Method and apparatus for transmitting uplink reference signal for full-duplex communication in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. In addition, the present disclosure relates to operations of a terminal and a base station in a wireless communication system and, more particularly, to a method by which a terminal transmits a sounding reference signal (SRS) to an uplink, and an apparatus capable of performing same.

Description

Method and device for transmitting uplink reference signals for full-duplex communication in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for a base station and a terminal to transmit and receive an uplink reference signal, and a device capable of performing the same.

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

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

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

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

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

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

[0008] Embodiments of the present disclosure aim to provide a device and method capable of effectively providing a service in a wireless communication system. In particular, a method and device for transmitting an uplink signal when subband non-overlapping full duplex (SBFD) is applied are provided.

[0009] According to an embodiment of the present invention for achieving the above-described technical problem, a method performed by a terminal of a communication system comprises the steps of: receiving SBFD (subband non-overlapping full duplex) configuration information from a base station, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband; receiving SRS (sounding reference signal) configuration information from the base station, wherein the SRS configuration information includes resource information for SRS transmission; identifying a frequency resource for SRS transmission based on the SBFD configuration information and the SRS configuration information; and transmitting an SRS to the base station on the frequency resource, wherein the SRS is characterized in that it is transmitted within the uplink subband.

[0010] In addition, a method performed by a base station of a communication system includes a step of transmitting SBFD (subband non-overlapping full duplex) configuration information to a terminal, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband; a step of transmitting SRS (sounding reference signal) configuration information to the terminal, wherein the SRS configuration information includes resource information for SRS transmission; and a step of receiving an SRS from the terminal, wherein the SRS is received in a frequency resource for SRS reception, the frequency resource is based on the SBFD configuration information and the SRS configuration information, and the SRS is received within the uplink subband.

[0011] In addition, a terminal of a communication system includes a transceiver; and a control unit configured to receive SBFD (subband non-overlapping full duplex) configuration information from a base station, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband, receive SRS (sounding reference signal) configuration information from the base station, wherein the SRS configuration information includes resource information for SRS transmission; and identify a frequency resource for SRS transmission based on the SBFD configuration information and the SRS configuration information, and transmit an SRS to the base station on the frequency resource, wherein the SRS is characterized in that it is transmitted within the uplink subband.

[0012] In addition, a base station of a communication system is characterized in that it transmits SBFD (subband non-overlapping full duplex) configuration information to a transceiver; and a terminal, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband, transmits SRS (sounding reference signal) configuration information to the terminal, the SRS configuration information includes resource information for SRS transmission, and includes a control unit configured to receive an SRS from the terminal, wherein the SRS is received in a frequency resource for SRS reception, the frequency resource is based on the SBFD configuration information and the SRS configuration information, and the SRS is received within the uplink subband.

[0013] According to one embodiment of the present disclosure, a service can be effectively provided in a wireless communication system. In particular, an uplink signal can be effectively transmitted and received in an SBFD system.

[0014] FIG. 1 is a diagram illustrating an example of 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.

[0015] FIG. 2 is a diagram illustrating an example of a frame, subframe, and slot structure in a 5G system.

[0016] Figure 3 is a diagram illustrating an example of bandwidth portion settings in a 5G communication system.

[0017] FIG. 4 is a diagram illustrating an example of a control region in which a downlink control channel is transmitted in a 5G system.

[0018] FIG. 5 is a diagram illustrating an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G system.

[0019] FIG. 6 is a diagram illustrating an example of a method in which a base station and a terminal transmit and receive data by considering downlink data channels and rate matching resources.

[0020] Figure 7 is a diagram illustrating an example of frequency axis resource allocation of PDSCH in a 5G system.

[0021] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a 5G system.

[0022] FIG. 9 is a diagram illustrating an example of time-domain resource allocation according to the subcarrier spacing of a data channel and a control channel in a 5G system.

[0023] Figure 10 is a diagram illustrating an example of a structure in which SRS is allocated for each subband.

[0024] Fig. 11 is a diagram illustrating an example of an SRS antenna switching operation.

[0025] FIG. 12 is a diagram illustrating an example of SBFD operation in a TDD band of a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 13 is a diagram illustrating an example of resource settings of SBFD of a wireless communication system according to one embodiment of the present disclosure.

[0027] Figure 14a is a diagram illustrating an example of TDD resource settings.

[0028] Figure 14b is a diagram illustrating an example of SBFD resource settings.

[0029] FIG. 15 is a diagram illustrating a physical resource mapping method of SRS resources according to one embodiment of the present disclosure.

[0030] FIG. 16 is a diagram illustrating another method of physical resource mapping of SRS resources according to one embodiment of the present disclosure.

[0031] FIG. 17 is a diagram illustrating an example of an SRS transmission method using UL sub-band frequency hopping according to one embodiment of the present disclosure.

[0032] FIG. 18a is a diagram illustrating an example of a method for setting an SRS transmission-enabled area when the frequency domain size of a UL BWP is different from that of a UL sub-band.

[0033] FIG. 18b is a diagram illustrating an example of a method for setting an SRS transmission-enabled area when the frequency domain size of the UL BWP is the same as the UL sub-band.

[0034] FIG. 19 is a diagram illustrating an example of an SRS transmission method using an SRS transmission possible region setting in a multi-carrier situation according to one embodiment of the present disclosure.

[0035] FIG. 20A is a diagram illustrating an example of terminal operation according to one embodiment of the present disclosure.

[0036] FIG. 20b is a diagram illustrating an example of base station operation according to one embodiment of the present disclosure.

[0037] FIG. 21 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0038] FIG. 22 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (base station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (user equipment), an MS (mobile station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although an LTE (Long-Term Evolution) or LTE-A (LTE-advanced) system may be described below as an example, embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, this may include the fifth-generation mobile communication technology (5G, new radio, NR) developed after LTE-A. The term "5G" below may also encompass existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure.

[0044] 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).

[0045] 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.

[0046] 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'. In addition, the components and '~parts' may be implemented to play one or more central processing units (CPUs) within the device or secure multimedia card. Also, in an embodiment, the '~part' may include one or more processors.

[0047] 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.

[0048] The LTE system, a representative example of the above broadband wireless communication system, employs the orthogonal frequency division multiplexing (OFDM) method in the downlink and the single carrier frequency division multiple access (SC-FDMA) method in the uplink. The above multiple access method typically allocates and operates the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so that orthogonality is achieved, thereby enabling each user's data or control information to be distinguished.

[0049] As a future communication system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, services that simultaneously satisfy these requirements must be supported. Services being considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0050] 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 provide not only the peak data rate but also the 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.

[0051] 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 Internet of Things, mMTC requires support for large-scale terminal connection within a cell, improved terminal coverage, improved battery life, and reduced terminal costs. The Internet of Things provides communication functions by attaching various sensors and various devices, so a large number of terminals (e.g., 1,000,000 terminals / km) are required within a cell. 2 ) must be able to support. Furthermore, terminals supporting mMTC are likely to be located in shadow areas not covered by cells, such as basements of buildings, due to the nature of the service, and thus may require wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC must be comprised of low-cost terminals, and because it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, may be required.

[0052] 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 requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller transmit time interval (TTI) than other services, while simultaneously requiring design considerations such as allocating a wide range of resources in the frequency band to ensure communication link reliability.

[0053] The three services of a 5G system—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, the 5G system is not limited to the three services described above.

[0054] Below, the frame structure of the 5G system is described in more detail with reference to drawings.

[0055] FIG. 1 is a diagram illustrating an example of 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.

[0056] Referring to Figure 1, the horizontal axis 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) in the time axis and 1 subcarrier (103) in the frequency axis. In the frequency domain (For example, 12) consecutive REs can form one resource block (RB, 104).

[0057] FIG. 2 is a diagram illustrating an example of a frame, subframe, and slot structure in a 5G system.

[0058] Referring to FIG. 2, an example of a structure of a frame (frame, 200), a subframe (subframe, 201), and a slot (slot, 202) is illustrated. 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 μ = 0 (204) and μ = 1 (205) as the subcarrier spacing setting value 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.

[0059] μ 0141011142022144043148084141601651432032

[0060] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0061] Figure 3 is a diagram illustrating an example of bandwidth portion settings in a 5G communication system.

[0062] FIG. 3 illustrates 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 information such as Table 2 below for each bandwidth portion.

[0063] BWP ::= SEQUENCE {bwp-Id BWP-Id,(bandwidth part identifier)locationAndBandwidth INTEGER (1..65536),(bandwidth part location)subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5},(subcarrier spacing)cyclicPrefix ENUMERATED { extended}(cyclic prefix)}

[0064] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion may be configured for the terminal. The above information may be transmitted from the base station to the terminal via upper layer signaling, for example, radio resource control (RRC) signaling. At least one of the configured bandwidth portions may be activated. Whether or not the configured bandwidth portion is activated may be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via downlink control information (DCI).

[0065] According to some embodiments, a terminal before RRC connection can be configured with 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 about 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 of a physical broadcast channel (PBCH) during the initial access phase. The control region and search space configured by the MIB may each be regarded as an identity (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 about 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 to control area #0 obtained from the MIB as the initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion may be considered 0. In addition to receiving SIB, the initial bandwidth portion may also be utilized for other system information (OSI), paging, and random access.

[0066] The settings for the bandwidth portion supported by the above 5G system can be used for various purposes.

[0067] 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.

[0068] 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.

[0069] 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, such as 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 traffic-free environment 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, such as 20 MHz, for the terminal. In a traffic-free environment, the terminal may perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it may transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0070] When one or more bandwidth parts are set for a terminal, the base station can instruct the terminal to change (or switch, transition) the bandwidth part using the bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station can instruct the terminal to bandwidth part #2 (302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

[0071] As described above, since DCI-based bandwidth part change can be indicated by DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth part change request, it must be able to receive or transmit PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard stipulates the delay time (T) required when changing the bandwidth part. BWP ) are specified, and for example, the delay time can be defined as in Table 3.

[0072] μNR Slot length (ms)BWP switch delay T BWP (slots)Type 1 Note 1 Type 2 Note 1 011310.52520.253930.125618Note 1: Depends on UE capability.Note 2: If the BWP switch involves changing of SCS, the BWP switch delay is determined by the larger one between the SCS before BWP switch and the SCS after BWP switch.

[0073] The bandwidth-partial change delay time requirement supports Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth-partial delay time type to the base station.

[0074] According to the requirement for bandwidth part change delay time mentioned above, when the terminal receives DCI including bandwidth part change indicator in slot n, the terminal changes to the new bandwidth part indicated by the bandwidth part change indicator in slot n+T. BWPIt can be completed at a later time, and transmission and reception for the data channel scheduled by the DCI can be performed in the new bandwidth portion that has been changed. If the base station wants to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP ), time domain resource allocation for the data channel can be determined. That is, when the base station schedules a data channel with a new bandwidth portion, the data channel can be scheduled after the bandwidth portion change delay time in the method of determining time domain resource allocation for the data channel. Accordingly, the terminal can determine whether the DCI instructing a bandwidth portion change is after the bandwidth portion change delay time (T BWP ) may not be expected to indicate a slot offset (K0 or K2) value smaller than that.

[0075] If the terminal receives DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth change, the terminal may not perform any transmission or reception during the time period corresponding to the third symbol of the slot in which the PDCCH including the DCI is received, to the start of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0076] Next, we will explain the SS (synchronization signal) / PBCH block (or SSB (synchronization signal block)) in the 5G system.

[0077] 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.

[0078] - PSS: A signal that serves as a reference for downlink time / frequency synchronization and provides some information about the cell ID.

[0079] - SSS: It serves as a reference for downlink time / frequency synchronization and provides remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0080] - PBCH: Provides essential system information required for transmission and reception of data and control channels on 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.

[0081] - 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.

[0082] The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. The terminal can obtain MIB from PBCH and set control region #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 quasi-co-located (QCL). 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 a 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.

[0083] Next, we will specifically explain downlink control information (DCI) in 5G systems.

[0084] 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 fallback DCI format and a non-fallback DCI format 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.

[0085] DCI can be transmitted over 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 over 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.

[0086] 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).

[0087] 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 4.

[0088] - Identifier for DCI formats - [1] bit- Frequency domain resource assignment - [ ] bits- Time domain resource assignment - X bits- Frequency hopping flag - 1 bit.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- TPC command for scheduled PUSCH - [2] bits- UL / SUL indicator (uplink / supplementary UL indicator) - 0 or 1 bit

[0089] 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 5 below.

[0090] - Carrier indicator - 0 or 3 bits- UL / SUL indicator - 0 or 1 bit- Identifier for DCI formats - [1] bits- Bandwidth part indicator - 0, 1, or 2 bits- Frequency domain resource assignment- For resource allocation type 0 bits- For resource allocation type 1, bits- Time domain resource assignment -1, 2, 3, or 4 bits- VRB-to-PRB mapping (virtual resource block-to-physical resource block mapping) - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- Frequency hopping flag - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- 1st downlink assignment index (first downlink allocation index)- 1 or 2 bits○ 1 bit for semi-static HARQ-ACK codebook (semi-static HARQ-ACK In case of codebook);○ 2 bits for dynamic HARQ-ACK codebook with single HARQ-ACK codebook(When dynamic HARQ-ACK codebook is used with single HARQ-ACK codebook).- 2nd downlink assignment index (2nd downlink assignment index) - 0 or 2 bits○ 2 bits for dynamic HARQ-ACK codebook with two HARQ-ACK sub-codebooks(When dynamic HARQ-ACK codebook is used with two HARQ-ACK sub-codebooks);○ 0 bit otherwise.TPC command for scheduled PUSCH - 2 bits- SRS resource indicator (SRS resource indicator) -. or bits○ bits for non-codebook based PUSCH transmission; ○ bits for codebook based PUSCH transmission. - Precoding information and number of layers - up to 6 bits - Antenna ports - up to 5 bits - SRS request - 2 bits - CSI request - 0, 1, 2, 3, 4, 5, or 6 bits - CBG transmission information - 0, 2, 4, 6, or 8 bits - PTRS-DMRS association (Phase tracking reference signal-demodulation reference signal relationship) - 0 or 2 bits - beta_offset indicator - 0 or 2 bits - DMRS sequence initialization - 0 or 1 bit

[0091] 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 6 below.

[0092] - Identifier for DCI formats - [1] bit- Frequency domain resource assignment -[ ] bits- Time domain resource assignment - X bits- VRB-to-PRB mapping - 1 bit.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- Downlink assignment index - 2 bits- TPC command for scheduled PUCCH - [2] bits- PUCCH resource indicator (physical uplink control channel, PUCCH) - 3 bits- PDSCH-to-HARQ feedback timing indicator (PDSCH-to-HARQ feedback timing indicator) - [3] bits

[0093] 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 7 below.

