Method and device for controlling interference between base stations in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. According to various embodiments of the present disclosure, a method performed by a first base station in a wireless communication system may include the steps of: transmitting, to a second base station, a first message including information for configuring semi-static subband full duplex (SBFD) associated with a first cell of the first base station and second information for configuring a resource for beam measurement; and receiving, from the second base station, a second message including information for requesting cross link interference (CLI) mitigation.

Description

Method and device for controlling interference between base stations in a wireless communication system

[0001] The present disclosure relates generally to wireless communication systems, and more particularly, to methods and devices for eliminating inter-cell interference due to transmission modes in wireless communication systems.

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

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

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

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

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

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

[0008] As described above and with the development of mobile communication systems, various services have become available, and methods for effectively providing these services are required.

[0009] Based on the discussion described above, the present disclosure aims to provide a method and device for controlling cross link interference that may occur between cells when considering subband full duplex in a wireless communication system.

[0010] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] According to various embodiments of the present disclosure, a method performed by a first base station in a wireless communication system may include the steps of transmitting, to a second base station, a first message including information for setting a semi-static subband full duplex (SBFD) associated with a first cell of the first base station and second information for setting a resource for beam measurement; and receiving, from the second base station, a second message including information for requesting cross link interference (CLI) mitigation.

[0012] One embodiment of the present invention provides a device and method by which each cell can effectively reduce interference signals from other cells.

[0013] One embodiment of the present invention provides a device and method capable of effectively providing a service in a wireless communication system.

[0014] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0015] FIG. 1 illustrates the structure of a wireless communication system according to one embodiment of the present disclosure.

[0016] FIG. 2 illustrates a wireless protocol structure in a wireless communication system according to one embodiment of the present disclosure.

[0017] FIG. 3 illustrates the structure of a wireless communication system according to one embodiment of the present disclosure.

[0018] FIG. 4 illustrates a wireless protocol structure in a wireless communication system according to one embodiment of the present disclosure.

[0019] FIG. 5 illustrates the structure of a terminal according to one embodiment of the present disclosure.

[0020] FIG. 6 illustrates the structure of a base station according to one embodiment of the present disclosure.

[0021] FIG. 7 illustrates the occurrence of inter-cell CLI (cross link interference) between cells operating a typical SBFD according to one embodiment of the present disclosure.

[0022] FIG. 8 illustrates the flow of signals between base stations for controlling CLI according to one embodiment of the present disclosure.

[0023] FIG. 9 illustrates various methods for indicating a UL subband according to one embodiment of the present disclosure.

[0024] FIG. 10 illustrates an example of an SBFD slot and symbol according to one embodiment of the present disclosure.

[0025] FIG. 11 illustrates a signal flow for instructing a terminal to set SBFD through a serving cell according to one embodiment of the present disclosure.

[0026] FIG. 12 illustrates a signal flow for performing coordinated scheduling according to one embodiment of the present disclosure.

[0027] FIG. 13 illustrates a signal flow for handling a cell's CLI through DL beam nulling according to SBFD information according to one embodiment of the present disclosure.

[0028] FIG. 14 illustrates a signal flow for performing UL muting to perform CLI measurement according to SBFD information according to one embodiment of the present disclosure.

[0029] The operating principles of the present invention will be described in detail below with reference to the attached drawings. In the following description of the present invention, detailed descriptions of known functions or components will be omitted if they are deemed to unnecessarily obscure the gist of the invention. Furthermore, the terms described below are defined based on their functions in the present invention and may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0030] The terms used in the following description to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, and terms referring to various identification information are provided for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms referring to objects with equivalent technical meanings may be used.

[0031] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, the downlink (DL) refers to a wireless transmission path of a signal transmitted from the base station to the terminal, and the uplink (UL) refers to a wireless transmission path of a signal transmitted from the terminal to the base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel form. For example, the fifth generation mobile communication technology (5G) (new radio, NR) developed after LTE-A may be included in a system to which the embodiments of the present disclosure may be applied, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. Furthermore, the present disclosure may be applied to other communication systems with some modifications, as determined by a person skilled in the art, without significantly departing from the scope of the present disclosure. It will be appreciated that each block of the processing flow diagrams and combinations of the flow diagrams can be executed by computer program instructions.

[0032] These computer program instructions may be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, so that the instructions executed by the processor of the computer or other programmable data processing apparatus create means for performing the functions described in the flowchart block(s). These computer program instructions may also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing apparatus to implement functions in a particular manner, so that the instructions stored in the computer-available or computer-readable memory can produce an article of manufacture that includes instruction means for performing the functions described in the flowchart block(s). The computer program instructions may also be installed on a computer or other programmable data processing apparatus, so that a series of operational steps are performed on the computer or other programmable data processing apparatus to create a computer-implemented process, so that the instructions executing on the computer or other programmable data processing apparatus can provide steps for performing the functions described in the flowchart block(s).

[0033] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function. In this case, the term '~unit' used in the present embodiment means software or a hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the '~unit' may perform certain roles. However, the '~unit' is not limited to software or hardware. The '~unit' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, the components and '~ units' may be implemented to reproduce one or more CPUs within a device or a secure multimedia card. Also, in an embodiment, the '~ unit' may include one or more processors.

[0034] For convenience of explanation, the present invention uses terms and names defined in the 5GS and NR standards, which are standards defined by the 3rd Generation Partnership Project (3GPP) among the existing communication standards. However, the present invention is not limited to the above terms and names and can be equally applied to wireless communication networks that follow other standards. For example, the present invention can be applied to the 3GPP 5GS / NR (5th generation mobile communication standard).

[0035] FIG. 1 illustrates the structure of a wireless communication system according to one embodiment of the present disclosure.

[0036] Referring to FIG. 1, a wireless access network of an LTE system may be composed of a next-generation base station (Evolved Node B) (hereinafter referred to as ENB, Node B or base station) (105, 110, 115, 120), a mobility management entity (MME) (125) and a serving gateway (S-GW) (130). A user equipment (hereinafter referred to as UE or terminal) (135) may access an external network through the ENB (105-120) and the S-GW (130).

[0037] In Fig. 1, ENBs (105-120) may correspond to existing Node Bs of a UMTS (Universal Mobile Telecommunication System) system. ENBs are connected to UEs (135) via a wireless channel and may perform more complex roles than existing Node Bs. In an LTE system, all user traffic, including real-time services such as VoIP (Voice over IP) via the Internet Protocol, may be serviced through a shared channel. Therefore, a device that collects status information such as the buffer status, available transmission power status, and channel status of UEs and performs scheduling is required, and ENBs (105-120) may be responsible for this. One ENB can typically control multiple cells. For example, in order to achieve a transmission rate of 100 Mbps, an LTE system may use, for example, Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology in a 20 MHz bandwidth. Additionally, the LTE system can apply an adaptive modulation and coding (AMC) method that determines the modulation scheme and channel coding rate according to the channel conditions of the terminal. The S-GW (130) is a device that provides a data bearer and can create or remove a data bearer under the control of the MME (125). The MME is a device that is responsible for various control functions as well as mobility management functions for the terminal and can be connected to multiple base stations.

