Csi and pmi signaling framework for ue measurement and feedback based full duplex device-to-device communication

Abstract

In one aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus can be a user equipment (UE). The UE receives a first channel state information reference signal (CSI-RS) directly from a base station on a first frequency band and receives a second CSI-RS from a cooperating device (CD) on a second frequency band. The second CSI-RS is a frequency-translated version of a CSI-RS transmitted by the base station to the CD on the first frequency band. The UE measures a direct channel based on the first CSI-RS. The UE measures a cascaded channel based on the second CSI-RS. The UE generates channel state information (CSI) feedback based on the measured direct channel and the measured cascaded channel. The CSI feedback includes at least a first precoding matrix indicator (PMI) for a first precoder used for transmission to the CD and a second PMI for a second precoder used for direct transmission to the UE. The UE transmits the CSI feedback to the base station.

Description

[0001] Cross-references

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 667,719, entitled “Full-duplex device-to-device communication: a signaling framework for channel state information (CSI) and precoding matrix indicator (PMI) based on user equipment (UE) measurements and feedback,” filed on July 4, 2024, the entire contents of which are hereby expressly incorporated by reference. Technical Field

[0003] This disclosure generally relates to wireless communications, and more particularly to channel state information (CSI) and precoding matrix indicator (PMI) signaling techniques based on user equipment (UE) measurements and feedback. Background Technology

[0004] The statements in this section provide only background information in relation to this disclosure and may not constitute prior art.

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunications services, such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies to support communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0006] These multiple access technologies have been adopted by various telecommunications standards to provide a common protocol enabling different wireless devices to communicate at the city, national, regional, and even global levels. One example of a telecommunications standard is 5G New Radio (NR). 5G NR is part of the ongoing evolution of mobile broadband driven by the Third Generation Partnership Project (3GPP) to meet new requirements related to latency, reliability, security, scalability (e.g., the Internet of Things (IoT)), and other needs. Some aspects of 5G NR are based on the 4G Long Term Evolution (LTE) standard. 5G NR technology still requires further improvement. These improvements can also be applied to other multiple access technologies and telecommunications standards that adopt them. Summary of the Invention

[0007] The following is a simplified summary of one or more aspects to provide a basic understanding of them. This summary is not a comprehensive overview of all hypothetical aspects, nor is it intended to identify key or essential elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present certain concepts of one or more aspects in a simplified form as a prelude to a more detailed description thereafter.

[0008] In one aspect of this disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment (UE). The UE directly receives a first channel state information reference signal (CSI-RS) from a base station on a first frequency band. The UE receives a second CSI-RS from a cooperating device (CD) on a second frequency band. The second CSI-RS is a frequency-converted version of the CSI-RS transmitted by the base station to the CD on the first frequency band. Based on the first CSI-RS, the UE measures the direct channel between the base station and the UE. The UE measures the cascaded channel between the base station and the UE via the CD based on the second CSI-RS. ). This indicates the channel from the base station to the CD. This indicates the channel from the CD to the UE. The UE generates Channel State Information (CSI) feedback based on the measured direct channel and the measured cascaded channel. The CSI feedback includes at least: information for the first precoder ( The first precoder matrix indicator (PMI) is used by the base station for transmission to the CD; and the first precoder is used for the second precoder ( The second PMI, the second precoder, is used by the base station for direct transmission to the UE. The UE sends the CSI feedback to the base station.

[0009] To achieve the foregoing and related objectives, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary features of one or more aspects in detail. However, these features only illustrate a portion of the possible ways in which the principles of the various aspects may be adopted, and this description is intended to include all such aspects and their equivalents. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating an example wireless communication system and access network.

[0011] Figure 2 This is a schematic diagram of communication between the base station and the UE in the access network.

[0012] Figure 3 Example of a distributed access network's logical architecture.

[0013] Figure 4 Example of a distributed access network physical architecture.

[0014] Figure 5 This is an example schematic diagram of the DL center time slot.

[0015] Figure 6 This is an example schematic diagram of the UL center time slot.

[0016] Figure 7 This is a schematic diagram of a full-duplex communication system between devices.

[0017] Figure 8 This is a schematic diagram illustrating how a gNB performs reception or transmission on a specific frequency resource in a full-duplex downlink scenario.

[0018] Figure 9 This is a schematic diagram illustrating how a gNB performs reception or transmission on a specific frequency resource in a non-full-duplex downlink scenario.

[0019] Figure 10 This is a schematic diagram illustrating how a gNB performs reception or transmission on a specific frequency resource in a non-full-duplex uplink scenario.

[0020] Figure 11 This is a schematic diagram illustrating how a gNB performs reception or transmission on a specific frequency resource in a full-duplex uplink scenario.

[0021] Figure 12 This is a schematic diagram of a downlink full-duplex gNB scenario.

[0022] Figure 13 This is a schematic diagram of a communication system in a downlink full-duplex gNB scenario.

[0023] Figure 14 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 1.

[0024] Figure 15 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 2.

[0025] Figure 16 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 3.

[0026] Figure 17 This is a schematic diagram of intra-carrier CLI.

[0027] Figure 18 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 4.

[0028] Figure 19 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 5.

[0029] Figure 20 This is a schematic diagram of the communication process between gNB, CD and UE, corresponding to scheme 6.

[0030] Figure 21 This is a schematic diagram of a downlink non-full-duplex gNB scenario.

[0031] Figure 22 This is a schematic diagram of a communication system in a downlink non-full-duplex gNB scenario.

[0032] Figure 23 This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 1.

[0033] Figure 24 This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 2.

[0034] Figure 25 This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 3.

[0035] Figure 26 This is a schematic diagram of CLI management within a cell between carriers.

[0036] Figure 27 This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 4.

[0037] Figure 28 This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 5.

[0038] Figure 29This is a schematic diagram of another communication process between gNB, CD and UE, corresponding to scheme 6.

[0039] Figure 30 This is a schematic diagram of CLI management within a cell between carriers.

[0040] Figure 31 This is a schematic diagram of another communication process between the gNB, CD and UE, corresponding to scheme 7.

[0041] Figure 32 Example 1: CSI and PMI signaling flowchart based on UE measurement and feedback.

[0042] Figure 33 Example 2: CSI and PMI signaling flowchart based on UE measurement and feedback.

[0043] Figure 34 Example 3: CSI and PMI signaling flowchart based on UE measurement and feedback.

[0044] Figure 35 Example 4: CSI and PMI signaling flowchart based on UE measurement and feedback. Detailed Implementation

[0045] The detailed description below, taken in conjunction with the accompanying drawings, is intended to describe various configurations and is not intended to represent the only configuration in which the concepts described herein can be practiced. The detailed description includes specific details to provide a thorough understanding of the various concepts. However, those skilled in the art will understand that these concepts can be practiced without these specific details. In some cases, to avoid obscuring these concepts, known structures and components are shown in block diagram form.

[0046] This document introduces several aspects of telecommunications systems using various apparatuses and methods. These apparatuses and methods will be described in detail below and illustrated with accompanying drawings as various modules, components, circuits, processes, algorithms, etc. (collectively, "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether an element is implemented in hardware or software depends on the specific application and design constraints imposed on the overall system.

[0047] For example, a single element, any part thereof, or any combination thereof can be implemented as a "processing system" containing one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other hardware suitable for performing the various functions described in this disclosure. One or more processors in a processing system can execute software. Software should be understood broadly as instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description languages, or other names.

[0048] Therefore, in one or more example aspects, the functionality can be implemented by hardware, software, or any combination thereof. If implemented by software, these functions can be stored or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media. Storage media can be any existing medium accessible to a computer. For example, but not limited to, such computer-readable media can include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), optical disc storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the above types, or any medium that can be used to store computer-executable code in the form of instructions or data structures and is accessible to a computer.

[0049] Figure 1 This diagram illustrates a wireless communication system and access network 100. The wireless communication system (also known as a Wireless Wide Area Network (WWAN)) includes a base station 102, user equipment (UE) 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femtocells, picocells, and microcells.

[0050] Base station 102 configured as 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with EPC 160 via backhaul link 132 (e.g., SI interface). Base station 102 configured as 5G NR (collectively referred to as Next Generation RAN, or NG-RAN) can interface with core network 190 via backhaul link 184. Among other functions, base station 102 can perform one or more of the following functions: user data transmission, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, non-access stratum (NAS) message distribution, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and equipment tracking, RAN information management (RIM), paging, location, and warning message delivery. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC 160 or core network 190) through backhaul link 134 (e.g., X2 interface). Backhaul link 134 can be wired or wireless.

[0051] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for a corresponding geographic coverage area 110. Overlapping geographic coverage areas 110 may exist. For example, small cell 102' may have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network containing small cells and macro cells can be called a heterogeneous network. Heterogeneous networks may also include Home Evolved Node B (HeNB), which can provide services to a restricted group called a Closed Subscriber Group (CSG). The communication link 120 between base station 102 and UE 104 may include uplink (UL) (also known as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also known as forward link) transmission from base station 102 to UE 104. Communication link 120 may employ multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link can be implemented using one or more carriers. Base station 102 / UE104 can use per-carrier spectrum with a bandwidth of up to 7 MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.) to allocate a total of Yx MHz (x component carriers) for transmission in carrier aggregation in each direction. Carriers can be adjacent or non-adjacent. Carrier allocation in the DL and UL directions can be asymmetrical (e.g., more or fewer carriers allocated to DL than to UL). Component carriers can include primary component carriers and one or more secondary component carriers. Primary component carriers can be referred to as primary cells (PCells), and secondary component carriers can be referred to as secondary cells (SCells).

[0052] Some UEs 104 can communicate via device-to-device (D2D) communication link 158. D2D communication link 158 can use DL / UL WWAN spectrum. D2D communication link 158 can use one or more sidelink channels, such as the Physical Sidelink Broadcast Channel (PSBCH), Physical Sidelink Discovery Channel (PSDCH), Physical Sidelink Shared Channel (PSSCH), and Physical Sidelink Control Channel (PSCCH). D2D communication can be implemented through various wireless D2D communication systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.

[0053] The wireless communication system may also include a Wi-Fi access point (AP) 150, which communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) before communication to determine whether the channel is available.

