Method and apparatus for transmitting and receiving downlink channel state information in wireless mobile communication system

Abstract

The present embodiments provide a method by which a terminal transmits downlink channel state information (CSI), the method comprising the steps of: receiving CSI subband configuration information including size configuration information of a CSI subband for reporting channel state information; configuring at least one first CSI subband on the basis of the size configuration information of the CSI subband and the size of a downlink bandwidth part; and reporting channel state information obtained for the at least one first CSI subband, wherein if a downlink (DL) subband for supporting a subband full duplex (SBFD) operation is configured by a base station, at least one second CSI subband distinguished from the first CSI subband is configured for SBFD symbols, and channel state information obtained for the at least one second CSI subband is further reported.

Description

Method and device for transmitting and receiving downlink channel status information in a wireless mobile communication system

[0001] The present embodiments propose a method and apparatus for transmitting and receiving downlink channel state information in a wireless mobile communication system in a next-generation wireless access network (in this disclosure, “5G,” “NR [New Radio],” “5G-Advanced,” “6G,” or a subsequent 3GPP wireless access network).

[0002] TDD (Time Division Duplex) is a duplexing method widely used in commercial New Radio (NR) and 5G mobile communication systems. In TDD, time-slot radio resources are divided into downlink and uplink slots. Typically, downlink slots are distributed at a higher rate than uplink slots, depending on the distribution ratio of uplink to downlink traffic.

[0003] However, these limitations on uplink slots negatively impact coverage and latency. Full-duplex communication has recently attracted attention as a technology to address these issues.

[0004] In such a full-duplex communication environment, especially when full-duplex communication is configured in units of symbols or slots based on subbands, a specific design is required for the operation of measuring and reporting channel state information.

[0005] Embodiments of the present disclosure can provide a method and device for transmitting and receiving downlink channel state information in a wireless mobile communication system.

[0006] In one aspect, the present embodiments provide a method for a terminal to transmit downlink channel state information (CSI), the method comprising: receiving CSI subband configuration information including size setting information of a CSI subband for reporting channel state information; configuring at least one first CSI subband based on the size setting information of the CSI subband and the size of a downlink bandwidth part; and reporting acquired channel state information for the at least one first CSI subband, wherein the configuring at least one first CSI subband comprises, when a downlink (DL) subband for supporting subband-based full duplex (SBFD) operation is configured by a base station, configuring at least one second CSI subband distinct from the first CSI subband for an SBFD symbol, and the reporting of the channel state information may provide a method for further reporting acquired channel state information for the at least one second CSI subband.

[0007] In another aspect, the present embodiments provide a method for a base station to receive downlink channel state information (CSI), the method comprising: transmitting CSI subband configuration information including size setting information of a CSI subband for reporting channel state information; and receiving channel state information for at least one first CSI subband configured based on the size setting information of the CSI subband and the size of a downlink bandwidth part, wherein the step of receiving the channel state information may further provide a method for receiving channel state information for at least one second CSI subband configured separately from the first CSI subband for an SBFD symbol when a downlink (DL) subband for supporting a subband-based full duplex (SBFD) operation is configured by the base station.

[0008] In another aspect, the present embodiments provide a terminal for transmitting downlink channel state information (CSI), the terminal including a transmitter, a receiver, and a control unit for controlling operations of the transmitter and the receiver, wherein the control unit receives CSI subband configuration information including size setting information of a CSI subband for reporting channel state information, configures at least one first CSI subband based on the size setting information of the CSI subband and the size of a downlink bandwidth part, and reports acquired channel state information for at least one first CSI subband, and when a downlink (DL) subband for supporting subband-based full duplex (SBFD) operation is configured by a base station, the terminal configures at least one second CSI subband distinct from the first CSI subband for an SBFD symbol, and further reports acquired channel state information for at least one second CSI subband.

[0009] In another aspect, the present embodiments provide a base station for receiving downlink channel state information (CSI), comprising a transmitter, a receiver, and a control unit for controlling operations of the transmitter and the receiver, wherein the control unit transmits CSI subband configuration information including size setting information of a CSI subband for reporting channel state information, and receives channel state information for at least one first CSI subband configured based on the size setting information of the CSI subband and the size of a downlink bandwidth part, and when a downlink (DL) subband for supporting subband-based full duplex (SBFD) operation is configured by the base station, the base station may further receive channel state information for at least one second CSI subband configured separately from the first CSI subband for an SBFD symbol.

[0010] According to the present embodiments, a method and device for transmitting and receiving downlink channel state information in an environment where full-duplex communication is applied can be provided.

[0011] FIG. 1 is a schematic diagram illustrating the structure of an NR wireless communication system to which the present embodiment can be applied.

[0012] FIG. 2 is a drawing for explaining a frame structure in an NR system to which the present embodiment can be applied.

[0013] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0014] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0015] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0016] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0017] Figure 7 is a drawing for explaining CORESET.

[0018] FIG. 8 is a diagram illustrating a procedure for a terminal to transmit downlink channel state information according to one embodiment.

[0019] FIG. 9 is a diagram illustrating a procedure for a base station to receive downlink channel state information according to one embodiment.

[0020] FIG. 10 and FIG. 11 are diagrams for explaining that an uplink subband is set in an arbitrary downlink slot according to one embodiment.

[0021] FIG. 12 and FIG. 13 are diagrams for explaining configuring CSI subbands for an SBFD symbol according to one embodiment.

[0022] Fig. 14 is a drawing showing the configuration of a terminal according to another embodiment.

[0023] Fig. 15 is a drawing showing the configuration of a base station according to another embodiment.

[0024] Hereinafter, some embodiments of the present disclosure will be described in detail with reference to exemplary drawings. When adding reference numerals to components in each drawing, identical components may have the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present embodiments, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the technical idea of ​​the present invention, the detailed description may be omitted. When "includes," "has," "consists of," etc. are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it may include a case in which the plural is included unless specifically stated otherwise.

[0025] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of the present disclosure. These terms are only intended to distinguish the components from other components, and the nature, order, sequence, or number of the components are not limited by the terms.

[0026] In a description of the positional relationship of components, when it is described that two or more components are "connected," "combined," or "connected," it should be understood that the two or more components may be directly "connected," "combined," or "connected," but that the two or more components may also be further "interposed" with another component to be "connected," "combined," or "connected." Here, the other component may be included in one or more of the two or more components that are "connected," "combined," or "connected" to each other.

[0027] In the description of the temporal flow relationship related to components, operation methods, or manufacturing methods, for example, when the temporal or flow relationship is described as “after”, “following”, “next to”, “before”, etc., it may also include cases where it is not continuous, unless “immediately” or “directly” is used.

[0028] Meanwhile, when numerical values ​​or corresponding information (e.g., levels, etc.) for components are mentioned, even without separate explicit description, the numerical values ​​or corresponding information may be interpreted as including an error range that may occur due to various factors (e.g., process factors, internal or external impact, noise, etc.).

[0029] The wireless communication system in this specification refers to a system for providing various communication services such as voice, data packets, etc. using wireless resources, and may include a terminal, a base station, or a core network.

[0030] The embodiments disclosed below can be applied to wireless communication systems using various wireless access technologies. For example, the embodiments can be applied to various wireless access technologies such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), SC-FDMA (single carrier frequency division multiple access), or NOMA (non-orthogonal multiple access). In addition, the wireless access technology may not only refer to a specific access technology, but also to each generation of communication technologies established by various communication agreement organizations such as 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, and ITU. For example, CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented in wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e.UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTSterrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink. Thus, the present embodiments can be applied to currently disclosed or commercialized wireless access technologies, as well as wireless access technologies currently under development or to be developed in the future.

[0031] Meanwhile, the term "terminal" in this specification is a comprehensive concept that refers to a device that includes a wireless communication module that performs communication with a base station in a wireless communication system, and should be interpreted as a concept that includes not only UE (User Equipment) in WCDMA, LTE, NR, HSPA, and IMT-2020 (5G or New Radio), but also MS (Mobile Station), UT (User Terminal), SS (Subscriber Station), and wireless device in GSM. In addition, the terminal may be a user portable device such as a smartphone depending on the usage type, and in a V2X communication system, it may mean a vehicle, a device including a wireless communication module in the vehicle, etc. In addition, in the case of a Machine Type Communication system, it may mean an MTC terminal, M2M terminal, URLLC terminal, etc. that is equipped with a communication module to perform machine type communication.

[0032] The base station or cell in this specification refers to an end that communicates with a terminal in terms of a network, and includes various coverage areas such as Node-B, eNB (evolved Node-B), gNB (gNode-B), LPN (Low Power Node), Sector, Site, various types of antennas, BTS (Base Transceiver System), Access Point, Point (e.g., Transmission Point, Reception Point, Transmission / Reception Point), Relay Node, Mega Cell, Macro Cell, Micro Cell, Pico Cell, Femto Cell, RRH (Remote Radio Head), RU (Radio Unit), and Small Cell. In addition, a cell may mean including a BWP (Bandwidth Part) in the frequency domain. For example, a serving cell may mean an Activation BWP of a terminal.

[0033] Since the various cells listed above have a base station that controls one or more cells, the base station can be interpreted in two meanings. 1) It can be a device itself that provides a mega cell, macro cell, micro cell, pico cell, femto cell, or small cell in relation to a wireless area, or 2) it can indicate the wireless area itself. In 1), all devices that provide a given wireless area are controlled by the same entity or that interact to cooperatively configure the wireless area are all indicated as a base station. Depending on how the wireless area is configured, a point, a transceiver point, a transmission point, a reception point, etc. can be an embodiment of a base station. In 2), the wireless area itself that receives or transmits a signal from the perspective of a user terminal or a neighboring base station can also be indicated as a base station.

[0034] In this specification, a cell may mean a component carrier having coverage of a signal transmitted from a transmission / reception point or a transmission / reception point itself.

[0035] Uplink (UL, or uplink) refers to a method of transmitting and receiving data from a terminal to a base station, and downlink (DL, or downlink) refers to a method of transmitting and receiving data from a base station to a terminal. Downlink may refer to communication or a communication path from multiple transmission / reception points to a terminal, and uplink may refer to communication or a communication path from a terminal to multiple transmission / reception points. In this case, in the downlink, the transmitter may be part of the multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission / reception points.

[0036] Uplink and downlink transmit and receive control information through control channels such as PDCCH (Physical Downlink Control CHannel) and PUCCH (Physical Uplink Control CHannel), and transmit and receive data by configuring data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel). Hereinafter, the situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also expressed in the form of 'transmitting and receiving PUCCH, PUSCH, PDCCH, and PDSCH'.

[0037] For clarity of explanation, the technical idea of ​​this invention is described below mainly with reference to the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the technical features of this invention are not limited to the communication system.

