Method and apparatus for SRS antenna switching in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate, and provides a method for transmitting a sounding reference signal (SRS) in a wireless communication system. The method may comprise the steps of: receiving configuration information for an SRS, the configuration information including first information indicating the number of antenna ports for the SRS; when the first information indicates 3 as the number of antenna ports, determining, from among four antenna ports for the SRS, one antenna port through which the SRS is not to be transmitted; and transmitting the SRS to a base station on the basis of three antenna ports excluding the one antenna port.

Description

Method and device for SRS antenna switching in a wireless communication system

[0001] The present disclosure relates to a method and apparatus for SRS antenna switching in a wireless communication system.

[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] Regarding SRS resource (set) related settings and SRS antenna port settings, the operations of the base station and terminal are proposed considering up to four antenna ports. Specifically, the operation of setting SRS resources or SRS resource sets in the RRC settings of the base station and terminal can be configured using parameters depending on the number of antenna ports.

[0009] This design approach does not consider electronics supporting three transmit antenna ports. Furthermore, the SRS antenna port switching operation, which is considered for up to four antenna ports, is not optimized for SRS resource configuration for three transmit antenna ports, resulting in limited performance in downlink channel estimation.

[0010] To overcome this degradation, rel-19 will discuss three uplink transmit (Tx) antenna ports. In particular, a method for a base station to configure SRS resources and / or SRS resource sets for an electronic device supporting three Tx is required. Therefore, through embodiments of the present disclosure, a method for configuring SRS resources and / or SRS resource sets to support three uplink transmit (Tx) antenna ports is proposed. In addition, various embodiments of the present disclosure propose parameters that the base station needs to add or expand during the SRS resource configuration process.

[0011] According to one embodiment of the present disclosure, a method performed by a terminal in a wireless communication system may include the steps of: receiving configuration information for a sounding reference signal (SRS) from a base station; the configuration information including first information indicating the number of antenna ports of the SRS; and, when the first information indicates 3 as the number of antenna ports, determining one antenna port among four antenna ports for the SRS through which the SRS is not to be transmitted; and transmitting the SRS to the base station based on three antenna ports excluding the one antenna port.

[0012] According to another embodiment of the present disclosure, a method performed by a base station in a wireless communication system includes the steps of transmitting, to a terminal, configuration information for a sounding reference signal (SRS), the configuration information including first information indicating the number of antenna ports of the SRS, and receiving, from the terminal, the SRS, wherein when the first information indicates 3 as the number of antenna ports, the SRS can be received based on three antenna ports excluding one antenna port from which the SRS is not transmitted among four antenna ports for the SRS.

[0013] According to another embodiment of the present disclosure, in a wireless communication system, a terminal may include a transceiver and a control unit functionally connected to the transceiver. The control unit may be configured to receive configuration information for a sounding reference signal (SRS) from a base station, wherein the configuration information includes first information indicating the number of antenna ports of the SRS, and when the first information indicates 3 as the number of antenna ports, determine one antenna port among four antenna ports for the SRS through which the SRS will not be transmitted, and transmit the SRS to the base station based on three antenna ports excluding the one antenna port.

[0014] According to one embodiment of the present disclosure, an SRS resource and / or a set of SRS resources may be set to support three uplink transmission (Tx) antenna ports.

[0015] Additionally, according to one embodiment of the present disclosure, an electronic device having multiple receiving antennas (e.g., 8, 12, 24, etc.) can transmit SRS through three or more Tx antenna ports based on antenna switching.

[0016] Additionally, according to one embodiment of the present disclosure, a guard interval between SRS resources can be set corresponding to various subcarrier spacings supported in a frequency band of 6 GHz or higher.

[0017] FIG. 1 is a diagram illustrating a basic structure of a time-frequency domain in a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 3 is a diagram illustrating an example of bandwidth portion settings in a wireless communication system according to one embodiment of the present disclosure.

[0020] FIG. 4 is a diagram illustrating an example of setting a control region of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0021] FIG. 5a is a diagram illustrating the structure of a downlink control channel in a wireless communication system according to one embodiment of the present disclosure.

[0022] FIG. 5b is a diagram illustrating a case in which a terminal can have multiple PDCCH monitoring positions within a slot through Span in a wireless communication system according to one embodiment of the present disclosure.

[0023] FIG. 6a illustrates an example of SRS resource configuration and transmission (Tx) / reception (RX) antenna port mapping in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0024] FIG. 6b is another example for explaining antenna ports set to SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0025] FIG. 6c is another example for explaining antenna ports set to SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0026] FIG. 7a illustrates an example of SRS resource configuration and Tx / RX antenna port mapping for SRS antenna switching in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0027] FIG. 7b is another example for explaining antenna ports set to SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0028] FIG. 8 is another example for explaining antenna ports set to SRS resources during carrier aggregation operation in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0029] FIG. 9 illustrates an example of SRS resource configuration and Tx / RX antenna port mapping in SRS antenna switching considering 3T6R according to an embodiment of the present disclosure.

[0030] FIG. 10 illustrates an example of SRS resource configuration and Tx / RX antenna port mapping in SRS antenna switching considering 3T8R according to an embodiment of the present disclosure.

[0031] FIG. 11 illustrates an example of a signaling procedure between an electronic device and a base station according to an embodiment of the present disclosure.

[0032] FIG. 12 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0033] FIG. 13 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0034] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Hereinafter, the 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. In the present disclosure, a downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0039] Furthermore, while the embodiments of the present disclosure are described below using a 5G system as an example, the embodiments of the present disclosure can also be applied to other communication systems with similar technical backgrounds or channel types. For example, this may include LTE or LTE-A mobile communication, and mobile communication technologies developed after 5G (6G). Accordingly, the embodiments of the present disclosure can 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 determined by a person skilled in the art. The contents of the present disclosure can be applied to FDD and TDD systems.

[0040] 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).

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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).

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] [NR time-frequency resources]

[0051] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G system.

[0052] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM (Orthogonal Frequency Division Multiplexing) symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form one Resource Block (RB, 104). In the time domain. The OFDM symbols of the dog can constitute one subframe (110).

[0053] FIG. 2 is a diagram illustrating a frame, subframe, and slot structure in a wireless communication system according to one embodiment of the present disclosure.

[0054] Figure 2 illustrates an example of a structure of a frame (Frame, 200), a subframe (Subframe, 201), and a slot (Slot, 202). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In an example of FIG. 2, the cases where the subcarrier spacing setting value μ = 0 (204) and μ = 1 (205) are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of 1 slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of 2 slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0055]

[0056] [Bandwidth Part (BWP)]

[0057] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0058] Figure 3 is a diagram illustrating an example of settings for the bandwidth portion in a 5G communication system.

[0059] Figure 3 shows an example in which the UE bandwidth (300) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1) (301) and bandwidth portion #2 (BWP#2) (302). The base station can set one or more bandwidth portions to the UE, and can set the information in Table 2 for each bandwidth portion.

[0060]

[0061] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion can be configured for the terminal. The above information can be transmitted from the base station to the terminal via upper layer signaling, for example, RRC (Radio Resource Control) signaling. At least one bandwidth portion among the configured one or more bandwidth portions can be activated. Whether or not the configured bandwidth portion is activated can be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI (Downlink Control Information).

[0062] According to some embodiments, a terminal before RRC (Radio Resource Control) connection can receive configuration information for an initial bandwidth portion (Initial BWP) for initial access from a base station through a Master Information Block (MIB). More specifically, the terminal can receive configuration information for a control region (Control Resource Set, CORESET) and a search space where a PDCCH for receiving system information (which may correspond to Remaining System Information (RMSI) or System Information Block 1 (SIB1)) required for initial access can be transmitted through the MIB during the initial access phase. The control region and search space configured by the MIB may each be regarded as identifier (ID) 0. The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control region #0 through the MIB. In addition, the base station can notify the terminal of configuration information for a monitoring cycle and occasion for control region #0, i.e., configuration information for search space #0, through the MIB. The terminal may consider the frequency range set as control area #0 obtained from the MIB as the initial bandwidth portion for initial connection. At this time, the identifier (ID) of the initial bandwidth portion may be considered as 0.

[0063] The settings for the bandwidth supported by the above 5G can be used for various purposes.

[0064] In some embodiments, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth portion configuration. For example, the base station can configure the bandwidth portion frequency location (configuration information 2) for the terminal, thereby allowing the terminal to transmit and receive data at a specific frequency location within the system bandwidth.

[0065] Additionally, in some embodiments, a base station may configure multiple bandwidth segments for a terminal to support different numerologies. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth segments may be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth segments may be frequency-division multiplexed, and when data is to be transmitted and received using a specific subcarrier spacing, the bandwidth segment configured for that subcarrier spacing may be activated.

[0066] Furthermore, in some embodiments, the base station may configure bandwidth portions with different bandwidth sizes for the terminal for the purpose of reducing power consumption of the terminal. For example, if the terminal supports a very large bandwidth, for example, 100 MHz, and constantly transmits and receives data using that bandwidth, very large power consumption may occur. In particular, monitoring unnecessary downlink control channels using a large bandwidth of 100 MHz in a situation where there is no traffic may be very inefficient in terms of power consumption. To reduce power consumption of the terminal, the base station may configure a bandwidth portion with a relatively small bandwidth, for example, 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0067] In the method for setting the bandwidth part, terminals before RRC connection (Connected) can receive setting information for the initial bandwidth part through the MIB (Master Information Block) in the initial access stage. More specifically, the terminal can set a control region (Control Resource Set, CORESET) for a downlink control channel on which DCI (Downlink Control Information) for scheduling a SIB (System Information Block) can be transmitted from the MIB of the PBCH (Physical Broadcast Channel). The bandwidth of the control region set by the MIB can be regarded as the initial bandwidth part, and the terminal can receive the PDSCH (Physical Downlink Shared Channel) on which the SIB is transmitted through the set initial bandwidth part. In addition to the purpose of receiving the SIB, the initial bandwidth part can also be utilized for other system information (Other System Information, OSI), paging, and random access.

[0068] [SS / PBCH block]

[0069] Next, we will explain the SS (Synchronization Signal) / PBCH block in 5G.

[0070] An SS / PBCH block may refer to a physical layer channel block consisting of a PSS (Primary SS), SSS (Secondary SS), and PBCH. Specifically, it is as follows.

[0071] - PSS: A signal that serves as a reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0072] - SSS: It serves as a reference for downlink time / frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0073] - PBCH: Provides essential system information required for transmission and reception of data and control channels of a terminal. Essential system information may include search space-related control information indicating radio resource mapping information for the control channel, and scheduling control information for a separate data channel that transmits system information.

[0074] - SS / PBCH Block: An SS / PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be transmitted within a 5ms period, and each transmitted SS / PBCH block can be distinguished by an index.

[0075] The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH, and can set control region (Control Resource Set; CORESET) #0 (which may correspond to a control region with a control region index of 0) therefrom. The terminal can monitor control region #0, assuming that the selected SS / PBCH block and the DMRS (Demodulation Reference Signal) transmitted in control region #0 are QCL (Quasi Co Location). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (Random Access Channel) related configuration information required for initial access from the received system information. The terminal can transmit PRACH (Physical RACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information on the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among each SS / PBCH block and monitors the control region #0 associated with it.

[0076] [PDCCH: DCI related]

[0077] Next, we will specifically explain downlink control information (DCI) in the 5G system.

[0078] In a 5G system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) is transmitted from a base station to a terminal via DCI. The terminal can monitor a DCI format for fallback and a DCI format for non-fallback for the PUSCH or PDSCH. The fallback DCI format can be composed of fixed fields defined between the base station and the terminal, and the non-fallback DCI format can include configurable fields.

[0079] DCI can be transmitted through the Physical Downlink Control Channel (PDCCH) after going through the channel coding and modulation process. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted on the PDCCH, it verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can determine that the message was transmitted to the UE.