[0038] FIG. 2 illustrates a wireless protocol structure in a wireless communication system according to one embodiment of the present disclosure.

[0039] Referring to Figure 2, the wireless protocol of the LTE system may be composed of Packet Data Convergence Protocol (PDCP) (205, 240), Radio Link Control (RLC) (210, 235), and Medium Access Control (MAC) (215, 230) in the terminal and ENB, respectively. PDCP may be responsible for operations such as IP header compression / decompression. The main functions of PDCP can be summarized as follows.

[0040] - Header compression and decompression (ROHC only)

[0041] - User data transfer function

[0042] - In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

[0043] - Order reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0044] - Duplicate detection function (Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM)

[0045] - Retransmission function (Retransmission of PDCP SDUs at handover and, for split bearers in DC, of ​​PDCP PDUs at PDCP data-recovery procedure, for RLC AM)

[0046] - Encryption and decryption functions (Ciphering and deciphering)

[0047] - Timer-based SDU discard in uplink.

[0048] Radio Link Control (RLC) (210, 235) can perform ARQ operations, etc. by reconfiguring PDCP packet data units (PDUs) to an appropriate size. The main functions of RLC can be summarized as follows.

[0049] - Data transfer function (Transfer of upper layer PDUs)

[0050] - ARQ function (Error Correction through ARQ (only for AM data transfer))

[0051] - Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

[0052] - Re-segmentation of RLC data PDUs (only for AM data transfer)

[0053] - Reordering of RLC data PDUs (only for UM and AM data transfer)

[0054] - Duplicate detection (only for UM and AM data transfer)

[0055] - Error detection function (Protocol error detection (only for AM data transfer))

[0056] - RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

[0057] - RLC re-establishment function

[0058] MAC (215, 230) is connected to multiple RLC layer devices configured in a single terminal, and can perform operations of multiplexing RLC PDUs into MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of MAC can be summarized as follows.

[0059] - Mapping function (Mapping between logical channels and transport channels)

[0060] - Multiplexing and demultiplexing function (Multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels into / from transport blocks (TB) delivered to / from the physical layer on transport channels)

[0061] - Scheduling information reporting function

[0062] - HARQ function (Error correction through HARQ)

[0063] - Priority handling between logical channels of one UE

[0064] - Priority handling between UEs by means of dynamic scheduling

[0065] - MBMS service identification function

[0066] - Transport format selection function

[0067] - Padding function

[0068] The physical layer (220, 225) can perform an operation of channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to a higher layer.

[0069] FIG. 3 illustrates the structure of a wireless communication system according to one embodiment of the present disclosure.

[0070] Referring to FIG. 3, a wireless access network of a next-generation mobile communication system (hereinafter referred to as NR or 5g) may be composed of a next-generation base station (New Radio Node B) (hereinafter referred to as NR gNB or NR base station) (310) and a next-generation radio core network (New Radio Core Network) (NR CN) (305). A next-generation radio user equipment (NR UE or terminal) (315) may access an external network through the NR gNB (310) and the NR CN (305).

[0071] In Fig. 3, the NR gNB (310) may correspond to the eNB (Evolved Node B) of the existing LTE system. The NR gNB is connected to the NR UE (315) via a wireless channel and can provide a service superior to that of the existing Node B. In the next-generation mobile communication system, all user traffic can be serviced through a shared channel. Therefore, a device that collects status information such as the buffer status of the UEs, the available transmission power status, and the channel status and performs scheduling is required, and the NR NB (310) can be in charge of such scheduling. One NR gNB can control multiple cells. In the next-generation mobile communication system, in order to implement ultra-high-speed data transmission compared to the general LTE, a bandwidth greater than the general maximum bandwidth can be applied. In addition, beamforming technology can be additionally grafted using Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology. In addition, the next-generation system may apply an adaptive modulation and coding (AMC) method that determines a modulation scheme and a channel coding rate according to the channel condition of the terminal. The NR CN (305) may perform functions such as mobility support, bearer setup, and QoS setup. The NR CN is a device that is responsible for various control functions as well as mobility management functions for the terminal and may be connected to multiple base stations. In addition, the next-generation mobile communication system may also be linked with the LTE system, and the NR CN may be connected to the MME (325) through a network interface. The MME may be connected to an eNB (330), which is an LTE base station.

[0072] FIG. 4 illustrates a wireless protocol structure in a wireless communication system according to one embodiment of the present disclosure.

[0073] Referring to FIG. 4, the wireless protocol of the next-generation mobile communication system is composed of NR Service Data Adaptation Protocol (SDAP) (401, 445), NR PDCP (405, 440), NR RLC (410, 435), NR MAC (415, 430), and NR PHY (420, 425) in the terminal and NR base station, respectively.

[0074] The main functions of NR SDAP (401, 445) may include some of the following functions:

[0075] - Transfer of user plane data

[0076] - Mapping function between QoS flow and data bearer for both DL and UL

[0077] - QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0078] - Ability to map relective QoS flow to data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs)

[0079] For an SDAP layer device, a terminal can be configured via a Radio Resource Control (RRC) message whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device for each PDCP layer device, for each bearer, or for each logical channel. When the SDAP header is configured, the terminal can instruct the terminal to update or reset the mapping information for the uplink and downlink QoS flows and data bearers by using a 1-bit indicator for reflecting the Non-Access Stratum (NAS) Quality of Service (QoS) of the SDAP header (e.g., NAS reflective QoS) and a 1-bit indicator for reflecting the Access Stratum (AS) QoS of the SDAP header (e.g., AS reflective QoS). The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0080] The main functions of NR PDCP (405, 440) may include some of the following functions:

[0081] - Header compression and decompression (ROHC only)

[0082] - User data transfer function

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

[0084] - Out-of-sequence delivery of upper layer PDUs

[0085] - PDCP PDU reordering for reception

[0086] - Duplicate detection of lower layer SDUs

[0087] - Retransmission function (Retransmission of PDCP SDUs)

[0088] - Encryption and decryption functions (Ciphering and deciphering)

[0089] - Timer-based SDU discard in uplink.

[0090] In the above, the reordering function of the NR PDCP device may refer to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP SN (sequence number). The reordering function of the NR PDCP device may include a function of transmitting data to an upper layer in the reordered order, or a function of transmitting data directly without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, or a function of requesting retransmission of lost PDCP PDUs.