[0038] After researching 4G (4th-Generation) communication technology, 3GPP develops 5G (5th-Generation) communication technology to meet the requirements of the next-generation wireless access technology of the ITU-R. Specifically, 3GPP develops LTE-A pro, which enhances LTE-Advanced technology to meet the requirements of the ITU-R, and NR, a new communication technology separate from 4G communication technology. Both LTE-A pro and NR refer to 5G communication technology, and in the following, 5G communication technology will be explained with NR as the focus, unless a specific communication technology is specifically mentioned.

[0039] The operating scenario in NR defines various operation scenarios by adding considerations for satellites, automobiles, and new verticals to the existing 4G LTE scenario, and in terms of service, it supports the eMBB (Enhanced Mobile Broadband) scenario, the mMTC (Massive Machine Communication) scenario that has high terminal density but is deployed over a wide area and requires low data rate and asynchronous access, and the URLLC (Ultra Reliability and Low Latency) scenario that requires high responsiveness and reliability and can support high-speed mobility.

[0040] To meet these scenarios, NR introduces a wireless communication system that incorporates new waveform and frame structure technologies, low latency technologies, support for ultra-high frequency bands (mmWave), and forward compatibility technologies. In particular, NR systems offer various technological changes in terms of flexibility to ensure forward compatibility. The key technical features of NR are described below with reference to the drawings.

[0041]

[0042] <NR 시스템 일반>

[0043] Figure 1 is a schematic diagram illustrating the structure of an NR system to which the present embodiment can be applied.

[0044] Referring to Fig. 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN parts, and the NG-RAN is composed of gNBs and ng-eNBs that provide user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocol termination for UE (User Equipment). gNBs or gNBs and ng-eNBs are interconnected via the Xn interface. gNBs and ng-eNBs are each connected to the 5GC via the NG interface. The 5GC can be configured to include an AMF (Access and Mobility Management Function) that is responsible for the control plane such as terminal access and mobility control functions, and an UPF (User Plane Function) that is responsible for the control function for user data. NR includes support for both frequency bands below 6 GHz (FR1, Frequency Range 1) and frequency bands above 6 GHz (FR2, Frequency Range 2).

[0045] gNB refers to a base station that provides NR user plane and control plane protocol termination to terminals, and ng-eNB refers to a base station that provides E-UTRA user plane and control plane protocol termination to terminals. The base station described in this specification should be understood to encompass both gNB and ng-eNB, and may also be used to refer to gNB or ng-eNB separately as needed.

[0046] <NR 웨이브 폼, 뉴머롤러지 및 프레임 구조>

[0047] NR uses the CP-OFDM waveform with a cyclic prefix for downlink transmission, and CP-OFDM or DFT-s-OFDM for uplink transmission. OFDM technology is easily combined with MIMO (Multiple Input Multiple Output) and offers the advantages of high spectral efficiency and low-complexity receivers.

[0048] Meanwhile, in NR, the requirements for data rates, latency, and coverage differ across the three scenarios mentioned above. Therefore, it is necessary to efficiently satisfy these requirements across the frequency bands that comprise any NR system. To this end, technologies have been proposed to efficiently multiplex radio resources based on multiple different numerologies.

[0049] Specifically, the NR transmission numerator is determined based on the sub-carrier spacing and the cyclic prefix (CP), and is changed exponentially using the μ value as an exponent value of 2 based on 15 kHz, as shown in Table 1 below.

[0050] μ서브캐리어 간격Cyclic prefixSupported for dataSupported for synch015NormalYesYes130NormalYesYes260Normal, ExtendedYesNo3120NormalYesYes4240NormalNoYes

[0051] As shown in Table 1 above, the numerology of NR can be divided into five types according to the subcarrier spacing. This is different from the fixed subcarrier spacing of LTE, one of the 4G communication technologies, at 15 kHz. Specifically, the subcarrier spacing used for data transmission in NR is 15, 30, 60, and 120 kHz, and the subcarrier spacing used for synchronization signal transmission is 15, 30, 12, and 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier spacing. Meanwhile, the frame structure in NR is defined as a 10 ms frame consisting of 10 subframes with the same length of 1 ms. One frame can be divided into half frames of 5 ms, and each half frame contains 5 subframes. In the case of a 15 kHz subcarrier spacing, one subframe consists of one slot, and each slot consists of 14 OFDM symbols. FIG. 2 is a diagram for explaining the frame structure in an NR system to which the present embodiment can be applied. Referring to FIG. 2, a slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length of the slot in the time domain may vary depending on the subcarrier spacing. For example, in the case of a numerology with a 15 kHz subcarrier spacing, a slot is composed of 1 ms, which is the same length as a subframe. In contrast, in the case of a numerology with a 30 kHz subcarrier spacing, a slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, a subframe and a frame are defined with a fixed time length, and a slot is defined by the number of symbols, so the time length may vary depending on the subcarrier spacing.

[0052] Meanwhile, NR defines slots as the basic scheduling unit and also introduces mini-slots (or sub-slots, or non-slot-based scheduling) to reduce transmission delay in the wireless section. Using wider subcarrier spacing reduces transmission delay in the wireless section by shortening the length of each slot inversely. Mini-slots (or sub-slots) are designed to efficiently support URLLC scenarios and allow scheduling in units of 2, 4, or 7 symbols.

[0053] Furthermore, unlike LTE, NR defines uplink and downlink resource allocation at the symbol level within a single slot. To reduce HARQ delay, a slot structure was defined that allows HARQ ACK / NACK to be transmitted directly within the transmission slot. This slot structure is referred to as a self-contained structure and will be described in detail.

[0054] NR is designed to support a total of 256 slot formats, of which 62 are used in 3GPP Rel-15. It also supports a common frame structure that configures FDD or TDD frames through various combinations of slots. For example, it supports a slot structure in which all symbols in a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink and uplink symbols are combined. NR also supports data transmission being distributed and scheduled across one or more slots. Therefore, a base station can use a slot format indicator (SFI) to inform a UE whether a slot is a downlink slot, an uplink slot, or a flexible slot. The base station can indicate the slot format by indicating an index of a table configured through UE-specific RRC signaling using the SFI, and can also indicate it dynamically through DCI (Downlink Control Information) or statically or semi-statically through RRC.

[0055] <NR 물리 자원 >

[0056] In relation to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered.

[0057] Antenna ports are defined such that the channel through which a symbol on an antenna port is carried can be inferred from the channel through which another symbol on the same antenna port is carried. Two antenna ports are said to be quasi co-located (or quasi co-located) if the large-scale properties of the channel through which a symbol on one antenna port is carried can be inferred from the channel through which a symbol on the other antenna port is carried. Here, the large-scale properties include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

[0058] FIG. 3 is a diagram for explaining a resource grid supported by a wireless access technology to which the present embodiment can be applied.

[0059] Referring to Figure 3, a resource grid may exist for each numeral, as NR supports multiple numerals on the same carrier. Furthermore, resource grids may exist based on antenna ports, subcarrier spacing, and transmission direction.

[0060] A resource block (RB) consists of 12 subcarriers and is defined solely in the frequency domain. Furthermore, a resource element (RE) consists of one OFDM symbol and one subcarrier. Therefore, as shown in Figure 3, the size of a single RB can vary depending on the subcarrier spacing. NR also defines "Point A," which serves as a common reference point for the RB grid, as well as common RBs and virtual RBs.

[0061] FIG. 4 is a diagram for explaining a bandwidth part supported by a wireless access technology to which the present embodiment can be applied.

[0062] Unlike LTE, where the carrier bandwidth is fixed at 20 MHz, NR sets the maximum carrier bandwidth from 50 MHz to 400 MHz for each subcarrier interval. Therefore, it is not assumed that all terminals will use the entire carrier bandwidth. Accordingly, NR allows terminals to designate bandwidth parts (BWPs) within the carrier bandwidth, as illustrated in Figure 4. Furthermore, bandwidth parts are associated with a single numerology, consist of a subset of consecutive common resource blocks, and can be dynamically activated over time. Each terminal is configured with up to four bandwidth parts for both the uplink and downlink, and data is transmitted and received using the bandwidth parts activated at a given time.

[0063] In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, the downlink and uplink bandwidth parts are set in pairs so that they can share a center frequency to prevent unnecessary frequency re-tuning between downlink and uplink operations.

[0064] <NR 초기 접속>

[0065] In NR, a terminal performs cell search and random access procedures to connect to a base station and perform communication.

[0066] Cell search is a procedure in which a terminal synchronizes to the cell of a corresponding base station, obtains a physical layer cell ID, and obtains system information using the synchronization signal block (SSB) transmitted by the base station.

[0067] FIG. 5 is a diagram illustrating an example of a synchronization signal block in a wireless access technology to which the present embodiment can be applied.

[0068] Referring to FIG. 5, SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), each occupying 1 symbol and 127 subcarriers, and a PBCH spanning 3 OFDM symbols and 240 subcarriers.

[0069] The terminal receives SSB by monitoring SSB in the time and frequency domain.

[0070] SSB can be transmitted up to 64 times in 5ms. Multiple SSBs are transmitted in different transmission beams within 5ms, and the terminal performs detection assuming that SSBs are transmitted every 20ms based on a specific beam used for transmission. The number of beams that can be used for SSB transmission within 5ms can increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 in the frequency band between 3GHz and 6GHz, and up to 64 different beams can be used for SSB transmission in the frequency band above 6GHz.

[0071] SSB contains two symbols in one slot, and the starting symbol and number of repetitions within the slot are determined as follows depending on the subcarrier spacing.

[0072] Meanwhile, unlike SS in conventional LTE, SSB is not transmitted at the center frequency of the carrier bandwidth. This means that SSB can be transmitted even in locations other than the center of the system bandwidth, and when supporting wideband operation, multiple SSBs can be transmitted in the frequency domain. Accordingly, the terminal monitors SSB using the synchronization raster, which is a candidate frequency location for monitoring SSB. The carrier raster, which is the center frequency location information of the channel for initial access, and the synchronization raster are newly defined in NR. The synchronization raster has a wider frequency interval than the carrier raster, which can support the terminal's fast SSB search.

[0073] A UE can obtain the MIB through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information required for the UE to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH may include information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (e.g., SIB1 numerology information, information related to SIB1 CORESET, search space information, PDCCH-related parameter information, etc.), offset information between the common resource block and the SSB (the absolute position of the SSB within the carrier is transmitted through SIB1), etc. Here, the SIB1 numerology information is also applied equally to some messages used in the random access procedure for the UE to access the base station after completing the cell search procedure. For example, the numerology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

[0074] The aforementioned RMSI may refer to SIB1 (System Information Block 1), and SIB1 is broadcast periodically (e.g., every 160 ms) in the cell. SIB1 contains information necessary for the UE to perform the initial random access procedure and is periodically transmitted via PDSCH. In order for the UE to receive SIB1, it must receive numerology information used for SIB1 transmission and CORESET (Control Resource Set) information used for SIB1 scheduling via PBCH. The UE checks scheduling information for SIB1 using SI-RNTI in CORESET and acquires SIB1 on PDSCH according to the scheduling information. The remaining SIBs, excluding SIB1, may be transmitted periodically or upon request of the UE.