[0080] For example, a DCI scheduling a PDSCH for System Information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a Paging message may be scrambled with P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

[0081] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 3.

[0082]

[0083] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include, for example, the information in Table 4.

[0084]

[0085]

[0086] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the information in Table 5.

[0087]

[0088] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the information in Table 6.

[0089]

[0090] [PDCCH: CORESET, REG, CCE, Search Space]

[0091] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0092] FIG. 4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system.

[0093] FIG. 4 illustrates an example in which two control regions (Control Region #1 (401), Control Region #2 (402)) are set within a UE bandwidth part (410) in the frequency axis and within one slot (420) in the time axis. The control regions (401, 402) can be set to specific frequency resources (403) within the entire UE bandwidth part (410) in the frequency axis. The time axis can be set to one or more OFDM symbols, which can be defined as the control region length (Control Resource Set Duration, 404). Referring to the example illustrated in FIG. 4, Control Region #1 (401) is set to a control region length of two symbols, and Control Region #2 (402) is set to a control region length of one symbol.

[0094] In the aforementioned 5G, the control region can be established by the base station to the terminal via higher-layer signaling (e.g., system information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Establishing a control region for the terminal means providing information such as the control region identifier, the frequency location of the control region, and the symbol length of the control region. For example, this information may include the information in Table 7.

[0095]

[0096] In Table 7, the tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control region.

[0097] FIG. 5a is a diagram showing an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in 5G.

[0098] Referring to FIG. 5a, the basic unit of time and frequency resources constituting the control channel can be referred to as a REG (Resource Element Group, 503), and the REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (Physical Resource Block, 502) on the frequency axis, i.e., 12 subcarriers. The base station can concatenate REGs (503) to form a downlink control channel allocation unit.

[0099] As illustrated in FIG. 5a, if the basic unit to which a downlink control channel is allocated in 5G is called a CCE (Control Channel Element, 504), 1 CCE (504) can be composed of multiple REGs (503). Taking the REG (503) illustrated in FIG. 5a as an example, the REG (503) can be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), 1 CCE (504) can be composed of 72 REs. When a downlink control region is set, the region can be composed of multiple CCEs (504), and a specific downlink control channel can be mapped to one or multiple CCEs (504) and transmitted according to the aggregation level (AL) within the control region. CCEs (504) within the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0100] The basic unit of the downlink control channel illustrated in Fig. 5a, that is, the REG (503), may include both the REs to which the DCI is mapped and the areas to which the DMRS (505), which is a reference signal for decoding the REs, is mapped. As in Fig. 5a, three DMRSs (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL = L, one downlink control channel may be transmitted through L CCEs. The terminal must detect a signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates (CCEs) that a terminal must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which can be a set of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured aggregation levels.

[0101] Search spaces can be categorized into common search spaces and UE-specific search spaces. A certain group of UEs, or all UEs, can search the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling of system information or paging messages. For example, PDSCH scheduling allocation information for transmitting SIBs, including cell operator information, can be received by searching the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. Scheduling allocation information for UE-specific PDSCH or PUSCH can be received by searching the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE's identity and various system parameters.

[0102] In 5G, parameters for the search space for PDCCH can be configured from the base station to the terminal through higher layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can configure the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol within the slot for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, the control region index to be monitored for the search space, etc. to the terminal. For example, the information in Table 8 can be included.

[0103]

[0104] Depending on the configuration information, the base station may configure one or more search space sets for the terminal. In some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal, and may configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and may configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

[0105] According to the configuration information, one or more search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as terminal-specific search spaces.

[0106] In the common search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these.

[0107] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0108] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0109] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0110] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0111] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0112] In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these examples.

[0113] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0114] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0115] The RNTIs specified may follow the definitions and uses below.

[0116] C-RNTI (Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0117] TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes

[0118] CS-RNTI (Configured Scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0119] RA-RNTI (Random Access RNTI): Used for PDSCH scheduling in the random access phase.

[0120] P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0121] SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0122] INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0123] TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0124] TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0125] TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control commands for SRS.

[0126] The aforementioned specified DCI formats may follow the definitions below.

[0127]

[0128] In 5G, the search space of aggregation level L in the control region p and search space set s can be expressed as in the following mathematical expression 1.

[0129]

[0130] - L: Integration level

[0131] - : Carrier Index

[0132] - : Total number of CCEs existing within the control region p

[0133] - : slot index

[0134] - : Number of PDCCH candidates for aggregation level L

[0135] - = 0,..., -1: PDCCH candidate index of aggregation level L

[0136] - i=0,...,L-1

[0137] - , , , , , D=65537.

[0138] - : Terminal identifier

[0139] The value can be 0 for a common search space.

[0140] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set to the terminal by the base station) and the time index.

[0141] In 5G, since multiple search space sets can be configured with different parameters (e.g., parameters in Table 8), the set of search space sets monitored by a terminal at each point in time can be different. For example, if search space set #1 is configured with an X-slot period and search space set #2 is configured with a Y-slot period and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a specific slot, or can monitor either search space set #1 or search space set #2 in a specific slot.

[0142] A terminal can perform terminal capability reporting for each subcarrier interval when it has multiple PDCCH monitoring positions within a slot, and at this time, the concept of Span can be used. A Span refers to consecutive symbols within a slot in which the terminal can monitor a PDCCH, and each PDCCH monitoring position is within one Span. A Span can be expressed as (X, Y), where x refers to the minimum number of symbols that must be spaced between the first symbols of two consecutive Spans, and Y refers to the number of consecutive symbols in which the PDCCH can be monitored within one Span. In this case, the terminal can monitor the PDCCH in the section from the first symbol of the Span to within Y symbols within the Span.

[0143] FIG. 5b is a diagram illustrating a case in which a terminal in a wireless communication system can have multiple PDCCH monitoring positions within a slot, through Span.

[0144] Span can be (X,Y) = (7,4), (4,3), (2,2), and each of these three cases is represented by (5b-00), (5b-05), and (5b-10) in Fig. 5b. For example, (5b-00) represents a case where there are two Spans that can be expressed as (7,4) within a slot. The interval between the first symbols of the two Spans is represented as X=7, and the PDCCH monitoring position can exist within a total of Y=3 symbols from the first symbol of each Span, and search spaces 1 and 2 each exist within Y=3 symbols. As another example, (5b-05) represents a case where there are three Spans that can be expressed as (4,3) within a slot, and the interval between the second and third Spans is X'=5 symbols, which is larger than X=4.

[0145] [PUSCH: Transmission method related]

[0146] 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.

[0147] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 10] 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 including rrc-ConfiguredUplinkGrant of [Table 10] 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 10], except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, and scaling of UCI-OnPUSCH provided by pusch-Config of [Table 11]. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 10], the terminal applies tp-pi2BPSK in pusch-Config of [Table 11] to PUSCH transmission operated by the configured grant.

[0148]

[0149] Next, the PUSCH transmission method is described.

[0150] The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow either a codebook-based or non-codebook-based transmission method, depending on whether the value of txConfig in the upper signaling, pusch-Config in [Table 11], is 'codebook' or 'nonCodebook'.

[0151] 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 11], the UE does not expect to be scheduled with DCI format 0_1.

[0152]

[0153] Next, we describe codebook-based PUSCH transmission.

[0154] 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), the Transmission Precoding Matrix Indicator (TPMI), and the transmission rank (the number of PUSCH transmission layers).

[0155] At this time, the SRI can be given through the SRS resource indicator field in the DCI or configured through the srs-ResourceIndicator higher-level signaling. The UE is configured with at least one SRS resource when transmitting a codebook-based PUSCH, and can be configured with up to two. When the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. In addition, the TPMI and transmission rank can be given through the precoding information and number of layers fields in the DCI or configured through the precodingAndNumberOfLayers higher-level signaling. The TPMI is used to indicate the precoder applied to the PUSCH transmission. If the UE is configured with one SRS resource, the TPMI is used to indicate the precoder to be applied to the configured one SRS resource. When a terminal is configured with multiple SRS resources, TPMI is used to indicate the precoder to be applied in the SRS resource indicated through SRI.

[0156] 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'.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] When multiple SRS resources are configured, the UE can determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, the SRI can be indicated through the SRS resource indicator field in the DCI or can be set through the srs-ResourceIndicator, which is a higher-level signaling. Similar to the codebook-based PUSCH transmission described above, when the UE receives an SRI through the DCI, the SRS resource indicated by the SRI refers to the SRS resource corresponding to the SRI among the SRS resources transmitted before the PDCCH containing the SRI. The UE can use one or more SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. At this time, the SRS resources that the UE simultaneously transmits occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set with the usage value set to 'nonCodebook' in the upper signaling SRS-ResourceSet can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

[0164] 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.

[0165] [SRS related]

[0166] Next, we describe an uplink channel estimation method using the Sounding Reference Signal (SRS) transmission of a terminal. The base station can configure at least one SRS configuration for each uplink BWP to convey configuration information for SRS transmission to the terminal, and can also configure at least one SRS resource set for each SRS configuration. For example, the base station and the terminal can exchange the following upper-level signaling information to convey information regarding the SRS resource set.

[0167] - srs-ResourceSetId: SRS resource set index

[0168] - srs-ResourceIdList: A set of SRS resource indices referenced in the SRS resource set.

[0169] - resourceType: This is the time axis transmission setting of the SRS resource referenced in the SRS resource set, and can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. If set to 'periodic' or 'semi-persistent', associated CSI-RS information can be provided depending on the usage of the SRS resource set. If set to 'aperiodic', an aperiodic SRS resource trigger list and slot offset information can be provided, and associated CSI-RS information can be provided depending on the usage of the SRS resource set.

[0170] - usage: This is a setting for the usage of the SRS resource referenced in the SRS resource set, and can be set to one of 'beamManagement', 'codebook', 'nonCodebook', and 'antennaSwitching'.

[0171] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for adjusting the transmission power of the SRS resource referenced in the SRS resource set.

[0172] The terminal can understand that the SRS resource included in the set of SRS resource indices referenced in the SRS resource set follows the information set in the SRS resource set.

[0173] In addition, the base station and the terminal can transmit and receive upper layer signaling information to convey individual configuration information for the SRS resource. For example, the individual configuration information for the SRS resource can include time-frequency axis mapping information within the slot of the SRS resource, which can include information about frequency hopping within or between slots of the SRS resource. In addition, the individual configuration information for the SRS resource can include the time axis transmission configuration of the SRS resource, which can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. This can be restricted to have the same time axis transmission configuration as the SRS resource set including the SRS resource. If the time axis transmission configuration of the SRS resource is set to 'periodic' or 'semi-persistent', the SRS resource transmission period and slot offset (e.g., periodicityAndOffset) can additionally be included in the time axis transmission configuration.

[0174] The base station can activate, deactivate, or trigger SRS transmission to the UE through higher layer signaling, including RRC signaling or MAC CE signaling, or L1 signaling (e.g., DCI). For example, the base station can activate or deactivate periodic SRS transmission to the UE through higher layer signaling. The base station can instruct the UE to activate an SRS resource set with resourceType set to periodic through higher layer signaling, and the UE can transmit an SRS resource referenced in the activated SRS resource set. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information set in the SRS resource, and the slot mapping, including the transmission period and slot offset, follows the periodicityAndOffset set in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information set in the SRS resource, or the associated CSI-RS information set in the SRS resource set that includes the SRS resource. A terminal can transmit SRS resources within an activated uplink BWP for periodic SRS resources activated through upper layer signaling.