[0091] The main functions of NR RLC (410, 435) may include some of the following functions:

[0092] - Data transfer function (Transfer of upper layer PDUs)

[0093] - In-sequence delivery of upper layer PDUs

[0094] - Out-of-sequence delivery of upper layer PDUs

[0095] - ARQ function (Error Correction through ARQ)

[0096] - Concatenation, segmentation and reassembly of RLC SDUs

[0097] - Re-segmentation of RLC data PDUs

[0098] - Reordering of RLC data PDUs

[0099] - Duplicate detection function

[0100] - Protocol error detection

[0101] - RLC SDU discard function

[0102] - RLC re-establishment function

[0103] In the above, the in-sequence delivery function of the NR RLC device may refer to the function of sequentially delivering RLC SDUs received from the lower layer to the upper layer. If a single RLC SDU is originally received divided into multiple RLC SDUs, the in-sequence delivery function of the NR RLC device may include the function of reassembling and delivering them.

[0104] The in-sequence delivery function of the NR RLC device may include a function to reorder received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function to record lost RLC PDUs by reordering them, a function to report status of lost RLC PDUs to the transmitter, and a function to request retransmission of lost RLC PDUs.

[0105] The in-sequence delivery function of the NR RLC device may include a function to sequentially deliver only the RLC SDUs up to the lost RLC SDU to the upper layer when there is a lost RLC SDU.

[0106] The in-sequence delivery function of the NR RLC device may include a function to deliver to the upper layer in sequence all RLC SDUs received before a predetermined timer starts if there are lost RLC SDUs and a predetermined timer has expired.

[0107] The in-sequence delivery function of the NR RLC device may include a function to deliver all RLC SDUs received so far to the upper layer in order if a predetermined timer has expired, even if there are lost RLC SDUs.

[0108] An NR RLC device can process RLC PDUs in the order they are received and deliver them to an NR PDCP device, regardless of the order of the sequence number (out-of-sequence delivery).

[0109] When an NR RLC device receives a segment, it can receive segments that are stored in a buffer or will be received later, reconstruct them into a complete RLC PDU, and then transmit them to the NR PDCP device.

[0110] The NR RLC layer may not include concatenation functionality, and the functionality may be performed by the NR MAC layer or replaced by the multiplexing functionality of the NR MAC layer.

[0111] In the above, the out-of-sequence delivery function of the NR RLC device may refer to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order. The out-of-sequence delivery function of the NR RLC device may include the function of reassembling and delivering the RLC SDUs when an original RLC SDU is received fragmented into multiple RLC SDUs. The out-of-sequence delivery function of the NR RLC device may include the function of storing and arranging the RLC SN or PDCP SN of the received RLC PDUs to record the lost RLC PDUs.

[0112] NR MAC (415, 430) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0113] - Mapping function (Mapping between logical channels and transport channels)

[0114] - Multiplexing / demultiplexing of MAC SDUs

[0115] - Scheduling information reporting function

[0116] - HARQ function (Error correction through HARQ)

[0117] - Priority handling between logical channels of one UE

[0118] - Priority handling between UEs by means of dynamic scheduling

[0119] - MBMS service identification function

[0120] - Transport format selection function

[0121] - Padding function

[0122] The NR PHY layer (420, 425) can perform an operation of channel coding and modulating upper layer data, converting it into an OFDM symbol and transmitting it through a wireless channel, or demodulating and channel decoding an OFDM symbol received through a wireless channel and transmitting it to a higher layer.

[0123] FIG. 5 illustrates the structure of a terminal according to one embodiment of the present disclosure.

[0124] Referring to FIG. 5, the terminal includes an RF (Radio Frequency) processing unit (510), a baseband processing unit (520), a storage unit (530), and a control unit (540).

[0125] The RF processing unit (510) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. The RF processing unit (510) up-converts the baseband signal provided from the baseband processing unit (520) into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (510) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), etc. With reference to FIG. 5, only one antenna is illustrated, but the terminal may include multiple antennas. In addition, the RF processing unit (510) may include multiple RF chains. Furthermore, the RF processing unit (510) may perform beamforming. For beamforming, the RF processing unit (510) can adjust the phase and magnitude of each signal transmitted and received through multiple antennas or antenna elements. In addition, the RF processing unit can perform MIMO and receive multiple layers when performing MIMO operations.

[0126] The baseband processing unit (520) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the system. For example, when transmitting data, the baseband processing unit (520) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (520) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (510). For example, in the case of following the OFDM (orthogonal frequency division multiplexing) method, when transmitting data, the baseband processing unit (520) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit (520) divides the baseband signal provided from the RF processing unit (510) into OFDM symbol units, restores signals mapped to subcarriers through FFT (fast Fourier transform), and then restores the received bit string through demodulation and decoding.

[0127] The baseband processing unit (520) and the RF processing unit (510) transmit and receive signals as described above. Accordingly, the baseband processing unit (520) and the RF processing unit (510) may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. Furthermore, at least one of the baseband processing unit (520) and the RF processing unit (510) may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit (520) and the RF processing unit (510) may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (e.g., IEEE 802.11), a cellular network (e.g., LTE), etc. Additionally, different frequency bands may include super high frequency (SHF) (e.g., 2.NRHz, NRhz) bands, millimeter wave (mm wave) (e.g., 60GHz) bands.

[0128] The storage unit (530) stores data such as basic programs, application programs, and configuration information for the operation of the terminal. In particular, the storage unit (530) can store information related to a second access node that performs wireless communication using a second wireless access technology. Furthermore, the storage unit (530) provides the stored data upon request from the control unit (540).

[0129] The control unit (540) controls the overall operations of the terminal. For example, the control unit (540) transmits and receives signals through the baseband processing unit (520) and the RF processing unit (510). In addition, the control unit (540) records and reads data in the storage unit (540). For this purpose, the control unit (540) may include at least one processor (or controller). For example, the control unit (540) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. According to various embodiments, the control unit (540) may be configured to perform various operations described below.

[0130] FIG. 6 illustrates the structure of a base station according to one embodiment of the present disclosure.

[0131] As shown in FIG. 6, the base station is configured to include an RF processing unit (610), a baseband processing unit (620), a backhaul communication unit (630), a storage unit (640), and a control unit (650).

[0132] The RF processing unit (610) performs functions for transmitting and receiving signals through a wireless channel, such as signal band conversion and amplification. The RF processing unit (610) upconverts the baseband signal provided from the baseband processing unit (620) into an RF band signal and transmits it through an antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the RF processing unit (610) may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. With reference to FIG. 6, only one antenna is illustrated, but the first access node may have multiple antennas. In addition, the RF processing unit (610) may include multiple RF chains. Furthermore, the RF processing unit (610) may perform beamforming. For beamforming, the RF processing unit (610) may adjust the phase and magnitude of each signal transmitted and received through multiple antennas or antenna elements. The RF processing unit can perform downlink MIMO operations by transmitting one or more layers.