[0094] - Carrier indicator - 0 or 3 bits- Identifier for DCI formats - [1] bits- Bandwidth part indicator - 0, 1 or 2 bits- Frequency domain resource assignment○ For resource allocation type 0, bits○ For resource allocation type 1, bits- Time domain resource assignment -1, 2, 3, or 4 bits- VRB-to-PRB mapping - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- PRB bundling size indicator - 0 or 1 bit - Rate matching indicator - 0, 1, or 2 bits - ZP CSI-RS trigger - 0, 1, or 2 bits For transport block 1 (for the first transport block): - Modulation and coding scheme - 5 bits - New data indicator - 1 bit - Redundancy version - 2 bits For transport block 2 (for the second transport block): - Modulation and coding scheme - 5 bits - New data indicator - 1 bit - Redundancy version - 2 bits - HARQ process number - 4 bits - Downlink assignment index - 0 or 2 or 4 bits - TPC command for scheduled PUCCH - 2 bits - PUCCH resource indicator - 3 bits - PDSCH-to-HARQ_feedback timing indicator - 3 bits - Antenna ports - 4, 5, or 6 bits- Transmission configuration indication - 0 or 3 bits- SRS request - 2 bits- CBG transmission information - 0, 2, 4, 6, or 8 bits- CBG flushing out information - 0 or 1 bit- DMRS sequence initialization - 1 bit.

[0095] Below, the downlink control channel in a 5G system will be described in more detail with reference to drawings.

[0096] FIG. 4 is a diagram illustrating an example of a control region in which a downlink control channel is transmitted in a 5G system.

[0097] Referring to FIG. 4, two control regions (control region #1 (401), control region #2 (402)) can be set within the UE bandwidth part (410) on the frequency axis and within 1 slot (420) on the time axis. The control regions (401, 402) can be set to specific frequency resources (403) within the entire UE bandwidth part (410) on 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). The control region #1 (401) is set to a control region length of 2 symbols, and the control region #2 (402) is set to a control region length of 1 symbol.

[0098] In the aforementioned 5G, the control region can be configured by the base station to the terminal via higher-layer signaling (e.g., system information (SI), MIB, RRC signaling). Configuring a control region for the terminal means providing information such as a control region identifier (iIdentity), the frequency location of the control region, and the symbol length of the control region. For example, the configuration information for the control region may include the information in Table 8.

[0099] ControlResourceSet ::= SEQUENCE {-- Corresponds to L1 parameter 'CORESET-ID' controlResourceSetId ControlResourceSetId,(Control domain identifier (Identity)) frequencyDomainResources BIT STRING (SIZE (45)),(Frequency axis resource allocation information) duration INTEGER (1..maxCoReSetDuration),(Time axis resource allocation information) cce-REG-MappingType CHOICE {(CCE-to-REG mapping method) interleaved SEQUENCE {reg-BundleSize ENUMERATED {n2, n3, n6},(REG bundle size) precoderGranularity ENUMERATED {sameAsREG-bundle, allContiguousRBs}, interleaverSize ENUMERATED {n2, n3, n6}(interleaver size) shiftIndex INTEGER(0..maxNrofPhysicalResourceBlocks-1) OPTIONAL(Interleaved Shift)},nonInterleaved NULL},tci-StatesPDCCH SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL,(QCL setting information)tci-PresentInDCI ENUMERATED {enabled} OPTIONAL, -- Need S}

[0100] In Table 8, the tci-StatesPDCCH (simply named TCI (transmission configuration indication) state) configuration information may include information on one or more SS / PBCH 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.

[0101] FIG. 5 is a diagram illustrating an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G system.

[0102] Referring to FIG. 5, the basic unit of time and frequency resources constituting a 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.

[0103] As illustrated in FIG. 5, 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. 5 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 and transmitted by one or multiple CCEs (504) 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.

[0104] The basic unit of the downlink control channel illustrated in FIG. 5, 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. 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, 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, consisting of 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.

[0105] 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.

[0106] In a 5G system, parameters for a search space for PDCCH can be configured from a base station to a terminal via 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 parameters (or configuration information) for the search space can include the information in Table 9.

[0107] SearchSpace ::= SEQUENCE {-- Identity of the search space. SearchSpaceId = 0 identifies the SearchSpace configured via PBCH (MIB) or ServingCellConfigCommon.searchSpaceId SearchSpaceId,(search space identifier)controlResourceSetId ControlResourceSetId,(control space identifier)monitoringSlotPeriodicityAndOffset CHOICE {(monitoring slot level period)sl1 NULL,sl2 INTEGER (0..1),sl4 INTEGER (0..3),sl5 INTEGER (0..4),sl8 INTEGER (0..7),sl10 INTEGER (0..9),sl16 INTEGER (0..15),sl20 INTEGER (0..19)} OPTIONAL,duration(monitoring length) INTEGER (2..2559)monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL,(슬롘 내 나이스 심보)nrofCandidates SEQUENCE {(집성 별보 PDCCH 이리군 수)aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}},searchSpaceType CHOICE {(தமாற்க்குக்க்கு திய்தை)-- Configures this search space as common search space (CSS) and DCI formats to monitor.common SEQUENCE {(공통이이국이)}ue-Specific SEQUENCE {(단말-특정이스국)-- Indicates whether the UE monitors in this USS for DCI formats 0-0 and 1-0 or for formats 0-1 and 1-1.formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1},...}.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] - 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

[0112] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0113] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0114] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0115] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0116] 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.

[0117] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0118] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0119] The RNTIs specified may follow the definitions and uses below.

[0120] C-RNTI (cell RNTI): For terminal-specific PDSCH scheduling purposes

[0121] TC-RNTI (temporary cell RNTI): For terminal-specific PDSCH scheduling purposes

[0122] CS-RNTI (configured scheduling RNTI): Used for semi-statically configured terminal-specific PDSCH scheduling.

[0123] RA-RNTI (random access RNTI): Used for PDSCH scheduling in the random access phase.

[0124] P-RNTI (paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0125] SI-RNTI (system information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0126] INT-RNTI (interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0127] TPC-PUSCH-RNTI (transmit power control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0128] TPC-PUCCH-RNTI (transmit power control for PUCCH RNTI): Used to indicate power control commands for PUCCH.

[0129] TPC-SRS-RNTI (transmit power control for SRS RNTI): Used to indicate power adjustment commands for SRS (sounding reference signal).

[0130] The aforementioned specified DCI formats may follow definitions such as the examples in Table 10.

[0131] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0132] In a 5G system, the search space of aggregation level L in CORESET p and search space set s can be expressed as in the following mathematical expression 1.

[0133] [Mathematical Formula 1]

[0134]

[0135] - L: Integration level

[0136] - nCI : Carrier Index

[0137] - n CCE,p : Total number of CCEs present in CORESET p

[0138] - : slot index

[0139] - : Number of PDCCH candidates for aggregation level L

[0140] - = 0, ..., -1: PDCCH candidate index of aggregation level L

[0141] - l = 0, ..., L -1

[0142] - , Y p,-1 = nRNTI≠0, A p = 39827 for p mod 3 = 0, A p = 39829 for p mod 3 = 1, A p = 39839 for p mod 3 = 2, D= 65537

[0143] - n RNTI : Terminal identifier

[0144] The value can be 0 for a common search space.

[0145] 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.

[0146] In a 5G system, since multiple search space sets can be set with different parameters (e.g., parameters in Table 9), 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 set with an X-slot period and search space set #2 is set 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.

[0147] Below, the rate matching operation and puncturing operation are described in detail.

[0148] When a time and frequency resource A, through which an arbitrary symbol sequence A is to be transmitted, overlaps with an arbitrary time and frequency resource B, a rate matching or puncturing operation may be considered for transmission and reception operations of channel A considering resource C, an area in which resources A and B overlap. The specific operations may follow the contents below.

[0149] The rate matching operation is as follows:

[0150] The base station can map and transmit channel A only for the remaining resource areas excluding resource C corresponding to the overlapping area with resource B among the entire resources A that want to transmit symbol sequence A to the terminal. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can sequentially map and transmit symbol sequence A to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A excluding {resource #3} corresponding to resource C. As a result, the base station can map and transmit symbol sequences {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4}, respectively.

[0151] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A, assuming that symbol sequence A was mapped and transmitted in the remaining area of ​​the entire resource A except for resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can receive symbol sequence A, assuming that it was sequentially mapped to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except for {resource #3}, which corresponds to resource C. As a result, the terminal can perform a series of subsequent reception operations, assuming that symbol sequences {symbol #1, symbol #2, symbol #3} were mapped and transmitted to {resource #1, resource #2, resource #4}, respectively.

[0152] The puncturing operation is as follows:

[0153] If a base station wants to transmit symbol sequence A to a terminal, and there is a resource C corresponding to an area overlapping with resource B among all resources A, the base station maps symbol sequence A to all resources A, but does not perform transmission in the resource area corresponding to resource C, and can perform transmission only for the remaining resource areas of resource A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the base station can map symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource #3, resource #4}, and transmit only the symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to the remaining resources {resource #1, resource #2, resource #4} excluding {resource #3} corresponding to resource C among resources A, and may not transmit {symbol #3} mapped to {resource #3} corresponding to resource C. As a result, the base station can transmit symbol sequences {symbol #1, symbol #2, symbol #4} by mapping them to {resource #1, resource #2, resource #4}, respectively.

[0154] The terminal can determine resources A and B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and B overlap. The terminal can receive symbol sequence A assuming that symbol sequence A is mapped to the entire resource A, but is transmitted only in the remaining area of ​​resource area A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, resource #4} respectively, but {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted, and can receive it assuming that symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to {resource #1, resource #2, resource #4}, which are the remaining resources among resource A except {resource #3} corresponding to resource C, are mapped and transmitted. As a result, the terminal can assume that the symbol sequence {symbol #1, symbol #2, symbol #4} is transmitted by being mapped to {resource #1, resource #2, resource #4}, respectively, and perform a series of subsequent receiving operations.

[0155] Below, we describe a method for configuring rate-matching resources for the purpose of rate matching in 5G systems. Rate matching refers to adjusting the size of a signal based on the amount of resources available for transmission. For example, rate matching for a data channel may mean adjusting the size of data accordingly, rather than mapping the data channel to a specific time and frequency resource region.

[0156] FIG. 6 is a diagram illustrating an example of a method in which a base station and a terminal transmit and receive data by considering downlink data channels and rate matching resources.

[0157] FIG. 6 illustrates a downlink data channel (PDSCH, 601) and a rate matching resource (602). A base station can configure one or more rate matching resources (602) to a terminal through upper layer signaling (e.g., RRC signaling). The rate matching resource (602) configuration information may include time-domain resource allocation information (603), frequency-domain resource allocation information (604), and period information (605). In the following, the bitmap corresponding to the frequency-domain resource allocation information (604) is named a first bitmap, the bitmap corresponding to the time-domain resource allocation information (603) is named a second bitmap, and the bitmap corresponding to the period information (605) is named a third bitmap. If all or part of the time and frequency resources of the scheduled data channel (601) overlap with the set rate matching resources (602), the base station can rate-match and transmit the data channel (601) in the rate matching resource (602) portion, and the terminal can perform reception and decoding after assuming that the data channel (601) is rate-matched in the rate matching resource (602) portion.

[0158] The base station can dynamically notify the terminal via DCI whether to rate-match the data channel in the set rate-matching resource portion through additional configuration (corresponding to the rate-matching indicator in the aforementioned DCI format). Specifically, the base station can select some of the set rate-matching resources and group them into rate-matching resource groups, and can use a bitmap to indicate to the terminal via DCI whether the data channel for each rate-matching resource group is rate-matched. For example, if four rate-matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2}, RMG#2={RMR#3, RMR#4} as the rate-matching groups, and can use two bits in the DCI field to indicate to the terminal whether to rate-match in RMG#1 and RMG#2, respectively, using a bitmap. For example, if rate matching is required, it can be indicated as "1", and if rate matching is not required, it can be indicated as "0".

[0159] In 5G systems, granularity at the RB symbol level and RE level is supported by setting the aforementioned rate matching resources on the terminal. More specifically, the following configuration method can be followed.

[0160] Below, the rate matching method at the RB symbol level is described.

[0161] A terminal can set up to four RateMatchPatterns for each bandwidth section through upper layer signaling, and one RateMatchPattern can include the following contents.

[0162] - As a reserved resource within the bandwidth section, a resource in which the time and frequency resource domains of the reserved resource are set by combining a bitmap at the RB level and a bitmap at the symbol level along the frequency axis may be included. The reserved resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may additionally be set.

[0163] - It may include a time and frequency domain resource area set as a control area within the bandwidth section and a resource area corresponding to a time domain pattern set as a search space setting in which the resource area is repeated.

[0164] Below we describe the RE level rate matching method.

[0165] The terminal can be configured with the following contents through upper layer signaling.

[0166] - The configuration information (lte-CRS-ToMatchAround) for RE corresponding to the LTE CRS (cell-specific reference signal or common reference signal) pattern may include the number of ports (nrofCRS-Ports) of LTE CRS and the LTE-CRS-vshift(s) value (v-shift), the center subcarrier location information (carrierFreqDL) of the LTE carrier from the reference frequency point (e.g., reference point A), the bandwidth size (carrierBandwidthDL) information of the LTE carrier, and the subframe configuration information (mbsfn-SubframConfigList) corresponding to the MBSFN (multicast-broadcast single-frequency network). Based on the above-described information, the terminal may determine the location of the CRS within the NR slot corresponding to the LTE subframe.

[0167] - It may include configuration information for a set of resources corresponding to one or more ZP (zero power) CSI-RSs within the bandwidth section.

[0168] Figure 7 is a diagram illustrating an example of frequency axis resource allocation of PDSCH in a 5G system.

[0169] In Fig. 7, three frequency axis resource allocation methods, type 0 (700), type 1 (705), and dynamic switch (710), which can be set via a higher layer in an NR wireless communication system, are illustrated. Referring to Fig. 7, if a terminal is set to use only resource type 0 (700) via higher layer signaling, some downlink control information (DCI) for allocating a PDSCH to the terminal is N RBGIt contains a bitmap consisting of N bits. The conditions for this will be explained later. In this case, N RBG refers to the number of RBGs (resource block groups) determined as shown in Table 11 below according to the BWP size allocated by the BWP indicator and the upper layer parameter rbg-Size, and data is transmitted to the RBG indicated as 1 by the bitmap.

[0170] Bandwidth Part SizeConfiguration 1Configuration 21-362437-724873-144816145-2751616

[0171] If the terminal is configured to use only resource type 1 through upper layer signaling (705), some DCIs that allocate PDSCH to the terminal It includes frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. Through this, the base station can set the starting VRB (720) and the length (725) of frequency axis resources allocated continuously therefrom.

[0172] If a terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (710), some DCIs that allocate PDSCH to the terminal include frequency-axis resource allocation information composed of bits of a larger value (735) among the payload (715) for configuring resource type 0 and the payload (720, 725) for configuring resource type 1. Conditions for this will be explained later. At this time, one bit may be added to the first part (MSB) of the frequency-axis resource allocation information in the DCI, and if the bit has a value of '0', it may indicate that resource type 0 is used, and if the bit has a value of '1', it may indicate that resource type 1 is used.