[0175] For example, a base station can activate or deactivate semi-persistent SRS transmission to a terminal through upper layer signaling. The base station can instruct the terminal to activate an SRS resource set through MAC CE signaling, and the terminal can transmit an SRS resource referenced in the activated SRS resource set. The SRS resource set activated through MAC CE signaling can be limited to an SRS resource set with resourceType set to semi-persistent. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information configured in the SRS resource, and the slot mapping including the transmission period and slot offset follows the periodicityAndOffset configured in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information configured in the SRS resource, or the associated CSI-RS information configured in the SRS resource set that includes the SRS resource. If spatial relation info is configured in an SRS resource, the spatial domain transmission filter can be determined by referring to the configuration information for spatial relation info transmitted through MAC CE signaling that activates semi-persistent SRS transmission without following it. The terminal can transmit SRS resources within the activated uplink BWP for the semi-persistent SRS resource activated through upper layer signaling.

[0176] For example, a base station can trigger aperiodic SRS transmission to a terminal via DCI. The base station can indicate one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTrigger) via the SRS request field of the DCI. The terminal can understand that an SRS resource set including the aperiodic SRS resource trigger indicated via DCI in the aperiodic SRS resource trigger list among the configuration information of the SRS resource set has been triggered. The terminal can transmit an SRS resource referenced in the triggered SRS resource set. The time-frequency domain resource mapping within the slot of the transmitted SRS resource follows the resource mapping information configured in the SRS resource. In addition, the slot mapping of the transmitted SRS resource can be determined through a slot offset between a PDCCH including the DCI and the SRS resource, which can refer to value(s) included in a slot offset set configured in the SRS resource set. Specifically, the slot offset between the PDCCH including DCI and the SRS resource can be applied by applying the value indicated in the time domain resource assignment field of the DCI among the offset value(s) included in the slot offset set configured in the SRS resource set. In addition, the spatial domain transmission filter applied to the transmitted SRS resource can refer to the spatial relation information configured in the SRS resource, or can refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. The UE can transmit the SRS resource within the activated uplink BWP for the aperiodic SRS resource triggered through the DCI.

[0177] When a base station triggers aperiodic SRS transmission to a terminal through DCI, a minimum time interval may be required between a PDCCH including the DCI that triggers aperiodic SRS transmission and the SRS to be transmitted, so that the terminal can transmit the SRS by applying configuration information for the SRS resource. The time interval for SRS transmission of the terminal can be defined as the number of symbols between the last symbol of the PDCCH including the DCI that triggers aperiodic SRS transmission and the first symbol to which the first SRS resource to be transmitted among the SRS resource(s) is mapped. The minimum time interval can be determined with reference to the PUSCH preparation procedure time required for the terminal to prepare for PUSCH transmission. In addition, the minimum time interval can have different values ​​depending on the usage of the SRS resource set including the SRS resource to be transmitted. For example, the minimum time interval can be determined as N2 symbols, which are defined by considering the terminal processing ability according to the capability of the terminal with reference to the PUSCH preparation procedure time of the terminal. In addition, considering the usage of the SRS resource set including the SRS resource being transmitted, if the usage of the SRS resource set is set to 'codebook' or 'antennaSwitching', the minimum time interval can be set to N2 symbols, and if the usage of the SRS resource set is set to 'nonCodebook' or 'beamManagement', the minimum time interval can be set to N2+14 symbols.The terminal may transmit an aperiodic SRS if the time interval for aperiodic SRS transmission is greater than or equal to the minimum time interval, and may ignore the DCI that triggers the aperiodic SRS if the time interval for aperiodic SRS transmission is less than the minimum time interval.

[0178]

[0179] The spatialRelationInfo setting information in Table 12 above refers to a single reference signal and applies the beam information of the reference signal to the beam used for the corresponding SRS transmission. For example, the spatialRelationInfo setting may include information as shown in Table 13 below.

[0180]

[0181] Referring to the above spatialRelationInfo setting, the index of the reference signal to be referenced in order to use the beam information of a specific reference signal, i.e., the SS / PBCH block index, CSI-RS index, or SRS index can be set. The upper signaling referenceSignal is setting information indicating which beam information of which reference signal is to be referenced for the corresponding SRS transmission, ssb-Index means the index of the SS / PBCH block, csi-RS-Index means the index of the CSI-RS, and srs means the index of the SRS, respectively. If the value of the upper signaling referenceSignal is set to 'ssb-Index', the terminal can apply the reception beam used when receiving the SS / PBCH block corresponding to the ssb-Index as the transmission beam of the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'csi-RS-Index', the terminal can apply the reception beam used when receiving the CSI-RS corresponding to the csi-RS-Index as the transmission beam of the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used when transmitting the SRS corresponding to the srs as the transmission beam for the corresponding SRS transmission.

[0182] [SRS antenna switching related]

[0183] Below, SRS for antenna switching is described.

[0184] SRS can be used to acquire DL (downlink) CSI (Channel State Information) information (e.g., DL CSI acquisition). As a specific example, in a single-cell or multi-cell (e.g., carrier aggregation (CA)) situation based on TDD (Time Division Duplex), after a BS (Base Station) schedules SRS transmission to a UE (User Equipment), the BS can measure the SRS transmitted from the UE. In this case, assuming DL / UL reciprocity, the BS can schedule DL signals / channels to the UE based on the measurement by SRS. In this case, with respect to DL CSI acquisition based on SRS, the usage of the SRS resource referenced in the SRS resource set can be set to antenna switching.

[0185] For example, according to the standard (e.g., 3gpp TS38.214), the usage of SRS can be set to the base station and / or terminal using a higher layer parameter (e.g., usage of RRC parameter SRS-ResourceSet). Here, the usage of SRS can be set to beam management usage, codebook transmission usage, non-codebook transmission usage, antenna switching usage, etc.

[0186] Below, we will specifically examine the case where SRS transmission (i.e., transmission of SRS resources or a set of SRS resources) is set for antenna switching purposes among the above purposes.

[0187] For example, for a terminal with partial reciprocity, SRS transmission based on antenna switching (i.e., transmit antenna switching) may be supported to acquire DL CSI through SRS transmission in situations such as TDD. When antenna switching is applied, the interval between SRS resources (and / or the resources between SRS resources and PUSCH / PUCCH) for antenna switching of the terminal may typically be approximately 15 μs. Taking this into account, a (minimum) guard period as shown in Table 14 may be defined.

[0188] Table 14 shows the minimum protection intervals according to numerology.

[0189]

[0190] In Table 14, μ represents numerology, represents the subcarrier spacing, and Y represents the number of symbols in the guard interval, i.e., the length of the guard interval. Referring to Table 14, the guard interval can be set based on the parameter μ that determines the numerology. In the guard interval, the terminal is set not to transmit any other signal, and the guard interval can be set to be used entirely for antenna switching. For example, the guard interval can be set considering SRS resources transmitted in the same slot. In particular, when the terminal is set and / or instructed to transmit an aperiodic SRS configured with intra-slot antenna switching, the terminal transmits the SRS using a different transmission antenna for each designated SRS resource, and the above-described guard interval can be set between each resource.

[0191] In addition, as described above, when the terminal is configured with SRS resources and / or SRS resource sets for antenna switching purposes through upper layer signaling, the terminal may be configured to perform SRS transmission based on UE capability related to antenna switching. The terminal may report capability information indicating whether it supports SRS antenna switching to the base station. The capability information may include a parameter indicating an SRS transmission port switching pattern supported by the terminal. Here, the capability of the terminal related to antenna switching reported by the parameter may be '1T2R', '2T4R', '1T4R', '1T4R / 2T4R', '1T1R', '2T2R', '4T4R', etc. Here, 'xTyR' may mean a terminal capability indicating that SRS transmission is possible on x antenna ports over y receiving antennas.

[0192] For example, for a terminal supporting 1T2R, up to two SRS resource sets can be configured with different values ​​for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each SRS resource set can have two SRS resources transmitted in different symbols, and each SRS resource in a given SRS resource set can configure a single SRS port. In addition, the SRS port for the second SRS resource in an SRS resource set can be configured to be associated with a different terminal antenna port than the SRS port for the first SRS resource in the same SRS resource set.

[0193] For another example, for a terminal supporting 2T4R, up to two SRS resource sets may be configured with different values ​​for the resourceType of the upper layer parameter SRS-ResourceSet. Here, each SRS resource set may have two SRS resources transmitted in different symbols, and each SRS resource in a given SRS resource set may configure two SRS ports. In addition, the SRS port pair for the second SRS resource in an SRS resource set may be configured to be associated with a different terminal antenna port than the SRS port pair for the first SRS resource in the same SRS resource set.

[0194] For another example, for a terminal supporting 1T4R, SRS resource sets may be configured in different ways depending on whether SRS transmission is configured to be periodic, semi-persistent, and / or aperiodic. First, if SRS transmission is configured to be periodic or semi-persistent, 0 or 1 SRS resource set configured based on the resourceType of the upper layer parameter SRS-ResourceSet may be configured with 4 SRS resources transmitted in different symbols. Here, each SRS resource in the given SRS resource set may configure a single SRS port. In addition, the SRS port for each SRS resource may be configured to be associated with different terminal antenna ports. In contrast, when SRS transmission is configured aperiodic, zero or two SRS resource sets configured based on the resourceType of the upper layer parameter SRS-ResourceSet can be configured with a total of four SRS resources transmitted in different symbols of two different slots. Here, the SRS port for each SRS resource in the given two SRS resource sets can be configured to be associated with different terminal antenna ports. Each SRS resource set can be configured with two SRS resources, or one SRS resource set can be configured with one SRS resource and the other SRS resource sets can be configured with three SRS resources.

[0195] For another example, for a terminal supporting 1T1R, 2T2R, or 4T4R, up to two SRS resource sets, each consisting of one SRS resource, may be configured for SRS transmission. The number of SRS ports of each SRS resource may be set to 1, 2, or 4.

[0196] If the indicated terminal capability is 1T4R / 2T4R, the terminal may expect the same number of SRS ports (e.g., 1 or 2) to be configured for all SRS resources in the SRS resource set(s). In addition, if the indicated terminal capability is 1T2R, 2T4R, 1T4R, or 1T4R / 2T4R, the terminal may not expect one or more SRS resource sets configured for antenna switching purposes in the same slot to be configured or triggered. In addition, even if the indicated terminal capability is 1T1R, 2T2R, or 4T4R, the terminal may not expect one or more SRS resource sets configured for antenna switching purposes in the same slot to be configured or triggered.

[0197] The various embodiments described above have been described without explicitly configuring panels for uplink and downlink transmission for the terminal. That is, the terminal antenna port for SRS antenna switching can be configured without explicit consideration of the terminal panel, and the base station and the terminal can operate accordingly. If at least two or more panels are explicitly configured, SRS resource set(s) for antenna switching purposes can be configured for each panel. In this case, UE capability may exist depending on whether the terminal can simultaneously transmit the corresponding SRS resource set(s) configured for each panel, whether they can be configured in the same slot, or whether they can be transmitted in the same slot.

[0198] [SRS comb offset / cyclic shift setting]

[0199] Next, we describe how to set comb offset and cyclic shift when transmitting the Sounding Reference Signal (SRS) of the terminal.

[0200] The terminal can be configured with SRS resources from the base station through upper layer signaling, SRS-Resource or SRS-PosResource, and can be configured with the following items.

[0201] - In the case of SRS-Resource, the terminal can set the number of antenna ports for each SRS resource, and the value is It can be defined as and can be set through upper layer signaling nrofSRS-Ports or nrofSRS-Ports-n8. If usage, which is upper layer signaling in SRS-ResourceSet, is set to a value other than nonCodebook, p i =1000+i can mean the number of the i-th antenna port, and i is 0 to -1 can be an integer. If the upper layer signaling usage within the SRS-ResourceSet is set to nonCodebook, each SRS resource =1 antenna port can be set, and the antenna port of the i+1th SRS resource in the SRS-ResourceSet is p i =1000+i can be defined. In the case of SRS-PosResource = can be defined as 1.

