period.

[0289] For example, when a terminal transmits an uplink signal using the first and third antenna ports, it is assumed that coherent UL transmission is possible. The terminal transmits a preceding UL transmission from the base station to a UL carrier of one band. It can be assumed that the UE is scheduled to transmit a UL signal (e.g., PUSCH) using two antenna ports that do not enable coherent transmission, and this is performed. If the UE implementation is as in Fig. 12, the UE can transmit the signal of the first (digital) antenna port (1201) of the first layer in the precoder using the second (physical) antenna port (1212) for the preceding UL transmission, and transmit the signal of the second (digital) antenna port (1202) of the second layer in the precoder using the first (physical) antenna port (1211). That is, the UE can perform the preceding UL transmission using two non-coherent antennas (1211, 1212). Thereafter, the base station can transmit scheduling information for UL transmission to the UE through the same UL carrier of the same band. At this time, the UE can transmit the precoder for the UL transmission to be currently performed. This can be identified through the TPMI field of DCI format 0_1 / 0_2 for scheduling UL transmission, and the terminal can transmit the currently scheduled UL signal using an antenna capable of coherent UL transmission. If the terminal implementation is as shown in Fig. 12, the terminal can transmit the currently scheduled UL signal using the signals of the first (digital) antenna port (1201) and the third (digital) antenna port (1203) of one layer indicated by the precoder, and the second (physical) antenna port (1212) and the third (physical) antenna port (1213). That is, the terminal can transmit the currently scheduled UL signal using two coherent antennas. If the terminal is connected to only the first physical antenna port (1211) and the second physical antenna port (1212) to perform preceding UL transmission on a UL carrier of a band, the terminal must perform Tx switching to transmit the currently scheduled UL signal to the two coherent physical antenna ports (1212, 1213). Similar to the first embodiment, if the terminal performs Tx switching to prepare for coherent UL transmission, the base station must perform Tx switching for a period greater than or equal to the period for Tx switching. The terminal must be scheduled not to perform UL transmission during During Tx switching, it is not expected that UL signals will be transmitted to all affected UL carriers. If a terminal has performed a preceding UL transmission through one UL carrier of a band through one antenna port (1211) that is not capable of coherent transmission among multiple antenna ports, and the terminal is currently scheduled to transmit a scheduled UL signal through two antenna ports (1212, 1213) capable of coherent transmission, and the terminal is capable of coherent UL transmission, the terminal can transmit the scheduled UL signal using the two coherent antenna ports (1212, 1213) without performing a separate Tx switching. Alternatively, if the terminal is scheduled to transmit a scheduled UL signal through two coherent antenna ports (1212, 1213) regardless of the preceding UL transmission performed by the terminal and the terminal is currently capable of performing coherent UL transmission, the terminal can transmit the scheduled UL signal using the two coherent antenna ports (1212, 1213) without performing separate Tx switching.

[0290] In another method, it is assumed that the terminal transmits multiple SRS resources supporting different SRS ports using the SRS support method 2 for supporting 3Tx, and the base station and the terminal identify antenna port combinations that can support the coherent transmission type using one or a combination of the terminal antenna identification methods 1 to 3 described above. If the base station instructs the terminal to schedule an UL signal to be transmitted through one UL carrier of one band by instructing the terminal to use an SRS resource with 2 SRS ports as an SRI and a corresponding 2Tx full coherent precoder, and the terminal performs a preceding UL transmission based on the SRS resource with 1 SRS port through the UL carrier of the same band as the one on which the current UL signal is scheduled, then the terminal determines for which carrier You may not expect to transmit during that period.

[0291] FIG. 13 illustrates an implementation example of a terminal capable of supporting 3Tx UL switching using SRS support method 2 according to one embodiment of the present disclosure.

[0292] If the terminal transmits an SRS resource (1301) with an SRS port number of 1 or transmits a PUSCH based on an SRS resource (1301) with an SRS port number of 1, the terminal may perform transmission using the first physical antenna port (1311). If the terminal transmits an SRS resource (1302) with an SRS port number of 2 or transmits a PUSCH based on an SRS resource (1302) with an SRS port number of 2, the terminal may perform transmission using the second physical antenna port (1312) and the third physical antenna port (1313). If the terminal transmits an SRS resource (1303) with 3 (or 4) SRS ports or transmits a PUSCH based on an SRS resource (1303) with 3 (or 4) SRS ports, the terminal can perform transmission using all of the first physical antenna port (1311), the second physical antenna port (1312), and the third physical antenna port (1313).