[0173] Below, a time domain resource allocation method for data channels in a 5G system is described.

[0174] A base station can set up a table for time domain resource allocation information for a downlink data channel (PDSCH) and an uplink data channel (PUSCH) to a terminal via higher layer signaling (e.g., RRC signaling). A table with up to maxNrofDL-Allocations=16 entries can be set up for the PDSCH, and a table with up to maxNrofUL-Allocations=16 entries can be set up for the PUSCH. In one embodiment, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time point of receiving a PDCCH and the time point of transmitting a PDSCH scheduled by the received PDCCH, denoted as K0), PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time point of receiving a PDCCH and the time point of transmitting a PUSCH scheduled by the received PDCCH, denoted as K2), information on the position and length of the start symbol for which a PDSCH or PUSCH is scheduled within a slot, the mapping type of the PDSCH or PUSCH, etc. For example, information such as Table 12 or Table 13 below may be transmitted from the base station to the terminal.

[0175] PDSCH-TimeDomainResourceAllocationList information elementPDSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofDL-Allocations)) OF PDSCH-TimeDomainResourceAllocationPDSCH-TimeDomainResourceAllocation ::= SEQUENCE {k0 INTEGER(0..32) OPTIONAL, -- Need S(PDCCH-to-PDSCH timing, in slot units)mappingType ENUMERATED {typeA, typeB},(PDSCH mapping type)startSymbolAndLength INTEGER (0..127)(PDSCH start symbol and length)}

[0176] PUSCH-TimeDomainResourceAllocationinformation elementPUSCH-TimeDomainResourceAllocationList ::= SEQUENCE (SIZE(1..maxNrofUL-Allocations)) OF PUSCH-TimeDomainResourceAllocationPUSCH-TimeDomainResourceAllocation ::= SEQUENCE {k2 INTEGER(0..32) OPTIONAL, -- Need S(PDCCH-to-PUSCH timing, in slot units)mappingType ENUMERATED {typeA, typeB},(PUSCH mapping type)startSymbolAndLength INTEGER (0..127)(PUSCH start symbol and length)}

[0177] The base station may notify the terminal of one of the entries in the table for the time domain resource allocation information described above via L1 signaling (e.g., DCI) (e.g., indicated by the 'Time Domain Resource Allocation' field in the DCI). The terminal may obtain the time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

[0178] FIG. 8 is a diagram illustrating an example of time axis resource allocation of PDSCH in a 5G system.

[0179] Referring to Figure 8, the base station uses the upper layer to set the subcarrier spacing (SCS) of the data channel and the control channel. PDSCH and μ PDCCH , the time axis position of the PDSCH resource can be indicated according to the scheduling offset (K0) value, and the start position (800) and length (805) of an OFDM symbol within a slot that are dynamically indicated through DCI.

[0180] FIG. 9 is a diagram illustrating an example of time-domain resource allocation according to the subcarrier spacing of a data channel and a control channel in a 5G system.

[0181] Referring to Fig. 9, when the subcarrier spacing of the data channel and the control channel is the same (900,μ PDSCH = μ PDCCH ), since the slot numbers for data and control are the same, the base station and the terminal can generate a scheduling offset according to the predetermined slot offset K0. On the other hand, if the subcarrier spacing of the data channel and the control channel are different (905,μ PDSCH ≠μ PDCCH), since the slot numbers for data and control are different, the base station and the terminal can generate a scheduling offset according to a predetermined slot offset K0 based on the subcarrier interval of the PDCCH.

[0182] 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.

[0183] Configured grant Type 1 PUSCH transmission can be semi-statically configured by receiving configuredGrantConfig including rrc-ConfiguredUplinkGrant of Table 14 through higher layer 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 14 through higher layer signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are applied through configuredGrantConfig of higher layer signaling of Table 14, except dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH provided by pusch-Config of Table 15. If the terminal has been provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of Table 14, the terminal applies tp-pi2BPSK in pusch-Config of Table 15 to PUSCH transmission operated by the configured grant.

[0184] ConfiguredGrantConfig ::= SEQUENCE {frequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need S,cg-DMRS-Configuration DMRS-UplinkConfig,mcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { CG-UCI-OnPUSCH} OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},rbg-Size ENUMERATED {config2} OPTIONAL, -- Need SpowerControlLoopToUse ENUMERATED {n0, n1},p0-PUSCH-Alpha P0-PUSCH-AlphaSetId,transformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need SnrofHARQ-Processes INTEGER(1..16),repK ENUMERATED {n1, n2, n4, n8},repK-RV ENUMERATED {s1-0231, s2-0303, s3-0000} OPTIONAL, -- Need Rperiodicity ENUMERATED {sym2, sym7, sym1x14, sym2x14, sym4x14, sym5x14, sym8x14, sym10x14, sym16x14, sym20x14,sym32x14, sym40x14, sym64x14, sym80x14, sym128x14, sym160x14, sym256x14, sym320x14, sym512x14,sym640x14, sym1024x14, sym1280x14, sym2560x14, sym5120x14,sym6, sym1x12, sym2x12, sym4x12, sym5x12, sym8x12, sym10x12, sym16x12, sym20x12, sym32x12,sym40x12, sym64x12, sym80x12, sym128x12, sym160x12, sym256x12, sym320x12, sym512x12, sym640x12,sym1280x12, sym2560x12},configuredGrantTimer INTEGER (1..64) OPTIONAL, -- Need Rrrc-ConfiguredUplinkGrant SEQUENCE {timeDomainOffset INTEGER (0..5119),timeDomainAllocation INTEGER (0..15),frequencyDomainAllocation BIT STRING (SIZE(18)),antennaPort INTEGER (0..31),dmrs-SeqInitialization INTEGER (0..1) OPTIONAL, -- Need RprecodingAndNumberOfLayers INTEGER (0..63),srs-ResourceIndicator INTEGER (0..15) OPTIONAL, -- Need RmcsAndTBS INTEGER (0..31),frequencyHoppingOffset INTEGER (1.. maxNrofPhysicalResourceBlocks-1) OPTIONAL, -- Need RpathlossReferenceIndex INTEGER (0..maxNrofPUSCH-PathlossReferenceRSs-1),...} OPTIONAL, -- Need R...}.

[0185] Next, the PUSCH transmission method is described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based or non-codebook-based transmission method, respectively, depending on whether the value of txConfig in the upper signaling, pusch-Config in Table 15, is 'codebook' or 'nonCodebook'.

[0186] 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 receive txConfig in pusch-Config of Table 15, the UE does not expect to be scheduled with DCI format 0_1.

[0187] PUSCH-Config ::= SEQUENCE {dataScramblingIdentityPUSCH INTEGER (0..1023) OPTIONAL, -- Need StxConfig ENUMERATED {codebook, nonCodebook} OPTIONAL, -- Need Sdmrs-UplinkForPUSCH-MappingTypeA SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mdmrs-UplinkForPUSCH-MappingTypeB SetupRelease { DMRS-UplinkConfig} OPTIONAL, -- Need Mpusch-PowerControl PUSCH-PowerControl OPTIONAL, -- Need MfrequencyHopping ENUMERATED {intraSlot, interSlot} OPTIONAL, -- Need SfrequencyHoppingOffsetLists SEQUENCE (SIZE (1..4)) OF INTEGER (1..maxNrofPhysicalResourceBlocks-1)OPTIONAL, -- Need MresourceAllocation ENUMERATED { resourceAllocationType0, resourceAllocationType1, dynamicSwitch},pusch-TimeDomainAllocationList SetupRelease { PUSCH-TimeDomainResourceAllocationList} OPTIONAL, -- Need Mpusch-AggregationFactor ENUMERATED { n2, n4, n8} OPTIONAL, -- Need Smcs-Table ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need Smcs-TableTransformPrecoder ENUMERATED {qam256, qam64LowSE} OPTIONAL, -- Need StransformPrecoder ENUMERATED {enabled, disabled} OPTIONAL, -- Need ScodebookSubset ENUMERATED {fullyAndPartialAndNonCoherent, partialAndNonCoherent,nonCoherent}OPTIONAL, -- Cond codebookBasedmaxRank INTEGER (1..4) OPTIONAL, -- Cond codebookBasedrbg-Size ENUMERATED { config2} OPTIONAL, -- Need Suci-OnPUSCH SetupRelease { UCI-OnPUSCH} OPTIONAL, -- Need Mtp-pi2BPSK ENUMERATED {enabled} OPTIONAL, -- Need S...}.

[0188] Next, we describe codebook-based PUSCH transmission. 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. 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 SRI (SRS resource indicator), TPMI (transmission precoding matrix indicator), and transmission rank (the number of PUSCH transmission layers).

[0189] 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.

[0190] 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'.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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 on the precoder for SRS transmission to be updated.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] Next, we will describe the PUSCH preparation procedure time. When the base station schedules a UE to transmit a PUSCH using DCI format 0_0, 0_1, or 0_2, the UE may require a PUSCH preparation procedure time to transmit the PUSCH using the transmission method indicated through the DCI (transmission precoding method of SRS resources, number of transmission layers, spatial domain transmission filter). In the 5G system, the PUSCH preparation procedure time has been defined taking this into account. The PUSCH preparation procedure time of the UE can be expressed as Equation 2 below.

[0200] [Equation 2]

[0201] T proc,2 = max(( N2+ d 2,1 + d2)( 2048 + 144 ) κ2 -μ T c + T ext + T switch , d 2,2 )

[0202] T as described in mathematical formula 2 proc,2 In , each variable can have the following meanings:

[0203] - N2: The number of symbols determined by the UE processing capability (UE processing capability) 1 or 2 and the numerology μ according to the UE's capability. If UE processing capability 1 is reported according to the UE's capability report, it may have the value in Table 16. If UE processing capability 2 is reported and the availability of UE processing capability 2 is set through upper layer signaling, it may have the value in Table 17.

[0204] μPUSCH preparation time N2[symbols]010112223336

[0205] μPUSCH preparation time N2[symbols]0515.5211 for frequency range 1

[0206] - d 2,1 : The number of symbols set to 0 if all REs of the first OFDM symbol of PUSCH transmission are configured to consist of only DM-RS, and 1 otherwise.

[0207] - κ: 64

[0208] - μ: μ DL or μ UL Medium, T proc,2 This follows the larger value μ DL refers to the numerology of the downlink in which the PDCCH containing the DCI scheduling the PUSCH is transmitted, and μ ULIt refers to the numerology of the uplink in which PUSCH is transmitted.

[0209] - T c : 1 / (Δf max *N f ), Δf max = 480×10 3 Hz, N f =has 4096.

[0210] - d 2,2 : If the DCI scheduling the PUSCH indicates BWP switching, it follows the BWP switching time, otherwise it has 0.

[0211] - d2: When the OFDM symbols of a PUCCH with a high priority index and a PUCCH with a low priority index overlap in time, the d2 value of the PUSCH with the high priority index is used. Otherwise, d2 is 0.

[0212] - T ext : If the terminal uses a shared spectrum channel access method, the terminal is T ext can be calculated and applied to the PUSCH preparation process time. Otherwise, T ext is assumed to be 0.

[0213] - T switch : T when the uplink switching interval is triggered switch is assumed to be the switching interval time. Otherwise, it is assumed to be 0.

[0214] When the base station and the terminal consider the time domain resource mapping information of the PUSCH scheduled through DCI and the influence of the timing advance between uplink and downlink, the base station and the terminal determine T from the last symbol of the PDCCH including the DCI that scheduled the PUSCH. proc,2If the first symbol of the PUSCH begins before the first uplink symbol of the CP, the PUSCH preparation time is determined to be insufficient. Otherwise, the base station and the UE determine that the PUSCH preparation time is sufficient. The UE transmits the PUSCH only when the PUSCH preparation time is sufficient, and may ignore the DCI scheduling the PUSCH if the PUSCH preparation time is insufficient.

[0215] Next, we describe an uplink channel estimation method using SRS (sounding reference signal) transmission from a terminal. To convey configuration information for SRS transmission to a terminal, a base station can configure at least one SRS configuration for each uplink bitmap (BWP) and at least one SRS resource set for each SRS configuration. For example, the base station and terminal can exchange the following upper-layer signaling information to convey information regarding SRS resource sets.

[0216] - srs-ResourceSetId: SRS resource set index

[0217] - srs-ResourceIdList: A set of SRS resource indices referenced in the SRS resource set.

[0218] - 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.

[0219] - 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'.

[0220] - alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for adjusting the transmission power of the SRS resource referenced in the SRS resource set.

[0221] - 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.

[0222] 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.

[0223] 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 the 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 info 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.

[0224] For example, a base station can activate or deactivate semi-persistent SRS transmission to a terminal through higher 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 via 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 via higher layer signaling.

[0225] 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 may apply a 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 may refer to the spatial relation information configured in the SRS resource, or may refer to the associated CSI-RS information configured in the SRS resource set including the SRS resource. The UE may transmit the SRS resource within the activated uplink BWP for the aperiodic SRS resource triggered through the DCI.

[0226] 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.

[0227] SRS-Resource ::= SEQUENCE {srs-ResourceId SRS-ResourceId,nrofSRS-Ports ENUMERATED {port1, ports2, ports4},ptrs-PortIndex ENUMERATED {n0, n1} OPTIONAL, -- Need RtransmissionComb CHOICE {n2 SEQUENCE {combOffset-n2 INTEGER (0..1),cyclicShift-n2 INTEGER (0..7)},n4 SEQUENCE {combOffset-n4 INTEGER (0..3),cyclicShift-n4 INTEGER (0..11)}},resourceMapping SEQUENCE {startPosition INTEGER (0..5),nrofSymbols ENUMERATED {n1, n2, n4},repetitionFactor ENUMERATED {n1, n2, n4}},freqDomainPosition INTEGER (0..67),freqDomainShift INTEGER (0..268),freqHopping SEQUENCE {c-SRS INTEGER (0..63),b-SRS INTEGER (0..3),b-hop INTEGER (0..3)},groupOrSequenceHopping ENUMERATED { neither, groupHopping, sequenceHopping},resourceType CHOICE {aperiodic SEQUENCE {...},semi-persistent SEQUENCE {periodicityAndOffset-sp SRS-PeriodicityAndOffset,...},periodic SEQUENCE {periodicityAndOffset-p SRS-PeriodicityAndOffset,...}},sequenceId INTEGER (0..1023),spatialRelationInfo SRS-SpatialRelationInfo OPTIONAL, -- Need R...}

[0228] The spatialRelationInfo setting information in Table 18 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 19 below.