[0054] Cell 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, cell 102' can employ New Radio (NR) and use the same 5 GHz unlicensed spectrum as Wi-Fi access point 150. When cell 102' employs NR in unlicensed spectrum, it can enhance the coverage and / or increase the capacity of the access network.

[0055] Base station 102, whether cell 102' or large area (e.g., macro base station), may include evolved Node B (eNB), gNodeB (gNB), or other types of base stations. Some base stations, such as gNB 180, can communicate with UE 104 in the conventional sub-6 GHz spectrum, millimeter wave (mmW) frequencies, and / or near-millimeter wave frequencies. When gNB 180 operates at millimeter wave or near-millimeter wave frequencies, gNB 180 may be referred to as a millimeter wave base station. Extremely high frequency (EHF) belongs to the radio frequency (RF) portion of the electromagnetic spectrum. The EHF range is from 30 GHz to 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this band are referred to as millimeter waves. Near-millimeter waves extend down to 3 GHz with wavelengths of 100 mm. The ultra-high frequency (SHF) band is between 3 GHz and 30 GHz, also known as centimeter waves. When communicating using millimeter-wave / near-millimeter-wave radio frequency bands (e.g., 3 GHz - 300 GHz), path loss is extremely high and coverage distance is short. Millimeter-wave base station 180 can use beamforming 182 with UE 104 to compensate for the extremely high path loss and short distance.

[0056] Base station 180 can transmit beamforming signals to UE 104 in one or more transmit directions 108a. UE 104 can receive beamforming signals from base station 180 in one or more receive directions 108b. UE 104 can also transmit beamforming signals to base station 180 in one or more transmit directions. Base station 180 can receive beamforming signals from UE 104 in one or more receive directions. Base station 180 / UE 104 can perform beam training to determine their respective optimal receive and transmit directions. The transmit and receive directions of base station 180 can be the same or different. The transmit and receive directions of UE 104 can be the same or different.

[0057] The evolved packet core (EPC) 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. MME 162 can communicate with the Home Subscriber Server (HSS) 174. MME 162 is the control node that handles signaling between UE 104 and EPC 160. Typically, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are forwarded through the serving gateway 166, which is itself connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and BM-SC 170 are connected to IP service 176. IP service 176 may include the Internet, intranets, IP Multimedia Subsystem (IMS), packet-switched streaming media services, and other IP services. The BM-SC 170 provides MBMS user service configuration and delivery capabilities. It serves as an entry point for content provider MBMS transmissions, enabling the authorization and initiation of MBMS bearer services within a Public Land Mobile Network (PLMN) and scheduling MBMS transmissions. The MBMS gateway 168 distributes MBMS traffic to base station 102 located in a Multicast-Broadcast Single Frequency Network (MBSFN) area, which broadcasts specific services, and is responsible for session management (initiation / stopping) and collecting eMBMS-related billing information.

[0058] The core network 190 may include Access and Mobility Management Function (AMF) 192, other AMFs 193, Location Management Function (LMF) 198, Session Management Function (SMF) 194, and User Plane Function (UPF) 195. AMF 192 can communicate with Unified Data Management (UDM) 196. AMF 192 is the control node that handles signaling between UE 104 and the core network 190. Typically, SMF 194 provides QoS flow and session management. All user Internet Protocol (IP) packets are forwarded through UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP service 197. IP service 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), packet-switched streaming media service, and other IP services.

[0059] A base station may also be referred to as a gNB, Node B, evolved Node B (eNB), access point, base transceiver station, wireless base station, wireless transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmit / receive point (TRP), or other appropriate terms. Base station 102 provides UE 104 with an access point to connect to EPC 160 or core network 190. Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, GPS devices, multimedia devices, video devices, digital audio players (such as MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electricity meters, gas pumps, large or small kitchen appliances, medical devices, implants, sensors / actuators, displays, or any other similarly functional device. Some UE 104 devices may be referred to as Internet of Things (IoT) devices (such as parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as site, mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, handheld device, user agent, mobile client, client or other appropriate terms.

[0060] Although this disclosure may relate to 5G New Radio (NR), it may also be applied to other similar fields, such as LTE, LTE-Advanced (LTE-A), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM) or other radio / radio frequency access technologies.

[0061] Figure 2This is a block diagram illustrating communication between base station 210 and user equipment (UE) 250 in the access network. In the downlink (DL), IP packets from EPC 160 are provided to controller / processor 275. Controller / processor 275 implements Layer 3 and Layer 2 functions. Layer 3 includes the radio resource control (RRC) layer, and Layer 2 includes the packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, and medium access control (MAC) layer. The controller / processor 275 provides RRC layer functions related to system information (e.g., Master Information Block (MIB), System Information Blocks (SIBs)) broadcasting; RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release); inter-Radio Access Technology (RAT) mobility; and measurement configuration for UE measurement reporting. It also provides PDCP layer functions related to header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support. Furthermore, it provides RLC layer functions related to uplink layer packet data units (PDUs) transmission, error correction via Automatic Repeat Request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs. Finally, it provides mapping between logical channels and transport channels, multiplexing of MAC SDUs to transport blocks (TBs), and MAC... SDUs handle MAC layer functions related to TBs, including demultiplexing, scheduling information reporting, error correction via Hybrid Automatic Repeat Request (HARQ), priority processing, and logical channel priority.

[0062] Transmit (TX) processor 216 and receive (RX) processor 270 implement Layer 1 functions related to various signal processing functions. Layer 1 includes the physical (PHY) layer, which may include error detection of the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and multiple-input multiple-output (MIMO) antenna processing. TX processor 216 processes the mapping to the signal constellation according to various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), and M-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be split into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and then combined via an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM streams are spatially precoded to generate multiple spatial streams. Channel estimates from channel estimator 274 are used to determine the coding and modulation schemes, as well as spatial processing. The channel estimates can be derived from the reference signal and / or channel state feedback transmitted by UE 250. Each spatial stream can then be provided to different antennas 220 via a separate transmitter 218TX. Each transmitter 218TX can modulate an RF carrier with the corresponding spatial stream for transmission.

[0063] At UE 250, each receiver 254RX receives signals through its corresponding antenna 252. Each receiver 254RX recovers the information modulated onto the RF carrier and provides the information to the receive (RX) processor 256. The TX processor 268 and RX processor 256 implement Layer 1 functions related to various signal processing functions. The RX processor 256 can perform spatial processing on the information to recover any spatial streams sent to UE 250. If multiple spatial streams are sent to UE 250, they can be merged into a single OFDM symbol stream by the RX processor 256. The RX processor 256 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, along with the reference signal, are recovered and demodulated by determining the most probable signal constellation point transmitted by base station 210. These soft decisions can be based on the channel estimate calculated by channel estimator 258. The soft decision is then decoded and deinterleaved to recover the data and control signals initially transmitted by base station 210 on the physical channel. The data and control signals are then provided to controller / processor 259, which implements Layer 3 and Layer 2 functions.

[0064] Controller / processor 259 may be associated with memory 260, which stores program code and data. Memory 260 may be referred to as computer-readable medium. In the uplink (UL), controller / processor 259 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets from EPC 160. Controller / processor 259 is also responsible for error detection using acknowledgment (ACK) and / or denial (NACK) protocols to support HARQ operation.

[0065] Similar to the downlink transmission function description of base station 210, controller / processor 259 provides RRC layer functions related to system information (e.g., MIB, SIBs) acquisition, RRC connection, and measurement reporting; PDCP layer functions related to header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions related to upper-layer PDU transmission, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions related to mapping between logical channels and transport channels, multiplexing of MAC SDUs to TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority processing, and logical channel priority.

[0066] The channel estimate derived by channel estimator 258 based on a reference signal or feedback from base station 210 can be used by TX processor 268 to select a suitable coding and modulation scheme and facilitate spatial processing. The spatial stream generated by TX processor 268 can be provided to different antennas 252 via individual transmitters 254TX. Each transmitter 254TX can modulate the RF carrier with the corresponding spatial stream for transmission. Uplink transmission is processed at base station 210 in a manner similar to that described for UE 250 reception. Each receiver 218RX receives the signal through its corresponding antenna 220. Each receiver 218RX recovers the information modulated onto the RF carrier and provides the information to RX processor 270.

[0067] The controller / processor 275 may be associated with a memory 276 storing program code and data. The memory 276 may be referred to as a computer-readable medium. In the uplink, the controller / processor 275 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transport channel and the logical channel to recover IP packets from the user equipment (UE) 250. IP packets from the controller / processor 275 may be provided to the evolved packet core (EPC) 160. The controller / processor 275 is also responsible for error detection using acknowledgment (ACK) and / or denial (NACK) protocols to support Hybrid Automatic Repeat Request (HARQ) operation.

[0068] New Radio (NR) can refer to a radio configured to operate under a new air interface (e.g., Orthogonal Frequency Divisional Multiple Access (OFDMA) air interface) or a fixed transport layer (e.g., non-Internet Protocol (IP)). NR may employ Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) in both uplink and downlink, and may include support for half-duplex operation using Time Division Duplex (TDD). NR may include Enhanced Mobile Broadband (eMBB) services targeting wide bandwidth (e.g., above 80 MHz); millimeter wave (mmW) services targeting high carrier frequencies (e.g., 60 GHz); massive machine-type communications (mMTC) services targeting non-backward-compatible MTC technologies; and mission-critical services targeting ultra-reliable low-latency communications (URLLC).

[0069] It supports a single component carrier bandwidth of 100 MHz. In one example, NR resource blocks (RBs) can span 12 subcarriers with a subcarrier bandwidth of 60 kHz and a duration of 0.25 ms, or a bandwidth of 30 kHz and a duration of 0.5 ms (similarly, a 15 kHz subcarrier spacing (SCS) corresponds to a 50 MHz bandwidth within a 1 ms duration). Each radio frame can contain 10 subframes (10, 20, 40, or 80 NR slots) with a length of 10 ms. Each slot can indicate the link direction (i.e., downlink (DL) or uplink (UL)) for data transmission, and the link direction of each slot can be dynamically switched. Each slot can include DL / UL data and DL / UL control data. See below for details on NR UL and DL slots. Figure 5 and Figure 6 A detailed description.