[0075] FIG. 6 is a diagram for explaining a random access procedure in a wireless access technology to which the present embodiment can be applied.

[0076] Referring to FIG. 6, once cell search is complete, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via the PRACH. Specifically, the random access preamble is transmitted to the base station via the PRACH, which consists of consecutive radio resources in a specific slot that is periodically repeated. Generally, when a terminal initially accesses a cell, a contention-based random access procedure is performed, and when performing random access for beam failure recovery (BFR), a non-contention-based random access procedure is performed.

[0077] The UE receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), an UL Grant (uplink radio resource), a temporary C-RNTI (Temporary Cell - Radio Network Temporary Identifier), and a TAC (Time Alignment Command). Since one random access response may include random access response information for one or more UEs, the random access preamble identifier may be included to indicate which UE the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, i.e., an RA-RNTI (Random Access - Radio Network Temporary Identifier).

[0078] Upon receiving a valid random access response, the terminal processes the information contained in the random access response and performs scheduled transmission to the base station. For example, the terminal applies TAC and stores a temporary C-RNTI. Furthermore, using the UL Grant, the terminal transmits data stored in its buffer or newly generated data to the base station. In this case, information that identifies the terminal must be included.

[0079] Finally, the terminal receives a downlink message for contention resolution.

[0080] <NR CORESET>

[0081] The downlink control channel in NR is transmitted in a CORESET (Control Resource Set) with a length of 1 to 3 symbols, and transmits uplink / downlink scheduling information, SFI (Slot format Index), and TPC (Transmit Power Control) information.

[0082] To ensure system flexibility, NR introduced the CORESET concept. CORESET (Control Resource Set) refers to time-frequency resources for downlink control signals. A terminal can decode control channel candidates using one or more search spaces within the CORESET time-frequency resources. A QCL (Quasi CoLocation) assumption is established for each CORESET, which is used to inform the characteristics of analog beam direction in addition to the delay spread, Doppler spread, Doppler shift, and average delay assumed by the conventional QCL.

[0083] Figure 7 is a drawing for explaining CORESET.

[0084] Referring to Figure 7, a CORESET can exist in various forms within the carrier bandwidth within a single slot, and in the time domain, a CORESET can consist of up to three OFDM symbols. In addition, a CORESET is defined as a multiple of six resource blocks up to the carrier bandwidth in the frequency domain.

[0085] The first CORESET is indicated via the MIB as part of the initial bandwidth part configuration, allowing the terminal to receive additional configuration and system information from the network. After establishing a connection with the base station, the terminal can receive and configure one or more CORESET information via RRC signaling.

[0086] Wider bandwidth operations

[0087] Existing LTE systems supported scalable bandwidth operation for any LTE Component Carrier (CC). That is, depending on the deployment scenario, any LTE operator could configure a single LTE CC with a bandwidth ranging from a minimum of 1.4 MHz to a maximum of 20 MHz, and a normal LTE terminal supported transmission and reception capabilities of 20 MHz bandwidth for a single LTE CC.

[0088] However, in the case of NR, the design is made to support NR terminals with different transmission and reception bandwidth capabilities through a single wideband NR CC, and accordingly, it is required to configure one or more bandwidth parts (BWP, bandwidth part(s)) consisting of segmented bandwidths for any NR CC, and to support flexible wider bandwidth operation through different bandwidth part configurations and activations for each terminal.

[0089] Specifically, in NR, one or more bandwidth parts can be configured through one serving cell configured from the terminal's perspective, and the terminal is defined to activate one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) in the serving cell to use them for uplink / downlink data transmission and reception. In addition, when multiple serving cells are configured in the terminal, that is, for the terminal to which CA is applied, it is defined to activate one downlink bandwidth part and / or uplink bandwidth part for each serving cell to use the radio resources of the serving cell to use them for uplink / downlink data transmission and reception.

[0090] Specifically, an initial bandwidth part for an initial access procedure of a terminal in an arbitrary serving cell is defined, one or more UE-specific bandwidth part(s) are configured for each terminal through dedicated RRC signaling, and a default bandwidth part for a fallback operation can also be defined for each terminal.

[0091] However, it can be defined that multiple downlink and / or uplink bandwidth parts can be activated and used simultaneously depending on the capability and bandwidth part(s) configuration of the terminal in any serving cell, but in NR rel-15, it is defined that only one downlink bandwidth part (DL bandwidth part) and one uplink bandwidth part (UL bandwidth part) can be activated and used in any terminal at any time.

[0092] In this specification, the terms frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) may be interpreted in the past or present meaning or in various meanings used in the future.

[0093] In the present disclosure, CSI reporting configuration information may be referred to as a CSI-reportconfig message. Furthermore, CSI resource configuration information may be referred to as CSI-resourceconfig information. Furthermore, subbands for supporting SBFD operations are referred to as DL subbands, UL subbands, and guardbands, respectively, and subbands for CSI reporting may be referred to as CSI subbands. However, this is merely an example, and other terms may also be used, and the present invention is not limited to specific terms.

[0094]

[0095] Below, a method for transmitting and receiving downlink channel state information in a wireless mobile communication system will be specifically described with reference to related drawings.

[0096] FIG. 8 is a diagram illustrating a procedure (800) in which a terminal transmits downlink channel state information according to one embodiment.

[0097] Referring to FIG. 8, the terminal can receive CSI subband configuration information including size setting information of a CSI subband for reporting channel state information (S810).

[0098] In the present disclosure, a terminal can perform communication in TDD (Time Division Duplex) mode and full-duplex mode. TDD is a method of using time-interval radio resources by dividing them into downlink slots and uplink slots, and the terminal can receive TDD configuration information from a base station to determine the format of symbols within a slot. In this case, the TDD configuration information can include configuration information regarding the format of a slot and configuration information for determining the format of symbols within the slot, and the information can be received via upper layer signaling or physical layer (L1) signaling.

[0099] That is, downlink symbols, uplink symbols, and flexible symbols with an undetermined transmission direction can be set for a certain period of time through an RRC message for setting the corresponding UL-DL slot. In addition, the terminal can receive terminal-specific RRC signaling that reallocates flexible symbols among the symbols set through cell-specific RRC signaling to uplink symbols, downlink symbols, or flexible symbols for each terminal.

[0100] Alternatively, the UE may be instructed to specify a dynamic slot format via a UE-group common PDCCH. For example, the UE may be dynamically instructed to specify a slot format via DCI format 2_0.

[0101] Additionally, the TDD configuration information may include information on reference subcarrier spacing (reference SCS), pattern 1, and pattern 2 that may be applied to the serving cell. In this case, the TDD configuration information may provide only pattern 1, or pattern 1 and pattern 2. Additionally, the TDD configuration information may include slot configuration period information of each pattern. The terminal may set a slot format per slot for a first number of slots as indicated by pattern 1, and if pattern 2 is provided, may set a slot format per slot for a second number of slots as indicated by pattern 2.

[0102] Full-duplex communication is a technology that allows a base station to simultaneously perform downlink transmission and uplink reception using the same radio resources. Terminals can also perform downlink and uplink transmission simultaneously. When a base station supports full-duplex communication based on subband non-overlapping, certain frequency resources within the same symbol in a TDD carrier can be used for downlink transmission, while other frequency resources can be used for uplink reception. In other words, within a TDD carrier, some frequency resources within a given downlink symbol can be utilized for uplink transmission by a terminal, or can be configured to be utilized as flexible symbols for downlink / uplink transitions.

[0103] To this end, the terminal may receive SBFD configuration information. That is, the terminal may receive information on a time domain and a frequency domain for configuring a downlink subband in an uplink slot or for configuring an uplink subband in a downlink slot. According to an example, the SBFD configuration information may include configuration information on at least one uplink subband and at least one downlink subband. In addition, the SBFD configuration information may include configuration information on an SBFD symbol in which an uplink subband and a downlink subband are configured in the frequency domain. Alternatively, the SBFD configuration information may include information on a frequency domain in which a guard band is configured and information on a time domain. Here, the frequency resource information may include resource block allocation information, and the time resource information may include SBFD symbol allocation information.

[0104] In addition, for configuring SBFD subbands, time resource information for uplink subbands can be set based on reference subcarrier spacing (SCS) information and pattern setting information. In this case, the time resource information can be set based on the reference subcarrier spacing (SCS) included in the TDD configuration information. That is, as described above, the reference subcarrier spacing (SCS) setting included in the TDD configuration information can be used as a reference SCS for setting time resources for configuring uplink subbands.

[0105] Additionally, time resource information can be set based on the number of TDD patterns and the period of the patterns included in the TDD configuration information. That is, as described above, the settings for Pattern 1 and Pattern 2 included in the TDD configuration information can be used as pattern setting information for setting time resources for configuring an uplink subband.

[0106] In this case, the SBFD symbol allocation information may be set to consecutive SBFD symbols within the cycle of a TDD pattern set to one or two. Each pattern setting information may include the cycle setting information of the corresponding pattern, offset information, and duration information. At this time, the duration information may be set to the number of consecutive SBFD symbols from the offset, or may be set to a combination of the number of consecutive SBFD slots and the number of consecutive SBFD symbols. Alternatively, according to an example, the offset may be set to an end point instead of a start point. That is, offset information corresponding to the end point and duration information from the end point may be set.

[0107] For configuring SBFD subbands, frequency resource configuration information for uplink subbands may be configured in units of common resource blocks (CRBs). In this case, frequency resource configuration for uplink subbands may be accompanied by guardband configuration or downlink subband configuration within the same symbol / slot. That is, frequency resource configuration information for uplink subbands may include at least one of guardbands accompanying an SBFD slot or SBFD symbol in which the uplink subband is configured, or frequency resource configuration information for downlink subbands. In this case, time resource configuration information for the guardband or downlink subbands may be configured according to the time resource configuration information of the uplink subband.

[0108] For example, for configuring SBFD subbands, frequency resource information for an uplink subband may include configuration information for one uplink subband and one or two guard bands based on a CRB. In this case, if the uplink subband is located in the center of the frequency band, two guard bands may be configured above and below the uplink subband. Alternatively, if the uplink subband is located at the upper boundary of the frequency band, one guard band may be configured below the uplink subband. Alternatively, if the uplink subband is located at the lower boundary of the frequency band, one guard band may be configured above the uplink subband. Accordingly, configuration information for one or two guard bands may be included in the frequency resource information. In this case, a downlink subband may be configured with a guard band in between, and the downlink subband may be inferred from the frequency resource information for the uplink subband and the guard band.