[0229] SRS-SpatialRelationInfo ::= SEQUENCE {servingCellId ServCellIndex OPTIONAL, -- Need SreferenceSignal CHOICE {ssb-Index SSB-Index,csi-RS-Index NZP-CSI-RS-ResourceId,srs SEQUENCE {resourceId SRS-ResourceId,uplinkBWP BWP-Id}}}

[0230] 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 CSI-RS index, 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 ssb-Index as the transmission beam for the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'csi-RS-Index', the terminal can apply the reception beam used when receiving the CSI-RS corresponding to csi-RS-Index as the transmission beam for the corresponding SRS transmission. If the value of the upper signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used when transmitting the SRS corresponding to the srs as the transmission beam for the corresponding SRS transmission.

[0231] SRSs of multiple terminals can be distinguished not only by cyclic shift value but also by frequency location. Frequency location can be distinguished by SRS subband unit allocation or comb. 5G systems can support comb2, comb4, and comb8. In the case of comb2, an SRS can be allocated only to the even or odd subcarriers within an SRS subband. In this case, the even and odd subcarriers can each form a comb.

[0232] Each terminal can be assigned an SRS subband based on a tree structure. Each terminal can hop to the SRS assigned to each subband at each SRS transmission point. This allows all transmit antennas on the terminal to transmit SRS using the entire uplink data transmission bandwidth.

[0233] Figure 10 is a diagram illustrating an example of a structure in which SRS is allocated for each subband.

[0234] Referring to Fig. 10, an example is shown in which an SRS is allocated to each terminal according to the tree structure described by the base station when the data transmission band corresponds to 40 RB in frequency.

[0235] In Fig. 10, when the level index of the tree structure is b, the top level (b=0) of the tree structure can be composed of one SRS subband with a 40 RB bandwidth. In the second level (b=1), two SRS subbands with a 20 RB bandwidth can be generated from the SRS subband of the b=0 level. Therefore, two SRS subbands can exist in the entire data transmission band of the second level (b=1). In the third level (b=2), five 4 RB SRS subbands can be generated from one 20 RB SRS subband of the level immediately above (b=1), and a structure can be formed in which ten 4 RB SRS subbands exist within one level.

[0236] The configuration of this tree structure can have various levels, SRS subband sizes, and number of SRS subbands per level depending on the settings of the base station. Here, the number of SRS subbands at level b generated from one SRS subband of the upper level is N b , and this N b The indices for the SRS subbands are n b ={0,...,N b-1} can be defined. As the subbands per level are different in this way, terminals can be allocated to each subband per level as illustrated in FIG. 10. For example, terminal 1 (1000) can be allocated to the first SRS subband (n1=0) of two SRS subbands having a 20 RB bandwidth at level b=1, and terminal 2 (1001) and terminal 3 (1002) can be allocated to the first SRS subband (n2=0) and the third SRS subband (n2=2) below the second 20 RB SRS subband, respectively. Through these processes, the terminal can simultaneously transmit SRS through multiple CCs (component carriers), and can simultaneously transmit SRS through multiple SRS subbands within one CC.

[0237] Specifically, for the SRS subband settings described above, NR supports SRS bandwidth configurations as shown in Table 20 below.

[0238] [Table 20]

[0239]

[0240]

[0241] Additionally, the 5G system supports SRS frequency hopping based on the values ​​in Table 20 above, and the detailed procedure is as follows.

[0242]

[0243]

[0244]

[0245]

[0246] According to the above, when mapping physical resources of SRS, the starting point of frequency resources can be determined according to mathematical expressions 3 to 5 below.

[0247] [Equation 3]

[0248]

[0249] [Equation 4]

[0250]

[0251] [Equation 5]

[0252]

[0253] In order to determine the frequency start position of the above SRS resource, a reference point of the resource grid can be determined. If the frequency shift value (frequency domain shift, n) set from the base station in the above mathematical expression 4 shift ) is the starting position of the uplink bandwidth portion that is set ( ), the reference point on the resource grid may be common resource block 0. Otherwise (i.e., the frequency shift value set from the base station is less than or equal to the start position of the uplink bandwidth portion), the reference point on the resource grid may be the lowest subcarrier index of the set bandwidth portion.

[0254] Below, SRS for antenna switching is described.

[0255] The SRS transmitted from the terminal can be used by the base station to acquire DL CSI (channel state information) information (e.g., DL CSI acquisition). As a specific example, in a TDD-based single cell or multi-cell (e.g., carrier aggregation (CA)) situation, the base station can schedule the transmission of the SRS to the terminal and then measure the SRS transmitted from the terminal. In this case, the base station can regard the uplink channel information estimated based on the SRS transmitted from the terminal as downlink channel information, assuming reciprocity between the DL (downlink) and UL (uplink) channels, and can perform downlink signal and / or channel scheduling for the terminal using the uplink channel information. In this case, the terminal can be configured to use antenna switching for the SRS for acquiring downlink channel information from the base station.

[0256] For example, according to the standard (e.g., 3gpp TS38.214), the purpose of SRS can be set to the base station and / or terminal using upper layer parameters (e.g., usage of RRC parameter SRS-ResourceSet). Here, the purpose of SRS can be set to beam management purpose, codebook transmission purpose, non-codebook transmission purpose, antenna switching purpose, etc.

[0257] As described above, if the terminal receives the usage parameter in the upper layer signaling SRS-ResourceSet from the base station as 'antennaSwitching', the terminal can receive at least one upper layer signaling from the base station according to the reported terminal capability. At this time, the terminal can report 'supportedSRS-TxPortSwitch' as ​​the terminal capability, and the value can be as follows. In the following, 'mTnR' can mean the terminal capability that supports transmission through m antennas and reception through n antennas.

[0258] - 't1r2': Terminal capability report value indicating that the terminal is capable of 1T2R operation.

[0259] - 't1r1-t1r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 1T2R operation.

[0260] - 't2r4': Terminal capability report value indicating that the terminal is capable of 2T4R operation.

[0261] - 't1r4': Terminal capability report value indicating that the terminal is capable of 1T4R operation.

[0262] - 't1r6': Terminal capability report value indicating that the terminal is capable of 1T6R operation.

[0263] - 't1r8': Terminal capability report value indicating that the terminal is capable of 1T8R operation.

[0264] - 't2r6': Terminal capability report value indicating that the terminal is capable of 2T6R operation.

[0265] - 't2r8': Terminal capability report value indicating that the terminal is capable of 2T8R operation.

[0266] - 't4r8': Terminal capability report value indicating that the terminal is capable of 4T8R operation.

[0267] - 't1r1-t1r2-t1r4': Terminal capability report value indicating that the terminal is capable of 1T1R, 1T2R, or 1T4R operation.

[0268] - 't1r4-t2r4': Terminal capability report value indicating that the terminal is capable of 1T4R or 2T4R operation.

[0269] - 't1r1-t1r2-t2r2-t2r4': Terminal capability reporting value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, or 2T4R operation.

[0270] - 't1r1-t1r2-t2r2-t1r4-t2r4': Terminal capability reporting value indicating that the terminal is capable of 1T1R, 1T2R, 2T2R, 1T4R, or 2T4R operation.

[0271] - 't1r1': Terminal capability report value indicating that the terminal is capable of 1T1R operation.

[0272] - 't2r2': Terminal capability report value indicating that the terminal is capable of 2T2R operation.

[0273] - 't1r1-t2r2': Terminal capability report value indicating that the terminal is capable of 1T1R or 2T2R operation.

[0274] - 't4r4': Terminal capability report value indicating that the terminal is capable of 4T4R operation.

[0275] - 't1r1-t2r2-t4r4': Terminal capability reporting value indicating that the terminal is capable of 1T1R, 2T2R, or 4T4R operation.

[0276] Fig. 11 is a diagram illustrating an example of an SRS antenna switching operation.

[0277] Figure 11 illustrates a situation where a terminal operates in 1T2R, and periodically configures SRS resource set #0 (1100) among two different resource type SRS resource sets (e.g., SRS resource set #0 or #1). The terminal can transmit SRS resources within the SRS resource set according to the period configured by the base station.

[0278] SRS resource #1 (1101) and SRS resource #2 (1102) included in SRS resource set #0 (1100) are transmitted at different OFDM symbol positions within the UL slot (slot #1), and at this time, Y number of OFDM symbols may exist as a guard interval between SRS resources #1 and #2 (1103). In addition, when transmitting for SRS resource #1 (1101), the terminal can perform SRS transmission by connecting one SRS port to the first receiving antenna port of the terminal (1104), and when transmitting for SRS resource #2 (1102), the terminal can perform SRS transmission by connecting one SRS port to the second receiving antenna port of the terminal (1105).

[0279] By connecting the two SRS resources #1 and #2 described above to different receiving antenna ports of the terminal and transmitting the SRS, the terminal can transmit the SRS through all different receiving antennas so as to obtain channel information connected to all receiving antennas of the terminal, and through this, the base station can obtain channel information between the base station and the terminal and utilize it for uplink or downlink scheduling.

[0280] Next, SRS carrier switching will be described. In a TDD system, SRS carrier switching is used to perform SRS transmission to support downlink channel estimation of the base station for supporting cells that do not have PUSCH / PUCCH transmission configured, i.e., cells that only support downlink transmission. This is because channel reciprocity is established between the downlink and uplink channels in a TDD system, so the base station can estimate the downlink channel based on the uplink channel estimated through SRS. This has the advantage of requiring less overhead for downlink channel estimation through SRS-based channel reciprocity compared to CSI-RS-based downlink channel estimation when the base station supports transmission with a large number of antennas but the terminal supports reception with a relatively small number of antennas.

[0281] In order to transmit SRS to a cell that only supports downlink transmission through SRS carrier switching, the UE must use the RF transmitter for uplink transmission of one of the other cells. This is because the target cell (hereinafter referred to as target cell or target CC) that performs SRS carrier switching is a frequency band that only supports downlink transmission for which PUCCH / PUSCH transmission is not configured, and thus the RF transmitter is not used except for the purpose of SRS carrier switching. Therefore, considering aspects such as the cost of the UE, an RF transmitter for uplink transmission to the target cell that performs SRS carrier switching is not separately deployed, and when SRS carrier switching is scheduled (hereinafter, scheduling for performing SRS carrier switching may include scheduling based on AP (aperiodic) triggering based on DCI (downlink control information) format 2_3 or SP (semi-persistent) or P (periodic) triggering based on higher layer configuration), the UE can transmit SRS by retuning the RF transmitter for uplink transmission of the other cell. In order to perform the above SRS carrier switching, the cell in which the RF transmitter is placed before the terminal retunes can be defined as a source cell (hereinafter referred to as source cell or source CC), and this can be set in the terminal through the upper layer parameters srs-SwitchFromServCellIndex and srs-SwitchFromCarrier of the terminal.The upper layer parameter srs-SwitchFromServCellIndex indicates the cell index of the source CC, and srs-SwitchFromCarrier indicates either NUL (normal uplink) or SUL (supplementary uplink) of the target CC to determine the RF transmitter to which the terminal should retun.

[0282] When performing SRS carrier switching, the UE requires a retuning time, which is the time it takes for the RF transmitter of the source CC to prepare to transmit SRS to the target CC, and a time for the RF transmitter to retun back to the source CC after transmitting all SRSs to the target CC. This is an additional time required in addition to the preparation time required to transmit SRS for purposes other than SRS carrier switching. In this way, the UE can report the UE capability to the base station to inform the base station of the required time for the RF transmitter retuning time before and after performing SRS carrier switching. At this time, the UE can report the retuning time of the RF transmitter to the base station through switchingTimeUL and switchingTimeDL.

[0283] Since the UE retunes the RF transmitter from the source CC to perform SRS carrier switching, it cannot transmit an uplink signal (e.g., PUCCH, PUSCH, or SRS) to the source CC while transmitting an SRS to the target CC. Therefore, to perform SRS carrier switching, the UE first checks whether an uplink transmission scheduled on the source CC overlaps with an SRS transmission including the RF retuning time. If an uplink transmission scheduled on the source CC overlaps with an SRS transmission (including the returning time) scheduled on the target CC, and simultaneous transmission is not possible behind the UE's indicated UL CA capability, the UE compares the priorities between the two signals and can transmit only one uplink signal. At this time, the priorities for SRS carrier switching defined in NR release 15 / 16 are as follows:

[0284] - If the PUSCH or PUCCH and / or PRACH (physical random access channel) that includes one or more pieces of information from the source CC, including HARQ-ACK / positive SR (scheduling request) / RI (rank indicator) / CRI (CSI-RS resource indicator) / SSBRI (SS / PBCH block resource indicator), and the SRS transmission to the target CC overlap, the UE may not transmit the SRS of the target CC. That is, the uplink signal scheduled for the source CC may be transmitted without performing SRS carrier switching.

[0285] - If a PUSCH containing aperiodic CSI in the source CC overlaps with a periodic or semi-persistent SRS transmission in the target CC, the UE may not transmit the periodic or semi-persistent SRS in the target CC. In other words, the UE may transmit the uplink signal scheduled for the source CC without performing SRS carrier switching.

[0286] - If the PUCCH or PUSCH and / or SRS including periodic or semi-persistent CSI consisting of only one or more pieces of information from CQI (channel quality indicator) / PMI (precoding matrix indicator) / L1-RSRP (layer 1 reference signal received power) / L1-SINR (layer 1 signal to interference plus noise ratio) overlaps with the SRS transmission on the target CC, the UE may not transmit the PUCCH or PUSCH and / or SRS of the source CC. That is, the UE may transmit the SRS to the target CC by performing SRS carrier switching.

[0287] - If a PUSCH including aperiodic CSI consisting of only one or more pieces of information among CQI / PMI / L1-RSRP / L1-SINR in the source CC overlaps with an aperiodic SRS transmission in the target CC, the UE may not transmit the PUSCH of the source CC. That is, the UE may transmit an aperiodic SRS to the target CC by performing SRS carrier switching.

[0288] When comparing the priorities between uplink transmissions of the source CC and SRS transmissions of the target CC, the time it takes for the UE to receive and decode the DCI scheduling each transmission, the time it takes for the UE to decide on uplink transmission based on higher layer settings, the preparation time required to transmit the uplink signal, and the SRS transmission preparation time, which includes the RF retuning time of the target CC, must be taken into account. This is because once the UE prepares for either the uplink transmission of the source CC or the SRS transmission of the target CC, it cannot be canceled. For example, even if a DCI scheduling a high-priority uplink signal transmission to the source CC is received while the UE is preparing for an SRS transmission to an already scheduled target CC (taking into account all preparation times, including DCI decoding and RF retuning time), the UE cannot cancel the SRS transmission to the target CC. Since this case is classified as a scheduling error, the base station must consider the following conditions when performing SRS carrier switching.

[0289] The terminal cancels one of the specific transmissions (uplink signal transmission from the source CC or SRS transmission from the target CC) by (target CC) symbol Start SRS transmission from the carrier Symbol of (source CC) For conflicting uplink transmissions, the above-described priority rules (priority rules between uplink transmissions of the source CC and SRS transmissions of the target CC) are applied, taking into account the following conditions:

[0290] - The last symbol of PDCCH and The gap between the livers is at least Symbols and is greater than the sum of the last symbol of the PDCCH and The gap between the livers is at least DCI(s) must be received by the terminal to be larger than the symbol. At this time, the DCI may correspond to both DCI scheduling uplink signal transmission on the source CC and DCI scheduling SRS transmission on the target CC.