[0293] If a terminal transmits a preceding UL PUSCH based on an SRS resource (1301) having an SRS port number of 1 through a UL carrier of a band, and the second physical antenna port (1312) and the third physical antenna port (1313) are not connected to the UL carrier, the terminal must perform Tx switching to transmit the currently scheduled UL signal to the two coherent physical antenna ports (1312, 1313) if the base station schedules the UL signal to perform coherent UL transmission based on an SRS resource (1302) having an SRS port number of 2 on the same UL carrier. Similar to the first embodiment, if the terminal performs Tx switching to prepare for coherent UL transmission, the base station must perform Tx switching for a period greater than or equal to the period for Tx switching. A terminal can be scheduled not to perform UL transmission during During Tx switching, we do not expect to transmit UL signals on all affected UL carriers.

[0294] If a terminal has performed a preceding UL transmission using one antenna port (1311) that is not capable of coherent transmission based on an SRS resource (1301) having an SRS port number of 1 through an UL carrier of a band, and the terminal is currently scheduled to transmit a scheduled UL signal using two antenna ports (1312, 1313) that are capable of coherent transmission based on an SRS resource (1302) having an SRS port number of 2, and the terminal is capable of coherent UL transmission, the terminal can transmit the scheduled UL signal using the two coherent antenna ports (1312, 1313) without performing separate Tx switching. Alternatively, if the terminal is scheduled to transmit the currently scheduled UL signal through two antenna ports (1312, 1313) capable of coherent transmission based on an SRS resource (1302) having 2 SRS ports, regardless of the preceding UL transmission performed by the terminal, and the terminal is capable of performing coherent UL transmission, the terminal can transmit the scheduled UL signal using the two coherent antenna ports (1312, 1313) without performing separate Tx switching.

[0295] FIG. 14 is a diagram illustrating the operation of a terminal according to an embodiment of the present disclosure.

[0296] Referring to FIG. 14, a terminal may receive a terminal capability report request from a base station (1410). Based on the request, the terminal may transmit terminal capability to the base station (1420). For example, the terminal may transmit to the base station at least one of information on band combinations that support uplink transmission antenna switching through the terminal capability, the number of band combinations supported (or information indicating that two or more bands are supported), the number of antenna switchings supported by the terminal (or information indicating that a number of antennas greater than two are switched), a switching period supported according to the number of antennas, and an uplink transmission method using two or more antennas (fullCoherent, partialCoherent, or noncoherent). In addition, the terminal may use BandCombination-UplinkTxSwitch included in the terminal capability message to report the information. In addition, when the base station requests information on antenna ports through which the terminal can transmit coherently, the terminal may report information on antenna ports through which coherent transmission is possible to the base station through the terminal capability message. Alternatively, antenna ports capable of coherent transmission can be identified through predefined rules without requiring terminal reporting. The specific details are identical to those described above and are therefore omitted below.

[0297] Meanwhile, steps 1410 and 1420 may be omitted depending on the circumstances. For example, in a situation where the base station has already received and stored terminal capabilities from the terminal, subsequent steps may be performed without a separate request for a terminal capability report.

[0298] At step 1430, the terminal may receive an RRC message from the base station. The RRC message may include, for example, an RRCSetup message or an RRCreconfiguration message. The terminal may receive configuration information related to antenna switching through the RRC message. Specifically, the base station may transmit information (e.g., uplinkTxSwitching) for configuring antenna switching for a band combination reported by the terminal to the terminal. In addition, if the terminal supports antenna switching for a number greater than 2, the base station may transmit antenna switching configurations for three or more antennas (e.g., enhanced UL Tx switching, uplinkTXSwitching3Tx, etc.) to the terminal. In addition, if the terminal supports antenna switching for bands greater than 2, the base station may configure antenna switching configurations for three or more bands (e.g., uplinkTxSwitching3TMoreBands) to the terminal. In addition, the terminal may receive SRS configuration information through the RRC message. The above SRS configuration information may include information about SRS resources.

[0299] The terminal can perform uplink transmission at step 1440. The terminal can perform uplink transmission by switching antennas according to the base station's settings. Furthermore, although not disclosed in this drawing, the terminal can receive downlink control information (DCI) for uplink transmission and perform uplink transmission on resources indicated by the DCI. The specific details are the same as those described in cases 1 to 8 and FIGS. 2 to 10.

[0300] Additionally, the uplink transmission may include SRS transmission. The terminal may perform SRS transmission using three or more antennas using a method similar to that illustrated in FIGS. 11 and 12. Specific details are the same as described above and are therefore omitted herein.

[0301] FIG. 15 is a diagram illustrating the operation of a base station according to an embodiment of the present disclosure.