[0109] In another example, for configuring SBFD subbands, frequency resource information for an uplink subband may include configuration information for one uplink subband and one or two downlink subbands based on a CRB. In this case, if the uplink subband is located in the center of the frequency band, two downlink subbands may be configured above and below the corresponding uplink subband. Alternatively, if the uplink subband is located at the upper boundary of the frequency band, one downlink subband may be configured below the corresponding uplink subband. Alternatively, if the uplink subband is located at the lower boundary of the frequency band, one downlink subband may be configured above the corresponding uplink subband.

[0110] For example, SBFD configuration information can be received via cell-specific upper layer signaling. That is, the terminal can receive SBFD subband configuration information from the base station via cell-specific RRC signaling. The terminal can receive the TDD configuration information and SBFD subband configuration information to configure a format for each slot.

[0111] A terminal may receive CSI reporting configuration information for reporting channel status information from a base station. For example, the CSI reporting configuration information may include CSI subband configuration information, including CSI subband size setting information. Alternatively, the CSI subband configuration information may be received via separate higher-layer signaling.

[0112] The size setting information for a CSI subband may be configured with a predetermined number of consecutive PRBs (Physical Resource Blocks) for the terminal's CSI reporting. In this case, the CSI subband size value may be set to one of two candidate values ​​depending on the total number of PRBs constituting the bandwidth part (BWP).

[0113] The terminal can receive a CSI subband size setting value of one of two candidate values ​​based on the bandwidth part size from the base station through CSI report configuration information. Furthermore, the CSI report configuration information includes frequency setting information for the CSI measurement target for CSI reporting. At this time, the frequency setting information for the CSI measurement target can be set on a per-CSI subband basis.

[0114] Referring again to FIG. 8, the terminal may configure at least one first CSI subband based on the size setting information of the CSI subband and the size of the downlink bandwidth part (S820), and report the acquired channel state information for at least one first CSI subband (S830).

[0115] The terminal may configure at least one CSI subband based on a CSI subband size determined by the size of a bandwidth part in which a reference signal for CSI measurement is transmitted, such as CSI-RS or SSB, and a CSI subband size setting value included in the CSI subband configuration information, based on a common resource block (CRB) #0, which is a reference point. That is, CSI subbands may be configured for frequency bands consecutively divided into PRBs corresponding to the CSI subband size value from CRB #0 and bands that overlap with the bands of the bandwidth part. This will be described in more detail in the description of FIG. 12 below.

[0116] As described above, UL subbands and DL subbands for supporting SBFD operation for a terminal can be configured for SBFD symbols. For a downlink bandwidth part (DL BWP) including the corresponding UL subband and DL subband, in the SBFD symbol, the DL subband is configured from some frequency resources among the entire frequency resources constituting the corresponding downlink bandwidth part. That is, in the SBFD symbol, some frequency resources of the downlink bandwidth part are configured as uplink subbands or guard bands, so it is necessary to configure a second CSI subband for the SBFD symbol that is distinct from the first CSI subband for the conventional non-SBFD symbol for the aforementioned CSI reporting.

[0117] When a downlink (DL) subband is configured by a base station to support subband-based full duplex (SBFD) operation, the terminal may configure at least one second CSI subband distinct from the first CSI subband for the SBFD symbol. In this case, the terminal may also obtain channel state information for at least one second CSI subband and report it to the base station.

[0118] For example, at least one second CSI subband may be configured with only first CSI subbands that are completely within the frequency bandwidth of the DL subband among at least one first CSI subband. That is, while maintaining the configuration for the existing BWP-based first CSI subband, when CSI reporting in SBFD symbols is configured, the terminal may be configured to limit the configurable CSI subbands.

[0119] In this case, the terminal can configure as the second CSI subband only the CSI subband that belongs entirely to the DL subband among the CSI subbands configured based on the CSI report configuration information or the CSI subband configuration information. Accordingly, if the CSI report configuration information is set to CSI reporting based on CSI-RS resources that are transmitted only through SBFD symbols, i.e., if the associated CSI-RS is transmitted only through SBFD symbols, the terminal can configure as the second CSI subband only at least one CSI subband that belongs entirely to the DL subband among the entire first CSI subbands that constitute the corresponding downlink bandwidth part.

[0120] According to another example, at least one second CSI subband may be configured only with the remaining first CSI subbands, excluding the first CSI subbands that are completely within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband. That is, the UE may limit the CSI subbands whose entire PRBs do not completely belong to the DL subband to CSI subbands that cannot be used for CSI reporting for SBFD symbols. In this case, all first CSI subbands, excluding the CSI subbands that are completely within the UL subband and the guard band among the first CSI subbands, may be configured as the second CSI subbands. Accordingly, for the CSI subbands among the second CSI subbands that include some PRBs that do not belong to the DL subband, the PRB configuration information of the corresponding CSI subband may be implicitly reset.

[0121] According to another example, at least one second CSI subband may be configured based on the size of the DL subband, separately from the configuration of at least one first CSI subband. That is, when the downlink bandwidth part configured for the terminal includes UL subband and DL subband configurations for supporting SBFD operation, the terminal may separately configure a first CSI subband for non-SBFD symbols and a second CSI subband for SBFD symbols. Accordingly, when CSI-RS transmission is performed through a non-SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on an existing downlink bandwidth part. On the other hand, when CSI-RS transmission is performed through an SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on a new DL subband.

[0122] That is, when one or two DL subbands are configured for SBFD operation, the CSI subband size may be determined by the number of PRBs constituting each DL subband, rather than the conventional method of determining the bandwidth of the aforementioned downlink bandwidth part, i.e., the number of PRBs. In the case of CSI reporting targeting the DL subband of the SBFD symbol, the terminal may configure the second CSI subband according to the size of the second CSI subband and the starting point and number of PRBs of each DL subband.

[0123] For example, at least one second CSI subband may be configured not to be configured if the size of the DL subband is smaller than 24 resource blocks. If the total number of PRBs constituting the DL subband is smaller than 24, the CSI measurement result reporting for the corresponding SBFD symbol may be restricted to be based only on the wideband CQI / PMI, regardless of the CSI subband configuration. That is, the second CSI subband for CSI reporting for the corresponding SBFD symbol may not be configured.

[0124] The terminal can report channel state information obtained from the configured first CSI subband and second CSI subband to the base station.

[0125] Accordingly, a method and device for transmitting and receiving downlink channel state information in an environment where full-duplex communication is applied can be provided.

[0126] FIG. 9 is a diagram illustrating a procedure (900) for a base station to receive downlink channel state information (CSI) according to one embodiment. The description given above in FIG. 8 may be omitted to avoid redundant description. In this case, the omitted content may be substantially equally applied to the base station, as long as it does not conflict with the technical spirit of the invention.

[0127] Referring to FIG. 9, the base station can transmit CSI subband configuration information including size setting information of a CSI subband for reporting channel state information (S910).

[0128] In this disclosure, a base station can communicate with a terminal in TDD (Time Division Duplex) mode and full-duplex mode. This has been described in FIG. 8, and specific details are omitted.

[0129] A base station may transmit CSI reporting configuration information to a terminal for reporting channel state information. For example, the CSI reporting configuration information may include CSI subband configuration information, including CSI subband size setting information. Alternatively, the CSI subband configuration information may be received via separate higher-layer signaling.

[0130] The size setting information for a CSI subband may be configured with a predetermined number of consecutive PRBs (Physical Resource Blocks) for the terminal's CSI reporting. In this case, the CSI subband size value may be set to one of two candidate values ​​depending on the total number of PRBs constituting the bandwidth part (BWP).

[0131] The base station can transmit to the terminal, via CSI reporting configuration information, one of two candidate values ​​for the CSI subband size setting based on the bandwidth part size. Furthermore, the CSI reporting configuration information includes frequency setting information for the CSI measurement target for the CSI report. At this time, the frequency setting information for the CSI measurement target can be set on a per-CSI subband basis.

[0132] Referring again to FIG. 9, the base station can receive channel state information for at least one first CSI subband configured based on the size setting information of the CSI subband and the size of the downlink bandwidth part (S920).

[0133] The terminal may configure at least one CSI subband based on a CSI subband size determined by a size of a bandwidth part in which a reference signal for CSI measurement is transmitted, such as CSI-RS or SSB, and a CSI subband size setting value included in CSI subband configuration information, based on a common resource block (CRB) #0, which is a reference point. That is, CSI subbands may be configured for frequency bands consecutively divided into PRBs corresponding to the CSI subband size value from CRB #0 and bands that overlap with the bands of the bandwidth part.

[0134] As described above, the base station can configure UL subbands and DL subbands for SBFD operation support for SBFD symbols. For a downlink bandwidth part (DL BWP) including the UL subband and DL subband, the DL subband is configured in some frequency resources among the entire frequency resources constituting the downlink bandwidth part in the SBFD symbol. That is, in the SBFD symbol, some frequency resources of the downlink bandwidth part are configured as uplink subbands or guard bands, so it is necessary to configure a second CSI subband for the SBFD symbol that is distinct from the first CSI subband for the conventional non-SBFD symbol for the CSI reporting described above.

[0135] When a base station configures a downlink (DL) subband to support subband-based full duplex (SBFD) operation, the terminal may configure at least one second CSI subband distinct from the first CSI subband for the SBFD symbol. In this case, the base station may further receive channel state information acquired for at least one second CSI subband from the terminal.

[0136] For example, at least one second CSI subband may be configured with only first CSI subbands that are completely within the frequency bandwidth of the DL subband among at least one first CSI subband. That is, while maintaining the configuration for the existing BWP-based first CSI subband, when CSI reporting in SBFD symbols is configured, the terminal may be configured to limit the configurable CSI subbands.

[0137] In this case, the base station may configure only the CSI subbands that belong entirely to the DL subband among the CSI subbands configured based on the CSI report configuration information or the CSI subband configuration information as the second CSI subband. Accordingly, if the CSI report configuration information is set to CSI reporting based on CSI-RS resources that are transmitted only through SBFD symbols, i.e., if the associated CSI-RS is transmitted only through SBFD symbols, the terminal may configure the second CSI subband by limiting only at least one CSI subband that belongs entirely to the DL subband among the entire first CSI subbands that constitute the corresponding downlink bandwidth part.

[0138] According to another example, at least one second CSI subband may be configured only with the remaining first CSI subbands, excluding the first CSI subbands that are completely within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband. That is, the UE may limit the CSI subbands whose entire PRBs do not completely belong to the DL subband to CSI subbands that cannot be used for CSI reporting for SBFD symbols. In this case, all first CSI subbands, excluding the CSI subbands that are completely within the UL subband and the guard band among the first CSI subbands, may be configured as the second CSI subbands. Accordingly, for the CSI subbands among the second CSI subbands that include some PRBs that do not belong to the DL subband, the PRB configuration information of the corresponding CSI subband may be implicitly reset.