[0291] - Semi-persistent CSI reporting or SRS transmission At least based on Symbols and is active before an interval greater than the sum of At least based on It must be activated before an interval greater than the symbol. The transmission activated at this time may include both uplink transmissions from the source CC and SRS transmissions from the target CC.

[0292] Here Is = max{switchingTimeUL,switchingTimeDL}, and the time interval unit of the OFDM symbol is , And it is determined based on the smallest SCS (subcarrier spacing) among the corresponding scheduling cells (if the overlapping uplink signal is not transmitted to the target CC or source CC). It refers to the processing ability according to the terminal's capability for the PUSCH preparation process time described later.

[0293] When a terminal receives an SRS request through DCI (or grant) for target CC c and transmits the nth aperiodic SRS, the terminal can start transmitting the SRS in the configured symbol and slot that satisfies the following conditions:

[0294] - The set symbol and slot are values ​​that are later than the sum of the detailed conditions below.

[0295] ■ The maximum time interval among the time intervals equal to the number of N OFDM symbols for each cell containing Target CC c and DCI (or grant)

[0296] ■ Uplink or downlink RF retuning time defined by switchingTimeUL and switchingTimeDL of upper layer parameters SRS-SwitchingTimeNR

[0297] - Does not collide with any previous SRS transmission (SRS transmission prior to the nth aperiodic SRS) and is not interrupted by uplink or downlink RF retuning time.

[0298] If the above condition is not satisfied, the terminal does not transmit the nth SRS, where N is the minimum time interval in symbol units between the DCI that triggers the aperiodic SRS and the aperiodic SRS, which is reported as the terminal capability.

[0299] In case of inter-band CA, based on the capabilities of the terminal, the terminal can simultaneously transmit SRS and PUCCH / PUSCH for CCs of different bands.

[0300] In case of inter-band CA, based on the capabilities of the terminal, the terminal can simultaneously transmit PRACH and SRS for CCs of different bands.

[0301] Meanwhile, 3GPP is discussing SBFD (Subband Non-Overlapping Full Duplex) as a new duplex method based on NR. SBFD is a technology that utilizes a portion of downlink resources as uplink resources in the TDD band (spectrum) of frequencies below 6 GHz or above 6 GHz, thereby receiving uplink transmissions from terminals equivalent to the increased uplink resources, thereby expanding the uplink coverage of the terminal, and receiving feedback from the terminal on downlink transmissions using the expanded uplink resources, thereby reducing feedback delay. In the present disclosure, a terminal that receives information on whether SBFD is supported from a base station and can perform uplink transmissions using a portion of downlink resources may be conveniently referred to as an SBFD terminal (SBFD-capable UE). The following methods may be considered for defining the SBFD method in the standard and for an SBFD terminal to determine whether SBFD is supported in a specific cell (or frequency, frequency band).

[0302] First method: In addition to the frame structure type of the existing unpaired spectrum (or time division duplex, TDD) or paired spectrum (or frequency division duplex, FDD), another frame structure type (e.g., frame structure type 2) may be introduced to define the SBFD described above. The frame structure type 2 may be defined to be supported in the specific frequency or frequency band, or the base station may indicate to the terminal whether SBFD is supported as system information. The SBFD terminal may receive the system information including whether SBFD is supported and determine whether SBFD is supported in the specific cell (or frequency, frequency band).

[0303] Second method: Whether SBFD is additionally supported in a specific frequency or frequency band of an existing unpaired spectrum (or TDD) can be indicated without defining a new frame structure type. In the second method, whether SBFD is additionally supported in a specific frequency or frequency band of an existing unpaired spectrum can be defined, or the base station can indicate to the terminal whether SBFD is supported as system information. The SBFD terminal can receive the system information including whether SBFD is supported and determine whether SBFD is supported in the specific cell (or frequency, frequency band).

[0304] In the first and second methods described above, information on whether SBFD is supported may be information that indirectly indicates whether SBFD is supported by additionally setting a portion of downlink resources as uplink resources in addition to the settings for TDD UL-DL resource configuration information indicating downlink slot (or symbol) resources and uplink slot (or symbol) resources of TDD (for example, SBFD resource configuration information in FIG. 15 described below), or may be information that directly indicates whether SBFD is supported.

[0305] In the present disclosure, the SBFD terminal can obtain cell synchronization by receiving a synchronization signal block during the initial cell access for connecting to a cell (or base station). The process for obtaining cell synchronization may be the same for the SBFD terminal and the existing TDD terminal. Thereafter, the SBFD terminal can determine whether the cell supports SBFD through a MIB acquisition process, a SIB acquisition process, or a random access process.

[0306] The system information for transmitting information on whether the above SBFD is supported may be system information transmitted separately from the system information for terminals supporting other versions of the standard within the cell (e.g., existing TDD terminals), and the SBFD terminal may determine whether SBFD is supported by obtaining all or part of the system information for the existing TDD terminal and the separately transmitted system information. If the SBFD terminal obtains only the system information for the existing TDD terminal or obtains system information on non-support of SBFD, the cell (or base station) may determine that it supports only TDD.

[0307] If the information on whether the above SBFD is supported is included in the system information for a terminal supporting a different version of the standard (e.g., an existing TDD terminal), the information on whether the above SBFD is supported may be inserted at the very end so as not to affect the acquisition of system information by the existing TDD terminal. If the SBFD terminal does not obtain the information on whether the above SBFD is supported inserted at the very end, or obtains information that SBFD is not supported, the SBFD terminal can determine that the cell (or base station) only supports TDD.

[0308] If the information on whether the SBFD is supported is included in the system information for a terminal supporting a different version of the standard (e.g., an existing TDD terminal), the information on whether the SBFD is supported may be transmitted through a separate PDSCH so as not to affect the acquisition of system information by the existing TDD terminal. That is, a terminal that does not support SBFD can receive a first SIB (or SIB1) including existing TDD-related system information from a first PDSCH. A terminal that supports SBFD can receive a first SIB (or SIB) including existing TDD-related system information from a first PDSCH, and a second SIB including SBFD-related system information from a second PDSCH. Here, the first PDSCH and the second PDSCH can be scheduled as the first PDCCH and the second PDCCH, and the CRCs of the first PDCCH and the second PDCCH can be scrambled with the same RNTI (e.g., SI-RNTI). The search space for monitoring the second PDCCH can be obtained from the system information of the first PDSCH, and if it is not obtained (i.e., the system information of the first PDSCH does not include information about the search space), the second PDCCH can be received in the same search space as the search space of the first PDCCH.

[0309] As described above, when the SBFD terminal determines that the cell (or base station) supports only TDD, the SBFD terminal can perform random access procedures and transmit and receive data / control signals in the same manner as a conventional TDD terminal.

[0310] The base station may configure separate random access resources for each of an existing TDD terminal or an SBFD terminal (e.g., an SBFD terminal supporting duplex communication and an SBFD terminal supporting half-duplex communication), and transmit configuration information (control information or configuration information indicating time-frequency resources that can be used for PRACH) for the random access resources to the SBFD terminal through system information. The system information for transmitting information for the random access resources may be separately transmitted system information that is distinct from system information for terminals supporting different versions of standards within a cell (e.g., an existing TDD terminal).

[0311] The base station may be able to distinguish whether a TDD terminal supporting a different version of the standard performs random access or an SBFD terminal performs random access by setting separate random access resources for the TDD terminal and the SBFD terminal. For example, the separate random access resource set for the SBFD terminal may be a resource that an existing TDD terminal determines to be a downlink time resource, and the SBFD terminal may perform random access through an uplink resource (or a separate random access resource) set to a part of the frequency of the downlink time resource, so that the base station may determine that a terminal attempting random access through the uplink resource is an SBFD terminal.

[0312] Alternatively, the base station may set a common random access resource for all terminals within the cell without setting a separate random access resource for the SBFD terminal. In this case, configuration information for the random access resource may be transmitted to all terminals within the cell through system information, and the SBFD terminal that has received the system information may perform random access based on the random access resource. Thereafter, the SBFD terminal may complete the random access process and proceed to an RRC connection mode for transmitting and receiving data with the cell. After the RRC connection mode, the SBFD terminal may receive a higher layer signal or a physical layer signal from the base station that can determine that some frequency resources of the downlink time resources are set as uplink resources, and may perform an SBFD operation, for example, transmit an uplink signal on the uplink resource.

[0313] When the SBFD terminal determines that the cell supports SBFD, the terminal may transmit capability information to the base station, including at least one of whether the terminal supports SBFD, whether the terminal supports full-duplex communication or half-duplex communication, or the number of transmit or receive antennas that the terminal has (or supports), thereby informing the base station that the terminal attempting to connect is an SBFD terminal. Alternatively, when half-duplex communication support is a mandatory implementation for the SBFD terminal, whether the terminal supports half-duplex communication may be omitted from the capability information. The SBFD terminal's report of the capability information may be reported to the base station through a random access procedure, may be reported to the base station after the random access procedure is completed, or may be reported to the base station after proceeding to an RRC connection mode for transmitting and receiving data with the cell.

[0314] The above SBFD terminal may support half-duplex communication, which performs only uplink transmission or downlink reception at a time like a conventional TDD terminal, or may support full-duplex communication, which performs both uplink transmission and downlink reception at a time. Accordingly, whether the above half-duplex communication or full-duplex communication is supported can be reported to the base station by the SBFD terminal through a capability report, and after the report, the base station can configure the SBFD terminal to transmit and receive using half-duplex communication or full-duplex communication. When the SBFD terminal reports the capability for the above half-duplex communication to the base station, since a duplexer generally does not exist, a switching gap may be required to change the RF between transmission and reception when operating in FDD or TDD.

[0315] FIG. 12 is a diagram illustrating an example of SBFD operation in a TDD band of a wireless communication system according to one embodiment of the present disclosure.

[0316] In Fig. 12, it can be assumed that the DDDSU slot format is set according to the TDD UL-DL resource configuration information. Here, 'D' is a slot composed entirely of downlink symbols, 'U' is a slot composed entirely of uplink symbols, and 'S' is a slot that is not 'D' or 'U', that is, a slot that includes a downlink symbol or an uplink symbol or includes a flexible symbol. Here, for convenience, it can be assumed that S is composed of 12 downlink symbols and 2 flexible symbols. In addition, the DDDSU slot format can be repeated according to the TDD UL-DL resource configuration information. That is, the repetition period of the TDD configuration can be 5 slots (5 ms for 15 kHz SCS, 2.5 ms for 30 kHz SCS, etc.).

[0317] Referring to (a) of Fig. 12, a case where TDD is operated in a specific frequency band is illustrated. In a cell where TDD is operated, a base station can transmit and receive signals including data / control information in downlink slots (or symbols), uplink slots (or symbols) (1201), and flexible slots (or symbols) based on settings for TDD UL-DL resource configuration information indicating downlink slot (or symbol) resources and uplink slot (or symbol) resources of TDD with an existing TDD terminal or SBFD terminal.

[0318] Next, in (b), (c) to (d) of FIG. 12, a case in which SBFD is operated together with TDD in a specific frequency band is illustrated.

[0319] Referring to (b) of FIG. 12, the terminal may set a portion of the frequency band of the cell as a frequency band (1210) capable of uplink transmission. This band may be referred to as an uplink subband (UL subband). And the uplink subband (UL subband) may be applied to all symbols of all slots. The terminal may transmit an uplink channel or signal scheduled for all symbols (1212) within the UL subband. However, the terminal may not transmit an uplink channel or signal in a band other than the UL subband of a downlink slot (or symbol) and a flexible slot (or symbol).

[0320] Referring to (c) of FIG. 12, the terminal may set a portion of the frequency band of the cell as a frequency band (1220) capable of uplink transmission, and may set a time region in which the frequency band is activated. Here, this frequency band may be called an uplink subband (UL subband). In the first slot within the repetition cycle of the TDD configuration, the uplink subband (UL subband) is deactivated, and in the remaining slots, the uplink subband (UL subband) may be activated. Accordingly, the terminal may transmit an uplink channel or signal in the uplink subband (UL subband) (1222) of the remaining slots. In the example of (c) of FIG. 12, the uplink subband (UL subband) is activated on a slot-by-slot basis, but the technical scope of the present disclosure is not limited thereto. Accordingly, whether or not the uplink subband (UL subband) is activated may also be set on a symbol-by-symbol basis.

[0321] Referring to (d) of FIG. 12, a terminal may be configured with time-frequency resources capable of uplink transmission. The terminal may configure one or more time-frequency resources as time-frequency resources capable of uplink transmission. For example, some frequency bands (1232) of the first and second slots may be configured as time-frequency resources capable of uplink transmission. In addition, some frequency bands (1233) of the third slot and some frequency bands (1234) of the fourth slot may be configured as time-frequency resources capable of uplink transmission. The terminal may transmit an uplink channel or signal in some frequency bands (1232, 1233, 1234) configured in each slot.

[0322] In the following description, a time-frequency resource capable of uplink transmission within a downlink symbol or slot may be referred to as an SBFD resource. Furthermore, a symbol within a downlink symbol for which an uplink subband is configured may be referred to as an SBFD symbol. Furthermore, a time-frequency resource capable of downlink reception within an uplink symbol or slot may be referred to as an SBFD resource. Furthermore, a symbol within an uplink symbol for which a downlink subband is configured may be referred to as an SBFD symbol.

[0323] For convenience, in the present disclosure, a band in which downlink channels or signals can be received, excluding uplink sub-bands, is referred to as a downlink sub-band. A terminal can configure at most one uplink sub-band per symbol, and at most two downlink sub-bands. For example, a terminal can be configured with one of {uplink sub-band, downlink sub-band}, {downlink sub-band, uplink sub-band}, or {first downlink sub-band, uplink sub-band, second downlink sub-band} in the frequency domain.

[0324] FIG. 13 is a diagram illustrating an example of resource settings of SBFD of a wireless communication system according to one embodiment of the present disclosure.