[0070] The NR Radio Access Network (RAN) may include central units (CUs) and distributed units (DUs). An NR base station (BS, e.g., gNB, 5G Node B, Node B, transmission reception point (TRP), access point (AP)) may correspond to one or more base stations. NR cells may be configured as access cells (ACells) or data-only cells (DCells). For example, the RAN (e.g., central units or distributed units) may configure these cells. DCells may be used for carrier aggregation or dual connectivity and may not be used for initial access, cell selection / reselection, or handover. In some cases, DCells may not transmit synchronization signals (SS), and in other cases, they may transmit SS. NR base stations may transmit downlink signals to user equipment (UEs) to indicate the cell type. Based on the cell type indication, the UE may communicate with the NR base station. For example, the UE may determine the NR base station for cell selection, access, handover, and / or measurement based on the indicated cell type.

[0071] Figure 3The logical architecture of a distributed radio access network (RAN) 300 is illustrated exemplarily according to relevant aspects of this disclosure. A 5G access node 306 may include an access node controller (ANC) 302. The ANC may be the central unit (CU) of the distributed RAN. The backhaul interface to the next-generation core network (NG-CN) 304 may terminate at the ANC. The backhaul interface to neighboring next-generation access nodes (NG-ANs) 310 may terminate at the ANC. The ANC may include one or more transceiver points (TRPs) 308 (also referred to as base stations, NR base stations, Node B, 5G NB, AP, or other terms). As mentioned above, TRP can be used interchangeably with "cell".

[0072] TRPs 308 may be distributed units (DUs). TRPs may connect to one ANC (ANC 302) or multiple ANCs (not shown). For example, for RAN sharing, radio as a service (RaaS) and service-specific ANC deployments, TRPs may connect to multiple ANCs. TRPs may include one or more antenna ports. TRPs may be configured to provide services to the UE individually (e.g., dynamically selected) or jointly (e.g., jointly transmitted).

[0073] The local architecture of the distributed RAN 300 can be used to illustrate the fronthaul definition. This architecture can be defined to support fronthaul solutions for different deployment types. For example, the architecture can be based on transport network capabilities (e.g., bandwidth, latency, and / or jitter). The architecture can share features and / or components with LTE. Depending on the relevant aspects, the Next Generation Access Node (NG-AN) 310 can support dual connectivity with NR. The NG-AN can share a common fronthaul for both LTE and NR.

[0074] This architecture enables collaboration between and within TRPs 308. For example, collaboration can be pre-defined within a TRP and / or implemented across TRPs via ANC 302. Depending on the relevant parties, inter-TRP interfaces may not be required or may not exist.

[0075] According to relevant sources, the architecture of the distributed RAN 300 allows for dynamic configuration with logical function splitting. Packet Data Convergence Protocol (PDCP), Radio Link Control (RLC), and Media Access Control (MAC) protocols can be adaptively deployed on the ANC or TRP.

[0076] Figure 4The physical architecture of a distributed radio access network (RAN) 400 is illustrated exemplarily according to relevant aspects of this disclosure. A centralized core network unit (C-CU) 402 can carry core network functions. The C-CU can be centrally deployed. C-CU functions can be offloaded (e.g., to advanced wireless services (AWS)) to handle peak capacity. A centralized RAN unit (C-RU) 404 can carry one or more ANC functions. Optionally, the C-RU can carry core network functions locally. The C-RU can be distributed. The C-RU can be closer to the network edge. A distributed unit (DU) 406 can carry one or more TRPs. The DU can be located at the network edge and has radio frequency (RF) functions.

[0077] Figure 5 This is a schematic diagram 500 illustrating an example of a DL center timeslot. The DL center timeslot may include a control section 502. The control section 502 may exist in the initial or beginning portion of the DL center timeslot. The control section 502 may include various scheduling and / or control information corresponding to the various portions of the DL center timeslot. In some configurations, the control section 502 may be a physical DL control channel (PDCCH), such as... Figure 5 As shown. The DL center time slot may also include a DL data portion 504. The DL data portion 504 is sometimes referred to as the payload of the DL center time slot. The DL data portion 504 may include communication resources used for transmitting DL data from a scheduling entity (e.g., a user equipment (UE) or a base station (BS)) to a subordinate entity (e.g., a UE). In some configurations, the DL data portion 504 may be a physical DL shared channel (PDSCH).

[0078] The DL center time slot may also include a common UL section 506. The common UL section 506 is sometimes referred to as a UL burst, common UL burst, and / or other various applicable terms. The common UL section 506 may include feedback information corresponding to other sections of the DL center time slot. For example, the common UL section 506 may include feedback information corresponding to the control section 502. Non-limiting examples of feedback information may include ACK signals, NACK signals, HARQ indicators, and / or other various applicable types of information. The common UL section 506 may include additional or alternative information, such as information related to random access channel (RACH) procedures, scheduling requests (SRs), and other various applicable types of information.

[0079] like Figure 5As shown, the end of the DL data section 504 and the beginning of the common UL section 506 are time-separated. This time separation is sometimes referred to as a gap, guard period, guard interval, and / or other various applicable terms. This separation provides time for the switch from DL communication (e.g., a receiving operation of a subordinate entity (e.g., a UE)) to UL communication (e.g., a transmitting operation of a subordinate entity (e.g., a UE)). Those skilled in the art will understand that the above is merely one example of a DL central timeslot, and alternative structures with similar characteristics may exist without departing from the various aspects described herein.

[0080] Figure 6 This is a schematic diagram 600 illustrating an example of a UL center time slot. The UL center time slot may include a control section 602. The control section 602 may be present at the beginning or start of the UL center time slot. Figure 6 The control section 602 can be similar to the above combination. Figure 5 The control portion 502 is described. The UL center timeslot may also include a UL data portion 604. The UL data portion 604 is sometimes referred to as the payload of the UL center timeslot. The UL portion may refer to the communication resources used for transmitting UL data from a dependent entity (e.g., UE) to a scheduling entity (e.g., UE or BS). In some configurations, the control portion 602 may be a physical DL control channel (PDCCH).

[0081] like Figure 6 As shown, the end of control section 602 and the start of UL data section 604 are time-separated. This time separation is sometimes referred to as a gap, protection period, protection interval, and / or other various applicable terms. This separation provides time for switching from DL communication (e.g., a receiving operation of a scheduling entity) to UL communication (e.g., a transmitting operation of a scheduling entity). The UL central time slot may also include the common UL section 606. Figure 6 The public UL section 606 in the document can be combined in a similar way to the above. Figure 5 The common UL section 506 is described. Common UL section 606 may also include, or alternatively include, information relating to Channel Quality Indicator (CQI), Measurement Reference Signal (SRS), and other various applicable types of information. Those skilled in the art will understand that the above is merely one example of a UL center slot, and alternative structures with similar characteristics may exist without departing from the various aspects described herein.

[0082] In some cases, two or more dependent entities (e.g., UEs) can communicate with each other using sidechain signals. Practical applications of this type of sidechain communication can include public safety, proximity services, UE-to-network relay, vehicle-to-vehicle (V2V) communication, Internet of Things (IoE) communication, Internet of Things (IoT) communication, mission-critical mesh networks, and / or various other applicable applications. Generally, a sidechain signal can refer to a signal transmitted from one dependent entity (e.g., UE1) to another dependent entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), although the scheduling entity may be used for scheduling and / or control purposes. In some examples, sidechain signals can communicate using licensed spectrum (unlike wireless LANs that typically use unlicensed spectrum).

[0083] In full-duplex device-to-device communication within a personal area network (PAN), device collaboration faces technical challenges, including limited multiple-input multiple-output (MIMO) gain due to device form factors, degraded wireless propagation characteristics at high frequencies, and the increasing prevalence of users carrying multiple devices.

[0084] To address these challenges, full-duplex cooperative devices can be introduced to enable in-band multi-carrier operation, where different carriers within the same frequency band can be used simultaneously. For example, band #1, deployed in low- or mid-band spectrum (e.g., 2.5 GHz or 3.5 GHz), provides wide-area coverage for the gNodeB (gNB), while band #2, deployed at higher mid-band frequencies (e.g., 4.7 GHz or 6 GHz), provides limited geographic coverage. Full-duplex cooperative devices are crucial for this operation.

[0085] Figure 7 This is a schematic diagram (700) illustrating an example of a full-duplex device-to-device communication system. It demonstrates cooperative MIMO or cooperative communication between a gNB, a user equipment (UE), and a cooperating device (CD). The gNB is deployed to serve the UE, such as smart glasses or similar low-capability devices. The system further introduces a CD with enhanced operational capabilities compared to the UE. The CD can assist in data transmission between the gNB and the UE, thereby improving downlink or uplink performance.

[0086] For example, in a MIMO transmission scheme, a gNB can transmit multiple signal streams, one directed to the UE and the other to the CD. Since both signal streams carry data directed to the UE, upon receiving its designated signal stream, the CD performs an amplified and forwarded (A&F) operation with frequency conversion, switching the signal from a first frequency band (e.g., band #1) to a second frequency band (e.g., band #2), and then relays the processed signal to the UE. Therefore, the UE receives two different signal streams: one directly from the gNB on band #1, and the other via the CD on band #2.

[0087] This cooperative transmission mechanism effectively enhances the spatial or multiple-input multiple-output (MIMO) dimension compared to the non-cooperative scenario where only the UE is connected to the base station (gNB). In this standalone configuration, the base station can send a single MIMO stream or layer to the UE. However, by introducing a cooperative device (CD), the system can utilize multiple transport layers (e.g., two layers).

[0088] The CD's full-duplex capability enables simultaneous reception on band #1 and simultaneous transmission on band #2, effectively achieving in-band multicarrier operation. Without full-duplex capability, the system would be unable to maintain a continuous data stream from the base station to the UE simultaneously via both direct and relay paths. Full-duplex operation of the CD must strictly adhere to delay constraints, specifically controlling the processing delay to below the cyclic prefix duration to ensure normal signal reception at the UE.

[0089] The amplified forwarding operation performed by the CD involves receiving the signal on band #1, performing necessary signal processing (including frequency conversion to band #2), and forwarding the signal to the UE. This operation differs from the decode-forward method because the CD does not decode the data to the bit level, but processes the signal at the symbol level, thus achieving lower latency operation. The frequency conversion between band #1 and band #2 enables the UE to receive multiple MIMO streams, although its antenna capabilities are limited, because these streams arrive at orthogonal frequency resources, rather than requiring spatial separation.