[0139] According to another example, at least one second CSI subband may be configured based on the size of the DL subband, separately from the configuration of at least one first CSI subband. That is, when the downlink bandwidth part configured for the terminal includes UL subband and DL subband configurations for supporting SBFD operation, the terminal may separately configure a first CSI subband for non-SBFD symbols and a second CSI subband for SBFD symbols. Accordingly, when CSI-RS transmission is performed through a non-SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on an existing downlink bandwidth part. On the other hand, when CSI-RS transmission is performed through an SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on a new DL subband.

[0140] That is, when one or two DL subbands are configured for SBFD operation, the CSI subband size may be determined by the number of PRBs constituting each DL subband, rather than the conventional method of determining the bandwidth of the aforementioned downlink bandwidth part, i.e., the number of PRBs. In the case of CSI reporting targeting the DL subband of the SBFD symbol, the base station may cause the terminal to configure the second CSI subband according to the size of the second CSI subband and the starting point and number of PRBs of each DL subband.

[0141] For example, at least one second CSI subband may be configured not to be configured if the size of the DL subband is smaller than 24 resource blocks. If the total number of PRBs constituting the DL subband is smaller than 24, the CSI measurement result reporting for the corresponding SBFD symbol may be restricted to be based only on the wideband CQI / PMI, regardless of the CSI subband configuration. That is, the second CSI subband for CSI reporting for the corresponding SBFD symbol may not be configured.

[0142] The base station can receive channel state information obtained from the configured first CSI subband and second CSI subband from the terminal.

[0143] Accordingly, a method and device for transmitting and receiving downlink channel state information in an environment where full-duplex communication is applied can be provided.

[0144]

[0145] Hereinafter, with reference to the relevant drawings, each embodiment related to a method for transmitting and receiving downlink channel state information in a wireless mobile communication system will be described in detail.

[0146] The present disclosure proposes a method for measuring and reporting a downlink channel at a terminal in a wireless communication system. In particular, the present disclosure proposes a method for measuring and reporting a downlink channel at a terminal in a mobile communication system supporting full-duplex communication.

[0147] TDD (Time Division Duplex) is a duplexing method widely used in commercial New Radio (NR) and 5G mobile communication systems. In TDD, time-slot radio resources are divided into downlink and uplink slots. Typically, downlink slots are distributed at a higher rate than uplink slots, depending on the distribution ratio of uplink to downlink traffic. However, this limitation on uplink slots negatively impacts coverage and latency. Full-duplex communication can be applied as a technology to address these issues.

[0148] Full-duplex communication is a technology that allows DL transmission and UL reception to be performed simultaneously on the same radio resources, specifically at the gNB, or base station. Simultaneous DL reception and UL transmission can also be performed at the terminal side. In other words, both the base station and the terminal can support full duplex. However, unlike the base station, which is structurally easy to cancel self-interference, the DL reception performance of the terminal is easily affected by self-interference of the UL transmission signal. Therefore, it is generally considered that the base station operates in full-duplex communication, and the terminal operates in half-duplex communication. Additionally, to reduce the influence of self-interference at the base station, a subband non-overlapping full-duplex (SBFD, also referred to as subband full-duplex in this disclosure) method can be primarily considered, which performs DL transmission and UL reception simultaneously, but transmits and receives by distinguishing frequency resources rather than using the same resources for DL ​​and UL.

[0149] That is, FIGS. 10 and 11 illustrate examples in which DL slots and UL slots are configured in a ratio of 4:1 in an arbitrary NR frequency band. However, some symbols of the last DL slot may be special slots including flexible symbols for DL / UL transition. In this way, when a TDD (Time Division Duplex) configuration is made, an uplink subband (UL subband) may be set to support UL transmission of a terminal in some (or all) of the DL slots. When a UL subband is set in an arbitrary DL slot, the UL subband may be set at the center of the frequency band, as shown in FIG. 10, or at the edge of the frequency band, as shown in FIG. 11. In this case, a guard band may be set between the UL subband and the downlink subband (DL subband) in the slot.

[0150] In addition, for frequency resources other than the UL subband and guard band, they can be utilized as DL subbands for DL ​​transmission and reception according to the existing slot / symbol configuration information. That is, as in FIG. 10, if the UL subband is configured around the center of the frequency band, two guard bands, one each above and below the UL subband, can be configured, and then similarly, two DL subbands, one each above and below the UL subband, can be configured. Alternatively, as in FIG. 11, if the UL subband is configured at the edge of the frequency band, one guard band and one DL subband can be configured following the UL subband.

[0151] The UL-DL slot configuration defined in NR is defined to be done on a cell-by-cell basis through cell-specific RRC signaling. That is, a pattern of DL symbols, UL symbols, and flexible symbols for a certain period is set through the RRC message 'tdd-UL-DL-ConfigurationCommon' for the corresponding UL-DL slot configuration. Additionally, through the UE-specific RRC signaling 'tdd-UL-DL-ConfigurationDedicated', only the flexible symbols set through the 'tdd-UL-DL-ConfigurationCommon' can be reallocated to UL symbols, DL symbols, or flexible symbols for each UE. Alternatively, a method for indicating a dynamic slot format through a UE-group common PDCCH is also defined. For this purpose, NR also supports a dynamic slot format indication method through DCI format 2_0.

[0152] According to the slot configuration method described above, any one symbol can be set or indicated as one of DL, UL, or Flexible. Fig. 10 is an example in which an arbitrary slot format is set to DDDSU through the existing slot configuration. D refers to a downlink slot, meaning that all OFDM symbols constituting the slot are set to DL. U refers to an uplink slot, meaning that all OFDM symbols constituting the slot are set to UL. S refers to a special slot, meaning a slot that includes a flexible symbol for DL / UL transition. Typically, in the case of a normal CP, the special slot can be configured with 12 DL symbols and 2 flexible symbols out of a total of 14 symbols. Alternatively, it can be configured with 10 DL symbols, 2 flexible symbols, and 2 UL symbols. That is, within any one TDD carrier, one symbol is configured or indicated as only one of DL, UL, or flexible.

[0153] However, as shown in FIGS. 10 and 11, if a UL subband is configured in any DL slot, DL transmission or UL transmission can occur simultaneously for each frequency resource in the symbol. In this way, a DL slot or symbol including a UL subband or a UL slot or symbol including a DL subband is referred to as an SBFD (subband full duplex) slot or SBFD symbol in the present disclosure.

[0154] In addition, in the present disclosure, a slot composed only of the SBFD symbols is referred to as an SBFD slot, and a slot composed only of symbols according to existing symbol settings (i.e., a slot composed only of symbols that do not include a UL subband, a DL subband, and a guardband) is referred to as a non-SBFD slot. Alternatively, a slot including at least one SBFD symbol may be referred to as an SBFD slot.

[0155]

[0156] Hereinafter, as described above, when any cell / network / base station supports SBFD operation, i.e., a method for configuring CSI-RS (Channel State Information Reference Signal) resources for downlink channel measurement at any terminal and a method for configuring CSI-reporting of the terminal accordingly are proposed. In particular, a method for configuring CSI subbands for subband-based CSI feedback in SBFD symbols is proposed.

[0157] Hereinafter, for convenience of explanation, the subbands for supporting SBFD operation are referred to as DL subband, UL subband, and guardband, respectively, and to distinguish them, the subband for CSI reporting is referred to as CSI subband.

[0158] According to the existing method of setting the CSI subband size for CSI reporting, the terminal sets a continuous Receives CSI subband configuration information consisting of PRBs (Physical Resource Blocks) from the base station. CSI subband size, The value is set to one of two candidate values ​​depending on the total number of PRBs that constitute the bandwidth part. Table 2 below summarizes the candidate values ​​of the CSI subband size defined according to the size of the bandwidth part.

[0159]

[0160] The base station transmits to the terminal one of the two candidate values ​​for the CSI subband size setting value according to the BWP (Bandwidth Part) size through the CSI-reportconfig information. In addition, the CSI-reportingBand, which is the CSI measurement target frequency setting information for CSI reporting, is set together with the cqi-formatindicator and pmi-formatindicator for wideband CQI / PMI or subband CQI / PMI reporting setting through the reportFreqConfiguration setting information included in the CSI-reportconfig. At this time, the CSI-reportingband setting is set in units of the CSI subband.

[0161] Referring to Figure 12, the activated BWP for the terminal is illustrated. The CSI subband is determined by the size of the BWP and the subband size setting value included in CSI-reportconfig. It is configured based on the reference point CRB #0. Accordingly, the first CSI subband (CSI SB1) and the last CSI subband (CSI SB7) in any BWP are the starting points of the corresponding DL BWP. and bandwidth, According to It can be composed of a smaller number of PRBs.

[0162] Specifically, the size of the first CSI reporting subband in any BWP can be determined as in mathematical expression 1, and the size of the last CSI reporting subband can be determined as in mathematical expression 2.

[0163] [Mathematical Formula 1]

[0164]

[0165] [Equation 2]

[0166] If,

[0167] If,

[0168] However, as described above, when a UL subband and a DL subband are set to support SBFD operation in an arbitrary cell, in the case of a DL BWP including the UL subband and DL subband, a DL subband (first DL subband) is configured in some frequency resources among the entire frequency resources constituting the DL BWP, as shown in FIG. 12, and accordingly, it is necessary to define the CSI subband setting for CSI reporting in the SBFD symbol.

[0169] As an embodiment for this, the existing BWP-based CSI subband configuration is maintained, but when CSI-reportconfig is set based on CSI-resourceconfig including CSI-RS (or SSB) transmission in SBFD symbols, and subband-based CQI and / or PMI reporting is set by the CSI-reportconfig, the CSI subbands that can be set in the corresponding CSI reporting band can be defined to be limited. Specifically, it is assumed that the CSI reporting configuration by the base station in any terminal includes the reporting configuration in the channel state information measured by receiving CSI-RS (or SSB) transmitted through SBFD symbols, and in particular, subband-based CQI and / or subband-based PMI reporting is set. In this case, the terminal expects the CSI reporting band configuration included in the corresponding CSI-reportconfig message to be a CSI subband that can be set as the corresponding CSI reporting band only for the CSI subband that completely belongs to the DL subband. That is, among all CSI subbands (CSI SB1 to CSI SB7) configured for CSI reporting in any DL BWP, only the CSI subbands (CSI SB1 to CSI SB4) that completely belong to the DL subband can be defined as available CSI subbands that can be set as CSI reporting bands through reportFreqConfiguration of CSI-ReportConfig.Accordingly, if the terminal is a CSI reporting configuration based on a CSI-RS resource in which any CSI-reportconfig is transmitted only through an SBFD symbol, i.e., if the associated CSI-RS is transmitted only through an SBFD symbol, the CSI subband included in the CSI reporting band configuration can be restricted to be configured only by limiting the configuration to CSI subbands (CSI SB1 to CSI SB4) that are completely included in the DL subband among all CSI subbands (CSI SB1 to CSI SB7) that constitute the corresponding DL BWP.