[0133] The baseband processing unit (620) performs a conversion function between a baseband signal and a bit stream according to the physical layer specifications of the first wireless access technology. For example, when transmitting data, the baseband processing unit (620) generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit (620) restores the reception bit stream by demodulating and decoding the baseband signal provided from the RF processing unit (610). For example, in the case of OFDM, when transmitting data, the baseband processing unit (620) generates complex symbols by encoding and modulating a transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processing unit (620) divides the baseband signal provided from the RF processing unit (610) into OFDM symbol units, restores the signals mapped to subcarriers through FFT operation, and then restores the received bit string through demodulation and decoding. The baseband processing unit (620) and the RF processing unit (610) transmit and receive signals as described above. Accordingly, the baseband processing unit (620) and the RF processing unit (610) may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0134] The above backhaul communication unit (630) provides an interface for communicating with other nodes within the network. The backhaul communication unit (630) converts a bit string transmitted from a primary base station to another node (e.g., an auxiliary base station, a core network, etc.) into a physical signal, and converts a physical signal received from the other node into a bit string.

[0135] The storage unit (640) stores data such as basic programs, application programs, and configuration information for the operation of the main base station. In particular, the storage unit (640) can store information on bearers assigned to connected terminals, measurement results reported from connected terminals, and the like. Furthermore, the storage unit (640) can store information that serves as a basis for determining whether to provide or terminate multiple connections to a terminal. Furthermore, the storage unit (640) provides the stored data upon request from the control unit (650).

[0136] The control unit (650) controls the overall operations of the base station. For example, the control unit (650) transmits and receives signals through the baseband processing unit (620) and the RF processing unit (610) or through the backhaul communication unit (630). In addition, the control unit (650) records and reads data from the storage unit (640). For this purpose, the control unit (650) may include at least one processor (or controller). According to various embodiments, the control unit (650) may be configured to perform various operations described below.

[0137] According to various embodiments of the present disclosure, the basic duplexing scheme of Release 15 NR may include time division duplex (TDD) and frequency division duplex (FDD). In particular, in the case of TDD, it includes dynamic TDD, and the base station can operate cell-based semi-static TDD configuration, and transmit DL / UL / flexible indications for each slot and each symbol within the slot in SIB1 (system information block 1). The base station can additionally configure each terminal, and can additionally instruct to identify a given flexible symbol as DL or UL. As a result, the DL / UL configurations for each terminal can be configured differently on a symbol-by-symbol basis. Through this method, the base station can adaptively schedule UL / DL traffic for each terminal / cell, and in the case of UL, it can also achieve the effect of coverage extension.

[0138] To complement the aforementioned TDD system, Release 19 introduces a duplexing scheme called subband full duplex (SBFD). SBFD, in addition to the existing TDD configuration, allows for separate frequency bands for the UL and DL subbands for DL ​​or flexible slots or symbols. Accordingly, for a single SBFD symbol, UL resources can be allocated to a specific UE in the UL subband, and DL resources can be allocated to a different UE in the DL subband. This allows UL and DL to coexist within a single symbol or slot in a single cell.

[0139] However, in the case of existing dynamic TDD, the frame synchronization between cells may not match, or if the TDD settings are different, UL and DL may occur simultaneously, which may result in interference between terminals between cells or between base stations of the cells. In addition, when SBFD is considered, interference may occur between legacy terminals and SBFD-capable terminals within a single cell, and inter-cell interference may also exist. The degree of interference is greater than the interference caused by simple DL / UL settings through existing TDD, and it can change dynamically.

[0140] FIG. 7 illustrates the occurrence of inter-cell CLI (cross link interference) between cells operating a typical SBFD according to one embodiment of the present disclosure.

[0141] FIG. 7 illustrates an example of a resource grid for signal transmission and reception between base station 1 (e.g., cell 1) and UE 1, a resource grid for signal transmission and reception between base station 2 (e.g., cell 2) and UE 2, and interference between base stations (e.g., DL-UL interference) that occurs according to each signal transmission and reception.

[0142] Referring to FIG. 7, a DL signal for UE 1 in cell 1 may become an interference signal when the base station receives an UL signal from UE 2 in cell 2. In this situation, cell 2 may become a victim cell, and cell 1 may become an aggressor cell. A victim cell may refer to a base station that receives an unnecessary interference signal due to the aggressor cell.

[0143] FIG. 8 illustrates the flow of signals between base stations for controlling CLI according to one embodiment of the present disclosure. More specifically, referring to FIG. 8, the flow of signals for managing CLI performed in an NR system is illustrated.

[0144] Referring to Fig. 8, simultaneous UL / DL coexistence is possible between cells in existing dynamic TDD. In such cases, a transmission signal from a specific terminal may interfere with reception in a neighboring cell, or a DL signal from a neighboring cell may interfere with DL reception in a specific terminal. In order to share the occurrence of such interference between base stations, specific signals can be transmitted and received between base stations.

[0145] In step (810), base station 1 may include the intended TDD DL-UL configuration for each cell in an Xn setup request or Xn setup response message or an NG-RAN node configuration update message and transmit it to base station 2 (e.g., concerned gNB). Fig. 8 illustrates specific information elements (IEs) included in the configuration information transmitted by base station 1. Accordingly, base station 2 may perform scheduling in step (820).

[0146] According to various embodiments of the present disclosure, in order to eliminate inter-cell interference, configuration information related to SBFD may be shared between base stations or distributed units (DUs) operating each cell. The SBFD information may be combined with previously shared semi-static TDD DL / UL configuration information, and based on this, a gNB or DU may predict that interference due to UL or DL ​​may arrive from a counterpart cell in a specific frequency band at a specific time, and based on the prediction result, the SBFD information may be used to reduce CLI in its own cell.

[0147] Among the various embodiments of the present disclosure, the SBFD configuration transmitted between gNBs or DUs may refer to information that configures specific frequencies for a specific time to be used as DL or UL as a semi-static configuration. This information is cell specific information and may be transmitted in SIB X of the corresponding cell. Of course, this is just an example, and SBFD may be UE specific information and may be transmitted through information that is not limited to SIB X. Among the terminals that have received this information, the terminals having SBFD capability may recognize that the corresponding cell is a cell that operates with the SBFD configuration and may recognize that a specific frequency band for a specific time is used as DL or UL. Based on this, the terminal may monitor the PDCCH (physical downlink control channel) in the time and frequency domain indicated as DL when transitioning to RRC connected mode or when in an idle / inactive state.

[0148] According to various embodiments of the present disclosure, for the above-described purpose, various methods are proposed in which a semi-static SBFD configuration is configured and transmitted to a terminal and also exchanged with a neighboring base station or other DU.

[0149] According to one embodiment, the semi-static SBFD may be distinguished into frequency domain information and time domain information, or a combination of frequency domain information indication methods and time domain information indication methods may be configured into one semi-static SBFD configuration information.

[0150] According to various embodiments, information in the frequency domain, indicating a UL subband, may consider the following options.