[0325] Fig. 13 is an example, and the present embodiment can be equally applied to other embodiments. Referring to Fig. 13, the terminal can be configured with an uplink symbol, a downlink symbol, or a flexible symbol according to the TDD configuration. Here, the 'D' slot (1301) represents a slot in which all symbols of the slot are downlink symbols. The 'U' slot (1303) represents a slot in which all symbols of the slot are uplink symbols. The 'S' slot represents a slot that is not a 'D' slot or a 'U' slot. The terminal can be configured with a BWP (1309). In addition, the terminal can be configured with a UL subband (1307) within a DL symbol. The terminal can be configured with a guard band (1308) from the base station. Here, the guard band may refer to a band between the downlink sub-band (1304, 1306) and the uplink sub-band (1305), and downlink transmission or uplink transmission may not occur in the corresponding region. In this embodiment, it is assumed that the UL BWP includes 275 RBs and the UL sub-band includes 50 RBs. It is assumed that the UL sub-band is not configured in the first slot. Therefore, the first slot is called a DL slot, and the symbol included in the first slot is called a DL symbol. It is assumed that the UL sub-band is configured in the second, third, and fourth slots. Therefore, the second, third, and fourth slots are called SBFD slots, and the symbols included in the second, third, and fourth slots are called SBFD symbols. More specifically, the base station can transmit a downlink channel to the terminal in the region (1304, 1306) corresponding to the downlink sub-band among the SBFD symbols. Additionally, in the area (1305) corresponding to the uplink subband among the SBFD symbols, the base station can receive an uplink channel from the terminal. The fifth slot is an uplink slot, and the symbol included in the fifth slot is called a UL symbol.

[0326] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. While the embodiments of the present disclosure will be 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. Therefore, 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 those skilled in the art. The contents of the present disclosure are applicable to FDD and TDD systems.

[0327] Additionally, when describing the present disclosure, detailed descriptions of related functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the contents of this specification.

[0328] In the following description of the present disclosure, upper layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

[0329] - MIB

[0330] - SIB or SIB

[0331] - RRC

[0332] - MAC (Medium Access Control) CE (Control Element)

[0333] In addition, L1 signaling may be signaling corresponding to at least one or a combination of one or more signaling methods using the physical layer channel or signaling below.

[0334] - PDCCH

[0335] - DCI

[0336] - UE-specific DCI

[0337] - Group common DCI

[0338] - Common DCI

[0339] - Scheduling DCI (e.g. DCI used for scheduling downlink or uplink data)

[0340] - Non-scheduled DCI (e.g. DCI not intended for scheduling downlink or uplink data)

[0341] - PUCCH

[0342] - UCI (uplink control information)

[0343] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0344] In the present disclosure below, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0345] Below we describe the RB index.

[0346] In the present disclosure, one of the following three can be used as the index of RBs in the frequency domain.

[0347] 1) Common RB index (for example, it can be called CRB index)

[0348] The common RB index is assigned from 0 and increases by 1 as the frequency increases. The terminal refers to the sub-carrier that matches 'point A' as sub-carrier 0, and a common RB index can be assigned by grouping 12 sub-carriers in ascending order of frequency from the sub-carrier. That is, when the sub-carrier index is k, the value representing floor(k / 12) is the common RB index of the RB to which the sub-carrier belongs.

[0349] The above common RB index is determined according to point A. Since point A is set commonly to all terminals in the cell, all terminals can have the same common RB index.

[0350] 2) Specific BWP RB index (BWP-specific RB index, for example, may be referred to as PRB index)

[0351] A terminal may be configured with a downlink BWP for receiving a DL signal (or DL ​​channel) and / or an uplink BWP for transmitting an UL signal (or UL channel). The terminal may assume that the index of the lowest RB of the BWP is 0, with a specific BWP RB index. More specifically, the location of the starting RB of the BWP is determined using a common RB index. can be given as, i.e., the common RB index The RB corresponding to can be assigned a specific BWP RB index of 0. That is, It could be. Here is the common RB index, is a specific BWP RB index.

[0352] 3) Subband-specific RB index

[0353] A terminal can be configured with an uplink subband (UL subband) in a downlink symbol. Conversely, a downlink subband (DL subband) can be configured in an uplink symbol. It can be assumed that the lowest RB index among the RBs included in the subband is 0.

[0354] More specifically, the location of the starting RB of the sub-band is determined using the common RB index. can be given as, that is, the terminal receives the above-mentioned information from the base station through a higher layer signal. The value of can be set. The starting RB position of the sub-band indicated using the common RB index. The RB corresponding to can be assigned the sub-band RB index 0. That is, It could be. Here is the common RB index, is the sub-band RB index. For reference, the above The subband whose starting RB position is set to the value can be applied to all BWPs of the terminal, i.e., it is not BWP specific.

[0355] In another way, the location of the starting RB of a subband is determined using a specific BWP RB index. can be given as, that is, the terminal receives the above-mentioned information from the base station through a higher layer signal. The value can be set. The value can be set to a specific BWP. The starting RB position of the sub-band indicated using a specific BWP RB index. The RB corresponding to can be assigned the sub-band RB index 0. That is, It could be. Here is a specific BWP RB index, is the sub-band RB index.

[0356] Through the above method, the sub-band RB index can be expressed as follows.

[0357]

[0358]

[0359] thus, , can be expressed as

[0360] FIG. 14a and FIG. 14b are diagrams illustrating an example of an SRS transmission area according to one embodiment of the present disclosure.

[0361] Figure 14a is a diagram illustrating an example of TDD resource configuration. The base station can configure SRS transmission-related settings for the terminal. The terminal can perform SRS transmission according to the SRS configuration information and transmission-available area configured by the base station. During TDD resource configuration, the terminal can transmit SRS in an area (1401) where UL resources are present. As mentioned above, if the base station has configured antenna switching for obtaining downlink channel information for the terminal, the terminal can transmit SRS to the base station, and the base station, assuming reciprocity between DL and UL channels, can regard the uplink channel information estimated based on the SRS as downlink channel information and utilize it for subsequent downlink scheduling of the terminal.

[0362] On the other hand, Fig. 14b is a diagram illustrating an example of SBFD resource configuration. The terminal can perform SRS transmission in the UL sub-band (1403), which is an area where UL resources are located, among the configured SBFD resource configuration information. Although the base station configures the UL BWP (1406) to the terminal as an area encompassing both the DL sub-band (1405) and the UL sub-band (1403), the terminal cannot perform SRS transmission in areas (1405 to 1404) that are not UL sub-bands. If the base station configures the SRS for antenna switching purposes when configuring the SRS for obtaining downlink channel information to the terminal, the terminal can perform SRS transmission only in the UL sub-band (1403), and the base station can regard the uplink channel information estimated based on the SRS as downlink channel information only for the UL sub-band (1403) area where reciprocity between DL and UL channels can be assumed. At this time, the base station may encounter limitations that make it impossible to obtain SRS-based downlink channel information for the DL sub-band (1405) area.

[0363] In the embodiments below, a method for configuring UL sub-band resources, a method for determining frequency resource reference points for UL sub-bands and UL-only symbols or / and slots, and a method for transmitting SRS for downlink channel acquisition in an SBFD system are described in detail. Through this, the ambiguity of SRS resource configuration in an SBFD system can be resolved, and scheduling convenience can be expected due to the possibility of acquiring SRS-based downlink channel information in a DL sub-band.

[0364] <Embodiment 1: SRS Resource Setting Method>

[0365] Method 1: How to set up SRS resources by UL resource type

[0366] SRS resources can be configured for each of an SBFD symbol or / and slot and a non-SBFD symbol or / and slot. That is, for an SBFD symbol or / and slot, an SRS configuration (e.g., information including at least one of a time-frequency resource configuration, a frequency hopping configuration, an uplink transmission power control parameter, a beam, and a spatial relation) can be configured. In addition, for a non-SBFD symbol or / and slot, an SRS configuration (e.g., information including at least one of a time-frequency resource configuration, a frequency hopping configuration, an uplink transmission power control parameter, a beam, and a spatial relation) can be configured. Accordingly, an SBFD symbol or / and slot-only SRS configuration can be applied to an SRS transmitted in an SBFD symbol or / and slot, and a non-SBFD symbol or / and slot-only SRS configuration can be applied to an SRS transmitted in a non-SBFD symbol or / and slot.

[0367] At this time, in order to switch from an SBFD symbol or / and slot to a non-SBFD symbol or / and slot or from a non-SBFD symbol or / and slot to an SBFD symbol or / and slot, the terminal may expect to receive a resource type switching instruction from the base station. If the terminal does not receive a resource type switching from the base station, the previously applied resource type may be maintained. For example, the terminal may perform SRS transmission by applying the SRS configuration of the SBFD symbol or / and slot. If the terminal receives a resource type switching from the base station, the terminal may change and apply the SRS configuration of the SBFD symbol or / and slot to the SRS configuration of the non-SBFD symbol or / and slot and transmit the SRS. If the terminal does not receive a resource type switching from the base station, the terminal may transmit the SRS while maintaining the SRS configuration of the SBFD symbol or / and slot. Alternatively, a terminal that knows the time-frequency resource settings of the SBFD system can perform SRS transmission by changing the SRS settings according to each symbol or / and slot type without expecting a separate base station instruction.

[0368] Method 2: How to set up SRS resources based on UL BWP

[0369] Alternatively, SRS resources may be configured for non-SBFD symbols and / or slots (i.e., based on UL BWP). That is, SRS configurations configured in non-SBFD symbols and / or slots may also be applied to SBFD symbols and / or slots. Among the SRS configurations applied to SBFD symbols and / or slots, the frequency domain configuration for SRS resources may be configured outside of the UL sub-band region within the SBFD symbol or / and slot. In this case, the terminal may determine the frequency resource of the SRS by performing rate matching or puncturing for the region outside the UL sub-band. Alternatively, the frequency resource of the region outside the UL sub-band may be omitted (i.e., the SRS may not be transmitted in the region), and the SRS frequency resource may be determined and transmitted only for the region overlapping with the UL sub-band.

[0370] Method 3: Setting SRS resources based on UL subbands

[0371] Alternatively, SRS resources may be configured as SBFD symbols and / or slots. That is, the SRS configuration configured in the SBFD symbol or / and slot may also be applied to non-SBFD symbols and / or slots. Among the SRS configurations applied to non-SBFD symbols and / or slots, the frequency domain configuration for SRS resources may be limited to the UL subband region within the SBFD symbol or / and slot and may not cover the frequency resource region of the entire non-SBFD symbol or / and slot. To address this, the base station may configure an RB offset value for frequency domain movement of SRS resources. Accordingly, the terminal may determine and transmit an SRS transmission location by applying the RB offset value to the SRS frequency domain location among the SRS configurations configured based on the SBFD symbol or / and slot for the non-SBFD symbol or / and slot.

[0372] <Second Embodiment: Method for Setting SRS Resources for Antenna Switching>

[0373] Method 1: How to set up SRS resources for antenna switching when UL-only slots or / and symbols exist

[0374] In an SBFD system, a slot configuration within a frame in which UL-only slots or / and symbols (i.e., non-SBFD symbols or / and slots) coexist may be assumed. If the slot configuration is assumed, an SRS resource (i.e., an SRS resource for acquiring downlink information) within an SRS resource set configured by antenna switching may be configured. At this time, the frequency domain size of the configured SRS resource may be smaller than or equal to the size of the UL BWP, and the corresponding SRS resource may be configured in an area overlapping with the frequency domain resources of two DL subbands including the UL subband. Alternatively, the frequency domain size of the configured SRS resource may be smaller than or equal to the size of the UL BWP, and the corresponding SRS resource may be configured in an area overlapping with the frequency domain resources of one DL subband. Alternatively, the frequency domain size of the configured SRS resource may be smaller than or equal to the size of the UL BWP, and the SRS resource may be a discontinuous frequency domain resource (i.e., a frequency domain resource that overlaps with the frequency domain sizes of two DL subbands, but excludes the frequency domain region corresponding to the middle UL subband).

[0375] Among the above SRS resource configuration methods, resource movement through frequency domain RB offset may be possible for SRS resources set in an area where the frequency domain size is smaller than or equal to the size of the UL BWP and overlaps with one DL sub-band frequency domain. The base station can set an RB offset for the SRS resources set through the above SRS resource configuration method, and if the terminal receives SRS resource frequency domain movement configuration or instruction information from the base station, the terminal can perform SRS transmission by moving the SRS resource by applying the set or instructed RB offset value.

[0376] Method 2: How to set up SRS resources for antenna switching when UL only slots or / and symbols do not exist

[0377] In an SBFD system, a slot configuration within a frame without UL-only slots or / and symbols (i.e., non-SBFD symbols or / and slots) can be assumed. If the above slot configuration is assumed, an SRS resource (i.e., an SRS resource for downlink information acquisition) within an SRS resource set configured by antenna switching can be configured. At this time, the configured SRS resource can be smaller than or equal to the frequency domain size of the UL subband. Alternatively, the frequency domain size of the configured SRS resource can be larger than or equal to the frequency domain size of the UL subband and smaller than or equal to the size of the UL BWP.

[0378] Method 3: DL BWP-based SRS resource configuration method for antenna switching

[0379] On the other hand, in the SBFD system, a slot configuration within a frame without UL-only slots or / and symbols (i.e., non-SBFD symbols or / and slots) may be assumed. If the above slot configuration is assumed, the frequency domain size of the UL BWP may also be set to be the same or similar to the frequency domain size of the UL subband, which does not correspond to the frequency domain size of the DL BWP. In the above situation, since the SRS cannot be transmitted in the DL BWP frequency domain area other than the UL subband, SRS-based downlink channel information acquisition cannot be expected.

[0380] To solve the above problem, it is possible to assume SRS resource configuration for antenna switching based on frequency domain resource configuration information of DL BWP. That is, the base station can configure SRS configuration information for SBFD symbols and / or slots to the terminal. At this time, the SRS configuration information can configure a separate SRS resource set having a frequency domain location and size calculated based on the DL BWP or a separate SRS resource within the SRS resource set. If the use of the corresponding resource is configured or instructed by the base station, the terminal can transmit an SRS by applying the corresponding resource set or resource in an area where the SRS resource set calculated based on the DL BWP or the SRS resource can be transmitted.

[0381] <Third embodiment: Method for determining a frequency domain reference point when mapping physical resources of SRS>

[0382] SRS can be transmitted by being mapped to physical resources based on configuration information established through upper layer signaling from a base station. As mentioned above, physical resource mapping of SRS resources based on TDD is performed based on UL BWP. However, in an SBFD system where UL and DL subbands coexist in the same time resource, the physical resource mapping method of SRS resources based on UL BWP may cause a problem in that the frequency domain start position of the SRS resource is located in the DL subband. To solve the above problem, the methods below describe a method for determining a frequency domain reference point when performing physical resource mapping of SRS resources in an SBFD system.

[0383] Method 1: UL sub-band standard, SRS frequency resource reference point determination method

[0384] Physical resource mapping in the frequency domain of SRS resources can be performed for each UL subband and UL BWP.

[0385] FIG. 15 is a diagram illustrating a physical resource mapping method of SRS resources according to one embodiment of the present disclosure.

[0386] Referring to FIG. 15, with respect to the reference point of the frequency domain starting point of the SRS resource (i.e., the SRS resource set in the SBFD slot or / and symbol) set for the UL sub-band (1503), the frequency domain shift value (n) set by the upper layer signaling shift ) is greater than the frequency domain starting point (1508) of the UL sub-band, the reference point may be determined as common resource block 0 (1507), otherwise (i.e., when the frequency domain shift value is less than or equal to the frequency domain starting point (1508) of the UL sub-band), it may be the smallest subcarrier (or subcarrier index) (1508) of the UL sub-band.