[0090] Figure 8 The diagram 800 illustrates a full-duplex downlink scenario where a base station performs reception (Rx) or transmission (Tx) on a specific frequency resource. Figure 9 The diagram 900 illustrates a scenario where a base station performs non-full-duplex downlink (Rx or Tx) on specific frequency resources. Figure 10 Schematic diagram 1000 illustrates a scenario where a base station performs non-full-duplex uplink (Rx or Tx) on specific frequency resources. Figure 11 The diagram 1100 illustrates a scenario where a base station performs full-duplex uplink (Rx or Tx) on specific frequency resources.

[0091] like Figures 8-11 As shown, each frequency resource can be divided into multiple frequency bands (sometimes simply referred to as frequency resources in this specification). For example, each frequency resource may include an upper section (also referred to as the blue band or blue resource in this specification), a middle section (also referred to as the orange band or orange resource), and a lower section.

[0092] For downlink W1 & W2 paths combined with intra-PAN inter-UE carrier cross-link interference (CLI), Figure 8 and Figure 9 In the two downlink scenarios shown, the base station performs Rx or Tx on the orange resources.

[0093] Similarly, for the uplink W1 & W2 paths combined with intra-PAN inter-UE carrier CLI, in Figure 10 and Figure 11 In the two uplink scenarios shown, the base station performs Rx or Tx on the orange resources.

[0094] In the downlink scenario, the base station can transmit two data streams, denoted as W1 and W2, using different frequency segments. These segments can correspond to different carriers or different sub-frequency bands within the same carrier, referred to as frequency band #1 and frequency band #2, respectively. In this configuration, W2 is transmitted directly to the UE on frequency band #1, while W1 is transmitted to the CD on frequency band #1. The CD then converts the signal from frequency band #1 to frequency band #2 and relays it to the UE.

[0095] This cooperative transmission scheme introduces potential interference, including co-channel interference (CCI) occurring within the same frequency band and CLI occurring between different frequency bands.

[0096] When a base station has full-duplex capability, it can transmit simultaneously on one frequency band and receive simultaneously on another. Conversely, if a base station does not have full-duplex capability, it can only transmit or receive at any given time.

[0097] In operational scenarios where the base station is configured to receive transmissions from other UEs (e.g., UE') on frequency band #2, simultaneous relay transmission from the CD to the target UE may cause interference to the base station (i.e., CCI). Furthermore, signal leakage from the CD's transmissions on frequency band #2 to frequency band #1 may adversely affect the UE (i.e., CLI). Specifically, when the UE receives its desired signal from the CD on frequency band #2, such leakage may degrade the reception quality of signals transmitted by the base station on frequency band #1.

[0098] In this configuration, additional interference may occur from external UEs (e.g., UE') operating outside the personal network. When an external UE transmits to the base station, its uplink transmission may interfere with the downlink reception of the target UE within the personal network (i.e., CLI). Furthermore, under operating conditions where the base station lacks full-duplex capability and is in a transmitting state, another set of interference scenarios may occur between base station transmissions and other concurrent network operations.

[0099] In this specification, the main technical objective focuses on optimizing transmission from the base station to the UE and CD, with the UE as the final destination. That is, the CD only acts as a relay node. Simultaneously, the system introduces an interference suppression mechanism, primarily focusing on minimizing CLI and CCI interference.

[0100] This specification also optimizes precoding techniques to enhance received signals and reduce interference. These precoding techniques can be applied to both downlink and uplink scenarios. In uplink operation mode, the UE transmits via dual communication paths: one transmission stream is sent directly to the base station on frequency band #1, and the other stream is sent via CD using frequency band #2. The CD converts the stream from frequency band #2 to frequency band #1 before forwarding it to the base station. This uplink configuration introduces additional interference issues similar to those in the downlink scenario.

[0101] The technical challenges of in-band multicarrier operation include the design and reporting of precoders and channel state information (CSI), measurement of CLI and CCI, and management of inter-carrier and intra-carrier CLI. These involve the custom design of combined CSI signaling, robust CLI receivers, CLI detection and reporting, and precoding matrix indicator (PMI) recommendation mechanisms, all based on the measurement and feedback of channel state information reference signals (CSI-RS) in downlink scenarios. The technical challenges of in-band multicarrier operation also include CCI management.

[0102] This specification relates to a CSI and PMI signaling framework based on UE measurement and feedback. The current specification lacks support for full-duplex cooperative devices, which could be beneficial. For both downlink scenarios, a CSI reporting mechanism for the UE based on CSI-RS measurements is required. This mechanism can benefit CD and facilitates CLI management for both the target UE and co-scheduled UEs.

[0103] Specifically, for downlink scenarios only, the CSI and PMI signaling frameworks propose operation and signaling methods in the absence of CLI, applicable to both full-duplex and non-full-duplex base stations. For example, Scheme 1 involves operation and signaling without a precoder at the CD (i.e., ,in (This is an identity matrix). Scheme 2 involves a pre-encoder at the CD location. The operation and signaling, as well as UE measurements / feedback, are reported as a whole to the base station (Option 1.a). Scheme 3 involves a pre-encoder at the CD location. Operations and signaling, as well as UE measurements / feedback, are reported to the base station and CD (option 1.b), respectively.

[0104] In these schemes, features include user equipment (UE) measuring channel state information reference signals (CSI-RS) on different frequency bands to obtain estimates of 1) the direct channel (H2) and 2) the concatenated channel (Hs·H1), which can be either CD-uncoded or CD-precoded depending on the precoder's cyclic operation. Furthermore, the UE can provide feedback to the base station (gNB) based on the extended channel matrix obtained from the direct channel and the (CD-precoded) concatenated channel, including a rank indicator (RI), a precoding matrix indicator (PMI), a channel quality indicator (CQI), and CD precoder information. Additionally, the UE measures demodulation reference signals (DM-RS) on both frequency bands to obtain estimates of 1) the precoded direct channel and 2) the gNB-precoded (and CD-precoded) concatenated channel.

[0105] Similarly, for downlink scenarios only, the Channel State Information (CSI) and PMI signaling frameworks also propose certain operational and signaling methods in the presence of Cross-Link Interference (CLI). In these schemes, full-duplex and non-full-duplex gNBs follow similar principles, but differ slightly due to the different CLI sources. Specifically, Scheme 4 involves operation and signaling without a precoder at the CD. Scheme 5 involves operation and signaling with a precoder at the CD, and UE measurement / feedback (for downlink scenarios) or feedback to the UE (for uplink scenarios) – reporting as a whole to the gNB (for downlink scenarios) or to the UE (for uplink scenarios). Scheme 6 involves operation and signaling with a precoder at the CD, and UE measurement / feedback (for downlink scenarios) or feedback to the UE (for uplink scenarios) – reporting separately to the gNB and CD (for downlink scenarios) or to the UE and CD (for uplink scenarios). Scheme 7 re-examines Schemes 4-6, specifically for in-band intra-cell CLI in non-full-duplex gNBs. The main ideas in these schemes include extending schemes 1-3 to employ CLI robust receivers during RI / PMI / CQI feedback and data demodulation at the target UE, and enabling co-scheduled UEs to measure CD-precoded CSI-RS and report recommended precoders.

[0106] The types of interference considered in these schemes include: (1) inter-carrier intra-cell CLI ( This indicates that the transmission of CD on frequency band #2 is leaked to the reception of UE on frequency band #1, where It receives the signal at the CD. Pre-encoder Frequency offset and modulation scheme functions; (2) intra-carrier intra-cell CLI ( ), which indicates interference from another UE (UE') to the target UE on the same frequency band; and (3) co-channel interference (CCI) ( This occurs when the gNB transmits on frequency band #2 in a non-full-duplex scenario, interfering with the transmission from CD to UE on frequency band #2.

[0107] The precoder selection process involves optimizing three different precoders: Used for the link from gNB to CD in frequency band #1. For direct link from gNB to UE on frequency band #1, and This is used for the link from CD to UE on frequency band #2. The effective received signal at the UE can be represented as: ,in and These represent the received signals in frequency band #1 and frequency band #2, respectively. It is the channel from gNB to CD. It is the direct channel from gNB to UE. It is the channel from CD to UE.

[0108] In the precoder loop operation mentioned in Schemes 2 and 3, CD is used cyclically from a predefined codebook. Candidate preencoders For each pre-encoder The CD applies it to the received CSI-RS and transmits a pre-coded signal to the UE on frequency band #2. The UE measures all... A number of pre-coded CSI-RS instances were selected, and the optimal precoder was chosen. This is to maximize overall system performance while taking into account desired signal strength and interference levels.

[0109] Figure 12 Figure 1200 illustrates a downlink full-duplex gNB scenario. Figure 13 Figure 1300 illustrates a communication system in a downlink full-duplex gNB scenario.

[0110] In this scenario, the gNB transmits reference signals to the UE via two different paths, specifically CSI-RS. The direct path involves the gNB directly transmitting CSI-RS to the UE on frequency band #1, denoted as... The UE will use this CSI-RS to measure the channel between the gNB and the UE. The indirect path involves the gNB sending a CSI-RS to the CD on frequency band #1. Before forwarding the signal to the UE, the CD performs frequency conversion from frequency band #1 to frequency band #2. The UE uses this frequency-converted CSI-RS to measure the cascaded channel response. During data transmission, different data streams may be required, i.e., different layers in MIMO. However, there is no need to provide different CSI-RS. The CSI-RS is merely a reference signal broadcast by the gNB and is not pre-coded.

[0111] like Figure 12 As shown, signals W1 and W2 are spatially multiplexed on the same frequency in the MIMO transmission scheme. However, due to the limited number of UE receiving antennas, the system operates in a manner similar to multi-user MIMO. Specifically, the UE directly receives W2, while the CD receives W1. The CD then performs frequency conversion on W1 and forwards it to the UE.

[0112] Given the limited number of antennas on the user equipment (UE) compared to the base station (gNB), the UE cannot simultaneously receive W1 and W2 on the same frequency band. It is worth noting that if the UE were equipped with a sufficient number of antennas, it could receive both signals together.