[0151] As Opt 1-1, the frequency domain information can indicate a specific region in frequency by indicating a starting PRB associated with a specific subcarrier spacing (SCS) configuration and an ending PRB. In this case, the starting PRB can include a frequency location that is offsetToCarrier PRB units or Hz (or larger) from point A based on the channel bandwidth of the cell. Here, point A can be recognized by the terminal as one of the following definitions.

[0152] Point A serves as a common reference point for resource block grids and is obtained from:

[0153] - offsetToPointA for a PCell downlink represents the frequency offset between point A and the lowest subcarrier of the lowest resource block of the SS / PBCH block used by the UE for initial cell selection, expressed in units of resource blocks assuming 15 kHz subcarrier spacing for FR1 and 60 kHz subcarrier spacing for FR2;

[0154] - absoluteFrequencyPointA for all other cases where absoluteFrequencyPointA represents the frequency-location of point A expressed as in ARFCN.

[0155] For example, point A can be a frequency point offset from the lowest subcarrier of the lowest RB (resource block) of SSB (SS / PBCH (synchronization signal / physical broadcast channel)) (in this case, the network can inform the terminal of the value of offsetToPointA), or it can be a frequency value indicating a separate point A.

[0156] As Opt 1-2, information in the frequency domain can indicate the starting PRB of Opt 1-1 and indicate frequencies equal to the number of PRBs from the starting PRB. In this case, the number of PRBs can indicate the bandwidth of the UL subband.

[0157] As Opt 1-3, information in the frequency domain can indicate the starting PRB of Opt 1-1 and indicate a value in BW units (e.g., Mega or KHz units) rather than PRB units from the starting PRB. This value can indicate the bandwidth of the UL subband.

[0158] As Opt 2-1, the information in the frequency domain may indicate the frequency value (or index) of the smallest subcarrier and the frequency value (or index) of the largest subcarrier of the corresponding UL subband, rather than the starting PRB value.

[0159] As Opt 2-2, the information in the frequency domain can indicate an offset from the center frequency of the channel BW, and a frequency lower than the center frequency by the offset can indicate the starting frequency of the UL subband. In addition, the information in the frequency domain can indicate the BW value in units of the number of PRBs or M / K Hz.

[0160] According to various embodiments of the present disclosure, the area of ​​the DL subband may also be indicated.

[0161] In one embodiment, if the information in the frequency domain indicates a frequency GAP (e.g., a frequency region between UL and DL subbands), the DL subband region may mean (e.g., implicitly) the remaining region excluding the UL subband and the GAP region. The region of the GAP may be configured according to the starting frequency value or PRB index of the gap and the ending frequency value or ending PRB index, or may be indicated through the starting frequency value or PRB index and the bandwidth.

[0162] In one embodiment, if the information in the frequency domain does not indicate a frequency gap, the DL subband may be explicitly indicated. In this case, the DL subband may be indicated in the same manner as the above-described UL subband indicating methods. Alternatively, the starting frequency position or the ending frequency position of the DL subband may be indicated by setting an offset value based on the starting frequency position or the ending frequency position of the UL subband. In this case, the frequency region excluding the region of the DL / UL subband may be regarded as a gap.

[0163] FIG. 9 illustrates various methods for indicating a UL subband according to one embodiment of the present disclosure.

[0164] According to various embodiments, the method of representing the time information of the Semi static SBFD can be divided into a method based on the Semi static TDD UL / DL configuration information as Opt 1 or a method based on a case independent of the TDD configuration as Opt 2.

[0165] For Opt 1, the timing information of the semi-static SBFD can be based on the already configured and indicated semi-static TDD DL / UL configuration. The semi-static TDD UL / DL configuration can be composed of a period indicating a set of specific consecutive slots. For each of these slots, it can be configured to indicate DL, UL, or flexible. The semi-static SBFD configuration can include information indicating whether each slot is an SBFD slot or not, based on the consecutive slots corresponding to the period given in the semi-static TDD DL / UL configuration.

[0166] According to one embodiment, for an SBFD slot, symbols in the slot may be defined as SBFD symbols. SBFD symbols allow UL and DL terminals to be configured simultaneously according to UL / DL subband information within the symbol, and in fact, DL reception and UL transmission may be scheduled simultaneously from the base station for the terminals. If at least one non-SBFD symbol exists in a slot, the slot may be referred to as a non-SBFD slot. At least one of the SBFD symbol or the SBFD slot needs to be associated with UL / DL subband information. Information indicating a specific frequency range of the UL / DL subband may be indicated based on at least one of the method for indicating UL subband frequency information or the method for indicating DL subband frequency information described above.

[0167] In one embodiment, if the slot is an SBFD slot, the subband frequency information described above may be linked to each slot. For example, if the same UL and DL subband frequency information is allocated to multiple slots, each of the multiple slots may be linked and configured with the corresponding subband frequency information.

[0168] In one embodiment, if the TDD information for a particular slot within a period is UL, that slot cannot be an SBFD slot. Furthermore, all symbols in that slot must be non-SBFD symbols. For example, only DL and flexible TDD slots may be configured to include SBFD symbols. The above constraints may apply when the network configures a semi-static SBFD configuration.

[0169] According to various embodiments, when multiple slots among the above-described methods are SBFD slots and the same SBFD subband setting is applied to them, the method of linking the slots and the SBFD subband setting is as follows.

[0170] In one embodiment, as Opt 1-1, a specific slot within a period of a Semi-static TDD configuration may be designated as a starting slot and an ending slot. If the period is longer than a subframe or a radio frame, the starting slot and the ending slot may be designated by combining a subframe or a radio frame within the period and a slot index within the subframe / radio frame. Alternatively, since period information is already provided, the starting / ending slot may be designated using the slot order or index for the slots within the corresponding period.

[0171] According to one embodiment, as Opt 1-2, when SBFD slots are indicated as non-consecutive slots rather than a group of consecutive slots as starting / ending slots for SBFD slots within a period of a Semi-static TDD configuration, each 1-bit signal corresponding to each slot within the period may be configured as a bit string of the number of periods, and each bit may indicate whether each slot is an SBFD slot or not.

[0172] According to one embodiment, in addition to the cases described above (methods of indicating an SBFD slot), there may be a case where an SBFD symbol is defined in a slot other than an SBFD slot in addition to the configuration of an SBFD slot. In this case, the configuration of the SBFD slot described above and the corresponding slot within a period may be linked, and additionally, when an SBFD symbol is defined in a slot other than an SBFD slot, the corresponding slot may be indicated within the period, and in the corresponding slot, the position of the SBFD symbol and at least one of the UL subband configuration information or the DL subband configuration information of the corresponding SBFD symbol may be linked (for example, in addition to the SBFD slot configuration, the SBFD symbol configuration of a non-SBFD slot may be provided as a separate slot configuration and symbol configuration). In contrast, the configuration of a non-SBFD slot of a corresponding slot and the symbols included therein may be indicated for each slot. As Opt 1-3, in this case, one slot may be linked to the information below.