[0202] - The terminal can be configured for the number of consecutive symbols in which SRS is transmitted through nrofSymbols in resourceMapping, which is an upper layer signaling from the base station, and the value is can be defined as

[0203] - The terminal can be configured for the position of the start symbol where SRS is transmitted within a slot through the startPosition in the resourceMapping, which is an upper layer signaling from the base station, and the value is can be defined as . At this time, can mean the number of symbols in the slot, and its value can be 14 for the normal cyclic prefix or 12 for the extended cyclic prefix. can mean an offset value that counts the number of symbols backwards from the symbol located at the very end of the slot. At this time, can satisfy.

[0204] - k0 may mean the starting position of the frequency resource where SRS is transmitted.

[0205] An SRS sequence that can be generated through an SRS resource defined based on the above information can be defined as in [Mathematical Formula 2] below.

[0206]

[0207] At this time, means the length of the SRS sequence. m SRS,b is determined through [Table 15] below, and can be determined through upper layer signaling, b-SRS and c-SRS. In this case, when b-SRS is set, B in [Table 15] below SRS ∈ {0, 1, 2, 3} values ​​can be determined, and m SRS,b The value of b, the subscript of , can be determined, and if b-SRS is not set, B SRS =0 can be. c-SRS is C in [Table 15] below SRS ∈ {0, 1, ..., 63} values ​​can be determined.

[0208]

[0209]

[0210] P F∈{2,4} can be determined through FreqScalingFactor, which is a higher layer signaling, and if that parameter is not set, P F =1. The terminal can expect the length of the SRS sequence to be a multiple of 6 when the upper layer signaling FreqScalingFactor is set.

[0211] can be defined as , K TC ∈{2,4,8} can determine the size of the comb. In this case, the size of the comb can mean the interval between REs where SRS is transmitted on the frequency resource. For example, if the size of the comb is K TC =2 may mean that the interval between REs where SRS is transmitted is 2 REs. The terminal can be configured for the size of the Comb through the upper layer signaling, transmissionComb. may mean the symbol index within the symbols in which the SRS resource is transmitted. The terminal may use K TC The maximum cyclic shift value is It can be determined as shown in [Table 16].

[0212]

[0213] means the cyclic shift of the i-th antenna port. And the basic sequence is It can be defined as follows:

[0214]

[0215] At this time, can mean the length of the SRS sequence. For one base sequence, different and Multiple SRS sequences can be generated depending on the value.

[0216] Multiple basic sequences can be divided into groups, and the index of a group can be defined as u∈{0,1,...,29}, and v can mean the index of the basic sequence within the group. If 1 / 2≤ If ≤5, each group can contain one base sequence, and v can be 0. If 6≤ In this case, each group can contain two base sequences, where v=0,1. The definition of is M, which is the length of the sequence. ZC It may vary depending on the value of .

[0217] If the length of the basic sequence is 36 or more, i.e. When the basic sequence can be defined as follows. At this time, N ZC is M ZC It can be the largest prime number smaller than .

[0218]

[0219] If the length of the basic sequence is 6, 12, 18, 24, i.e. M ZC When ∈{6, 12, 18, 24}, the basic sequence can be defined as follows.

[0220]

[0221] At this time, M ZC for The value of can be defined through [Table 17] to [Table 20] according to the index u.

[0222] If the length of the base sequence is 30, i.e. M ZC =30, basic sequence can be defined as follows.

[0223]

[0224] If the terminal has the upper layer signaling nrofSRS-Ports-n8 set to ports8tdm, can be defined as follows, otherwise = can be defined as 1.

[0225] - if and p i If ∈{1000, 1001, 1004, 1005}, = can be defined as 1.

[0226] - if and p i If ∈{1002, 1003, 1006, 1007}, = can be defined as 1.

[0227] - When neither of the above cases is true, = can be defined as 0.

[0228] antenna port p i which means the cyclic shift corresponding to can be defined as follows.

[0229]

[0230] At this time, can be defined as follows.

[0231] - =8 and When =6, can be defined as

[0232] - =4 and =6 or, =8 and When =12,

[0233] can be defined as

[0234] - When neither of the above cases is true, can be defined as

[0235] At this time, is a parameter that determines the cyclic shift value, which can be set through cyclicShift-n2, cyclicShift-n4, or cyclicShift-n8 in the upper layer signaling transmissionComb. can be determined through the above [Table 16].

[0236] and can be determined as follows.

[0237] - If the upper layer signaling nrofSRS-Ports-n8 is set to ports8tdm, = can be defined as 4, In case of p i If -1000<4 =1000+p i is defined as mod 2, and p i If -1000≥4 =1000+p i It can be defined as mod 2 + 2. That is, when the terminal transmits in TDM mode for an SRS resource consisting of 8 antenna ports, p, which is the antenna port to be transmitted in the first symbol, i =For 1000, 1001, 1004, 1005 respectively = Defined as 1000, 1001, 1002, 1003, and p is the antenna port to be transmitted in the second symbol. i =For 1002, 1003, 1006, 1007 respectively = By defining 1000, 1001, 1002, 1003, when allocating resources for 4 different antenna ports transmitted in each symbol, the resource allocation method for SRS resources consisting of 4 antenna ports can be applied as is.

[0238] - In cases other than the above, i.e. when the upper layer signaling nrofSRS-Ports-n8 is not set to ports8tdm, = and =p i can be defined as

[0239] It means the starting position in the frequency dimension of the SRS corresponding to the i-th antenna port. can be defined as follows.

[0240]

[0241] At this time, can be defined as follows.

[0242]

[0243] At this time, can be defined as follows.

[0244] - =8, ∈{1003, 1007}, If =6, can be defined as

[0245] - =8, ∈{1002, 1006}, If =6, can be defined as

[0246] - =8, ∈{1001, 1005}, If =6, can be defined as

[0247] - =8, ∈{1001, 1003, 1005, 1007}, If =12, can be defined as

[0248] - =8, ∈{1001, 1003, 1005, 1007}, =8, If, can be defined as

[0249] - =4, ∈{1001, 1003}, If =6, can be defined as

[0250] - =4, ∈{1001, 1003}, ∈{8,12}, If, can be defined as

[0251] - For all other cases except the above, can be defined as

[0252] At this time, can be defined as follows.

[0253]

[0254] At this time, can be defined as follows.

[0255]

[0256] k F ∈{0,1,...,P F -1} can be set to StartRBIndex, which is a higher layer signaling, and if not set, k F = can be defined as 0.

[0257] k hop For cases where the upper layer signaling EnableStartRBHopping is set, the following and Based on the value, it can be determined through [Table 21], otherwise k hop = can be defined as 0.

[0258]

[0259] If SRS transmission is performed based on SRS-PosResource, the above can be defined based on [Table 22] below, otherwise (if SRS transmission is performed based on SRS-Resource), = can be defined as 0.

[0260] n, which is the offset value in the frequency dimension shift is a value that determines how far the SRS is transmitted in the frequency dimension from the reference position, and can be set through the upper layer signaling freqDomainShift. Comb offset value is indicated. can be set via combOffset-n2, combOffset -n4, or combOffset -n8 in the upper layer signaling transmissionComb.

[0261] As a higher layer signaling related to frequency hopping of SRS, b-hop within freqHoping can be set, and the b hop It can be defined as ∈{0,1,2,3}.

[0262] n b is a value representing the index of the frequency position, and can be defined as follows.

[0263] - If b hop ≥B SRS In this case, frequency hopping of SRS is not supported, and n represents the index of frequency position. b is all A symbol can have a constant value during a period and can be defined as follows:

[0264]

[0265] At this time, n RRCis a value set through the upper layer signaling freqDomainPosition, and if not set, the value can be 0.

[0266] - If b hop SRS If , frequency hopping of SRS is supported, and n b can be defined as follows.

[0267] If b≤b hop If, can be defined as follows.

[0268] If not, can be defined as follows.

[0269] At this time, F b (n SRS ) is if N b If is even, can be defined as , and if N b If is odd, can be defined as Silver N b It can be defined as 1 regardless of the value.

[0270] n SRS can be defined as a parameter that counts the number of SRS transmissions. If the terminal transmits an aperiodic SRS resource, the number of SRS transmissions within a specific slot Within the symbol can be defined as follows. At this time, s can be defined as s=2 if the upper layer signaling nrofSRS-Ports-n8 is set to ports8tdm, and s=1 otherwise. At this time, R≤ can be a value set by the repetitionFactor, which is a higher layer signaling, and if not set, R= can be defined as

[0271] If the terminal transmits periodic or semi-persistent SRS resources,​ In slots satisfying n SRS can be defined as follows.

[0272]

[0273] At this time, T SRS Wow T offset can mean the period and slot offset of a periodic or semi-persistent SRS, respectively.

[0274]

[0275]

[0276]

[0277]

[0278]

[0279]

[0280]

[0281]

[0282] [Regarding terminal capability reporting]

[0283] 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.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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 configured BC candidate list. This operation can only occur when the LTE base station (eNB) requests the "eutra" capability.

[0288] 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."

[0289] 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.

[0290] 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.

[0291] After terminal capabilities are configured, the terminal transmits a terminal capability information message containing the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for the terminal.

[0292] Referring to the descriptions related to the above-described SRS resource (set) settings and SRS antenna port settings, operations of a base station and a terminal are proposed considering up to four antenna ports. Specifically, the operation of setting SRS resources or SRS resource sets in the RRC settings of the base station and the terminal can be set using parameters (e.g., srs-ResourceID, nrofSRS-Ports, transmissionComb, combOffset, cyclicShift, resourceMapping, startPostition, nrofSymbols, repetitionFator, freqDomainPosition, FreqDomainShfit, freqHopping, groupOrSequenceHopping, resourceType, sequenceID, spatialRelationInfo, etc.) according to the number of antenna ports.

[0293] This design approach does not consider electronics supporting three transmit antenna ports. Furthermore, the SRS antenna port switching operation, which is considered for up to four antenna ports, is not optimized for SRS resource configuration for three transmit antenna ports, resulting in limited performance in downlink channel estimation.

[0294] To overcome this degradation, rel-19 will discuss three uplink transmit (Tx) antenna ports. In particular, a method for a base station to configure SRS resources and / or SRS resource sets for an electronic device supporting three Tx is required. Therefore, through embodiments of the present disclosure, a method for configuring SRS resources and / or SRS resource sets to support three uplink transmit (Tx) antenna ports is proposed. In addition, various embodiments of the present disclosure propose parameters that the base station needs to add or expand during the SRS resource configuration process.

[0295] Below, the operation of a base station and an electronic device to support multiple SRS ports is described in detail by describing various embodiments.

[0296] In the present disclosure, a base station is an entity that performs resource allocation of an electronic device, 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 electronic device may include a terminal, 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, a CPE, a FWA, a vehicle, an industrial device, etc. The electronic device may support three or more Tx antenna ports.

[0297] <Example 1: Terminal Capability Report for a Terminal Supporting Three Transmit Antennas>

[0298] Below, various embodiments are specifically described to describe a method for transmitting a specific terminal capability report message to a base station in relation to the capability of supporting three transmit antennas.

[0299] As an example, for a terminal supporting three transmit antennas, the FeatureSetUplink message may include at least one piece of information related to antenna switching. Here, the information related to antenna switching may include various parameter information considering "3T4R", "3T6R", and "3T8R".

[0300] In one embodiment, the terminal may include in the parameter information information (e.g., srs-AntennaSwitching2SP-1Periodic-r19) information regarding whether the terminal can configure resources for two semi-persistent SRS transmissions and one periodic SRS transmission when switching antennas for SRS transmission based on three transmit antennas. The base station may receive the message from the terminal and configure the resources, thereby enabling the terminal to transmit at least two semi-persistent SRS signals and one periodic SRS signal. In another embodiment, the terminal may include in the parameter information information (e.g., srs-ExtensionAperiodicSRS-r19) information regarding whether the terminal can configure resources for at least one aperiodic SRS transmission when switching antennas for SRS transmission based on three transmit antennas. The base station may receive the message from the terminal and configure the resources, thereby enabling the terminal to transmit at least one aperiodic SRS.