[0113] The UE uses this signal to measure the aggregation channel response, covering the link from the base station to the cooperating device (CD) (denoted as H1) and the link from the CD to the UE (denoted as Hs). Therefore, the UE receives two instances of the same CSI-RS, one in the original frequency band (direct path, blue band) and the other in the converted frequency band (indirect path, orange band). Accordingly, the UE needs to perform two measurements, one on the direct channel and the other on the aggregation channel (i.e., the concatenated channel). Furthermore, the system may have two precoders, one reaching the UE directly through this channel and the other via the CD. The UE can then provide CSI feedback reports to the base station, such as the precoding matrix indicator (PMI) and the rank indicator (RI). The same CSI-RS can be transmitted by the base station on the initial frequency band. The relevant parameters can be obtained using the following formula.

[0114] Transmissions by the base station on frequency band #1 resource: Used for multi-user multiple-input multiple-output (mu-mimo) mode. in It is a multicast message that encodes only one message W1 or multiple messages (e.g., W1 and W2).

[0115] Spatial Time-Division Block Coding (STBC) for W1 and W2.

[0116] CD reception: .

[0117] UE receives: in .

[0118] - If there is zero delay, frequency conversion is easier, therefore there is no Analog domain processing is applicable to FR2, but may not be applicable to FR1. It is cross-link interference (CLI) from UE' to UE. .

[0119] .

[0120] The system operates in an efficient point-to-point multiple-input multiple-output (MIMO) configuration. The UE observes the received signal vector. This vector contains signals from frequency band #1 and frequency band #2 to determine the transmitted data stream. For multi-user MIMO coding, the system needs to locate the transmitted symbols. For multicast scenarios, it is necessary to determine the multicast message. .

[0121] System performance is affected by several design variables, specifically the pre-encoder. , , and Precoder and These are conventional precoders, applied to the data streams sent by the base station to the CD and directly to the UE, respectively. The precoder at the CD... Effective MIMO channels are affected by shaping the cascaded channel response from the base station through the CD to the UE. The presence of cross-link interference (CLI) increases the effective noise in the system and degrades overall performance.

[0122] In the formula, self-interference (SI) is ignored, and CLI from CD to UE and CLI from UE' to UE are considered, while interference from the base station is ignored. To UE Co-channel interference (CCI).

[0123] Because CSI-RS is not precoded and beamformed, it can be used for multiple measurements. Despite using the same reference signal, the frequency-offset versions will experience different channel responses due to relay operations. Therefore, the UE utilizes these different received CSI-RS instances for independent channel measurements—one for the direct link from the base station to the UE, and another for the aggregated link from the base station to the UE via CD.

[0124] In this disclosure, design and reporting , and The framework for the signaling between the UE and the base station, as well as the related RI and PMI feedback, follows the formula below.

[0125] The choice will affect the band #2 and band #1 resources at the UE, and and The choice depends on / with The selective coupling therefore requires computation. , and Based on overall performance across two resources .

[0126] .

[0127] For this part, ignore. And it is assumed to be Gaussian noise, therefore we focus on item.

[0128] This framework proposes several options for precoder selection and reporting between the UE and the base station (gNB). The first option, called Option 0 and corresponding to Scheme 1, involves selecting the precoder... Set as identity matrix This means that pre-coding is not performed at the CD (CD-based) device. This approach simplifies the system by eliminating the need for pre-encoder selection at the CD.

[0129] When you need to select the precoder on the CD Option 1 employs a UE measurement and feedback mechanism. This option has two different reporting methods. Option 1.a, corresponding to Scheme 2, adopts a centralized reporting strategy, where the UE directly reports all measurement results and precoder recommendations to the base station (gNB), and the base station subsequently notifies the CD of the selected precoder via downlink control signaling. Option 1.b, corresponding to Scheme 3, adopts a distributed reporting method, where the UE reports to both the base station (gNB) and the CD. Under this configuration, the UE will recommend the precoder... and The report is sent to the base station (gNB), and the selected CD precoder index is also reported directly to the CD, which requires establishing a direct communication channel between the UE and the CD.

[0130] In scheme 1 (option 0), CD is not pre-encoded. ,in (This is an identity matrix). The base station (gNB) transmits Channel State Information Reference Signal (CSI-RS) on frequency band #1, which the UE directly receives to measure the channel. Simultaneously, the CD receives the same CSI-RS, performs frequency conversion to band #2, and forwards it to the UE. The UE measures the cascaded channel through the frequency-converted signal. Based on these measurements, the UE calculates and reports to the base station (gNB) for pre-coding. and The precoded matrix indicator (PMI) and rank indicator (RI).

[0131] In scheme 2 (option 1.a), CD performs precoding and employs centralized reporting. CD iterates through the predefined codebook. Candidate preencoders For each pre-encoder The CD applies it to the received CSI-RS and transmits the pre-coded signal to the UE on frequency band #2. The UE measures all... A number of pre-coded CSI-RS instances were selected, and the optimal precoder that maximized system performance was chosen. The UE will index the selected precoder. and recommended pre-encoders and The report is sent to the base station (gNB). The base station then sends a downlink indication to the CD, specifying which precoder to use. .

[0132] In Option 3 (Option 1.b), the system operates similarly to Option 2, but uses distributed reporting. The UE will recommend the precoder. and Report to the base station (gNB) and simultaneously index the selected precoder. Report directly to the CD. This method requires establishing a direct communication channel between the UE and the CD, which may be more complex than the centralized reporting method in Scheme 2.

[0133] Precoder cyclic operation can be optimized to reduce overhead. The base station (gNB) does not need to transmit CSI-RS. The CD can store the first received CSI-RS, and then apply different precoders and... Re-upload of resources This approach significantly reduces signaling overhead on the base station-to-CD link while maintaining the ability to evaluate multiple precoding options.

[0134] Figure 14 Figure 1400 illustrates the communication process between the base station (gNB), CD, and UE, corresponding to Scheme 1. Scheme 1 involves a scenario where the CD has no precoder, and its related calculations follow the formula below.

[0135] Option 0 - P=I

[0136] CSI-RS is used for measurement. and .

[0137] Selected and Based on CSI-RS and the estimated covariance matrix Then report it to gNB.

[0138] The receiver design is similar to the Y1 robust receiver.

[0139] Depend on and Both the DM-RS precoding and the robust receiver are based on The estimated covariance matrix.

[0140] In Scheme 1, since CD does not perform precoding during operation ( The system complexity is reduced because the CD does not require precoder selection. The gNB transmits CSI-RS, which the UE receives through two paths: one is direct reception on frequency band #1 for measurement. The other method involves frequency conversion to band #2 via CD to measure the cascaded channel. Based on these measurements and the estimated interference covariance matrix, the UE determines the optimal precoder. and And report to gNB via PMI and RI feedback.

[0141] Scheme 1's simplicity makes it particularly suitable for scenarios where minimizing latency and implementation complexity at the CD is critical. Since the CD only performs an amplified forwarding operation with frequency conversion and does not perform precoding, processing latency can be kept well below the cyclic prefix duration. This method serves as a baseline for comparison with more complex schemes that include CD precoding.

[0142] Figure 15Figure 1500 illustrates the communication process between the gNB, CD, and UE, corresponding to scheme 2. It shows option 1.a: all reports are sent to the gNB. In this scheme, the precoder is selected at the CD. To optimize the cascaded channel, the gNB transmits CSI-RS on band #1, which can be received by both the UE (directly) and the CD. The CD will precode the... The CSI-RS received from the gNB is frequency-converted (from band #1 to band #2) and forwarded to the UE. This enables the optimization of the effective MIMO channel. This can reduce interference.

[0143] The CD loop traversal includes Codebooks of candidate precoders For each pre-encoder The CD applies it to the CSI-RS received from the gNB and transmits the precoded and frequency-converted signal to the UE on band #2. The UE measures all [signals / data] on band #2. Each precoded CSI-RS instance is used to evaluate the cascaded channel response for each precoder. Based on these measurements and direct channel measurements from band #1. The UE determines and reports to the gNB: 1) the optimal precoder for the gNB-CD link. 2) Optimal precoder for the direct link from gNB to UE , and 3) Indicate which precoder should be used for the CD. Preferred precoder index .

[0144] The precoder used by a CD can be digital or analog. Analog precoders are simpler, applying different weights only at the antenna, but are more challenging in minimizing latency. For digital processing, the CD needs to decode the CSI-RS to the digital domain (not bits, but symbols), apply the precoder, and then retransmit the CSI-RS.

[0145] Regardless of whether the precoder is implemented digitally or analog, the UE will measure the signal received on band #2. The channel quality of each precoded CSI-RS instance. Although the CSI-RS transmitted by the gNB is the same, the signals received by the UE are different because different precoders are applied to the CD. The UE comprehensively considers the direct channel on band #1 and the cascaded channel on band #2 to evaluate the overall system performance, and then determines which index in the precoder sequence. To maximize effective channel capacity, select the optimal precoder. .

[0146] For P1 and P2, the selection of these precoders can be determined because the UE is measuring the channel. The UE then feeds this information directly back to the gNB, which in turn instructs the CD to use which precoder P. This method is simpler and more practical because it eliminates the need to establish a communication link (such as a dedicated control channel) between the UE and the CD.

[0147] The UE performs joint optimization when selecting the precoder because the precoder at CD... The choice of frequency band #1 and frequency band #2 will affect the performance. The effective received signal at the UE can be represented as: ,in and These represent the received signals in frequency band #1 and frequency band #2, respectively. The UE must calculate based on the overall performance across both frequency bands. , and .

[0148] Upon receiving CSI feedback from the UE, the gNB sends a downlink control signal to the CD, instructing the selected precoder. This requires adding a downlink field to the control signaling, such as in the Physical Downlink Control Channel (PDCCH). The gNB then uses the reported precoder. and To perform actual data transmission, among which Applied to data streams transmitted via CD relay ,and Data streams applied to direct transmission to the UE .

[0149] To reduce signaling overhead, the implementation is optimized to allow the cooperating device (CD) to store the CSI-RS received in a single operation, instead of requiring the base station (gNB) to transmit CSI-RS for precoder cyclic operation. Next. CD will then A different precoder is applied to the stored signal, and the precoded versions are sequentially transmitted to the user equipment (UE). This method significantly reduces the overhead on the gNB-CD link while maintaining the ability to evaluate all precoding options.