[0387] In addition, with respect to the reference point of the frequency domain starting point of the SRS resource (i.e., the SRS resource set in the non-SBFD slot or / and symbol) set in the UL BWP (1506), if the frequency domain shift value set by the upper layer signaling is greater than the frequency domain starting point (1509) of the UL BWP, the reference point may be determined as common resource block 0 (1507), and otherwise (i.e., if the frequency domain shift value is less than or equal to the frequency domain starting point of the UL BWP), the reference point may be the smallest subcarrier (or subcarrier index) (1509) of the UL BWP. Through the above method, the SRS resource may be mapped onto the physical resource only for the area where UL transmission is possible (i.e., the UL subband area other than the DL transmission area and the UL BWP area).

[0388] Method 2: Determining the SRS Frequency Resource Reference Point Using Offset Settings

[0389] Alternatively, the frequency domain starting point of the SRS resource set for the UL subband can be located within the UL subband through the Offset value. That is, the above mathematical expressions 3 and 4 can be changed as shown in the following mathematical expressions 6 and 7, respectively.

[0390] [Equation 6]

[0391]

[0392] [Equation 7]

[0393]

[0394] The reference point of the frequency domain starting point of the SRS resource (i.e., the SRS resource set in the SBFD slot and / or symbol) can be set based on the UL BWP, and if the frequency domain shift value set by the upper layer signaling is greater than the frequency domain starting point of the UL BWP, the reference point can be determined as common resource block 0, otherwise (i.e., if the frequency domain shift value is less than or equal to the starting point of the UL BWP), it can be the smallest subcarrier (or subcarrier index) of the UL BWP. Thereafter, the frequency domain starting point of the SRS resource can be determined using Equation 6. The base station can set an offset value to map the SRS resource to an area where UL transmission is possible, and the offset value can be applied as in Equation 7. Through this, the SRS resource can be mapped only for an area where UL transmission is possible (i.e., an area other than a DL transmission area).

[0395] For the above method, a guard band may be additionally considered. The guard band may represent a gap between the UL subband and the DL subband, in which neither DL nor UL may be transmitted. The guard band may be explicitly or implicitly set. If an implicitly set guard band is assumed, the Offset in Equation 7 UL SB may be a value that includes the frequency domain size of the guard band. Alternatively, assuming an explicitly set guard band, the above equation (7) can be changed to equation (8) with the size of the guard band added.

[0396] [Equation 8]

[0397]

[0398] Method 3: After determining the SRS frequency resource reference point based on the UL BWP, a method of transmitting SRS only in the transmission-capable area.

[0399] In another way, SRS resources configured for UL sub-bands can be utilized only for the area corresponding to the UL sub-band after physical resource mapping based on the UL BWP. Specifically, the reference point of the frequency domain starting point of the SRS resource (i.e., the SRS resource configured for the SBFD slot or / and symbol) can be set based on the UL BWP. Specifically, if the frequency domain shift value configured by the upper layer signaling is greater than the frequency domain starting point of the UL BWP, the reference point can be determined as common resource block 0, and otherwise (i.e., if the frequency domain shift value is less than or equal to the starting point of the UL BWP), it can be the smallest subcarrier (or subcarrier index) of the UL BWP. The SRS resource mapped to the physical resource can have an area exceeding the UL sub-band area (i.e., an area overlapping with the DL sub-band and the guard band). At this time, the terminal does not transmit SRS for areas other than the UL subband (i.e., areas overlapping with the DL subband and guard band), and can perform SRS transmission only for areas overlapping with the UL subband.

[0400] Alternatively, the reference point of the frequency domain starting point of the SRS resource set for the UL subband may be fixed to the starting point of the UL subband. Even if the reference point of the frequency domain starting point of the SRS resource is set based on the UL BWP, if the SRS resource is an SRS resource for the UL subband, the reference point of the SRS resource frequency domain starting point may be fixed to the frequency domain starting point of the UL subband.

[0401] Method 4: Determining the SRS Frequency Resource Reference Point Based on DL BWP

[0402] Physical resource mapping of SRS resources in the frequency domain can be performed based on UL subbands and DL BWPs. Specifically, as an example of an SBFD system's operation, a situation in which the UL BWP size is identical to the UL subband can be assumed. If such an operation situation exists, it may be difficult to configure SRS resources in an area overlapping with the DL BWP for SRS-based downlink channel information acquisition. Therefore, to solve the above problem, a method for performing frequency domain mapping of SRS resources based on DL BWP configuration is described.

[0403] FIG. 16 is a diagram illustrating another method of physical resource mapping of SRS resources according to one embodiment of the present disclosure.

[0404] Referring to FIG. 16, with respect to the reference point of the frequency domain starting point of the SRS resource (i.e., the SRS resource set in the SBFD slot or / and symbol) set for the UL sub-band (1603), the frequency domain shift value (n) set by the upper layer signaling shift ) is greater than the frequency domain starting point (1608) of the UL sub-band, the reference point may be determined as common resource block 0 (1607), otherwise (i.e., when the frequency domain shift value is less than or equal to the starting point (1608) of the UL sub-band), it may be the smallest subcarrier (or subcarrier index) (1608) of the UL sub-band. In addition, since the reference point of the frequency domain starting point of the SRS resource set in the UL BWP (1606) has the same size as the frequency domain starting points of the UL sub-band (1603) and the UL BWP (1606), the same result may be derived.

[0405] At this time, in order to set up SRS resources for acquiring SRS-based downlink channel information, the SRS resources may be set based on the configuration information of the DL BWP (i.e., frequency domain starting point (1609), size (1610)). For example, with respect to the reference point of the frequency domain starting point of the SRS resource (i.e., SRS resource for acquiring SRS-based downlink channel information) set based on the DL BWP (1610), if the frequency domain shift value set by the upper layer signaling is greater than the frequency domain starting point (1609) of the DL BWP, the reference point may be determined as common resource block 0 (1607), and otherwise (i.e., if the frequency domain shift value is less than or equal to the starting point of the DL BWP), it may be the smallest subcarrier (or subcarrier index) (1609) of the DL BWP.

[0406] <Example 4: SRS Transmission Method>

[0407] In the following, an SRS transmission method for obtaining SRS-based downlink channel information in an area corresponding to a DL sub-band is described.

[0408] Method 1: SRS transmission method using UL subband frequency hopping

[0409] FIG. 17 is a diagram illustrating an example of an SRS transmission method using UL sub-band frequency hopping according to one embodiment of the present disclosure.

[0410] Referring to FIG. 17, a terminal can perform frequency hopping of a UL sub-band (1701) according to a period (1702) set by a base station. More specifically, the terminal can receive an uplink bandwidth portion (1706) from the base station through upper layer signaling. At this time, the uplink bandwidth portion may be a value greater than or equal to the UL sub-band. The terminal can receive time-frequency resources of a UL sub-band (1701) capable of uplink transmission. The terminal can receive time and frequency resources for an initial UL sub-band (1703) from the base station. At this time, the time resource may be a period value (1702) indicating a periodicity of (1703), (1704), or (1705) during which the UL sub-band configuration continues. The terminal can perform uplink signal / channel transmission, including SRS transmission, in the set UL sub-band region during the set period (1702). At this time, the terminal cannot perform uplink signal / channel transmission, including SRS transmission, in areas outside the UL subband. The terminal can perform downlink signal / channel transmission in areas outside the UL subband, i.e., the DL subband. After a set period (1702), the terminal can change the position of the UL subband to the set position and transmit (1704). The terminal can repeat this operation every period (1702).

[0411] The period set for the terminal may be one of radio frame units, half-frame units, subframe units, slot units, or symbol units, depending on the SCS used by the cell. For example, the base station may set a period of N ms for changing the UL subband location to the terminal. In this case, the period set to N ms may be interpreted and used as at least one of symbol units, slot units, subframe units, half-frame units, or radio frames, depending on the SCS value operated or set in the cell.

[0412] The frequency hopping position of the UL sub-band set to the terminal can be set by at least one of the following methods.

[0413] In one method, the terminal can perform UL sub-band frequency hopping based on a UL sub-band-DL sub-band configuration list. The UL sub-band-DL sub-band configuration list may be a list indicating the frequency positions of UL and DL sub-bands configured in frequency units. Here, "U" may represent a UL sub-band, and "D" may represent a DL sub-band. Additionally, "G" may represent a guard band between "U" and "D". (The guard band is omitted in the description below.) The configuration of the UL sub-band-DL sub-band configuration list may vary depending on the channel bandwidth of the base station and the frequency size of the UL sub-band. For example, assuming that the channel bandwidth of the base station is 100 MHz and the channel bandwidth of the UL sub-band is 20 MHz, the first row of the list may be composed of {DDUDD}, the second row may be composed of {DUDDD}, the third row may be composed of {UDDDD}, the fourth row may be composed of {DDDDU}, and the fifth row may be composed of {DDDUD}. (The above list composition is an example for explanation, and the contents of the list may vary depending on the channel bandwidth and UL sub-band of the base station as described above.) The terminal may move the UL sub-band to the position of each row of the UL sub-band-DL sub-band configuration list according to the period set by the base station. For example, in the first transmission and period, the terminal may determine the UL sub-band position according to the UL sub-band-DL sub-band configuration of the first row of the list, and in the next period, may move the UL sub-band to the position of the second row of the list.

[0414] Alternatively, the terminal can perform UL sub-band frequency hopping according to an offset setting. The base station can set an offset value for UL sub-band frequency hopping to the terminal, and the offset value can be greater than or equal to the size of the UL sub-band. The terminal can determine the UL sub-band location to a location where the offset value is not applied in the first transmission and cycle according to the set offset value, and in the next cycle, the UL sub-band can be moved to a location that is moved by the set offset value from the frequency starting point of the UL sub-band. In this case, if the frequency starting point and the size of the UL sub-band are outside the channel bandwidth, the frequency starting point of the UL sub-band can be determined as the frequency starting point of the channel bandwidth. The set offset value can be in RB units.

[0415] Alternatively, the base station can divide the channel bandwidth into sub-bands and configure the terminal to move to the configured sub-band index for each cycle. For example, assuming that the base station's channel bandwidth is 100 MHz and the UL sub-band's channel bandwidth is 20 MHz, the sub-bands can be divided into a total of five, and can be composed of index #0, index #1, index #2, index #3, and index #4 from the lowest frequency band. If the base station configures index #2 as the initial UL sub-band location for the terminal, the terminal can determine the initial UL sub-band location as the sub-band corresponding to the third sub-band among the entire channel bandwidth. Thereafter, the terminal can move the location of the UL sub-band in ascending or descending order of the index. For example, if index #2 is set as the initial UL sub-band location and the locations of the UL sub-bands are moved in ascending order, the terminal can hop to the sub-bands corresponding to the order of index #2, index #3, index #4, index #0, and index #1.

[0416] Through the above-mentioned methods, the terminal can perform frequency hopping of the UL sub-band, and the base station can obtain SRS-based downlink channel information for the entire channel bandwidth.

[0417] The above-mentioned channel bandwidth is an example to explain the detailed method, and the same concept can be applied to the frequency domain of CC, bandwidth portion (BWP) as well as the channel bandwidth (carrier bandwidth).

[0418] Method 2: SRS transmission method using SRS transmission-enabled area setting

[0419] A base station can set an area where SRS transmission is possible for a terminal and allow SRS transmission in the area. The terminal can transmit SRS to the base station according to SRS configuration information in the configured SRS transmission possible area. However, at this time, uplink channel (PUSCH or PUCCH) transmission other than SRS transmission may not be allowed. The SRS transmission possible area can be set using time-frequency resource configuration information. The frequency domain size of the SRS transmission possible area may be greater than or equal to the frequency domain size of the UL subband, or may be less than or equal to the frequency domain size of the UL BWP. The time domain length of the SRS transmission possible area may consist of a maximum of N symbols. In the configured SRS transmission possible area, the terminal may not allow uplink channel transmission other than SRS transmission and may not expect to receive downlink signals and channels.

[0420] The time domain operation of the SRS transmittable region may include at least one of aperiodic, semi-persistent, or periodic operations. In the time domain operation of the periodic SRS transmittable region, the time-frequency domain resource configuration of the SRS transmittable region may be repeated at a period of N ms set by the base station. In this case, N ms may be interpreted and used as a slot unit, a subframe unit, a half-frame unit, or a radio frame unit depending on the SCS value set and operated by the base station. In the time domain operation of the semi-periodic SRS transmittable region, the base station may set a trigger status list for the terminal for the semi-periodic SRS transmittable region and a period value in units of N ms for periodic operation after the trigger. The base station may instruct the terminal to activate the semi-periodic SRS transmittable region using at least one of octet information of MAC-CE or activation indication information in DCI. The SRS transmittable region may be repeated according to the set period until the terminal receives a deactivation instruction from the base station. Afterwards, the base station can deactivate the SRS transmission-capable region by instructing the terminal to deactivate the corresponding region. In the case of time-domain operation of the aperiodic SRS transmission-capable region, the base station can set an aperiodic SRS transmission-capable region trigger status list for the terminal. The base station can trigger the SRS transmission-capable region for the terminal using the SRS transmission-capable region trigger request field in the DCI field.

[0421] FIG. 18a and FIG. 18b are diagrams illustrating a method for setting a periodic SRS transmission-enabled area according to one embodiment of the present disclosure.

[0422] FIG. 18A is a diagram illustrating an example of a method for setting an SRS transmission-enabled area when the frequency domain size of the UL BWP is different from that of the UL sub-band. Referring to FIG. 18A, the base station can set a UL BWP (1803) and a UL sub-band (1802) for SBFD operation to the terminal. In addition, the base station can set an SRS transmission-enabled area (1804) for acquiring SRS-based downlink channel information, and the frequency domain size of the area can be greater than or equal to the size of the UL sub-band (1802) and less than or equal to the UL BWP (1803). For example, the frequency domain size of the SRS transmission-enabled area can be equal to the UL BWP (1803). The base station can set a period value (1801) for periodic SRS transmission-enabled area operation. The SRS transmission-enabled area having the above-described time (1804) and frequency (1803) resources can be repeated every cycle (1801).

[0423] On the other hand, unlike the above-mentioned, there may be a situation where the UL BWP, which is one of the criteria for setting the frequency domain size of the SRS transmission-capable area, is the same as the UL sub-band. In such a setting, there is no problem with the UL sub-band frequency setting and uplink channel transmission, but defining the frequency domain size of the SRS transmission-capable area may be difficult for the SRS-based downlink channel information acquisition operation.

[0424] To address the aforementioned issues, the SRS transmittable region can be set based on the frequency domain size of the DL BWP, rather than the UL BWP. That is, the frequency domain size of the SRS transmittable region can be greater than or equal to the frequency domain size of the UL subband, and less than or equal to the frequency domain size of the DL BWP. Alternatively, the frequency domain size of the SRS transmittable region can be greater than or equal to the frequency domain size of the UL BWP, and less than or equal to the frequency domain size of the DL BWP.