[0301] Below, various embodiments are described in more detail to describe a method for transmitting a terminal capability report message to a base station regarding a specific band pair and delay time in relation to the capability of supporting three transmit antennas.

[0302] The terminal can transmit a specific terminal capability report message to the base station regarding the switching delay of the three transmit antennas. Table 23 shows the message structure of the band combination (BandCombination-UplinkTxSwitch-v1900), band pair (ULTxSwitchingBandPair), and specific band parameters (UplinkTxSwitchingBandParameters) for switching during uplink transmission. Here, the uplink transmission scenario may include PUSCH transmission and SRS transmission.

[0303]

[0304] BandCombination-UplinkTxSwitch can specify the band combinations supported by the UE for uplink transmission switching. For each supported band pair (SupportedBandPairList) from the band combinations, the UE can specify whether it supports switched uplink operation mode (switchedUL), dual operation mode (dualUL), or both. For each band pair (ULTxSwitchingBandPair), the UE can also specify timing information (uplinkTxSwitchingPeriod) between the bands (bandIndexUL1, UL2) to which the UE can switch, by switching (e.g., the time it takes to switch the power amplifier from one band to another).

[0305] In one embodiment, the terminal may, according to its capability, designate a time taken to switch while maintaining the same number of transmit antennas to a different second band while operating with three transmit antennas in the first band. As a specific example, the timing information value by the switch may be designated as at least one value among n35us, n70us, n140us, n210us, and n280us. In another embodiment, the terminal may, according to its capability, designate a time taken to switch while changing a different number (e.g., 1 or 2) of transmit antennas to a different second band while operating with three transmit antennas in the first band. As a specific example, the timing information value by the switch may be designated as at least one value among n35us, n70us, n140us, n210us, and n280us. In another embodiment, the terminal may, according to its capability, designate a time taken to switch while changing three transmit antennas to a different second band while operating with one or two transmit antennas in the first band. As a specific example, the timing information value by the switch can be specified as at least one of n35us, n70us, n140us, n210us, and n280us.

[0306] <Second embodiment: Antenna port determination method for a terminal supporting three transmission antennas>

[0307] Below, a specific antenna port determination method of a terminal supporting three transmission antennas is described by specifically describing various embodiments.

[0308] When configuring SRS resources for a terminal supporting three transmit antennas, antenna ports can be determined based on SRS sequence generation and mapping to physical resources. Specifically, the base station can set cyclic shift values ​​and comb offset values ​​for the terminal to configure three SRS antenna ports. The terminal can transmit SRS on the allocated time and frequency resources (SRS resources) by using the cyclic shift value in the SRS sequence generation step and the comb offset value in the resource mapping step.

[0309] Since the antenna ports associated with the SRS transmitted by the terminal and the PUSCH antenna ports that the base station can schedule based on the SRS transmitted by the terminal can be assumed to be the same by the terminal and the base station, a method of minimizing the impact of the standard can be considered by using a method of modifying some of the four transmission antenna ports that have already been determined. In the following embodiments, for determining the SRS antenna ports, it is assumed that the base station basically configures three or four SRS resources for the terminal in RRC and determines three SRS antenna ports among them.

[0310] As an example, if four antenna ports of PUSCH are indicated, such as 1000, 1001, 1002, and 1003, and three SRS resources and SRS antenna ports are indicated, the base station and the terminal may determine the SRS antenna port by considering that the first antenna port, 1000, is not transmitted.

[0311] As an example, when four antenna ports of PUSCH are indicated, such as 1000, 1001, 1002, and 1003, and three SRS resources and SRS antenna ports are set, the base station and the terminal can determine the SRS antenna port by considering that the last antenna port, 1003, is not transmitted.

[0312] In one embodiment, when four antenna ports of PUSCH are indicated, such as 1000, 1001, 1002, and 1003, and three SRS resources and SRS antenna ports are indicated, the base station and the terminal can determine the number of one of the SRS antenna ports based on at least one of an RRC configuration, a MAC CE message, or DCI information, for determining the SRS antenna port and the SRS antenna port that is not transmitted. For example, when the terminal confirms at least one piece of information corresponding to antenna port 1002 based on the above information, the terminal can consider antenna port 1002 as not being transmitted, and determine SRS antenna ports corresponding to the remaining 1000, 1001, and 1003.

[0313] In one embodiment, when the base station and the terminal are indicated with four antenna ports of PUSCH, such as 1000, 1001, 1002, and 1003, and three SRS resources and SRS antenna ports are indicated, the RRC configuration determines the SRS antenna port and the comb (K) of Table 16 for the SRS antenna port that does not transmit. TC ) is 2, and the maximum cyclic shift value If is set to 8, the comb offset value ( ) can be determined by checking whether it is even or odd, and if it is even, the last antenna port 1003 is considered as not transmitting, and if it is odd, the first antenna port 1000 is considered as not transmitting. Conversely, under the same conditions, the terminal can determine that if it is even, the first antenna port 1000 is not transmitting, and if it is odd, the first antenna port 1003 is not transmitting.

[0314] As an example, when four antenna ports of PUSCH are indicated, such as 1000, 1001, 1002, and 1003, and three SRS resources and SRS antenna ports are indicated, the base station and the terminal can determine the non-transmitting antenna port based on the parameter comb offset value and cyclic shift value of Table 16 in the RRC configuration for determining the SRS antenna port and the non-transmitting SRS antenna port. Specifically, the terminal can determine the non-transmitting antenna port based on the set comb offset value ( ) can be determined not to transmit the antenna port for which the comb offset value corresponds to the minimum value (e.g., 0) and the cyclic shift value corresponds to the maximum value (e.g., 0). Conversely, the terminal may determine that the comb offset value ( ) is the maximum value (e.g., 1), and the antenna port corresponding to the cyclic shift value is the maximum value (e.g., 8) can be determined not to transmit.

[0315] In this way, various embodiments have taken into account minimizing noise or interference between SRS signals transmitted by terminals scheduled by base stations.

[0316] Additionally, in the above embodiments, when the port numbers of the antenna ports constituting the SRS antenna port are 1000, 1001, and 1002, and the port numbers of the antenna ports constituting the PUSCH antenna port are also 1000, 1001, and 1002, the connection / association relationship between the SRS antenna port and the PUSCH antenna port may be maintained.

[0317] Alternatively, if the port numbers of the antenna ports constituting the SRS antenna port are 1001, 1002, and 1003, and the port numbers of the antenna ports constituting the PUSCH antenna port are 1000, 1001, and 1002, the connection relationship between the SRS antenna port and the PUSCH antenna port is not maintained, but the order sequence (e.g., SRS 1001-PUSCH 1000, SRS 1002-PUSCH 1001, SRS 1003-PUSCH 1002) may be maintained similarly.

[0318] Alternatively, if the port numbers of the antenna ports constituting the SRS antenna port are 1001, 1002, and 1003, and the port numbers of the antenna ports constituting the PUSCH antenna port are 1000, 1001, and 1002, the SRS antenna port number can be readjusted to match the PUSCH antenna number in order to maintain the connection relationship between the SRS antenna port and the PUSCH antenna port. In a case like the above embodiment, there may be an advantage of minimizing the impact of standard changes.

[0319] The various embodiments described below can be operated based on at least one of the various embodiments of the above SRS antenna port configuration, and it can be assumed that the details are sufficiently taken into account even if omitted.

[0320] <Third embodiment: SRS resource configuration for antenna switching of a terminal supporting three transmission antennas>

[0321] Below, a method for setting SRS resources for specific antenna switching of a terminal supporting three transmission antennas is described by specifically describing various embodiments.

[0322] A base station can configure resources to transmit uplink sounding signals (SRS) to a terminal to improve downlink throughput. The following example describes SRS resources configured for a terminal, considering up to three transmit antennas and y receive antennas (e.g., y is 4, 6, 8). The resources configured here are configured by the base station to the terminal via an RRC message and are configured to perform an antenna switching operation.

[0323] In one embodiment, a base station may configure a separate SRS resource, SRS resource set, for a terminal for the purpose of antenna switching. Specifically, a terminal configured to use up to three antennas for transmission from the base station may be configured with at least one type of SRS resource type among periodic, semi-persistent, and aperiodic. For example, for periodic and semi-persistent SRS resource configurations, the number of SRS resource sets may be configured as 0 or 1, and for aperiodic SRS resource configurations, the number of SRS resource sets may be configured as 0 to 2. Here, one SRS resource set may include four SRS resources transmitted in different symbols. For another example, for periodic and semi-persistent SRS resource configurations, the number of SRS resource sets may be configured as 0 or 1, and for aperiodic SRS resource configurations, the number of SRS resource sets may be configured as 0 to 4. Here, one SRS resource set may include four SRS resources transmitted in different symbols.

[0324] In one embodiment, the SRS resources that the base station sets for the terminal can be configured with up to 16 per BWP, and the number of SRS resources that are set can be set respectively according to the types of aperiodic / periodic / semi-persistent SRS resources. Specifically, the number of SRS resources per BWP that are set for the terminal can be determined as one of the values ​​{1, 2, 4, 8, 16}. In addition, the number of SRS resources per BWP per slot that are set for the terminal can be determined as one of the values ​​{1, 2, 3, 4, 5, 6}. In addition, the maximum number of SRS ports per resource that are set for the terminal can be determined as one of the values ​​{1, 2, 3, 4}. Additionally, the list of transmit-receive pairs (Tx-Rx pairs) that support the SRS Tx port switch set to the terminal can be determined as one of {"Not supported", "3T4R", "3T3R", "3T6R", "3T8R"}.

[0325] In one embodiment, the terminal may report information to the base station regarding whether uplink switching for SRS and PUSCH in a specific band affects downlink reception and whether uplink switching for SRS and PUSCH in a specific band is also performed in other bands.

[0326] As an example, the base station may instruct the terminal, during the RRC configuration phase, to initially keep the value of the parameter "nrofSRS-Ports" related to the number of antenna ports for SRS transmission to 4, and to configure 3 ports using separate signaling. As another example, the base station may also set the value of the parameter "nrofSRS-Ports-n3-r19" related to the number of antenna ports for SRS transmission to 3 during the RRC configuration phase.

[0327] <Fourth embodiment: SRS antenna switching method of a terminal supporting y receiving antennas and 3 transmitting antennas>

[0328] Below, various embodiments are described in detail to describe specific antenna switching methods for a terminal supporting y receive antennas and 3 transmit antennas. The SRS antenna switching operation of a terminal supporting 3 transmit antennas may take into account the maximum number of receive antennas reported by the terminal to the base station.

[0329] When the base station receives that the terminal supports 3TyR (three transmit antennas and y receive antennas) in the terminal capability report, the base station can set SRS resources, SRS resource sets, and SRS resource types (e.g., periodic, semi-persistent, aperiodic), etc. for the terminal equipped with 3TyR. In the embodiments of the present disclosure, an example is described with reference to the case where y=4, but this is only an example for convenience of explanation and does not limit the scope of the present disclosure, and the present disclosure can also be applied when y is set to a different value.

[0330] First, in one embodiment, an embodiment is described that seeks to improve performance with less resource allocation by minimizing SRS resource intervals and cycles as much as possible.

[0331] FIG. 6a illustrates an example of SRS resource configuration and Tx / RX antenna port mapping in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0332] Referring to FIG. 6a, the terminal can map the antenna port of the terminal supporting 3T4R capability and the SRS antenna port accordingly.

[0333] For example, the base station may configure two SRS resources for three transmit antennas to the terminal, or configure at least one SRS resource set including two SRS resources. In addition, as in the fourth embodiment described above, the base station may configure various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for designating three SRS antenna ports in the first SRS resource configuration, and may designate the same antenna ports as the first SRS resource or some different antenna ports for designating three SRS antenna ports in the second SRS resource.