[0150] Figure 16 Diagram 1600 illustrates the communication process between the gNB, CD, and UE, corresponding to scheme 3. It shows option 1.b: reporting to both the gNB and CD respectively.

[0151] like Figure 15 and Figure 16As shown, in option 1.a, the UE reports all measurement results directly to the gNB without communicating with the CD, while in option 1.b, the UE sends reports to both the gNB and the CD.

[0152] The underlying processes for both options remain consistent, except for the reporting mechanism. Option 3 introduces direct UE-CD reporting, which increases complexity.

[0153] Precoder looping may require selecting a suitable precoder. One method for implementing precoder looping is to store the received CSI-RS during the initial transmission on a CD, and then... In terms of resources Secondary precoding and transmission, instead of requiring the gNB to transmit CSI-RS Next. Specifically, regarding CSI-RS transmission on the path (gNB to CD, first part of the cascaded channel): No need to repeat the same reference signal This only requires one transmission. The CD can then cycle through different precoders and retransmit the signal multiple times, significantly reducing overhead. That is, band #1 (i.e. The path requires only one transmission, while band #2 (CD to UE precoded CSI-RS, i.e.) The path (the second part of the cascaded channel) then needs The next transmission is used for channel estimation. The precoder can be selected based on CSI-RS and the covariance matrix.

[0154] Schemes 1-3 do not consider the direct path of CD transmission on the gNB (i.e. Cross-link interference (CLI, denoted as) caused on the path) In contrast, options 4, 5, and 6 consider CLI. The main difference between options 1-3 and options 4-6 is that the latter extends the CLI robust receiver framework at the target UE during RI / PMI / CQI feedback and data demodulation. With CLI present, the UE needs to select a precoder... and At this time, the CLI effect is considered through the estimated interference and noise covariance matrix. This changes the precoder selection criteria and receiver design.

[0155] In Option 1.b (Scheme 3), a direct communication channel is established between the UE and the CD, introducing additional complexity compared to Option 1.a. Option 1.a only requires adding a downlink field to the control signaling (such as PDCCH), with the gNB informing the CD which precoder to use, while Option 1.b requires a separate control channel architecture between the UE and the CD. This architectural difference makes Option 1.a more suitable for initial deployment.

[0156] The precoder selection process in schemes 2 and 3 includes the UE selecting each candidate precoder. Measuring the effective channel matrix ,in The UE evaluates the overall system performance, taking into account both direct channels in band #1 and cascaded channels in band #2. The selection criteria consider CD. Choice and gNB and When choosing the coupling relationship between options, maximize the effective channel capacity.

[0157] When CLI is considered in schemes 4-6, the effective received signal model includes an interference term. ,in It receives the signal at the CD. Pre-encoder Frequency offset And the function of the modulation scheme. For pre-encoder The nonlinear dependence of the precoder significantly increases the complexity of the precoder optimization problem, because the level of disturbance varies with the choice of precoder.

[0158] Figure 17 Diagram 1700 illustrates intra-carrier CLI. The calculation can be performed following the procedure below.

[0159] The system implements a CLI-robust PMI recommendation mechanism within the cooperative MIMO framework to manage interference. This mechanism enables the UE to provide precoder recommendations, striking a balance between maximizing desired signal strength and minimizing cross-link interference.

[0160] During the PMI recommendation process, UE recommends that CD use a specific PMI for the precoder. To prevent high cross-link interference in frequency band #1 This recommendation aims to minimize the interference leakage from CD transmissions in band #2 to the UE's reception of direct gNB signals in band #1. Simultaneously, the UE must report Channel State Information (CSI) to the CD in order to calculate the precoder. The goal is to achieve a high channel quality indicator (CQI) on band #2. This dual requirement presents an optimization challenge, as the UE must balance achieving strong signal reception via the band #2 cascaded path with minimizing interference on band #1.

[0161] The choice affects the UE's resources on band #2 and band #1, and and The choice depends on and is coupled with The choice. Therefore, , and Must be based on two types of resources The overall performance is calculated.

[0162] .

[0163] The system needs to address the impact of CLI (Cross-Link Interference). The challenge lies in yes and The function, therefore also , and The function.

[0164] Considering interference and noise terms At that time, it is necessary to , and The pre-encoder calculations were modified.

[0165] The system needs to re-examine options 0, 1.a, and 1.b in order to... Consider CLI item .

[0166] item This indicates interference caused by the transmission leakage of CD in frequency band #2 to the reception of UE in frequency band #1. This interference is the received signal at CD. Precoder applied to CD Frequency offset between frequency band #1 and frequency band #2 And the nonlinear function of the modulation scheme used. right The nonlinear dependence of the precoder significantly increases the complexity of the precoder optimization problem, because the level of disturbance changes dynamically with the choice of precoder.

[0167] This CLI management is particularly critical in full-duplex cooperative device scenarios because the CD simultaneously receives signals from the gNB on band #1 and transmits signals to the UE on band #2. Without proper CLI management through optimized precoder selection, signal leakage from band #2 to band #1 can severely degrade the quality of direct transmission from the gNB to the UE on band #1, potentially negating the advantages of cooperative MIMO schemes.

[0168] The CLI robust PMI recommendation mechanism forms a key component of schemes 4, 5, and 6, which extend the basic schemes (schemes 1, 2, and 3) to explicitly consider interference effects. In these enhanced schemes, the UE's precoder selection criteria must balance two competing objectives: [the need for] cascading paths on band #2. Maximize the desired signal strength while minimizing CLI that affects reception in band #1. This multi-objective optimization requires the UE to evaluate the overall system performance across two frequency bands when recommending a precoder.

[0169] Figure 18 This is a diagram (1800) illustrating the communication process between the gNB, CD, and UE, corresponding to Scheme 4. It re-examines Scheme 1 but takes into account the presence of CLI. The process can be followed as follows.

[0170] Option 0 with CLI .

[0171] because Uncontrollable .

[0172] The selected and Based on CSI-RS and The estimated covariance matrix is ​​then reported to gNB.

[0173] The receiver design is similar to the Y1 robust receiver.

[0174] Depend on and Both the DM-RS precoding and the robust receiver are based on The estimated covariance matrix.

[0175] CSI Feedback (PMI and RI) The report was submitted to the gNB, and the selected content was based on CSI-RS and The estimated covariance matrix.

[0176] Both are used to detect transmitted messages. The robust receiver (Robust Rx) is based on the estimated covariance matrix of noise and interference. .

[0177] Option 4 extends Option 1 by introducing CLI-aware processing throughout the system. Option 1 assumes negligible interference and focuses only on maximizing the desired signal strength, while Option 4 explicitly considers cross-link interference (CLI) leaked from CD's transmission in band #2 to the UE's reception in band #1. The interference is from the CD receiver signal. The nonlinearity of the function makes the optimization problem more complex.

[0178] The CLI robust receiver design in Scheme 4 utilizes the estimated covariance matrix of the noise and interference terms to perform interference rejection combining (IRC) or similar techniques. This enables the UE to suppress CLI while demodulating the desired signal. For and The precoder selection criteria have been modified to strike a balance between maximizing desired signal power and minimizing interference levels, thereby achieving more robust system performance in the presence of CLI.

[0179] Since CD is not pre-encoded in this scheme ( The system cannot optimize the active control CLI via the CD precoder. However, the gNB precoder... and It can still be optimized to minimize overall interference while maintaining good signal quality for both the direct path (band #1) and the cascaded path (band #2). This simplified approach serves as a baseline comparison with Schemes 5 and 6, which introduce CD precoding to enhance CLI management capabilities.

[0180] Figure 19 This is a diagram (1900) illustrating the communication process between the gNB, CD, and UE, corresponding to Scheme 5. It re-examines Scheme 2 but takes into account the presence of CLI. The process can be followed as follows.

[0181] Option 1.a includes CLI and The selection is based on CSI-RS and the estimated covariance matrix. Then report it to gNB.

[0182] The receiver design is similar to the Y1 robust receiver.

[0183] Depend on and Both the DM-RS precoding and the robust receiver are based on the estimated covariance matrix. .

[0184] P to be selected – Option 1: UE measurement and feedback

[0185] CSI feedback to gNB: UE based on CSI-RS and the estimated covariance matrix Joint decision on the best option (and report the corresponding index) and [ (Or decide P first, then decide [) Therefore, the PMI for P. Feedback, and regarding [ The PMI feedback.

[0186] Selected Downlink instruction sent to CD

[0187] Both are used to detect transmitted messages. The robust receiver is based on the estimated covariance matrix. .

[0188] Option 5 extends Option 2 by introducing CLI-aware processing throughout the system. The CD selects from a predefined codebook in a cyclic manner. Candidate preencoders Before frequency conversion and transmission to the UE in band #2, each CSI-RS applied to the receiver is used. The UE measures all [interference covariance matrix]. A pre-encoded CSI-RS instance, implementing a CD pre-encoder. With gNB precoder and Joint optimization in the presence of CLI.

[0189] Precoder , and The selection is based on the covariance matrix of CSI-RS measurements and noise versus interference. The covariance matrix for CSI feedback is... , and The function. For Dependencies can be achieved through CSI-RS is used for measurement, but for and The dependence is difficult to determine because of the nonlinear function. It is unknown. This interdependence significantly increases the complexity of the precoder optimization problem.

[0190] To fully capture the impact of all precoders on the noise and interference covariance matrix, a hierarchical precoder iterative method can be used: First, iterate through the layers... [ The codebook of the precoder; secondly, for each given pair of precoders... ], loop through Precoder The codebook; third, measure all A pre-coded CSI-RS instance is used, and based on the CSI-RS measurement results and the noise and interference covariance matrix, the one that maximizes performance is selected. ]and This method allows the covariance matrix to be measured as a function of the precoder applied in the codebook. However, its drawback is increased latency due to the need for transmission and measurement. Pre-coded CSI-RS transmission.

[0191] Another method involves transmission Precoded CSI-RS: When transmitting [ When pre-encoded CSI-RS, only one precoder is used. When transmitting CSI-RS loop traversal At that time, only one precoder is used for [ Although this method cannot capture [ ]and It uses the full combination of pre-encoders, but significantly reduces CSI-RS transmission time compared to the layered approach.

[0192] Figure 20 Diagram 2000 illustrates the communication process between the gNB, CD, and UE, corresponding to Scheme 6. It re-examines Scheme 3 but takes into account the presence of CLI. The process can be followed as follows.