[0170] Alternatively, in a case where a CSI-RS transmission instance according to the configuration of the associated CSI-RS by any CSI-reportconfig includes some SBFD symbols, or only the CSI measurement results for the CSI-RS instance through the SBFD symbol among the entire CSI-RS transmission instances according to the associated CSI-RS are reported, the CSI subband included in the CSI reporting band configuration may be limited to only the CSI subband that fully belongs to the DL subband among the entire CSI subbands that constitute the corresponding DL BWP.

[0171] As another embodiment of determining a valid CSI subband in an SBFD symbol, an unavailable CSI subband can be limited to a CSI subband in which all PRB resources of the corresponding CSI subband do not completely belong to a DL subband. That is, all CSI subbands (CSI SB1 to CSI SB5) except for CSI subbands (CSI SB6 to CSI SB7) that completely belong to a UL subband and a guardband can be defined as CSI subbands in which the subband-based CSI reporting configuration is possible in the SBFD symbol. Accordingly, in the case of a CSI subband (CSI SB5) that includes some PRB(s) that do not belong to a DL subband among any CSI subbands configured in the corresponding DL BWP transmitted through the SBFD symbol, the PRB configuration information of the corresponding CSI subband can be implicitly reset. For example, it can be defined that the CSI subband is reconstructed using PRBs belonging to the DL subband among all PRBs that constitute the CSI subband (CSI SB5).

[0172] As above, when a valid CSI subband is defined for reporting CSI measurement results for SBFD symbols, if the CSI reporting band for any terminal includes an unavailable CSI subband, the terminal can report only the CSI measurement results based on the valid CSI subband, excluding the unavailable CSI subband, or can ignore the CSI reporting setting.

[0173] As another embodiment of defining a CSI subband for CSI reporting for CSI-RS transmission of an SBFD symbol, the CSI subband may be defined to be reconfigured based on a DL subband. That is, if any DL BWP configured for any terminal includes UL subband and DL subband configurations for supporting SBFD operation, the terminal may separately configure a CSI subband for non-SBFD symbols and a CSI subband for SBFD symbols when configuring a CSI subband for CSI reporting. Accordingly, if a CSI-RS transmission targeted by any CSI-reporting configuration is performed via a non-SBFD symbol, the corresponding CSI reporting band configuration is configured based on a CSI subband based on an existing DL BWP. On the other hand, if a CSI-RS transmission targeted by any CSI reporting configuration is performed via an SBFD symbol, the corresponding CSI reporting band configuration is configured based on a CSI subband based on a new DL subband.

[0174] That is, when one or two DL subbands are configured for SBFD operation, the CSI subband size can be determined by the bandwidth of the DL subband, i.e., the number of PRBs constituting each DL subband, rather than the conventional method of determining the bandwidth of the DL BWP, i.e., the number of PRBs. That is, referring to FIG. 13, any base station and terminal can determine the CSI subband size included in CSI-reportconfig, It can be set for the CSI subband (CSI SB1' to CSI SB7') that is separately configured for the SBFD symbol. In addition, when the base station and the terminal interpret this, in the case of CSI reporting for the DL subband of the SBFD symbol, the starting point of each DL subband, not the number of PRBs of the DL BWP, and the number of PRBs, It can be defined to set and interpret the corresponding CSI subband size according to .

[0175] Specifically, the size of the first CSI reporting subband in any downlink subband within the bandwidth part can be determined as in mathematical expression 3, and the size of the last CSI reporting subband can be determined as in mathematical expression 4.

[0176] [Equation 3]

[0177]

[0178] [Equation 4]

[0179] If,

[0180] If,

[0181] However, even in the case where the number of PRBs constituting the DL BWP configured for an arbitrary terminal is greater than 24, in order to support SBFD operation within the DL BWP, if 1 or 2 DL subbands are configured as in FIG. 10 or FIG. 11, and the total number of PRBs constituting the DL subband is less than 24, the reporting of the CSI measurement result for the SBFD symbol can be restricted to be based only on wideband CQI / PMI regardless of the CSI subband configuration. That is, the CSI subband for CSI reporting for the SBFD symbol may not be configured.

[0182]

[0183] In addition, the present disclosure proposes a method for setting CSI-RS resources for downlink channel measurement in an arbitrary terminal when an arbitrary cell / network / base station supports SBFD operation, and a method for setting CSI reporting of the terminal accordingly.

[0184] Any terminal can multiplex CSI feedback information including a channel measurement result performed on a CSI reference signal (CSI-RS (Channel State Information - Reference Signal) or SSB (Synchronization Signal Block)) transmitted in a non-SBFD symbol and CSI feedback information including a channel measurement result performed on a CSI reference signal transmitted in an SBFD symbol, and transmit the multiplexed CSI feedback information to a base station through a single CSI report message. That is, a single CSI report message can include both a downlink channel measurement result value in a non-SBFD symbol and a downlink channel measurement result value in an SBFD symbol.

[0185] Specifically, when the terminal configures a single CSI feedback message to be transmitted to the base station, the terminal may encode each absolute CSI measurement value based on the CSI-RS (or SSB) received in a non-SBFD symbol and the absolute CSI measurement value based on the CSI-RS (or SSB) received in the SBFD symbol into separate codewords, multiplex them, and report them to the base station through a single PUCCH or PUSCH. Alternatively, the terminal may configure and transmit a single absolute CSI measurement value and a relative CSI value (e.g., a differential CQI value) for the corresponding CSI measurement value. For example, the terminal may report to the base station CSI feedback information including the non-SBFD symbol-targeted CSI feedback information and the SBFD symbol-targeted differential CSI feedback information, including the SBFD symbol-targeted differential CSI value based on the corresponding non-SBFD symbol-targeted CSI information together with the non-SBFD symbol-targeted CSI feedback information (e.g., CQI information). In this way, a terminal supporting SBFD operation can be configured to report CSI feedback information including one or more CSI measurement results to a base station.

[0186] As one method of setting the above-described single CSI report message to include both CSI feedback information measured in a non-SBFD symbol and CSI feedback information measured in an SBFD symbol, a CSI-reportconfig message for any terminal can include separate sub-configuration information for measuring CSI through CSI-RS (or SSB) reception in an SBFD symbol. Specifically, the CSI-reportconfig message set for the terminal includes one CSI-resourceconfig information for CSI measurement, and an NZP-CSI-RS transmission resource or CSI-SSB transmission resource included in the CSI-resourceconfig can include both a CSI-RS transmission resource through a non-SBFD symbol and a CSI-RS transmission resource through an SBFD symbol. In this way, when one CSI-resourceconfig included in CSI-reportconfig includes CSI-RS (or SSB) transmission resources in both non-SBFD symbols and SBFD symbols, the CSI feedback information according to the CSI-reportconfig is calculated by distinguishing between CSI information based on reception of CSI reference signals (CSI-RS or SSB) transmitted through non-SBFD symbols and CSI information based on reception of CSI reference signals transmitted through SBFD symbols, and the results are multiplexed into one CSI reporting message and fed back to the base station. However, at this time, the CSI reference signal transmission resource configuration included in the CSI-resourceconfig includes only resource allocation information for CSI reference signal transmission in non-SBFD symbols, and based on this, sub-configuration information for CSI reference signal transmission in SBFD symbols is included in the CSI-reportconfig and transmitted to the terminal.That is, any CSI-reportconfig may include CSI-resourceconfig information for channel measurement in a non-SBFD symbol, and additional sub-configuration information for channel measurement in an SBFD symbol based on the corresponding CSI-resourceconfig information. The sub-configuration information may include modification information of a CSI-RS transmission or SSB transmission format when CSI-RS or SSB transmission according to the corresponding CSI-resourceconfig is performed through an SBFD symbol, and this may be antenna port sub-configuration information, power offset setting information, codebook restriction setting information, etc. In this way, when the CSI-resourceconfig included in one CSI-reportconfig message includes both CSI-RS transmission in a non-SBFD symbol and an SBFD symbol, and includes sub-configuration information for CSI-RS reception in an SBFD symbol, the UE may calculate the CSI values ​​for the non-SBFD symbol and the CSI values ​​for the SBFD symbol, respectively, and feed them back to the base station through one CSI report message.

[0187] Alternatively, one CSI-resourceconfig information may include NZP-CSI-RS-Resourceset configuration information or CSI-SSB-Resourceset configuration information for configuring CSI reference signal (CSI-RS or SSB) transmission in non-SBFD symbols, respectively, and NZP-CSI-RS-Resourceset_SBFD or CSI-SSB-Resourceset_SBFD information for configuring CSI reference signal transmission in SBFD symbols separately. That is, one CSI-resourceconfig information includes one NZP-CSI-RS-Resourceset including one or more NZP-CSI-RS-Resource configurations for CSI-RS transmission restricted to non-SBFD symbols, or one CSI-SSB-Resourceset including one or more SSB index information restricted to non-SBFD symbols, respectively. In addition, the CSI-resourceconfig information includes one NZP-CSI-RS-Resourceset_SBFD including one or more NZP-CSI-RS-Resource configurations for CSI-RS transmissions limited to separate SBFD symbols or one CSI-SSB-Resourceset_SBFD information including one or more SSB transmission information limited to SBFD symbols.If the CSI-resourceconfig included in the CSI-reportconfig set for any terminal includes the NZP-CSI-RS-Resourceset or CSI-SSB-Resourceset limited to non-SBFD symbols, as described above, and the NZP-CSI-RS-Resourceset or CSI-SSB-Resourceset limited to SBFD symbols, the terminal multiplexes the CSI feedback information based on the CSI-RS or SSB reception of the non-SBFD symbols and the CSI feedback information based on the CSI-RS or SSB reception of the SBFD symbols into the CSI feedback information according to the CSI-reportconfig and transmits the multiplexed CSI feedback information to the base station. At this time, the number of antenna ports of one NZP-CSI-RS-Resourceset included in one CSI-resourceconfig and one NZP-CSI-RS-Resources included in one NZP-CSI-RS-Resourceset_SBFD can be maintained to have the same number of antenna ports for each resourceset unit (i.e., different numbers of CSI-RS transmission antenna ports can be set between NZP-CSI-RS-Resourceset and NZP-CSI-RS-Resourceset_SBFD), or the same number of antenna ports can be maintained for each CSI-resourceconfig unit (i.e., the same number of CSI-RS transmission antenna ports can be set between NZP-CSI-RS-Resourceset and NZP-CSI-RS-Resourceset_SBFD).