[0334] When the upper layer parameter 'usage' is set to 'antenna switching', the terminal can utilize the correspondence between the SRS antenna port indicated by the base station for SRS transmission and the receiving antenna within the terminal mapped.

[0335] As shown in Table 24, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the first SRS resource, the terminal can transmit the SRS signal by mapping the terminal's transmit / receive antenna port 0, transmit / receive antenna port 1, and transmit / receive antenna port 2. In addition, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the second SRS resource, the terminal can transmit the SRS signal by mapping the terminal's transmit / receive antenna port 1, transmit / receive antenna port 2, and transmit / receive antenna port 3. In this way, the base station and the terminal can transmit the SRS signal from antennas configured with three different transmit antenna sets among the four receive antennas, thereby enabling the terminal supporting 3T4R to determine a better antenna set later.

[0336]

[0337] In the above description, an embodiment is described in which the SRS antenna port numbers indicated for each of the first SRS resource and the second SRS resource are identically indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2}. However, an embodiment in which some different antenna ports are explicitly indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2} for the SRS antenna port numbers indicated for the first SRS resource and {SRS antenna port 1, SRS antenna port 2, SRS antenna port 3} for the SRS antenna port numbers indicated for the second SRS resource, may also be similarly applied and extended.

[0338] Second, in one embodiment, an embodiment is shown in which the optimal transmit and receive antenna set is found through a large resource allocation by maximizing the SRS resource interval and period as much as possible.

[0339] FIG. 6b is another example for explaining antenna ports set to SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0340] Referring to FIG. 6b, the terminal can map the antenna port of the terminal supporting 3T4R capability and the SRS antenna port accordingly.

[0341] For example, the base station may configure a total of four SRS resources for three transmit antennas to the terminal, or configure at least one SRS resource set including four SRS resources. In addition, as in the second and third embodiments described above, the base station may configure (i) various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for designating three SRS antenna ports in the first SRS resource, (ii) parameters for designating three SRS antenna ports, which have at least one different antenna port number from the first SRS resource in the second SRS resource, (ii) parameters for designating three SRS antenna ports, which have at least one different antenna port number from the first and second SRS resources in the third SRS resource, and (iv) parameters for designating three SRS antenna ports, which have at least one different antenna port number from the first to third SRS resources in the fourth SRS resource.

[0342] For example, if the upper layer parameter 'usage' is set to 'antenna switching', at least one SRS resource set including four SRS resources is set, and the value of "nrofSRS-Ports-n3-r19" is set to 3, the terminal can utilize the correspondence between the SRS antenna port indicated by the base station for SRS transmission and the receiving antenna inside the terminal mapped.

[0343] As shown in Table 25, if the SRS antenna port {0, 1, 2} is set in the first SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {0, 1, 2} of the terminal. In addition, if the SRS antenna port {0, 1, 2} is set in the second SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {0, 1, 3} of the terminal. In addition, if the SRS antenna port {0, 1, 2} is set in the third SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {0, 2, 3} of the terminal. In addition, if the SRS antenna port {0, 1, 2} is set in the fourth SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {1, 2, 3} of the terminal. Ultimately, the terminal will use three antenna ports out of four receiving antennas.

[0344]

[0345] Thirdly, in one embodiment, an embodiment is shown in which the optimal set of transmitting and receiving antennas is found through allocation of many resources by maximizing the SRS resource interval and period as much as possible.

[0346] The terminal can map the antenna port of the 3T4R terminal to the SRS antenna port. This embodiment introduces a method of updating some information to information previously set in RRC.

[0347] For example, the base station may configure two SRS resources for four transmit antennas to the terminal, or configure at least one SRS resource set including two SRS resources. In addition, as in the fourth embodiment described above, the base station may configure various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for designating four SRS antenna ports in the first SRS resource configuration, and configure the same antenna ports as the first SRS resource for designating four SRS antenna ports in the second SRS resource.

[0348] When the upper layer parameter 'usage' is set to 'antenna switching', the terminal can utilize the correspondence between the SRS antenna port indicated by the base station for SRS transmission and the receiving antenna within the terminal mapped.

[0349] If SRS antenna port 0, SRS antenna port 1, SRS antenna port 2, and SRS antenna port 3 are configured for the first and second SRS resources, the terminal can sequentially map the terminal's transmit / receive antenna port 0, transmit / receive antenna port 1, transmit / receive antenna port 2, and transmit / receive antenna port 3. After mapping, the terminal can omit transmission of antenna ports based on information indicated by the base station or a predetermined pattern. For example, the indicated information may include information related to the SRS or PUSCH antenna port not to be transmitted (e.g., 3) or pattern information of the antenna port not to be transmitted (e.g., {3,1}). Consequently, the terminal can perform the 3T4R SRS antenna switching operation by performing a two-step operation of reflecting some updated information to the preset resource and antenna port information without significantly modifying the existing four SRS antenna port configuration information.

[0350] FIG. 6c is another example for explaining antenna ports set to SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0351] Referring to FIG. 6c, the terminal can map the antenna port of the 3T4R terminal to the SRS antenna port. This embodiment introduces a method of updating some information to information previously set in RRC.

[0352] For example, the base station may configure a total of four SRS resources for three transmit antennas to the terminal, or configure at least one SRS resource set including four SRS resources.

[0353] The base station can configure various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) to designate four SRS antenna ports to the terminal in the first to fourth SRS resource configurations.

[0354] For example, if the upper layer parameter 'usage' is set to 'antenna switching', at least one SRS resource set including four SRS resources is set, and the value of "nrofSRS-Ports-n3-r19" is set to 3, the terminal can use the correspondence between the SRS antenna ports indicated by the base station for SRS transmission and the mapped reception antennas inside the terminal. If the SRS antenna ports {0, 1, 2, 3} are set for each of the first to fourth SRS resources, the terminal can sequentially map the transmit / receive antenna ports {0, 1, 2, 3} of the terminal. After the mapping, the terminal can not transmit an antenna port based on information indicated by the base station or a predetermined pattern. For example, the indicated information may include information related to the SRS or PUSCH antenna port not to be transmitted (e.g., number 3) or pattern information of the antenna port not to be transmitted (e.g., an identifier corresponding to {3 → 2 → 1 → 0}). Ultimately, the terminal can perform the 3T4R SRS antenna switching operation by performing a two-step operation of reflecting some updated information to the preset resource and antenna port information without significantly modifying the existing four SRS antenna port configuration information.

[0355] Fourth, an embodiment shows an embodiment that seeks to improve performance by allocating SRS resources that consider both 3T4R and 1T4R.

[0356] FIG. 7a illustrates an example of SRS resource configuration and Tx / RX antenna port mapping for SRS antenna switching in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0357] Referring to FIG. 7a, the terminal can map the antenna port of the terminal supporting 3T4R capability and the SRS antenna port accordingly.

[0358] For example, a base station may configure one SRS resource set for a terminal, including a total of four SRS resources for three transmit antennas and four SRS resources for one transmit antenna. In addition, as in the second and third embodiments described above, the base station may set various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for specifying three SRS antenna ports in the first SRS resource, and various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for specifying one SRS antenna port in the second SRS resource. Thereafter, the base station may set parameters for specifying three SRS antenna ports, at least one antenna port being different from the first SRS resource, in the third SRS resource, and parameters for specifying one SRS antenna port being different from the second SRS resource in the fourth SRS resource. The base station may set various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for specifying three SRS antenna ports, at least one antenna port being different from the first and third SRS resources, in the fifth SRS resource, and one SRS antenna port being different from the second and fourth SRS in the sixth SRS resource. You can set various parameters for specifying the SRS antenna port (e.g. SRS resource, transmission type, comb, cyclic shift, etc.).Thereafter, the base station can set parameters for designating three SRS antenna ports, each having at least one antenna port different from the first, third, and fifth SRS resources, for the seventh SRS resource, and can set parameters for designating one SRS antenna port different from the second, fourth, and sixth SRS resources for the eighth SRS resource. By setting one SRS resource set including eight SRS resources in this way, the base station can cause the terminal to alternately select three of the four receive antennas for odd-numbered resources and to alternately select and transmit one antenna other than the first three receive antennas for even-numbered resources, thereby measuring SRS performance based on 3T and 1T periodically, semi-persistently, and aperiodicly depending on the transmission type.

[0359] For example, if the upper layer parameter 'usage' is set to 'antenna switching', and at least one SRS resource set including eight SRS resources is set, and the value of "nrofSRS-Ports-n3-r19" is set to 3 in four of the eight SRS resources, and the value of "nrofSRS-Ports-n3-r19" is set to 1 in the remaining four SRS resources, the terminal can use the correspondence between the SRS antenna ports indicated by the base station for SRS transmission and the mapped reception antennas within the terminal. If SRS antenna ports {0, 1, 2} are set in the first SRS resource, the terminal can transmit an SRS signal by mapping the transmit / receive antenna ports {0, 1, 2} of the terminal. In addition, if the third SRS antenna port {0, 1, 2} is set, the terminal can transmit an SRS signal by mapping the transmit / receive antenna ports {0, 1, 3} of the terminal. In addition, when the fifth SRS antenna port {0, 1, 2} is set, the terminal can transmit an SRS signal by mapping the transmit / receive antenna ports {0, 2, 3} of the terminal. In addition, when the seventh SRS antenna port {0, 1, 2} is set, the terminal can transmit an SRS signal through a mapping operation of the transmit / receive antenna ports {1, 2, 3} of the terminal. As a result, the terminal uses three antenna ports out of four receive antennas. In addition, when the SRS antenna port {0} or {3} is set in the second SRS resource, the terminal can transmit an SRS signal by mapping the transmit / receive antenna port {3} of the terminal. In addition, when the fourth SRS antenna port {0} or {2} is set, the terminal can transmit an SRS signal by mapping the transmit / receive antenna port {2} of the terminal.In addition, when the sixth SRS antenna port {0} or {1} is set, the terminal can transmit an SRS signal by mapping the terminal's transmit / receive antenna port {1}. In addition, when the eighth SRS antenna port {0} is set, the terminal can transmit an SRS signal through the terminal's transmit / receive antenna port {0} through a mapping operation. Ultimately, the terminal uses one antenna port out of four receive antennas one at a time.

[0360] In the embodiment of FIG. 7a described above, an embodiment including a total of 8 SRS resources in one SRS resource set was described, but in order to reduce waste of resources and reduce the transmission cycle, the base station can be set to include a total of 4 SRS resources in one SRS resource set, as shown in FIG. 7b, and although a detailed description is omitted, those skilled in the art can sufficiently understand that it is set and operated similarly.

[0361] FIG. 7b is another example for explaining antenna ports set for SRS resources in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure. Referring to FIG. 7b, for example, if the upper layer parameter 'usage' is set to 'antenna switching', at least one SRS resource set including four SRS resources is set, and the value of "nrofSRS-Ports-n3-r19" is set to 3 in two of the four SRS resources, and the value of "nrofSRS-Ports-n3-r19" is set to 1 in the remaining two SRS resources, the terminal can utilize the correspondence between the SRS antenna ports indicated by the base station for SRS transmission and the mapped reception antennas within the terminal. If SRS antenna ports {0, 1, 2} are set in the first SRS resource, the terminal can transmit an SRS signal by mapping the transmit / receive antenna ports {0, 1, 2} of the terminal. In addition, when the third SRS antenna port {0, 1, 2} is set, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {0, 1, 3} of the terminal. In addition, when the SRS antenna port {0} or {3} is set in the second SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {3} of the terminal. In addition, when the fourth SRS antenna port {0} or {2} is set, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port {2} of the terminal.

[0362] Fifthly, in one embodiment, in a terminal configured with multiple carriers by a base station, when one uplink carrier is configured to operate at 3T and the remaining at least one carrier is configured to operate at 1T to 3T, an embodiment is shown for improving performance by allocating SRS resources to the terminal.

[0363] FIG. 8 is another example for explaining antenna ports set to SRS resources during carrier aggregation operation in SRS antenna switching considering 3T4R according to an embodiment of the present disclosure.