[0193] Option 1.b with CLI

[0194] Selected and Based on CSI-RS and the estimated covariance matrix Then report it to gNB.

[0195] The receiver design is similar to the Y1 robust receiver.

[0196] Depend on and Both the DM-RS precoding and the robust receiver are based on the estimated covariance matrix. .

[0197] P to be selected – Option 1: UE measurement and feedback

[0198] Feedback to gNB's CSI: UEs jointly decide on the preferred option. and[ (or decide first) Then decide [ ]), and select [ Report to gNB.

[0199] Feedback to CD's CSI: UEs jointly decide on the preferred option. and[ (or decide first) Then decide [ ]), and the selected Report to CD.

[0200] Both are used to detect transmitted messages. The robust receiver is based on the estimated covariance matrix. .

[0201] Option 1.b requires establishing a connection between the CD and the UE. This may be more difficult than adding a downlink field for the gNB to notify the CD, as in option 1.a.

[0202] Solution 6 extends Solution 3 by introducing CLI-aware processing into the system, while maintaining the distributed reporting architecture. Similar to Solution 5, CD loops through the predefined codebook. Candidate precoder Before frequency conversion and transmission to the UE in band #2, each CSI-RS applied to the received data is processed. However, unlike Scheme 5, which uses centralized reporting via gNB, Scheme 6 maintains a distributed reporting structure, whereby the UE submits the selected precoder... and Report to gNB, and simultaneously select the preferred precoder index. Report directly to the CD.

[0203] Scheme 6 requires the UE to jointly optimize all three precoders in the CLI-aware precoder selection process. , and The interference covariance matrix is ​​also considered. This optimization problem is significantly more complex than Scheme 3 because of the interference term. It is a pre-encoder The nonlinear function requires the UE to evaluate each candidate precoder for the cascaded path. The desired signal strength and the impact of interference levels in band #1 are considered. This joint optimization ensures that the selected precoder maximizes overall system performance across both bands while minimizing the adverse effects of CLI.

[0204] While the distributed reporting architecture in Scheme 6 increases implementation complexity due to the required UE-CD communication channel, it offers potential advantages in reducing CD precoder update latency and gNB-CD link signaling overhead. However, in practical deployments, especially in mobile scenarios, the challenge of establishing and maintaining a reliable control channel between the UE and CD may make the centralized reporting approach in Scheme 5 more suitable for initial deployments. Ultimately, the choice between Scheme 5 and Scheme 6 depends on the specific deployment scenario and the relative importance of signaling efficiency versus implementation complexity.

[0205] Figure 21 Figure 2100 illustrates a downlink non-full-duplex gNB scenario. Figure 22 Figure 2200 illustrates a communication system in a downlink non-full-duplex gNB scenario. In this scenario, the relevant calculations follow the formulas below. In these formulas, SI is ignored, CLI is included, CCI across carriers from the gNB transmitter (TX) to the CD receiver (RX) and CCI across carriers from the gNB TX to the UE RX are ignored, and CCI within the carrier from the gNB TX to the UE RX is included.

[0206] In non-full-duplex gNB scenarios, the gNB lacks the ability to simultaneously transmit and receive on different frequency bands. Therefore, while the gNB transmits to the UE and CD on frequency band #1, it also transmits on frequency band #2 to serve other UEs in the network. This introduces a fourth precoder for gNB transmissions on frequency band #2. , recorded as .Signal This indicates that data sent to other UEs will cause co-channel interference (CCI) with CD-to-UE transmissions on band #2.

[0207] The main difference between full-duplex and non-full-duplex scenarios lies in the interference mode. Full-duplex scenarios experience cross-link interference (CLI) between UEs (i.e., UE's transmission to the gNB in ​​band #2), while non-full-duplex scenarios experience CCI transmitted by the gNB itself in band #2. This CCI is represented in the signal model by the term... This means that it directly affects the UE's reception of relay signals from the CD in frequency band #2.

[0208] At the gNB transmitter (TX) ; .

[0209] At the CD receiver (RX) .

[0210] At the UE receiver (RX) ,in ; .

[0211] .

[0212] At the UE's receiving end (RX) .

[0213] The system operates as an efficient point-to-point multiple-input multiple-output (MIMO) configuration, wherein the received signal vector The observed symbol is used to determine the transmitted symbol. The system design involves four precoding matrices, namely... , , and All of these significantly impact overall system performance. Among these precoders, , and It is a conventional precoder used in base stations (gNB), while As a pre-encoder at the cooperating device, it affects the effective MIMO channel characteristics.

[0214] In non-full-duplex base station (gNB) scenarios, the fourth pre-encoder The presence of this introduces additional complexity compared to the full-duplex scenario (denoted as (a.1)). Precoder Designed specifically for base station transmissions to other user equipment (UEs) in the network on frequency band #2, this design directly impacts the performance of the target UE due to the co-channel interference (CCI) it generates. Furthermore, both cross-link interference (CLI) and co-channel interference (CCI) contribute to an increase in the effective noise level experienced by the system.

[0215] MIMO system configuration requirements for the received signal vector Careful observation is required to accurately recover the transmitted signal vector. Four design variables , , and Optimization must be carried out in conjunction with other methods to achieve the best system performance. , and As a conventional precoder, it is responsible for shaping the transmitted signal at the base station, while the precoder at the cooperating equipment... It plays a unique role in determining the effective MIMO channel from the base station to the UE via the relay path. Compared to the baseline case (a.1), in this scenario, it is... The added complexity stems from the need to manage the interference environment resulting from simultaneous transmissions on band #2 while providing quality of service to multiple UEs. The combined effect of CLI and CCI significantly reduces signal quality by raising the system's effective noise floor.

[0216] In non-full-duplex scenarios, the fourth pre-encoder The existence of this introduces additional optimization complexity. In full-duplex scenarios, the precoder optimization problem involves three variables ( , , In non-full-duplex scenarios, four pre-encoders need to be jointly optimized. It must be designed to provide services to other UEs on band #2 while minimizing the CCI experienced by the target UE. This creates a multi-objective optimization problem, where the base station needs to balance the quality of service for multiple UEs across different frequency bands.

[0217] CCI term in the received signal model This represents a deterministic interference component, unlike the random interference from the UE' in a full-duplex scenario. This deterministic characteristic allows for more sophisticated interference management techniques because the base station can better manage the transmitted signals. Possessing complete knowledge and the potential to design This aims to minimize interference with the target UE while maintaining acceptable service quality for other UEs. However, this requires coordination of precoder designs for different UEs, significantly increasing the computational complexity of the base station.

[0218] This disclosure discloses the design and reporting between the UE and the base station. , , , The framework, and the associated rank indicator (RI) and precoded matrix indicator (PMI) feedback signaling.

[0219] The choice affects the frequency band #2 and frequency band #1 resources at the UE. and The choice depends on / with The choice of coupling therefore requires a basis across two resources. Overall performance calculation , and .

[0220]

[0221] For this section, ignore. And it is assumed to be Gaussian noise, therefore we focus on item.

[0222] The precoder selection framework provides several options for system implementation. In option 0 (corresponding to scheme 1), the cooperating devices do not perform precoding, i.e. ,in It is an identity matrix. Alternatively, when precoding is required at the cooperating device, the pre-encoder... Selection must be made through specific measurement and feedback mechanisms.

[0223] For scenarios requiring precoder selection at the cooperating device (CD), Solution 1 employs a User Equipment (UE) measurement and feedback process. This solution has two different reporting methods. Solution 1.a, corresponding to Solution 2, implements a centralized reporting mechanism, where all measurement results and precoder recommendations are reported to the gNodeB (gNB). In contrast, Solution 1.b, corresponding to Solution 3, uses a distributed reporting method, with feedback sent to both the gNB and the cooperating device (CD).

[0224] The framework for non-full-duplex scenarios remains consistent with that for full-duplex scenarios in terms of process. Schemes 1 to 3, which do not explicitly consider cross-link interference (CLI) during system operation, primarily focus on optimizing the desired signal path. Meanwhile, Schemes 4 to 6 extend these basic schemes by introducing cross-link interference sensing processing, enabling the system to achieve more robust performance when interference exists between frequency band #1 and frequency band #2 transmissions.

[0225] The difference lies in the interference model: in full-duplex scenarios, it is necessary to manage CLI signals from UE' to the target UE (represented as...). In non-full-duplex scenarios, co-channel interference (CCI) from gNB transmissions on band #2 needs to be managed. This difference affects precoder optimization criteria and robust receiver design, although the overall signaling framework and measurement procedures remain consistent in both scenarios.

[0226] Figure 23 Figure 2300 illustrates another communication process between the gNB, CD, and UE, corresponding to Scheme 1 in the downlink non-full-duplex gNB scenario. The relevant calculations can be performed using the following formula.

[0227] Option 0 -

[0228] CSI-RS is used for measurement. and

[0229] In Scheme 1, CD is not pre-encoded during operation. ,in (Using an identity matrix) simplifies system implementation while maintaining the advantages of cooperative MIMO. The gNB transmits CSI-RS, which the UE receives via two paths: direct reception on frequency band #1 for measurement. And frequency conversion to band #2 via CD for measuring cascaded channels. .

[0230] Based on these channel measurements, the UE calculates the optimal precoder transmitted by the gNB. and Precoder Applied to data streams via CD relay, and This is applied to the data stream sent directly to the UE. The UE reports these precoder recommendations to the gNB via PMI and RI feedback.

[0231] In non-full-duplex gNB scenarios, co-channel interference (CCI) must also be considered. The interference originates from gNB transmissions to other UEs on band #2. This CCI directly affects UE reception of signals from CD relays on band #2; therefore, precoder selection must take this interference into account using the estimated covariance matrix.

[0232] For scenarios requiring precoder selection at the CD (Scheme 2 and Scheme 3), the system employs a more complex approach. The CD performs a precoder cyclic operation, applying different precoders from a predefined codebook to the received CSI-RS before frequency conversion and transmission to the UE.

[0233] In scheme 2 (option 1.a), CD loop is applied. Candidate preencoders For each pre-encoder The CD applies it to the received CSI-RS and transmits the pre-coded signal to the UE on frequency band #2. The UE measures all... A number of pre-coded CSI-RS instances were selected, and the optimal precoder was chosen. To maximize system performance.