[0188] Alternatively, a single CSI-reportconfig may include an associated CSI resource pair, wherein a CSI-resourceconfig includes CSI-RS (or SSB) transmission resource configurations restricted to non-SBFD symbols and a CSI-resourceconfig_SBFD includes CSI-RS (or SSB) transmission resource configurations restricted to separate SBFD symbols, i.e., one non-SBFD symbol-targeted CSI-resourceconfig and another SBFD symbol-targeted CSI-resourceconfig_SBFD. In this way, when a single CSI-reportconfig includes two different associated CSI-resourceconfigs, the UE multiplexes CSI feedback information based on CSI-RS (or SSB) received in a non-SBFD symbol according to CSI-resourceconfig and CSI feedback information based on CSI-RS (or SSB) received in a SBFD symbol according to CSI-resourceconfig_SBFD into a single CSI report message and transmits the multiplexed CSI feedback information to the base station.

[0189] Alternatively, one NZP-CSI-RS-resource information may include sub-configuration information for CSI-RS transmission targeting SBFD symbols together with CSI-RS transmission resource allocation information for non-SBFD symbols. That is, one NZP-CSI-RS-resource configuration may include sub-configuration information for CSI-RS transmission targeting SBFD symbols together with settings such as resourceMapping), powercontroloffset, periodicityAndoffset, and QCL (Quasi Co Location) information for CSI-RS transmission targeting non-SBFD symbols. The sub-configuration information may include antenna sub-configuration information for SBFD symbols, powercontroloffset information for SBFD symbols, etc.

[0190] Additionally, when a single CSI report message includes multiple pieces of CSI feedback information through the aforementioned settings, when transmitting wideband or subband CSI feedback information according to the size of the corresponding CSI payload, the CSI feedback information to be included in the corresponding CSI report can be selected based on the priority in the order of type 1 CSI feedback information measured for non-SBFD symbols, type 1 CSI feedback information measured for SBFD symbols, type 2 CSI feedback information measured for non-SBFD symbols, and type 2 CSI feedback information measured for SBFD symbols. Alternatively, the CSI feedback information to be included in the corresponding CSI report can be selected based on the priority in the order of type 1 CSI feedback information measured for non-SBFD symbols, type 2 CSI feedback information measured for non-SBFD symbols, type 1 CSI feedback information measured for SBFD symbols, and type 2 CSI feedback information measured for SBFD symbols.

[0191] However, the above-described transmission of one CSI report message by the terminal to the base station includes all CSI reporting operations, such as transmitting one CSI report to one CSI report instance via PUCCH according to periodic CSI report configuration, transmitting one CSI report message to one CSI report instance via PUCCH or PUSCH according to semi-persistent CSI report configuration and activation, or transmitting one CSI report message to one CSI report instance via PUCCH or PUSCH according to aperiodic CSI report configuration and trigger indication information.

[0192] With respect to the above-described embodiments, each embodiment is included in the scope of the invention according to the present disclosure not only in an independent case but also in all cases in which the embodiments are combined.

[0193]

[0194] Hereinafter, the configuration of a terminal and a base station capable of performing some or all of the embodiments described with reference to FIGS. 1 to 11 will be described with reference to the drawings. The above description may be omitted to avoid redundant description, and in this case, the omitted content may be substantially equally applied to the following description, as long as it does not contradict the technical spirit of the invention.

[0195] Fig. 14 is a drawing showing the configuration of a terminal (1400) according to another embodiment.

[0196] Referring to FIG. 14, a terminal (1400) according to another embodiment includes a transmitter (1420), a receiver (1430), and a control unit (1410) that controls the operations of the transmitter and receiver.

[0197] The control unit (1410) controls the overall operation of the terminal (1400) according to the method of transmitting and receiving downlink channel state information in the wireless mobile communication system required to perform the present invention described above.

[0198] The control unit (1410) can receive CSI subband configuration information including CSI subband size setting information for reporting channel state information. The control unit (1410) can perform communication in TDD (Time Division Duplex) mode and full-duplex mode. This has been described in FIG. 8, and thus, specific details will be omitted.

[0199] The control unit (1410) may receive CSI reporting configuration information for reporting channel state information from a base station. For example, the CSI reporting configuration information may include CSI subband configuration information including CSI subband size setting information. Alternatively, the CSI subband configuration information may be received via separate upper layer signaling.

[0200] The size setting information for a CSI subband may be configured with a predetermined number of consecutive PRBs (Physical Resource Blocks) for the terminal's CSI reporting. In this case, the CSI subband size value may be set to one of two candidate values ​​depending on the total number of PRBs constituting the bandwidth part (BWP).

[0201] The control unit (1410) can receive, from the base station, a CSI subband size setting value among two candidate values ​​according to the size of the bandwidth part through CSI reporting configuration information. In addition, the CSI reporting configuration information includes frequency setting information that is the target of CSI measurement for CSI reporting. In this case, the frequency setting information that is the target of the CSI measurement can be set on a CSI subband basis.

[0202] The control unit (1410) may configure at least one first CSI subband based on the size setting information of the CSI subband and the size of the downlink bandwidth part, and may report the acquired channel state information for the at least one first CSI subband. The control unit (1410) may configure at least one CSI subband based on the CSI subband size determined by the size of the bandwidth part through which a reference signal for CSI measurement is transmitted, such as CSI-RS or SSB, and the CSI subband size setting value included in the CSI subband configuration information, based on a common resource block (CRB) #0, which is a reference point. That is, CSI subbands may be configured for frequency bands consecutively divided into PRBs corresponding to the CSI subband size value from CRB #0 and bands in which the bands of the bandwidth part overlap.

[0203] As described above, UL subbands and DL subbands for supporting SBFD operation for a terminal can be configured for SBFD symbols. For a downlink bandwidth part (DL BWP) including the corresponding UL subband and DL subband, in the SBFD symbol, the DL subband is configured from some frequency resources among the entire frequency resources constituting the corresponding downlink bandwidth part. That is, in the SBFD symbol, some frequency resources of the downlink bandwidth part are configured as uplink subbands or guard bands, so it is necessary to configure a second CSI subband for the SBFD symbol that is distinct from the first CSI subband for the conventional non-SBFD symbol for the aforementioned CSI reporting.

[0204] When a downlink (DL) subband is configured by a base station to support subband-based full duplex (SBFD) operation, the control unit (1410) may configure at least one second CSI subband distinct from the first CSI subband for the SBFD symbol. In this case, the control unit (1410) may also obtain channel state information for at least one second CSI subband and report it to the base station.

[0205] For example, at least one second CSI subband may be configured with only first CSI subbands that are completely within the frequency bandwidth of the DL subband among at least one first CSI subband. That is, while maintaining the configuration for the existing BWP-based first CSI subband, when CSI reporting in the SBFD symbol is configured, the control unit (1410) may be configured to limit the configurable CSI subbands.

[0206] In this case, the control unit (1410) may configure as the second CSI subband only the CSI subbands that belong entirely to the DL subband among the CSI subbands configured based on the CSI report configuration information or the CSI subband configuration information. Accordingly, if the CSI report configuration information is set to CSI reporting based on CSI-RS resources that are transmitted only through SBFD symbols, i.e., if the associated CSI-RS is transmitted only through SBFD symbols, the control unit (1410) may configure as the second CSI subband only at least one CSI subband that belongs entirely to the DL subband among the entire first CSI subbands that constitute the corresponding downlink bandwidth part.

[0207] According to another example, at least one second CSI subband may be configured only with the remaining first CSI subbands, excluding the first CSI subbands that are completely within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband. That is, the control unit (1410) may limit the CSI subbands whose entire PRBs do not completely belong to the DL subband to CSI subbands that cannot be used for CSI reporting for SBFD symbols. In this case, all first CSI subbands, excluding the CSI subbands that are completely within the UL subband and the guard band among the first CSI subbands, may be configured as the second CSI subbands. Accordingly, for the CSI subbands that include some PRBs that do not belong to the DL subband among the second CSI subbands, the PRB configuration information of the corresponding CSI subband may be implicitly reset.

[0208] According to another example, at least one second CSI subband may be configured based on the size of the DL subband separately from the configuration of at least one first CSI subband. That is, when the downlink bandwidth part configured for the terminal includes UL subband and DL subband configurations for supporting SBFD operation, the control unit (1410) may separately configure a first CSI subband for non-SBFD symbols and a second CSI subband for SBFD symbols. Accordingly, when CSI-RS transmission is performed through a non-SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on an existing downlink bandwidth part. On the other hand, when CSI-RS transmission is performed through an SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on a new DL subband.

[0209] That is, when one or two DL subbands are configured for SBFD operation, the CSI subband size may be determined by the number of PRBs constituting each DL subband, rather than the conventional method of determining the bandwidth of the aforementioned downlink bandwidth part, i.e., the number of PRBs. In the case of CSI reporting targeting the DL subband of the SBFD symbol, the control unit (1410) may configure the second CSI subband according to the size of the second CSI subband and the starting point and number of PRBs of each DL subband.

[0210] For example, at least one second CSI subband may be configured not to be configured if the size of the DL subband is smaller than 24 resource blocks. If the total number of PRBs constituting the DL subband is smaller than 24, the CSI measurement result reporting for the corresponding SBFD symbol may be restricted to be based only on the wideband CQI / PMI, regardless of the CSI subband configuration. That is, the second CSI subband for CSI reporting for the corresponding SBFD symbol may not be configured.

[0211] The control unit (1410) can report channel state information obtained from the configured first CSI subband and second CSI subband to the base station.

[0212] Accordingly, a method and device for transmitting and receiving downlink channel state information in an environment where full-duplex communication is applied can be provided.

[0213] Fig. 15 is a drawing showing the configuration of a base station (1500) according to another embodiment.

[0214] Referring to FIG. 15, a base station (1500) according to another embodiment includes a transmitter (1520), a receiver (1530), and a control unit (1510) that controls the operations of the transmitter and receiver.

[0215] The control unit (1510) controls the overall operation of the base station (1500) according to the method of transmitting and receiving downlink channel status information in the wireless mobile communication system required to perform the aforementioned present invention. The transmitter (1520) transmits downlink control information, data, and messages to the terminal through the corresponding channel. The receiver (1530) receives uplink control information, data, and messages from the terminal through the corresponding channel.

[0216] The control unit (1510) may transmit CSI subband configuration information, including information on sizing the CSI subband for reporting channel status information. The control unit (1510) may communicate with the terminal in TDD (Time Division Duplex) mode and full-duplex mode. This has been described in FIG. 8, and thus, specific details will be omitted.

[0217] The control unit (1510) may transmit CSI reporting configuration information for reporting channel status information to the terminal. For example, the CSI reporting configuration information may include CSI subband configuration information including CSI subband size setting information. Alternatively, the CSI subband configuration information may be received via separate upper layer signaling.

[0218] The size setting information for a CSI subband may be configured with a predetermined number of consecutive PRBs (Physical Resource Blocks) for the terminal's CSI reporting. In this case, the CSI subband size value may be set to one of two candidate values ​​depending on the total number of PRBs constituting the bandwidth part (BWP).