[0425] FIG. 18b is a diagram illustrating an example of a method for setting an SRS transmission-enabled area when the frequency domain size of the UL BWP is the same as the UL sub-band. Referring to FIG. 18b, the base station can set a UL BWP (1806), a DL BWP (1807), and a UL sub-band (1805) for SBFD operation to the terminal. In addition, the base station can set an SRS transmission-enabled area (1808) for acquiring SRS-based downlink channel information, and the frequency domain size of the area can be greater than or equal to the size of the UL sub-band (1805), greater than or equal to the UL BWP (1806), and less than or equal to the DL BWP (1807). Alternatively, the frequency domain size of the SRS transmission-enabled area can be set based on the DL BWP (1807), and for example, can be the same as the frequency domain size of the DL BWP (1807). The base station can set a period value (1809) for periodic SRS transmission possible area operation. The SRS transmission possible area having the set time (1808) and frequency (1807) resources can be repeated every period (1809).

[0426] Method 3: SRS transmission method using SRS transmission area setting in multi-carrier situation

[0427] The above method 2 can also be applied in a multi-carrier situation. The terminal can perform SRS transmission by moving the SRS resource set in the TDD cell to the SRS transmission available area (specifically, the existing DL sub-band area) of the SBFD cell through SRS carrier switching. That is, when SRS carrier switching is scheduled, the terminal can transmit SRS by retuning the RF transmitter for uplink transmission of another cell, without separately arranging an RF transmitter for uplink transmission for the target cell (SBFD cell) where SRS carrier switching is performed. In order to perform the above SRS carrier switching, the cell where the RF transmitter is deployed before the terminal retunes can be defined as the source cell (TDD cell), and this can be set in the terminal through a higher layer parameter. At this time, the upper layer parameters may include cell index information for the source cell, information indicating one of the NUL and SUL of the target cell, and information indicating the frequency location of the SRS transmission-enabled area (e.g., offset information from the source cell to the SRS transmission-enabled area of ​​the target cell or subband index information within the SRS transmission-enabled area of ​​the target cell). In addition, technical details related to SRS carrier switching may follow the contents defined in the aforementioned NR release 15 / 16.

[0428] FIG. 19 is a diagram illustrating an example of an SRS transmission method using an SRS transmission possible region setting in a multi-carrier situation according to one embodiment of the present disclosure.

[0429] The base station can set multiple CCs for the terminal, and setting information can be set for each CC. CC#1 (1906) can be set as a TDD cell including at least one UL slot, and CC#2 (1905) can be set as an SBFD cell. For the SBFD cell, the base station can set a UL subband (1902) for SBFD operation to the terminal. In addition, the base station can set an SRS transmission-available region (1904) for acquiring SRS-based downlink channel information, and the frequency domain size of the region can be greater than or equal to the size of the UL subband (1902) and less than or equal to the UL BWP (1903). For example, the frequency domain size of the SRS transmission-available region can be equal to the UL BWP (1903). For example, assuming periodic SRS transmission-available region operation, the base station can set a period value (1901) of the SRS transmission-available region to the terminal. The SRS transmission-capable region having the above-described time (1904) and frequency (1903) resources may be repeated every cycle (1901). The base station may instruct the terminal to perform SRS carrier switching, and the terminal may perform SRS transmission by moving the SRS resources set in the source cell (CC#1, 1906) to the target cell (CC#2, 1905). The SRS transmission may be performed in the SRS transmission-capable region (1904) of CC#2 (1905).

[0430] <Example 5: Method for setting SRS transmission location>

[0431] Below, we describe how to set up resources for SRS that can be transmitted in the SRS transmission area.

[0432] A terminal can receive SRS resources from a base station based on the frequency domain start position and size of the UL subband. As mentioned above, an SRS resource may refer to an SRS resource included in an SRS resource set. For convenience, the SRS resource set and SRS resources are referred to as SRS resources. In this case, SRS transmission in the SRS transmission-capable area can utilize SRS resources set based on the UL subband.

[0433] A base station can set an offset value to support SRS transmission to a terminal in an SRS transmission-available area. The terminal can transmit SRS to the base station by shifting the SRS resource set based on the UL subband in the SRS transmission-available area by the set offset value. At this time, the SRS resource setting maintains the information set based on the initial UL subband, and can transmit by changing only the SRS frequency resource start position. The above-mentioned offset value can be applied not only in a single-cell situation but also in a multiple-cell situation. The base station can set one cell among multiple cells as a source cell and a TDD cell, and set another cell as an SBFD cell. At this time, the set offset value may be an offset value from the start point of the SRS resource of the source cell, the TDD cell, to the start point of the frequency domain area to be transmitted within the target cell, the SBFD cell.

[0434] Alternatively, the base station can divide the channel bandwidth into subbands and configure the terminal to move to a set subband index for each cycle. For example, assuming that the base station's channel bandwidth is 100 MHz and the UL subband's channel bandwidth is 20 MHz, the subbands can be divided into a total of five, and can be composed of index #0, index #1, index #2, index #3, and index #4 from the lowest frequency band. The base station can configure index #2 as the initial UL subband location for the terminal and configure SRS resources based on the UL subband. Thereafter, the terminal can perform SRS transmission at the changed UL subband location according to the UL subband index value configured and indicated by the base station. At this time, the SRS resource configuration maintains the information configured based on the initial UL subband, and only the subband location can be changed to transmit the SRS.

[0435] The above-mentioned channel bandwidth is an example to explain the detailed method, and the same concept can be applied to the frequency domain of CC, bandwidth portion (BWP) as well as the channel bandwidth (carrier bandwidth).

[0436] The above-mentioned subband index-based operation can be applied not only to a single-cell situation but also to a multi-cell situation. The base station can configure one of the multiple cells as a source cell, a TDD cell, and another cell as an SBFD cell. When configuring SRS carrier switching, the base station can configure not only the cell index information of the target cell but also the subband index value of the target cell. Therefore, when the base station instructs the terminal to perform SRS carrier switching and simultaneously instructs the terminal to indicate the subband index of the target cell, the terminal can perform SRS transmission by moving the SRS resource set in the source cell to the subband index of the indicated target cell.

[0437] Alternatively, the base station can configure an SRS resource set and SRS resources for the terminal only for the SRS transmission-capable region. The SRS resources configured in the region can be configured based on the time-frequency domain resource configuration of the SRS transmission-capable region. For example, the SRS transmission-capable region can be larger than or equal to the frequency domain size of the UL BWP and smaller than or equal to the frequency domain size of the DL BWP. When configuring SRS resources for the SRS transmission-capable region, the base station can consider the frequency domain starting point and size of the SRS transmission-capable region.

[0438] FIG. 20A is a diagram illustrating an example of terminal operation according to one embodiment of the present disclosure.

[0439] Referring to FIG. 20A, a terminal can transmit terminal capabilities to a serving base station (2002). The terminal can receive higher layer signaling transmitted from the base station (2004) and confirm configuration information for an uplink channel. Thereafter, the terminal can confirm SRS configuration information configured by the base station, and as described above, can confirm SRS resource configuration information for acquiring downlink channel information according to a resource type (2006). Steps 2004 and 2006 may be performed together, in which case the terminal can receive SRS configuration information through higher layer signaling. Accordingly, the terminal can determine physical resource mapping of SRS resources and an SRS transmission location (2008). The terminal can transmit an SRS to the base station according to scheduling information configured and indicated by the base station (2010).

[0440] 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.

[0441] FIG. 20b is a diagram illustrating an example of base station operation according to one embodiment of the present disclosure.

[0442] Referring to FIG. 20b, the base station can receive terminal capabilities from the terminal (2012). The base station can transmit higher-layer signaling to the terminal (2014). The base station can transmit SRS configurations for acquiring downlink channel information according to resource types to the terminal (2016). Steps 2014 and 2016 may be performed together, in which case the SRS configuration information may be transmitted to the terminal via higher-layer signaling. Thereafter, the base station may instruct the terminal on scheduling information. Thereafter, the base station may receive the SRS transmitted from the terminal based on the scheduling information, and perform downlink channel estimation as well as uplink channel estimation based on the SRS (2018). Thereafter, based on the estimated downlink channel, the base station may schedule a downlink signal / channel to the terminal (2020).

[0443] 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.

[0444] FIG. 21 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0445] Referring to FIG. 21, the terminal may include a transceiver, which refers to a terminal receiving unit (2100) and a terminal transmitting unit (2110), a memory (not shown), and a terminal processing unit (2105, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (2100, 2110), the memory, and the terminal processing unit (2105) 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, the memory, and the processor may be implemented in the form of a single chip.

[0446] 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 merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0447] 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.

[0448] 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.

[0449] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. For example, the processor can receive SRS configuration information and control components of the terminal to transmit SRS to the base station based on the SRS configuration information. There may be multiple processors, and the processors can perform terminal component control operations by executing programs stored in memory.

[0450] FIG. 22 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0451] Referring to FIG. 22, the base station may include a transceiver, which refers to a base station receiver (2200) and a base station transmitter (2210), a memory (not shown), and a base station processing unit (2205, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver units (2200, 2210), the memory, and the base station processing unit (2205) 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.

[0452] 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.

[0453] 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.

[0454] 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.

[0455] The processor can control a series of processes to enable the base station to operate according to the aforementioned embodiments of the present disclosure. For example, the processor can control each component of the base station to transmit SRS configuration information to the terminal and receive SRS from the terminal. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0456] 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.

[0457] 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 embodiments described in the claims or specification of the present disclosure.

[0458] 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.

[0459] 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 implementing 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 implementing an embodiment of the present disclosure.

[0460] In the specific embodiments of the present disclosure described above, components included in the invention are expressed singularly or plurally, 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 plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0461] 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, each of the above embodiments can be combined and operated as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined to operate a base station and a terminal. For example, parts of the first to fifth embodiments of the present disclosure can be combined to operate a base station and a terminal. In addition, although the above embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above embodiments can also be implemented in other systems, such as a TDD LTE system, a 5G or NR system.

[0462] Meanwhile, the order of description in the drawings explaining the method of the present invention does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0463] Alternatively, the drawings illustrating the method of the present invention may omit some components and include only some components within a scope that does not harm the essence of the present invention.

[0464] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the invention.

[0465] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal of a communication system, A step of receiving SBFD (subband non-overlapping full duplex) configuration information from a base station, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband; A step of receiving SRS (sounding reference signal) configuration information from the base station, wherein the SRS configuration information includes resource information for SRS transmission; A step of checking frequency resources for SRS transmission based on the above SBFD setting information and the above SRS setting information; and Comprising a step of transmitting SRS over the frequency resource to the base station, A method characterized in that the above SRS is transmitted within the above uplink sub-band.

2. A method according to claim 1, characterized in that the reference point for confirming the starting point of the frequency resource is CRB (common resource block) 0 if the shift value is greater than or equal to the starting value in the frequency domain of the uplink sub-band, and is the starting value in the frequency domain of the uplink sub-band if the shift value is less than the starting value in the frequency domain of the uplink sub-band.

3. A method according to claim 1, characterized in that the reference point for confirming the starting point of the frequency resource is based on an offset value based on the frequency band of the uplink sub-band or an offset value based on the frequency band of the uplink sub-band and the guard band.

4. A method according to claim 1, characterized in that the frequency resources are resources that overlap with the uplink sub-band, and resources that do not overlap with the uplink sub-band are excluded.

5. In a method performed by a base station of a communication system, A step of transmitting SBFD (subband non-overlapping full duplex) configuration information to a terminal, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband; A step for transmitting SRS (sounding reference signal) setting information to the terminal, wherein the SRS setting information includes resource information for SRS transmission; and Comprising a step of receiving SRS from the terminal, The above SRS is received in the frequency resources for SRS reception, The above frequency resources are based on the above SBFD setting information and the above SRS setting information, A method characterized in that the above SRS is received within the above uplink sub-band.

6. In the fifth paragraph, a method characterized in that a reference point for confirming a starting point of the frequency resource is CRB (common resource block) 0 when the shift value is greater than or equal to a starting value in the frequency domain of the uplink sub-band, and a starting value in the frequency domain of the uplink sub-band when the shift value is less than the starting value in the frequency domain of the uplink sub-band.

7. In the fifth paragraph, a method characterized in that the reference point for confirming the starting point of the frequency resource is based on an offset value based on a frequency band of the uplink sub-band or an offset value based on a frequency band of the uplink sub-band and a guard band.

8. A method according to claim 5, characterized in that the frequency resources are resources that overlap with the uplink sub-band, and resources that do not overlap with the uplink sub-band are excluded.

9. At the terminal of the communication system, Transmitter and receiver; and Receive SBFD (subband non-overlapping full duplex) configuration information from a base station, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband, Receive SRS (sounding reference signal) configuration information from the base station, wherein the SRS configuration information includes resource information for SRS transmission; Check the frequency resources for SRS transmission based on the above SBFD setting information and the above SRS setting information, and Including a control unit set to transmit SRS on the frequency resource to the base station, A terminal characterized in that the above SRS is transmitted within the above uplink sub-band.

10. In the 9th paragraph, a terminal characterized in that a reference point for confirming a starting point of the frequency resource is CRB (common resource block) 0 when the shift value is greater than or equal to a starting value in the frequency domain of the uplink sub-band, and a starting value in the frequency domain of the uplink sub-band when the shift value is less than the starting value in the frequency domain of the uplink sub-band.

11. In paragraph 9, a terminal characterized in that the reference point for confirming the starting point of the frequency resource is based on an offset value based on the frequency band of the uplink sub-band or an offset value based on the frequency band of the uplink sub-band and a guard band.

12. A terminal characterized in that in paragraph 9, the frequency resource is a resource overlapping with the uplink sub-band, and resources that do not overlap with the uplink sub-band are excluded.

13. In the base station of the communication system, Transmitter and receiver; and Transmitting SBFD (subband non-overlapping full duplex) configuration information to a terminal, wherein the SBFD configuration information includes an instruction to change a part of downlink resources to an uplink subband, Transmitting SRS (sounding reference signal) configuration information to the terminal, wherein the SRS configuration information includes resource information for SRS transmission, and Including a control unit set to receive SRS from the terminal, The above SRS is received in the frequency resources for SRS reception, The above frequency resources are based on the above SBFD setting information and the above SRS setting information, A base station, characterized in that the above SRS is received within the above uplink sub-band.

14. In the fifth paragraph, a base station characterized in that a reference point for confirming a starting point of the frequency resource is CRB (common resource block) 0 when the shift value is greater than or equal to a starting value in the frequency domain of the uplink sub-band, and a starting value in the frequency domain of the uplink sub-band when the shift value is less than the starting value in the frequency domain of the uplink sub-band.

15. In the fifth paragraph, a base station characterized in that the reference point for confirming the starting point of the frequency resource is based on an offset value based on a frequency band of the uplink sub-band or an offset value based on a frequency band of the uplink sub-band and a guard band.

Images