[0173]

[0174] According to various embodiments, as Opt 2, multiple slots are sBFD slots as in the examples described above, and in addition, an independent period other than the period defined in the TDD UL / DL configuration may be considered. In this case, a period for the SBFD configuration needs to be defined first. This period may be composed of an SCS and a slot period to which the SBFD configuration applies (for example, a starting slot may be designated using at least one of a specific radio frame or subframe index, and the corresponding period section may be indicated by the number of slots, or an ending slot may be indicated using at least one of a radio frame or subframe index. Instead of an index, an offset of a specific radio frame or subframe may be indicated, or a time value indicating an actual duration based on a specific slot may be indicated). According to one embodiment, the SBFD slot indication and SBFD symbol indication methods used in Opt 1 may also be used for slots of a given period.

[0175] FIG. 10 illustrates an example of an SBFD slot and symbol according to one embodiment of the present disclosure.

[0176] According to one embodiment, Opt 1-1 of FIG. 10 illustrates a case where a starting slot and an ending slot are additionally designated based on the period in the existing TDD UL / DL semi-static configuration in the aforementioned Opt 1-1. According to one embodiment, this may mean a case where the UL subband / DL subband of each slot is indicated. In this case, this may mean the same SBFD configuration for each SBFD slot.

[0177] According to one embodiment, Opt 1-2 of FIG. 10 may mean a case in which, instead of indicating a starting slot and an ending slot in the above-described case, it indicates an SBFD slot within a period as a bit string.

[0178] In one embodiment, Opt 2 of FIG. 10 may mean introducing a separate period and designating specific slots within that period as SBFD slots. In this case, the method of opt 1-1 or opt 1-2 described in the previous drawings may be used to designate SBFD slots.

[0179] FIG. 11 illustrates a signal flow for instructing a terminal to set SBFD through a serving cell according to one embodiment of the present disclosure.

[0180] In step (1110), a serving cell (e.g., cell 1) may transmit SIB1 to the terminal. In one embodiment, a DU or CU (central unit) of the serving cell may determine an SBFD semi-static configuration for operating its own cell, and then broadcast the determined SBFD semi-static configuration via SIB x. Here, SIB x may include SIB1.

[0181] At step (1120), the terminal and the serving cell can establish (or setup) an RRC connection.

[0182] In step (1130), a terminal that has received broadcast information can perform DL / UL-related operations using the SBFD semi-static configuration together with the TDD UL / DL configuration. For example, if the current slot is a non-SBFD slot and a DL slot in the semi-static TDD UL / DL configuration and the semi-static SBFD configuration of the terminal, the terminal can monitor the PDCCH in the entire DL frequency region. If the current slot is an SBFD slot, the terminal can monitor the PDCCH in the DL subband region. If the current slot is a non-SBFD slot and a UL slot, the terminal can perform transmission using the UL resources allocated to it or the common UL resources.

[0183] In step (1140), the serving cell may transmit an RRC reset message to the terminal. In one embodiment, for example, the network (e.g., the serving cell) may additionally designate a specific (e.g., dedicated) SBFD slot or symbol for each terminal in the SBFD configuration and transmit it to the terminal.

[0184] In step (1150), the terminal may overwrite terminal-specific information. In one embodiment, for example, the terminal may overwrite existing semi-static SBFD information with additionally indicated slots or symbols.

[0185] At step (1160), the network can perform DL / UL scheduling according to the above-described information and transmit a signal to the terminal.

[0186] At step (1170), the network can schedule DCI in the PDCCH to the terminal based on the information described above.

[0187] In step (1180), the terminal can perform DL reception and UL transmission operations using the overwritten UL / DL information.

[0188] According to various embodiments, by exchanging SBFD settings between gNBs / DUs, each gNB / DU can resolve CLI in the concerned cell. Below, methods for resolving CLI by receiving SBFD settings from neighboring cells in each gNB / DU are described in detail. In particular, methods for coordinated scheduling and Tx beam nulling with / without UL muting in this context are described in detail.

[0189] FIG. 12 illustrates a signal flow for performing coordinated scheduling according to one embodiment of the present disclosure.

[0190] In step (1210), gNB1 (e.g., serving base station) may transmit at least one of tdd-related configuration information or SBFD-related configuration information to the terminal.

[0191] In step (1220), when a victim / aggressor is determined between gNBs, the victim gNB or the aggressor gNB, or a specific gNB without such distinction, may transmit the semi-static SBFD configuration determined by itself to other associated gNBs. At this time, the specific base station may transmit the above-described configuration to other base stations through at least one of an Xn setup request, an Xn setup response, an NG-RAN node configuration update message, or a new Xn message.

[0192] In one embodiment, the transmitted message may include a cell-specific SBFD semi-static configuration together with at least one of cell identification information such as an index, PCI, AFRCN, CGI, etc. for a specific cell, or tdd-UL-DL-ConfigCommon information. In this case, the above-described information may be transmitted together with an indicator indicating that it is for the purpose of CLI handling between gNBs.

[0193] At step (1230), the terminal and gNB1 can establish (or set up) an RRC connection.

[0194] At step (1240), gNB2 (or gNB1 may also be included) may schedule DL or UL considering the interference level between base stations.

[0195] At step (1250), the terminal and gNB1 can transmit and receive signals according to scheduling based on a combination of TDD and SBFD settings according to scheduling.

[0196] According to various embodiments, specific examples of step (1220) are described below.

[0197] In one embodiment, a concerned gNB (e.g., gNB2) that has received configuration information may, based on the received information, avoid reception interference from neighboring cells or resource allocation that may cause interference to neighboring cells when scheduling its terminals. At this time, the concerned gNB may also know the identity of the cell providing the potential CLI.

[0198] In one embodiment, before or during transmission of the SBFD configuration, the gNB may transmit an indication indicating a request to process the CLI. This indication may also be transmitted via at least one of the Xn setup request, Xn setup response, NG-RAN node configuration update message, or new Xn message.

[0199] According to one embodiment, if the gNB that received the above-described request information determines that CLI handling is possible through its own scheduling or decides to perform CLI handling, it may transmit at least one of a positive response or a general response to the gNB that transmitted the CLI request via an Xn message. If the response information is positive, the gNB that transmitted the CLI request may assume that the CLI level will be reduced to some extent and may perform scheduling for its own terminals. At this time, the gNB may not consider the interference impact on the terminals of its own cell. The gNB that received the request information may transmit, in the response message, the identity of a cell that is affected by CLI due to the cell to which the request information was transmitted when requesting CLI handling among its own cells. This identity may include PCI, AFRCN, or CGI. According to one embodiment, if the response to the CLI request is negative, the gNB that transmitted the CLI request may perform scheduling of its own cell by considering the CLI from the cell that sent the negative response.