[0302] Referring to FIG. 15, a base station may transmit a terminal capability report request to a terminal (1510). The base station may then receive terminal capability information from the terminal (1520). For example, the base station may receive, from the terminal, at least one of information about a band combination that supports uplink transmission antenna switching, the number of band combinations supported (or information indicating that two or more bands are supported), the number of antenna switching operations supported by the terminal (or information indicating that a number of antennas greater than two are switched), a switching period supported depending on the number of antennas, and an uplink transmission method using two or more antennas (fullCoherent, partialCoherent, or noncoherent). In addition, the information may be received through BandCombination-UplinkTxSwitch included in the terminal capability message. In addition, the base station may request information about an antenna port that the terminal can transmit coherently, and may receive information about an antenna port that can transmit coherently through the terminal capability message. Since specific details are the same as described above, they are omitted below.

[0303] Meanwhile, steps 1510 and 1520 may be omitted depending on the circumstances. For example, in a situation where the base station has already received and stored terminal capabilities from the terminal, subsequent steps may be performed without a separate request for a terminal capability report.

[0304] At step 1530, the base station may transmit an RRC message to the terminal. The RRC message may include, for example, an RRCSetup message or an RRCreconfiguration message. The base station may transmit configuration information related to antenna switching through the RRC message. Specifically, the base station may transmit information (e.g., uplinkTxSwitching) for configuring antenna switching for a band combination reported by the terminal to the terminal. In addition, if the terminal supports antenna switching for a number greater than 2, the base station may transmit antenna switching configurations for three or more antennas (e.g., enhanced UL Tx switching, uplinkTXSwitching3Tx, etc.) to the terminal. In addition, if the terminal supports antenna switching for bands greater than 2, the base station may configure antenna switching configurations for three or more bands (e.g., uplinkTxSwitching3TMoreBands) to the terminal. In addition, the base station may transmit SRS configuration information to the terminal through the RRC message. The above SRS configuration information may include information about SRS resources.

[0305] The base station can receive an uplink transmission at step 1540. The terminal can perform uplink transmission by switching antennas according to the base station's settings, and the base station can receive the uplink transmission. In addition, although not disclosed in this drawing, the base station can transmit downlink control information (DCI) for uplink transmission and receive an uplink signal from the resource indicated by the DCI. The specific details are the same as those described in cases 1 to 8 and FIGS. 2 to 10.

[0306] In addition, the uplink transmission may include SRS transmission. The terminal may perform SRS transmission using a method similar to that shown in FIGS. 11 and 12 using three or more antennas. Specific details are the same as those described above and are therefore omitted below. The base station may receive the SRS to estimate the UL channel, and based on the estimated UL channel, may instruct the terminal on the uplink precoder and the SRS resource to be referenced when transmitting the PUSCH.

[0307] Additionally, the base station can determine a combination of antenna ports among the terminal's multiple antennas that can transmit coherently. The specific details are the same as described above.

[0308] FIG. 16 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0309] Referring to FIG. 16, the terminal may include a transceiver, which refers to a terminal receiving unit (16-00) and a terminal transmitting unit (16-10), a memory (not shown), and a terminal processing unit (16-05, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (16-00, 16-10), the memory, and the terminal processing unit (16-05) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0310] A transceiver unit can transmit and receive signals to and from a base station. The signals may include control information and data. To this end, the transceiver unit may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0311] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0312] Memory can store programs and data necessary for the terminal's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0313] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. For example, the processor can receive DCI consisting of two layers and control components of the terminal to simultaneously receive multiple PDSCHs. There may be multiple processors, and the processors can perform terminal component control operations by executing programs stored in memory.

[0314] FIG. 17 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0315] Referring to FIG. 17, the base station may include a transceiver, which refers to a base station receiver (17-00) and a base station transmitter (17-10), a memory (not shown), and a base station processing unit (17-05, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver units (17-00, 17-10), the memory, and the base station processing unit (17-05) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0316] The transceiver can transmit and receive signals with the terminal. Here, the signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0317] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0318] The memory can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0319] The processor 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 can configure two layers of DCIs containing allocation information for multiple PDSCHs and control each component of the base station to transmit them. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0320] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0321] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0322] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0323] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0324] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0325] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are only specific examples to easily explain the technical contents of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-mentioned embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above-mentioned embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above-mentioned embodiments can be implemented with other systems such as a TDD LTE system, 5G, or NR system.

[0326] Meanwhile, the order of description in the drawings explaining the method of the present invention does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0327] Alternatively, the drawings illustrating the method of the present invention may omit some components and include only some components within a scope that does not harm the essence of the present invention.

[0328] 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 harm the essence of the invention.