[0364] For example, referring to FIG. 8, the base station can configure a first SRS resource set including a total of four SRS resources for three transmit antennas on one uplink carrier and another second SRS resource set including four SRS resources for at least one transmit antenna to the terminal.

[0365] In addition, as in the second and third embodiments described above, the base station may set various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for designating three SRS antenna ports in the first SRS resource of the first uplink carrier, set parameters for designating three SRS antenna ports, at least one antenna port being different from the first SRS resource in the second SRS resource, set various parameters for designating three SRS antenna ports, at least one antenna port being different from the first and second SRS resources in the third SRS resource, and set parameters for designating three SRS antenna ports, at least one antenna port being different from the first to third SRS resources in the fourth SRS resource.

[0366] In addition, the base station may set various parameters (e.g., SRS resource, transmission type, comb, cyclic shift, etc.) for designating one to three SRS antenna ports in the first SRS resource of the second uplink carrier, set parameters for designating one to three SRS antenna ports, which have at least one antenna port different from the first SRS resource, in the second SRS resource, set various parameters for designating one to three SRS antenna ports, which have at least one antenna port different from the first and second SRS resources, in the third SRS resource, and set parameters for designating one to three SRS antenna ports, which have at least one antenna port different from the first to third SRS resources, in the fourth SRS resource.

[0367] In this case, if the frequency difference between the first and second uplinks is a significant interband combination, the terminal can set separate time gaps for SRS transmissions on the first and second uplinks. Specifically, the size of the gap can be set based on the minimum time required to switch the elements of the SRS antenna transmitted on the first carrier to match the second carrier.

[0368] Meanwhile, for a carrier of a serving cell c1 that is not configured for PUSCH / PUCCH transmission and has a slot format consisting of DL and UL symbols, let c2 be the corresponding carrier of the serving cell where UL transmission is temporarily suspended as signaled by the higher layer parameters srs-SwitchFromServCellIndex and srs-SwitchFromCarrier, the set S(c2)={c2,S1(c2),...,S N-1(c2)} is defined as a set of carriers of a serving cell where each carrier satisfies one of the following conditions.

[0369] S i (c2) is in the same band and same TAG (timing advance group) as c2. S i (c2) is the carrier of interband CA with c2, and S i (c2) is indicated as being affected by the SRS switch from c2 to c1 via the srs-SwitchingAffectedBandsListNR capability signaling, where 1≤i≤N-1.

[0370] Symbol of carrier c1 For SRS transmissions starting from and colliding transmissions starting from any carrier within the set S(c2), the terminal may apply priority decision / drop rules considering the following:

[0371] The last symbol of the PDCCH that starts SRS transmission and The time interval between is at least N2 symbols and the additional time duration , and the last symbol of PDCCH and N S DCI(s) with a time interval of at least N2 symbols; and

[0372] Semi-persistent CSI reporting or SRS It is considered to have been active for at least N2 symbols and an additional time duration T_(SRS_CS), and N S It can be considered to have been activated for at least N2 symbols previously.

[0373] Here, = max{switchingTimeUL, switchingTimeDL}, and the time interval unit of an OFDM symbol is calculated based on the smaller subcarrier interval across any carrier within the set S(c2), c1, and their corresponding scheduling cells.

[0374] Here, the time of switchingTimeUL can be determined as at least one value among {n0us, n30us, n100us, n140us, n200us, n300us, n500us, n900us} depending on whether the ports used in each carrier are used to overlap partially within the same slot, a certain number of symbols, or not to overlap at all in the carrier of the serving cell c1 supported by the terminal, and the terminal can report it to the base station.

[0375] <Example 5: UE sounding procedure depending on whether a terminal supporting 3T4R supports srs-AntennaSwitching2SP-1Periodic, srs-ExtensionAperiodicSRS>

[0376] Below, various embodiments are described in detail to describe UE sounding procedures depending on whether a terminal supporting four receive antennas and three transmit antennas supports a specific semi-persistent or aperiodic SRS combination.

[0377] A base station can configure a terminal with zero or one SRS resource set, where the resourcesType of SRS-ResourceSet is set to 'periodic' by default. Here, for one resource set, two SRS resources are transmitted using different symbols, and each SRS resource in a given set can consist of three SRS ports.

[0378] Additionally, the base station may configure 0 or 1 SRS resource sets for the terminal, indicating that the SRS ports of the resources within the SRS resource set are associated with other terminal antenna port pairs or sets. If the terminal does not report srs-AntennaSwitching2SP-1Periodic, the base station may configure the resourcesType of SRS-ResourceSet to 'semi-persistent' for the terminal.

[0379] Alternatively, the base station can set the ResourceType of SRS-ResourceSet to 'aperiodic' for 0, 1, 2, or 4 SRS resource sets to the terminal. In this case, in the configuration operation of the terminal,

[0380] 1) If a resource set has two or four SRS resources transmitted with different symbols, each SRS resource of the given set consists of three SRS ports, and a set of SRS ports (e.g., three SRS ports) of that resource can be associated with a different set of UE antenna ports.

[0381] 2-1) When two SRS resources of two resource sets are transmitted in different symbols of two different slots, the SRS port sets of each SRS resource of the two given sets can be associated with different UE antenna ports. One resource set can consist of one SRS resource, and the other resource set can consist of one resource.

[0382] 2-2) When two resource sets, each with a total of four SRS resources, are transmitted in different symbols of two different slots, the SRS port sets of each SRS resource of the two given sets can be associated with antenna port sets of different terminals. One set can consist of two SRS resources, and the other set can consist of two SRS resources.

[0383] 3) For four resource sets, a total of four SRS resources are transmitted in different symbols of four different slots, and the SRS port sets of each SRS resource within the given four sets can be associated with the antenna port sets of different terminals.

[0384] On the other hand, if the terminal reports the "srs-AntennaSwitching2SP-1Periodic" parameter, and if the terminal indicates only srs-AntennaSwitching2SP-1Periodic, the base station can configure up to two semi-persistent resource sets and up to one periodic resource set, but cannot activate two semi-persistent resource sets simultaneously.

[0385] A base station can configure up to two SRS resource sets with different values ​​for the upper layer parameter resourcesType of SRS-ResourceSet, and two SRS resource sets configured as 'semi-persistent' cannot be activated simultaneously.

[0386] A base station can configure a terminal with up to two SRS resource sets configured as 'semi-persistent' and up to one SRS resource set configured as 'periodic', and the two SRS resource sets configured as 'semi-persistent' cannot be activated simultaneously. Each SRS resource set has two SRS resources transmitted with different symbols, and each SRS resource in a given set consists of three SRS ports, and the SRS ports of the resources in the set can be associated with antenna port sets of different terminals.

[0387] Meanwhile, when the terminal reports the "srs-ExtensionAperiodicSRS" parameter, as an example, the base station may set up to two SRS resource sets in which the resourcesType of the SRS-ResourceSet is set to 'aperiodic' and up to one SRS resource set in which the resourcesType of the SRS-ResourceSet is set to 'periodic' or 'semi-persistent'.

[0388] In another embodiment, when the terminal reports the "srs-ExtensionAperiodicSRS" parameter, the base station may configure up to two SRS resource sets with different values ​​for the upper layer parameter resourcesType of SRS-ResourceSet.

[0389] For example, if two resource sets are configured in which the resourcesType of SRS-ResourceSet is set to 'aperiodic', a total of two SRS resources are transmitted in different symbols of two different slots, and each SRS resource of the two given sets can be configured with three SRS ports. In addition, the SRS ports of the SRS resources in each set can be associated with antenna port sets of different terminals, and the two sets can each be configured with one SRS resource.

[0390] For example, if one resource set is configured in which the resourcesType of SRS-ResourceSet is set to 'aperiodic', a total of two SRS resources are transmitted with different symbols within the same slot, and each SRS resource of the given set consists of three SRS ports, and the three SRS ports of the second resource can be associated with the three SRS ports of the first resource and a pair of antenna ports of a different terminal.

[0391] For example, if a resource set is configured in SRS-ResourceSet where 'resourceType' is set to 'periodic' or 'semi-persistent', two SRS resources transmitted in different symbols can be configured, and each SRS resource in the given set can consist of three SRS ports. The SRS ports of the second resource can be associated with the three SRS ports of the first resource and a different set of antenna ports of the terminal.

[0392] In another embodiment, the base station can configure up to four SRS resource sets for the terminal, each of which has different resourcesTypes in the SRS-ResourceSet.

[0393] For example, if the resourcesType of SRS-ResourceSet is set to 'aperiodic' and all four resource sets are set, the terminal transmits SRS signals in different symbols of four different slots using a total of four SRS resources, and each SRS resource in the given four sets can be associated with three SRS ports. Here, the SRS resources have different antenna ports of the terminal, and each of the four sets can be composed of one SRS resource.

[0394] For example, if two resource sets are set to 'aperiodic' for the resourcesType of SRS-ResourceSet, the terminal transmits SRS signals in different symbols of two different slots using a total of four SRS resources, and each SRS resource of the two given sets can be associated with three SRS ports. Here, the SRS resources are associated with antenna ports of different terminals, and the two sets can each be composed of two SRS resources.

[0395] For example, if a single resource set is configured in which the resourcesType of SRS-ResourceSet is set to 'aperiodic', the terminal transmits an SRS signal using a total of four SRS resources in different symbols within the same slot, and each SRS resource of the given set can be configured with three SRS ports. In this case, the three SRS ports of the second resource can be associated with the three SRS ports of the first resource and a different antenna port set of the terminal.

[0396] For example, if four SRS resources are configured to be transmitted in different symbols in each SRS resource set in which 'resourceType' is set to 'periodic' or 'semi-persistent' in SRS-ResourceSet, the terminal can transmit SRS signals using the four SRS resources in different symbols. In addition, the terminal configures three SRS ports in each SRS resource of the given set, and at this time, the three SRS ports of the second resource can be associated with the three SRS ports of the first resource and a different antenna port set of the terminal.

[0397] <Example 6: SRS antenna switching method of a terminal supporting y receiving antennas and 3 transmitting antennas>

[0398] FIG. 9 illustrates an example of SRS resource configuration and Tx / RX antenna port mapping in SRS antenna switching considering 3T6R according to an embodiment of the present disclosure.

[0399] Referring to FIG. 9, the terminal can map the antenna port of the terminal supporting 3T6R capability and the SRS antenna port accordingly.

[0400] For example, the base station may configure two SRS resources for three transmit antennas for the terminal, or configure at least one SRS resource set including two SRS resources. In addition, as in the fourth embodiment described above, the base station may designate three antenna ports for the first SRS resource, and designate the same antenna ports as the first SRS resource for the second SRS resource, or designate different antenna ports.

[0401] When the upper layer parameter 'usage' is set to 'antenna switching', the terminal can utilize the correspondence between the SRS antenna port indicated by the base station for SRS transmission and the receiving antenna within the terminal mapped.

[0402] As shown in Table 26, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the first SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port 0, transmit / receive antenna port 1, and transmit / receive antenna port 2 of the terminal. In addition, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the second SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port 3, transmit / receive antenna port 4, and transmit / receive antenna port 5 of the terminal, which are different from the antenna ports used in the first SRS resource. In this way, the base station and the terminal can transmit the SRS signal from the antennas configured with three different transmit antenna sets among the six receive antennas, thereby enabling the terminal supporting 3T6R to determine a better antenna set later.

[0403]

[0404] In the above description, an embodiment is described in which the SRS antenna port numbers indicated for each of the first SRS resource and the second SRS resource are identically indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2}. However, an embodiment in which different antenna ports are explicitly indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2} for the SRS antenna port numbers indicated for the first SRS resource and {SRS antenna port 3, SRS antenna port 4, SRS antenna port 5} for the SRS antenna port numbers indicated for the second SRS resource, may also be similarly applied and extended.