[0200] According to another embodiment, in the case described above, signal transmission between different DUs within a single gNB may also be possible, rather than between each gNB. In this case, the victim DU operating the victim cell and the aggressor DU operating the aggressor cell may each correspond to the gNBs of the embodiments described above. For example, when one DU transmits cell information, (intended) TDD DL / UL configuration information, or semi-static SBFD configuration information to another DU, the receiving DU may perform CLI handling operation in its own cell, considering the CLI status of a specific cell related to the corresponding cell and its own cells. For example, the receiving DU may perform coordinated scheduling. In addition, an indicator indicating a CLI handling request may be included and transmitted before or during transmission of the SBFD configuration information. The DU receiving this request information may perform CLI handling through its own scheduling, or, if it decides to perform CLI handling, may transmit a positive response or a general response to the CLI request via an F1 message to the DU that sent the CLI request.

[0201] In one embodiment, if the response information is positive, the DU that sent the CLI request may perform scheduling for its own terminals, assuming that the CLI level will be reduced to some extent. At this time, the DU may not consider the interference impact on the terminals of its own cell. In one embodiment, the response message may include and transmit the identity of a cell affected by CLI due to the cell transmitted when requesting the CLI handling among its own cells. The identity may include PCI, AFRCN, or CGI. In one embodiment, if the response to the CLI request is negative, the DU that sent the CLI request may perform scheduling for its own cell by considering the CLI from the cell that sent the negative response.

[0202] According to various embodiments, for inter-DU signaling, instead of direct transmission between DUs, each DU may transmit the above-described message as an F1 message to the CU, and then the CU may transmit the message to another DU through the CU of another DU (e.g., when the DUs are served by different CUs). Alternatively, the CU may transmit the message directly to another DU (e.g., when the DUs are served by the same CU). The message transmission between DUs and CUs may use either the existing F1 message or a new dedicated F1 message.

[0203] FIG. 13 illustrates a signal flow for handling a cell's CLI through DL beam nulling according to SBFD information according to one embodiment of the present disclosure.

[0204] Referring to FIG. 13, in steps (1310) to (1330), as in the case of FIG. 12, SBFD configuration information may be transmitted between gNBs or between DUs, and SBFD configuration information and TDD configuration information may be directly transmitted, or an instruction requesting CLI handling may be included in the same message and transmitted before or during transmission of the above-described information.

[0205] According to various embodiments, the information included when additionally transmitted may include at least one of cell identity, TDD DL / UL configuration information, semi-static SBFD configuration information, or information on a specific resource that the receiving gNB / DU wants to measure. The measurement resource information may include time and frequency information on a resource through which SSB or NZP-CSI-RS transmitted in the corresponding cell is transmitted, and may include at least one of a resource ID of each resource unit or an ID of a resource set. In addition, the measurement resource information may include a type of RS (reference signal) (e.g., SSB or CSI-RS), a quantity value for which measurement is to be performed (e.g., RSRP or RSRQ or RSSI, or Channel state information such as CQI, PMI, RI, etc.), or a threshold value to be used when determining a measurement result (e.g., whether the measurement result value of a previously given quantity exceeds this threshold value should be included in the feedback). Additionally, a beam index may be included as information on a resource through which each RS is transmitted and a beam that includes the resource and is transmitted in the corresponding cell.

[0206] In step (1340), the cell requesting CLI handling can transmit the RS described above.

[0207] In step (1350), the cell requesting CLI handling may measure the RS of a given resource. The measurement result may include a CLI by DL from the CLI handling requesting cell in the corresponding time / frequency domain.

[0208] In step (1360), the cell that is the target of the CLI handling request may report the corresponding measurement result value according to the measurement result. To this end, a quantity value may be set as information on a specific resource transmitted together with the SBFD configuration information described above from the cell that requested the CLI handling, and a threshold value may additionally be included. If the above-described information is given, the gNB or DU of the cell that received the CLI handling request may perform measurement with the given quantity and include the result value in the response message. In this case, a result value (e.g., measured signal strength) linked to the resource or resource set ID of each RS may be included. In addition, a beam index value for a beam through which each resource is transmitted may also be linked and included. In addition, if a threshold value for resource measurement is included in the CLI handling request message, the receiving gNB / DU may include an indicator indicating whether it is greater than or less than the threshold value (e.g., if it is greater than or equal to the threshold value, it may be indicated as CLI detected, or if it is not, it may be indicated as not detected). In one embodiment, a conditional operation of displaying a result in a response message only when the result is greater than or equal to a threshold value may be considered. For this purpose, a directive indicating conditional reporting may be added to the request message. In another embodiment, when multiple threshold values ​​(for example, two) for the measured result value are included in the CLI handling request message, the response message may include a CLI high value if the measured value is greater than the larger threshold value, a CLI medium value if the measured value is between the larger threshold value and the smaller threshold value, or a CLI low value if the measured value is less than the smaller threshold value. In one embodiment, the message sequence may be the same as that of FIG. 12.For CUs, the Xn message may be used, or for DUs, the F1 message may be used through the CU.

[0209] According to various embodiments, in FIG. 13, cell 2 may feed back the measured values ​​of each resource, including the beam index, through an Xn message. At this time, this response message may include its own specific cell ID, and this cell may mean a cell within the gNB / DU that the CLI is concerned about through the SBFD configuration information received from cell 1. SBFD semi-static information of this cell may be added to the response message.

[0210] In step (1370), cell 1, which has received the response message, may perform DL beam nulling by using a method of reducing the signal intensity of a signal transmitted on a specific beam (e.g., methods of making the weight value on the precoding matrix small or 0 in MIMO) if the measured CLI for the specific beam is sufficiently large, taking into account the measured value. At this time, cell 1 may use the CSI information fed back through the response message.

[0211] At step (1380), cell 1 can schedule DL for PDSCH according to DL beam nulling.

[0212] FIG. 14 illustrates a signal flow for performing UL muting to perform CLI measurement according to SBFD information according to one embodiment of the present disclosure.

[0213] Referring to FIG. 14, the basic operation including steps (1410) to (1440) or steps (1460) to (1480) may be similar to the transmission and reception of SBFD setting information described in FIG. 13.

[0214] In step (1450), if information including SBFD semi-static configuration information is transmitted to the gNB or DU of cell 2, the receiving gNB or DU may schedule resources to the terminals, excluding specific UL resources of the terminals serving it, with reference to the measurement resource information. For example, this may be performed for the purpose of making CLI measurement more accurate by avoiding and allocating UL resources of its own (e.g., cell 2) terminals in the time / frequency domain where the resources of cell 1 appear for CLI measurement.

[0215] More specifically, in step (1450) of FIG. 14, cell 2, which has received SBFD configuration information and a CLI handling request message (e.g., Xn message), can schedule UL resources to its terminals by avoiding the corresponding CLI measurement resource locations, taking into account CLI measurement resource information. To this end, cell 2 can configure the corresponding UL muting resources to its terminals through an RRCReconfiguration message, or can schedule the UL resources by avoiding the corresponding resources when scheduling them through a PDCCH. In this situation, cell 2 can perform measurements on the CLI measurement resources more accurately. The measured result value can be fed back to the cell that transmitted the CLI handling request as a response message.