[0329] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of receiving an RRC (radio resource control) message including configuration information related to antenna switching from a base station, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas; A step of receiving DCI (downlink control information) from the base station; and A step of performing antenna switching when the number of antenna ports indicated by the DCI is different from the number of antenna ports used in the previous transmission; A step of transmitting an uplink signal based on the above DCI is included, A method characterized in that the terminal does not expect to transmit an uplink signal during an antenna switching period.

2. In paragraph 1, Further comprising a step of transmitting terminal capability information including information indicating whether the terminal supports switching of three or more antennas, The above terminal capability information includes information on switching sections for three or more antennas supported by the terminal, A method characterized in that the antenna switching interval is greater than or equal to a interval indicated by information about the uplink antenna switching interval included in the RRC message.

3. In paragraph 1, A method characterized by further comprising a step of determining whether to perform antenna switching based on the coherent type of the antenna ports indicated by the DCI.

4. In paragraph 2, The terminal capability information further includes at least one of information on a band combination that supports the antenna switching or information on an antenna port capable of coherent transmission. A method characterized in that the setting information related to the above antenna switching is set for the above band combination.

5. In a method performed by a base station in a wireless communication system, A step of transmitting an RRC (radio resource control) message including configuration information related to antenna switching to a terminal, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas; A step of transmitting DCI (downlink control information) to the terminal; and A step of receiving an uplink signal based on the above DCI is included, A method characterized in that, if the number of antenna ports indicated by the DCI is different from the number of antenna ports used for previous transmission, the terminal is scheduled not to transmit an uplink signal during the antenna switching period.

6. In paragraph 5, Further comprising a step of receiving terminal capability information including information indicating whether the terminal supports switching of three or more antennas, The above terminal capability information includes information on switching sections for three or more antennas supported by the terminal, A method characterized in that the antenna switching interval is greater than or equal to a interval indicated by information about the uplink antenna switching interval included in the RRC message.

7. In paragraph 5, A method characterized in that antenna switching of the terminal is performed based on the coherent type of the antenna ports indicated by the DCI.

8. In paragraph 6, The terminal capability information further includes at least one of information on a band combination that supports the antenna switching or information on an antenna port capable of coherent transmission. A method characterized in that the RRC message further includes antenna switching setting information for the band combination.

9. In a wireless communication system, at the terminal, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, such that said terminal, Receive an RRC (radio resource control) message including configuration information related to antenna switching from a base station, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas. Receive DCI (downlink control information) from the above base station, If the number of antenna ports indicated by the above DCI is different from the number of antenna ports used in the previous transmission, antenna switching is performed, Transmit an uplink signal based on the above DCI, A terminal including a memory storing a command that causes the terminal not to expect to transmit an uplink signal during an antenna switching period.

10. In paragraph 9, The instructions executable by at least one processor individually or in any combination thereof cause the terminal to transmit terminal capability information including information indicating whether the terminal supports switching of three or more antennas, The above terminal capability information includes information on switching sections for three or more antennas supported by the terminal, A terminal characterized in that the antenna switching interval is greater than or equal to a interval indicated by information about the uplink antenna switching interval included in the RRC message.

11. In paragraph 9, A terminal characterized in that the instructions executable individually or in any combination of the at least one processor cause the terminal to determine whether to perform antenna switching based on the coherent type of the antenna ports indicated by the DCI.

12. In paragraph 10, The terminal capability information further includes at least one of information on a band combination that supports the antenna switching or information on an antenna port capable of coherent transmission. A terminal characterized in that the configuration information related to the above antenna switching is set for the above band combination.

13. In a wireless communication system, at a base station, At least one transceiver; At least one processor communicatively connected to said at least one transceiver; and Communicably connected to at least one processor, and executable individually or in any combination of said at least one processor, such that said base station, Transmitting an RRC (radio resource control) message including configuration information related to antenna switching to a terminal, wherein the configuration information related to antenna switching includes information indicating switching of three or more antennas. Transmit DCI (downlink control information) to the above terminal, Receive an uplink signal based on the above DCI, A base station including a memory storing a command for scheduling the terminal not to transmit an uplink signal during an antenna switching period when the number of antenna ports indicated by the DCI is different from the number of antenna ports used for previous transmission.

14. In paragraph 13, The instructions executable by at least one processor individually or in any combination thereof cause the terminal to receive terminal capability information including information indicating whether the terminal supports switching of three or more antennas, The above terminal capability information includes information on switching sections for three or more antennas supported by the terminal, A base station characterized in that the antenna switching interval is greater than or equal to a interval indicated by information about the uplink antenna switching interval included in the RRC message.

15. In paragraph 14, The terminal capability information further includes at least one of information on a band combination that supports the antenna switching or information on an antenna port capable of coherent transmission. A base station characterized in that the RRC message further includes antenna switching setting information for the band combination.

Images