[0405] FIG. 10 illustrates an example of SRS resource configuration and Tx / RX antenna port mapping in SRS antenna switching considering 3T8R according to an embodiment of the present disclosure.

[0406] Referring to FIG. 10, the terminal can map the antenna port of the terminal supporting 3T8R capability and the SRS antenna port accordingly.

[0407] For example, the base station may configure two SRS resources for three transmit antennas for the terminal, or configure at least one SRS resource set including two SRS resources. In addition, as in the fourth embodiment described above, the base station may designate three antenna ports for the first SRS resource, and designate the same antenna ports as the first SRS resource for the second SRS resource, or designate different antenna ports.

[0408] When the upper layer parameter 'usage' is set to 'antenna switching', the terminal can utilize the correspondence between the SRS antenna port indicated by the base station for SRS transmission and the receiving antenna within the terminal mapped.

[0409] As shown in Table 27, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the first SRS resource, the terminal can transmit an SRS signal by mapping the terminal's transmit / receive antenna port 0, transmit / receive antenna port 1, and transmit / receive antenna port 2. In addition, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the second SRS resource, the terminal can transmit an SRS signal by mapping the terminal's transmit / receive antenna port 3, transmit / receive antenna port 4, and transmit / receive antenna port 5, which are different from the antenna ports used in the first SRS resource.

[0410] Alternatively, if SRS antenna port 0, SRS antenna port 1, and SRS antenna port 2 are set in the second SRS resource, the terminal can transmit the SRS signal by mapping the transmit / receive antenna port 4, transmit / receive antenna port 5, and transmit / receive antenna port 6 of the terminal, which are different from the antenna ports used in the first SRS resource, by considering the switching operation for each of the four receive antenna sets due to the structure of the physical internal elements, etc. In this way, the base station and the terminal can transmit the SRS signal from the antennas configured with three different transmit antenna sets among the eight receive antennas, thereby allowing the terminal supporting 3T8R to determine a better antenna set later.

[0411]

[0412] In the above description, an embodiment is described in which the SRS antenna port numbers indicated for each of the first SRS resource and the second SRS resource are identically indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2}. However, an embodiment in which different antenna ports are explicitly indicated, such as {SRS antenna port 0, SRS antenna port 1, SRS antenna port 2} for the SRS antenna port numbers indicated for the first SRS resource and {SRS antenna port 3, SRS antenna port 4, SRS antenna port 5} for the SRS antenna port numbers indicated for the second SRS resource, may also be similarly applied and extended.

[0413] The operations of 3T6R and 3T8R of the base station and terminal described above can be extended like the first to fifth embodiments for 3T4R described above, and the SRS resources and antenna switching related settings that are set can also be applied by switching at least some of them.

[0414] The embodiments of the present disclosure described above (e.g., the first embodiment to the sixth embodiment) can be performed in combination with each other.

[0415] FIG. 11 is a diagram illustrating the operation of a base station and a terminal according to an embodiment of the present disclosure.

[0416] The base station and terminal operations of FIG. 11 can be performed based on the embodiments of the present disclosure described above (e.g., the first embodiment to the sixth embodiment).

[0417] In operation 1100, the base station may receive terminal capability information from the terminal. The terminal capability that may be reported at this time may include the terminal capability associated with the uplink transmission function of the terminal supporting three transmit antennas defined in the first to sixth embodiments, and the SRS support method for antenna switching. For example, the terminal capability information may include information indicating the antenna switching capability of the terminal, and the information indicating the antenna switching capability of the terminal may indicate that the terminal is capable of SRS transmission on three transmit antenna ports across four or more receive antenna ports. For example, the terminal capability information may further include information indicating a band pair for uplink transmission switching and information on a switching cycle for the uplink transmission switching. Operation 1100 may be omitted.

[0418] In operation 1105, the base station may transmit configuration information (e.g., configuration information for SRS) to the terminal through upper layer signaling based on the terminal capability information reported by the terminal. For example, the base station may signal including an SRS resource configuration for a terminal supporting three transmission antennas defined in the first to sixth embodiments and an SRS support method for antenna switching, and may define upper layer signaling for at least one combination and configure it to the terminal. The terminal may check parameters related to the configuration of SRS resources and SRS resource sets based on the configuration information. For example, the configuration information may include information indicating the number of antenna ports of the SRS.

[0419] In operation 1110, the base station can receive an SRS from the terminal. For example, the 3TX terminal can determine one antenna port among four antenna ports for SRS on which the SRS will not be transmitted, and transmit the SRS to the base station based on three antenna ports excluding the one antenna port. For example, the one antenna port on which the SRS will not be transmitted can be determined based on the second embodiment described above. For example, the base station can receive the SRS from the terminal based on a method set for the terminal by antenna switching for the terminal supporting three transmit antennas defined in the first to sixth embodiments.

[0420] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0421] The embodiments of the present disclosure described above (e.g., the first embodiment to the sixth embodiment) can be performed by the terminal of FIG. 12 and the base station of FIG. 13.

[0422] FIG. 12 is a diagram illustrating the structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0423] Referring to FIG. 12, the terminal may include a transceiver, which refers to a terminal receiving unit (12-00) and a terminal transmitting unit (12-10), a memory (not shown), and a terminal processing unit (12-05, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (12-00, 12-10), the memory, and the terminal processing unit (12-05) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver unit, the memory, and the processor may be implemented in the form of a single chip.

[0424] 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.

[0425] 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.

[0426] 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.

[0427] In addition, the processor may control a series of processes so that the terminal can operate according to the above-described embodiment. For example, the processor may determine that the usage of the SRS resource set is set to antenna switching, and control components of the terminal to transmit the SRS based on x antennas among y receiving antennas of the terminal. There may be multiple processors, and the processors may perform the component control operation of the terminal by executing a program stored in the memory.

[0428] FIG. 13 is a diagram illustrating the structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

[0429] Referring to FIG. 13, the base station may include a base station receiver (13-00) and a transceiver, which refers to a base station transmitter (13-10), a memory (not shown), and a base station processor (13-05, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver (13-00, 13-10), the memory, and the base station processor (13-05) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0430] 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.

[0431] 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.

[0432] 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.

[0433] The processor may control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. For example, the processor may control each component of the base station to transmit configuration information including configuration for SRS resources and / or configuration for an SRS resource set to the terminal. In addition, the processor may control the components of the base station to set the usage of the SRS resource set to antenna switching and receive an SRS transmitted based on x antennas among y receiving antennas of the terminal. There may be a plurality of processors, and the processors may perform the operation of controlling the components of the base station by executing a program stored in a memory.

[0434] 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.

[0435] 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.

[0436] 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.

[0437] 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.

[0438] 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.

[0439] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, the above-described embodiments may be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment may be combined to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure may be combined to operate a base station and a terminal. In addition, the embodiments of the present disclosure are applicable to other communication systems, and other modifications based on the technical scope of the embodiments may also be implemented.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of receiving configuration information for a sounding reference signal (SRS) from a base station, the configuration information including first information indicating the number of antenna ports of the SRS; When the first information indicates 3 as the number of the antenna ports, a step of determining one antenna port among four antenna ports for SRS through which SRS is not transmitted; and A method comprising the step of transmitting SRS based on three antenna ports excluding the one antenna port to the base station.

2. In paragraph 1, A method characterized in that the one antenna port through which the SRS is not transmitted is an antenna port corresponding to the lowest antenna port number among the four antenna ports or an antenna port corresponding to the highest antenna port number.

3. In paragraph 1, Further comprising the step of receiving second information indicating one antenna port from which the SRS is not transmitted from the base station, A method characterized in that one antenna port through which the SRS is not transmitted is determined based on the second information.

4. In paragraph 1, One antenna port where the above SRS is not transmitted is determined based on the comb offset value, If the above comb offset value is an even number, one antenna port where the SRS is not transmitted is determined as the antenna port corresponding to the highest antenna port number among the four antenna ports, and A method characterized in that, when the comb offset value is an odd number, one antenna port through which the SRS is not transmitted is determined as the antenna port corresponding to the lowest antenna port number among the four antenna ports.

5. In paragraph 1, A method characterized in that one antenna port through which the above SRS is not transmitted is determined based on a comb offset value and a cyclic shift value.

6. In paragraph 1, Further comprising a step of transmitting terminal capability information including third information indicating the antenna switching capability of the terminal to the base station, The third information indicates that the terminal is capable of transmitting SRS on three transmitting antenna ports across four or more receiving antenna ports, The above configuration information further includes information about a set of SRS resources for antenna switching purposes, and A method characterized in that the above SRS resource set includes a plurality of SRS resources and each SRS resource of the plurality of SRS resources corresponds to four SRS ports.

7. In paragraph 6, A step of receiving, from the base station, pattern information indicating one SRS port among the four SRS ports of each SRS resource through which SRS is not transmitted; A step of determining three SRS ports corresponding to the three transmission antenna ports among the four SRS ports based on the above pattern information; and A method characterized by further comprising the step of transmitting an SRS to the base station based on the plurality of SRS resources and the three SRS ports.

8. In paragraph 6, The terminal capability information further includes fourth information indicating a band pair for uplink transmission switching and fifth information regarding a switching cycle for the uplink transmission switching, The fourth information indicates that the terminal supports switching from three transmit antenna ports to two transmit antenna ports, and A method characterized in that the switching cycle comprises 280 us.

9. In a method performed by a base station in a wireless communication system, A step of transmitting configuration information for a sounding reference signal (SRS) to a terminal, the configuration information including first information indicating the number of antenna ports of the SRS; and A step of receiving SRS from the terminal is included, A method in which, when the first information indicates 3 as the number of antenna ports, the SRS is received based on 3 antenna ports excluding 1 antenna port through which the SRS is not transmitted among 4 antenna ports for the SRS.

10. In paragraph 9, Further comprising a step of transmitting second information indicating one antenna port to which the SRS is not transmitted to the terminal; A method characterized in that one antenna port through which the SRS is not transmitted is determined based on the second information.

11. In paragraph 9, One antenna port where the above SRS is not transmitted is determined based on the comb offset value, If the above comb offset value is an even number, one antenna port where the SRS is not transmitted is determined as the antenna port corresponding to the highest antenna port number among the four antenna ports, and A method characterized in that, when the comb offset value is an odd number, one antenna port through which the SRS is not transmitted is determined as the antenna port corresponding to the lowest antenna port number among the four antenna ports.

12. In paragraph 9, Further comprising a step of receiving terminal capability information including third information indicating antenna switching capability of the terminal from the terminal, The third information indicates that the terminal is capable of transmitting SRS on three transmitting antenna ports across four or more receiving antenna ports, The above configuration information further includes information about a set of SRS resources for antenna switching purposes, and A method characterized in that the above SRS resource set includes a plurality of SRS resources and each SRS resource of the plurality of SRS resources corresponds to four SRS ports.

13. In paragraph 12, A step of transmitting pattern information indicating one SRS port from among the four SRS ports of each SRS resource to the terminal, wherein three SRS ports corresponding to the three transmission antenna ports among the four SRS ports are identified based on the pattern information; and A method characterized by further comprising a step of receiving an SRS from the terminal based on the plurality of SRS resources and the three SRS ports.

14. In a wireless communication system, at a terminal, Transmitter and receiver; and A control unit functionally connected to the above transmitter and receiver, wherein the control unit: Receive configuration information for a sounding reference signal (SRS) from a base station, wherein the configuration information includes first information indicating the number of antenna ports of the SRS, If the first information indicates 3 as the number of antenna ports, one antenna port among the four antenna ports for SRS is determined for which SRS is not transmitted, and A terminal configured to transmit SRS based on three antenna ports excluding the one antenna port to the above base station.

15. In paragraph 14, A terminal characterized in that the one antenna port through which the SRS is not transmitted is an antenna port corresponding to the lowest antenna port number among the four antenna ports or an antenna port corresponding to the highest antenna port number.

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