[0216] According to various embodiments, the operations of FIG. 14 are described based on signals between gNBs, but can also be applied equally to signals between DUs. In the case of signals between DUs, SBFD configuration and transmission of CLI handling request and a response signal thereto can be operated through an F1 message. Additionally, if UL muting is to be performed in FIG. 14, in the case of a DU, the DU can directly instruct UL resource muting of the UE through scheduling of a PDCCH, but cannot directly instruct UL muting through RRCReconfiguration. Instead, the CU can operate by transmitting the determined UL muting pattern information to the CU serving itself, and then, when the CU writes an RRCReconfiguration message, storing the muting pattern information and transmitting it back to the UE.

[0217] According to various embodiments, all, some, or a combination of some of the embodiments or operations of FIGS. 9 to 14 described above may be performed in combination.

[0218] In one embodiment, a base station or DU may determine a duplexing configuration for a specific cell and may communicate its SBFD configuration to a base station or DU that determines duplexing for another cell. Here, the SBFD configuration may be a semi-static SBFD configuration and may include UL subband information for at least one of a specific slot or symbol.

[0219] According to one embodiment, when a base station or DU transmits the above-described SBFD configuration information, an instruction requesting CLI processing or removal may be further transmitted before or at the time of the above-described transmission, and a response thereto may be transmitted and received. At this time, the base station or DU that has received the instruction requesting CLI processing or removal may, based on the received information, perform its own duplex configuration or scheduling or transmission beam / power control for the terminals it operates. The base station or DU that has received the instruction requesting CLI processing or removal may transmit information indicating that it performs the above-described control as a response to the request. Alternatively, the base station or DU that has received the instruction requesting CLI processing or removal may transmit information indicating that it cannot perform the above-described control.

[0220] The methods according to the embodiments described in the claims or specification of the present invention may be implemented in the form of hardware, software, or a combination of hardware and software.

[0221] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present invention.

[0222] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0223] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present invention via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present invention.

[0224] In the specific embodiments of the present invention described above, components included in the invention are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present invention is not limited to singular or plural components. Even components expressed in plural may be composed of singular elements, or even components expressed in singular may be composed of plural elements.

[0225] While the detailed description of the present invention has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. A method performed by a first base station in a wireless communication system, A step of transmitting a first message to a second base station, the first message including information for setting a semi-static SBFD (subband full duplex) associated with the first cell of the first base station and second information for setting a resource for beam measurement; and A method comprising the step of receiving a second message including information requesting CLI (cross link interference) mitigation from the second base station.

2. In claim 1, The resource for the beam measurement includes at least one of an SSB (SS (synchronization signal) / PBCH (physical broadcast channel) block) resource or a CSI (channel state information)-RS (reference signal) resource, The second message includes information about the results of the beam measurement, and A method wherein the result of the above beam measurement includes at least one of an SSB index or a CSI-RS resource indicator.

3. A method according to claim 1, wherein the first message is one of an Xn setup request message, an Xn setup response, or a RAN (radio access network) node configuration update message.

4. In claim 1, the method, Further comprising a step of transmitting SIB1 (system information block1) including cell-specific SBFD configuration information to a user equipment (UE) associated with the first cell, A method wherein the above cell-specific SBFD configuration information includes information for muting at least one UL (uplink) resource.

5. In a method performed by a second base station in a wireless communication system, A step of receiving a first message from a first base station, the first message including information for setting a semi-static SBFD (subband full duplex) associated with a first cell of the first base station and second information for setting a resource for beam measurement; and A method comprising the step of transmitting a second message including information requesting CLI (cross link interference) mitigation to the first base station.

6. In claim 5, The resource for the beam measurement includes at least one of an SSB (SS (synchronization signal) / PBCH (physical broadcast channel) block) resource or a CSI (channel state information)-RS (reference signal) resource, The second message includes information about the results of the beam measurement, and A method wherein the result of the above beam measurement includes at least one of an SSB index or a CSI-RS resource indicator.

7. A method according to claim 5, wherein the first message is one of an Xn setup request message, an Xn setup response, or a RAN (radio access network) node configuration update message.

8. In claim 5, the method comprises: Further comprising a step of transmitting, to a user equipment (UE) associated with a second cell of the second base station, a SIB1 (system information block1) including cell-specific SBFD configuration information, A method wherein the above cell-specific SBFD configuration information includes information for muting at least one UL (uplink) resource.

9. In a wireless communication system, the first base station is: At least one transceiver; At least one processor communicatively coupled to said at least one transceiver; and At least one memory communicatively coupled to said at least one processor and storing instructions, The above commands are executed individually or in any combination by the at least one processor, so that the first base station: Transmitting a first message to a second base station, the first message including information for setting a semi-static SBFD (subband full duplex) associated with the first cell of the first base station and second information for setting a resource for beam measurement, and A first base station configured to receive a second message including information requesting CLI (cross link interference) mitigation from the second base station.

10. In claim 9, The resource for the beam measurement includes at least one of an SSB (SS (synchronization signal) / PBCH (physical broadcast channel) block) resource or a CSI (channel state information)-RS (reference signal) resource, The second message includes information about the results of the beam measurement, and A first base station according to the above beam measurement result, which includes at least one of an SSB index or a CSI-RS resource indicator.

11. In claim 9, the first base station, wherein the first message is one of an Xn setup request message, an Xn setup response, or a RAN (radio access network) node configuration update message.

12. In claim 9, the commands cause the first base station to: To transmit SIB1 (system information block1) including cell-specific SBFD configuration information to a user equipment (UE) associated with the first cell, The above cell-specific SBFD configuration information is a first base station including information for muting at least one UL (uplink) resource.

13. In a wireless communication system, the second base station, At least one transceiver; At least one processor communicatively coupled to said at least one transceiver; and At least one memory communicatively coupled to said at least one processor and storing instructions, The above commands are executed individually or in any combination by the at least one processor so that the second base station: Receive a first message from a first base station, including information for setting a semi-static SBFD (subband full duplex) associated with a first cell of the first base station and second information for setting a resource for beam measurement, and A second base station that transmits a second message including information requesting CLI (cross link interference) mitigation to the first base station.

14. In claim 13, The resource for the beam measurement includes at least one of an SSB (SS (synchronization signal) / PBCH (physical broadcast channel) block) resource or a CSI (channel state information)-RS (reference signal) resource, The second message includes information about the results of the beam measurement, and A second base station comprising at least one of an SSB index or a CSI-RS resource indicator according to the above beam measurement.

15. In claim 13, the second base station, wherein the first message is one of an Xn setup request message, an Xn setup response, or a RAN (radio access network) node configuration update message.

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