[0219] The control unit (1510) may transmit to the terminal, through CSI reporting configuration information, one of two candidate values ​​for setting the CSI subband size according to the bandwidth part size. Furthermore, the CSI reporting configuration information includes frequency setting information for the CSI measurement target for CSI reporting. At this time, the frequency setting information for the CSI measurement target may be set on a per-CSI subband basis.

[0220] The control unit (1510) may receive channel state information for at least one first CSI subband configured based on the size setting information of the CSI subband and the size of the downlink bandwidth part. The terminal may configure at least one CSI subband based on the CSI subband size determined by the size of the bandwidth part through which a reference signal for CSI measurement is transmitted, such as CSI-RS or SSB, and the CSI subband size setting value included in the CSI subband configuration information, based on a common resource block (CRB) #0, which is a reference point. That is, CSI subbands may be configured for frequency bands consecutively divided into PRBs corresponding to the CSI subband size value from CRB #0 and bands overlapping with the bands of the bandwidth part.

[0221] As described above, the control unit (1510) can set the UL subband and DL subband for supporting the SBFD operation for the SBFD symbols. In the case of the downlink bandwidth part (DL BWP) including the UL subband and DL subband, the DL subband is configured in some frequency resources among the entire frequency resources constituting the downlink bandwidth part in the SBFD symbol. That is, in the SBFD symbol, some frequency resources of the downlink bandwidth part are configured as uplink subbands or guard bands, so it is necessary to configure a second CSI subband for the SBFD symbol that is distinct from the first CSI subband for the conventional non-SBFD symbol for the CSI reporting described above.

[0222] When the control unit (1510) configures a downlink (DL) subband to support subband-based full duplex (SBFD) operation, the terminal may configure at least one second CSI subband distinct from the first CSI subband for the SBFD symbol. In this case, the control unit (1510) may further receive channel state information acquired for at least one second CSI subband from the terminal.

[0223] For example, at least one second CSI subband may be configured with only first CSI subbands that are completely within the frequency bandwidth of the DL subband among at least one first CSI subband. That is, while maintaining the configuration for the existing BWP-based first CSI subband, when CSI reporting in SBFD symbols is configured, the terminal may be configured to limit the configurable CSI subbands.

[0224] In this case, the control unit (1510) may configure only the CSI subbands that belong entirely to the DL subband among the CSI subbands configured based on the CSI report configuration information or the CSI subband configuration information as the second CSI subband. Accordingly, if the CSI report configuration information is set to CSI reporting based on CSI-RS resources that are transmitted only through SBFD symbols, i.e., if the associated CSI-RS is transmitted only through SBFD symbols, the terminal may configure the second CSI subband by limiting only at least one CSI subband that belongs entirely to the DL subband among the entire first CSI subbands that constitute the corresponding downlink bandwidth part.

[0225] According to another example, at least one second CSI subband may be configured only with the remaining first CSI subbands, excluding the first CSI subbands that are completely within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband. That is, the UE may limit the CSI subbands whose entire PRBs do not completely belong to the DL subband to CSI subbands that cannot be used for CSI reporting for SBFD symbols. In this case, all first CSI subbands, excluding the CSI subbands that are completely within the UL subband and the guard band among the first CSI subbands, may be configured as the second CSI subbands. Accordingly, for the CSI subbands among the second CSI subbands that include some PRBs that do not belong to the DL subband, the PRB configuration information of the corresponding CSI subband may be implicitly reset.

[0226] According to another example, at least one second CSI subband may be configured based on the size of the DL subband, separately from the configuration of at least one first CSI subband. That is, when the downlink bandwidth part configured for the terminal includes UL subband and DL subband configurations for supporting SBFD operation, the terminal may separately configure a first CSI subband for non-SBFD symbols and a second CSI subband for SBFD symbols. Accordingly, when CSI-RS transmission is performed through a non-SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on an existing downlink bandwidth part. On the other hand, when CSI-RS transmission is performed through an SBFD symbol, the corresponding CSI reporting band may be configured based on a CSI subband based on a new DL subband.

[0227] That is, when one or two DL subbands are configured for SBFD operation, the CSI subband size may be determined by the number of PRBs constituting each DL subband, rather than the conventional method of determining the bandwidth of the aforementioned downlink bandwidth part, i.e., the number of PRBs. In the case of CSI reporting targeting the DL subband of the SBFD symbol, the base station may cause the terminal to configure the second CSI subband according to the size of the second CSI subband and the starting point and number of PRBs of each DL subband.

[0228] For example, at least one second CSI subband may be configured not to be configured if the size of the DL subband is smaller than 24 resource blocks. If the total number of PRBs constituting the DL subband is smaller than 24, the CSI measurement result reporting for the corresponding SBFD symbol may be restricted to be based only on the wideband CQI / PMI, regardless of the CSI subband configuration. That is, the second CSI subband for CSI reporting for the corresponding SBFD symbol may not be configured.

[0229] The control unit (1510) can receive channel state information obtained from the configured first CSI subband and second CSI subband from the terminal.

[0230] Accordingly, a method and device for transmitting and receiving downlink channel state information in an environment where full-duplex communication is applied can be provided.

[0231] The above-described embodiments may be supported by standard documents disclosed in at least one of the wireless access systems, IEEE 802, 3GPP, and 3GPP2. That is, steps, components, and parts not described in the present embodiments to clearly illustrate the technical concepts herein may be supported by the above-described standard documents. Furthermore, all terms disclosed in this specification may be explained by the above-described standard documents.

[0232] The embodiments described above may be implemented through various means. For example, the embodiments may be implemented through hardware, firmware, software, or a combination thereof.

[0233] In the case of hardware implementation, the method according to the present embodiments may be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, or microprocessors.

[0234] When implemented using firmware or software, the methods according to the present embodiments may be implemented in the form of devices, procedures, or functions that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor using various known means.

[0235] Additionally, terms such as "system," "processor," "controller," "component," "module," "interface," "model," or "unit" as described above may generally refer to a computer-related entity, such as hardware, a combination of hardware and software, software, or software in execution. For example, the aforementioned components may be, but are not limited to, a process driven by a processor, a processor, a controller, a control processor, an object, a thread of execution, a program, and / or a computer. For example, both an application running on a controller or a processor and the controller or the processor may be components. One or more components may be within a process and / or thread of execution, and the components may be located on a single device (e.g., a system, a computing device, etc.) or distributed across two or more devices.

[0236] The above description is merely an illustrative example of the technical idea of ​​the present disclosure, and those skilled in the art to which the present disclosure pertains will appreciate that various modifications and variations can be made without departing from the essential characteristics of the technical idea of ​​the present disclosure. In addition, the present embodiments are not intended to limit the technical idea of ​​the present disclosure but rather to explain it, and therefore the scope of the technical idea of ​​the present disclosure is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included within the scope of the rights of the present disclosure.

[0237]

[0238] CROSS-REFERENCE TO RELATED APPLICATION

[0239] This patent application claims priority under 35 USC §119(a) to Korean Patent Application No. 10-2024-0019236, filed in Korea on February 7, 2024, and Korean Patent Application No. 10-2025-0015438, filed in Korea on February 6, 2025, the entire contents of which are incorporated herein by reference. In addition, this patent application claims priority in countries other than the United States for the same reasons, the entire contents of which are incorporated herein by reference.

Claims

1. In a method for a terminal to transmit downlink channel state information (CSI), A step of receiving CSI subband configuration information including size setting information of a CSI subband for reporting channel state information; A step of configuring at least one first CSI subband based on the size setting information of the CSI subband and the size of the downlink bandwidth part; and Comprising a step of reporting acquired channel state information for at least one first CSI subband, The step of configuring at least one first CSI subband comprises: When a downlink (DL) subband is configured by a base station to support subband-based full duplex (SBFD) operation, at least one second CSI subband distinct from the first CSI subband is configured for the SBFD symbol, The step of reporting the above channel status information is: A method for further reporting acquired channel state information for at least one second CSI subband.

2. In paragraph 1, At least one second CSI subband is, A method comprising only first CSI subbands that are completely included within the frequency bandwidth of the DL subband among the at least one first CSI subband.

3. In paragraph 1, At least one second CSI subband is, A method comprising only the remaining first CSI subbands, excluding the first CSI subband that is completely included within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband.

4. In paragraph 1, At least one second CSI subband is, A method configured based on the size of the DL subband separately from the configuration of the at least one first CSI subband.

5. In paragraph 1, At least one second CSI subband is, If the size of the above DL subband is less than 24 resource blocks, the method is not configured.

6. In a method for a base station to receive downlink channel state information (CSI), A step of transmitting CSI subband configuration information including size setting information of a CSI subband for reporting channel state information; and A step of receiving channel state information for at least one first CSI subband configured based on size setting information of the above CSI subband and the size of the downlink bandwidth part, The step of receiving the above channel status information is: A method for further receiving channel state information for at least one second CSI subband configured separately from the first CSI subband for an SBFD symbol, when a downlink (DL) subband is configured to support subband-based full duplex (SBFD) operation by the base station.

7. In paragraph 6, At least one second CSI subband is, A method comprising only first CSI subbands that are completely included within the frequency bandwidth of the DL subband among the at least one first CSI subband.

8. In paragraph 6, At least one second CSI subband is, A method comprising only the remaining first CSI subbands, excluding the first CSI subband that is completely included within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband.

9. In paragraph 6, At least one second CSI subband is, A method configured based on the size of the DL subband separately from the configuration of the at least one first CSI subband.

10. In paragraph 6, At least one second CSI subband is, If the size of the above DL subband is less than 24 resource blocks, the method is not configured.

11. In a terminal transmitting downlink channel state information (CSI), Transmitter; Receiver; and Including a control unit that controls the operation of the above transmitter and receiver, The above control unit, Receive CSI subband configuration information including size setting information of a CSI subband for reporting channel state information, configure at least one first CSI subband based on the size setting information of the CSI subband and the size of a downlink bandwidth part, and report acquired channel state information for the at least one first CSI subband. A terminal configured to configure at least one second CSI subband distinct from the first CSI subband for an SBFD symbol when a downlink (DL) subband is configured by a base station to support subband-based full duplex (SBFD) operation, and further report channel state information acquired for the at least one second CSI subband.

12. In paragraph 11, At least one second CSI subband is, A terminal configured with only a first CSI subband that is completely included within the frequency bandwidth of the DL subband among the at least one first CSI subband.

13. In paragraph 11, At least one second CSI subband is, A terminal configured only with the remaining first CSI subbands, excluding the first CSI subband that is completely included within the frequency bandwidth of the uplink (UL) subband and the guard band among the at least one first CSI subband.

14. In paragraph 11, At least one second CSI subband is, A terminal configured based on the size of the DL subband separately from the configuration of at least one first CSI subband.

15. In paragraph 11, At least one second CSI subband is, If the size of the above DL subband is less than 24 resource blocks, the terminal is not configured.

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