[0234] The UE will index the selected precoder. and recommended pre-encoders and The report is sent to the gNB. The gNB then sends a downlink instruction to the CD, specifying which precoder the CD should use. This centralized reporting method avoids the need for a direct control channel between the UE and the CD.

[0235] In Option 3 (Option 1.b), the system operates similarly, but uses distributed reporting. The UE will use the recommended precoder. and Report to gNB, and simultaneously index the selected precoder. Report directly to the CD. This method requires establishing a communication channel between the UE and the CD.

[0236] Based on the selected precoder UE constructs effective channel matrix Then select from the codebook and To optimize the overall system performance across band #1 and band #2, and to report these choices to the gNB.

[0237] Figure 24 Figure 2400 illustrates another communication flow between the gNB, CD, and UE, corresponding to Scheme 2. It shows option 1.a: All reports are sent to the gNB.

[0238] Figure 25 Figure 2500 illustrates another communication flow between the gNB, CD, and UE, corresponding to scheme 3. It shows option 1.b: reporting to both the gNB and CD respectively.

[0239] Figure 26 Figure 2600 illustrates the management of CLI within a cell between carriers.

[0240] In downlink control signaling (such as the Physical Downlink Control Channel (PDCCH)), the gNB may need to add a downlink field to indicate which precoder should be used at the CD.

[0241] Option 1.a can be adopted This type of CSI-RS is sent from the gNB but requires no buffering and operates without delay at the CD. This option can also be implemented via a single CSI-RS transmission from the gNB, assuming a buffer exists at the CD. The CSI-RS is stored before the phase is sent to the UE.

[0242] Can be based solely on or To carry out the design. yes The function, and in order to maximize rate performance, The design will be and The function. and For example, The optimal choice is ,in This refers to the power distribution applied to each data stream at the cooperating device (CD). If uniform power distribution is used at the CD, then... The optimal choice is It is still and Characteristic functions.

[0243] Pre-encoder at CD The design plays a crucial role in the overall system performance. When Based on channel and When using Singular Value Decomposition (SVD) for optimal design, it can effectively align the transmitted signal with the channel characteristic patterns, thereby maximizing the signal power transfer from the base station (gNB) through the CD to the user equipment (UE). This optimization must consider the coupling relationship between precoder selection, because... The choice will directly affect the effective channel matrix seen by the UE. .

[0244] In non-full-duplex base station (gNB) scenarios, the precoder design must also consider co-channel interference (CCI) caused by the base station's transmission on frequency band #2. This interference term differs from cross-link interference (CLI) from the UE in full-duplex scenarios; it is deterministic and known at the base station, and therefore can be detected by all four pre-encoders. , , and Coordinated design between them enables more complex interference management.

[0245] Managing inter-carrier intra-cell cross-link interference (CLI), denoted as This involves several key processes, primarily focusing on CLI robust precoding matrix indicator (PMI) recommendations and limitations.

[0246] Within the CLI robust PMI recommendation and constraint framework, the PMI recommendation process plays a crucial role. In this process, the User Equipment (UE) provides the cooperating equipment (CD) with information about the precoder. Recommendations for the selection of precoding matrix indicators. The main objective of these recommendations is to prevent high cross-link interference in band #1. At the same time, the UE must also report Channel State Information (CSI) to the CD so that the CD can correctly calculate the precoder. This allows for the acquisition of a high channel quality indicator (CQI) in band #2. This dual requirement presents an optimization challenge, as the system must balance minimizing interference in band #1 with maximizing signal quality in band #2.

[0247] The choice will affect the UE's resources on band #2 and band #1, and and The choice depends on / with The selective coupling therefore requires a basis across two resources. Calculate the overall performance , and .

[0248]

[0249] Need to deal with CLI The impact. The challenge lies in... yes and The function, therefore also , , The function.

[0250] If considering items ,but , , How will the calculation method change?

[0251] Options 0, 1.a, 1.b, 2.a, and 2.b need to be re-examined in order to... Consider CLI item .

[0252] Interference items For pre-encoder The nonlinear dependency of this leads to a complex optimization problem. This refers to inter-band transmission (IBE) caused by amplified forwarding operations with frequency conversion performed by a cooperating device (CD). This interference leaks from band #2 to band #1 and may degrade direct transmission performance from the base station (gNB) to the user equipment (UE). Optimization must jointly consider the desired signal enhancement achieved through cascaded paths and the minimization of cross-link interference (CLI) on the direct path.

[0253] In a non-full-duplex base station (gNB) scenario, the interference term during reception in frequency band #2 is determined by... (Interference from UE' in full-duplex mode) becomes (Co-channel interference from the gNB itself). The differences in interference sources necessitate different precoder selection optimization strategies, especially for the precoder. It must balance the needs of other UEs on the service band #2 with minimizing interference to the target UE.

[0254] In the PMI restriction mechanism, the affected UE recommends that the cooperating device (CD) avoid using certain restricted PMI values. The precoder at the CD... The choice of frequency band #2 and frequency band #1 has a significant impact on the UE's resources. This constraint method is similar in principle to the PMI recommendation mechanism, in that the UE provides guidance to optimize system performance and minimize interference.

[0255] CLI Robust Rank Recommendation and Constraint Process Based on Synthetic Signal Model Using this signal model, the UE calculates the rank indicator (RI), which takes into account both the desired signal component and the interference term. The calculated RI is then reported to the base station (gNB) to enable appropriate rank adaptation in the presence of cross-link interference and co-channel interference.

[0256] The framework also introduces a friendly PMI mechanism to provide additional coordination between devices, further optimizing precoding selection and minimizing interference in the network.

[0257] The CLI robust receiver design has been adopted as a core part of the aforementioned PMI recommendation process. Based on the estimated noise and interference covariance matrix, this receiver employs interference suppression combining techniques to effectively suppress cross-link interference on band #1 and co-channel interference on band #2, while preserving the desired signal components from both direct and cascaded transmission paths.

[0258] The CLI robust receiver design employs interference rejection combining (IRC) technology, utilizing the estimated covariance matrix of noise and interference terms. For non-full-duplex base station (gNB) scenarios, this covariance matrix must simultaneously consider the CLI terms on frequency band #1. CCI terms on band #2 The receiver is designed to suppress these interference components while preserving the desired signal components from both the direct path and the CD cascaded path.

[0259] For the non-full-duplex base station (gNB) scenarios proposed in schemes 4, 5, and 6, the framework maintains the same signaling flow as in the full-duplex case, but the optimization criteria are adjusted to adapt to different interference modes. The consistency of the signaling framework across different deployment scenarios simplifies implementation and allows for optimization of the precoding matrix for specific scenarios to maximize system performance under varying interference conditions.

[0260] Figure 27 Diagram 2700 illustrates another communication process between the base station (gNB), cooperating equipment (CD), and user equipment (UE), corresponding to Scheme 4 in a non-full-duplex base station (gNB) scenario. The process can be followed by the following steps: Option 0, including CLI

[0261] because Uncontrollable .

[0262] and The selection is based on CSI-RS and The estimated covariance matrix is ​​then reported to the base station (gNB).

[0263] The receiver design is similar to the Y1 robust receiver.

[0264] Depend on and DM-RS precoding and robust receiver based on The estimated covariance matrix.

[0265] In the non-full-duplex base station (gNB) scenario, Scheme 4 extends Scheme 1 by introducing CLI sensing processing, while maintaining the precoding-free simplified operation of CD. The main difference from the full-duplex scenario lies in the interference on frequency band #2: the system needs to handle co-channel interference transmitted by the base station (gNB) itself on frequency band #2. ), rather than managing interference from the UE's ( The CCI is deterministic and known to the base station (gNB), therefore it can be optimized by modifying the pre-encoder. , and possible (Used for base station (gNB) transmission in band #2) to achieve cooperative interference management.

[0266] In Scheme 4, the CLI robust receiver utilizes the estimated covariance matrix for interference suppression combining to suppress cross-link interference on band #1. and co-channel interference on band #2 .for and The selection criteria for the precoder must maximize the desired signal power while minimizing the impact of the two types of interference on both frequency bands.

[0267] Figure 28Figure 2800 illustrates another communication process between the gNB, CD, and UE, corresponding to Scheme 5 in a downlink non-full-duplex gNB scenario. The process can be followed by the following steps.

[0268] Option 1.a, includes CLI and The selection is based on CSI-RS and The estimated covariance matrix is ​​then reported to gNB.

[0269] The receiver design is similar to the Y1 robust receiver.

[0270] Depend on and DM-RS for precoding and robust receiver based on The estimated covariance matrix.

[0271] When it is necessary to determine through UE measurement and feedback During the precoder selection process (Option 1), the system faces a significant challenge in accurately capturing the interdependencies between different precoders. Precoder , and The selection of the precoder depends on the Channel State Information Reference Signal (CSI-RS) measurement and the estimated covariance matrix of noise and interference. This covariance matrix is ​​crucial for the selection of the optimal precoder, and it depends on all three precoders during CSI feedback. , and .

[0272] Although the covariance matrix is ​​important for the precoder Dependencies can be achieved through CSI-RS transmission direct measurement (where collaborative equipment is used cyclically) (multiple precoder candidates), but for the gNodeB precoder and The dependence remains difficult to determine. This difficulty stems from the nonlinear function. The unknown function describes the inter-band transmission characteristics of cross-link interference caused by transmission leakage from cooperating equipment in band #2 to reception by user equipment in band #1. This unknown nonlinear relationship between the precoder and the generated interference significantly increases the complexity of the optimization problem because the system cannot fully predict... and How will these changes affect the overall level of interference experienced by user devices?

[0273] To fully capture the impact of all pre-encoders on the noise and interference covariance matrix, the following can be done: , as well as A hierarchical precoder loop operation is adopted: 1) M [ ] The codebook of the precoder, 2) For a given precoder , Use N times in a cycle The codebook of the pre-encoder, 3) then measure all A pre-coded CSI-RS, and based on the CSI-RS and the noise and interference covariance matrix, a decision is made. , and The combination of these parameters maximizes performance. In this method, the covariance matrix varies with the precoder applied in the codebook, thus allowing measurement of the covariance matrix's impact on performance. , , The method suffers from increased latency due to the need for transmission and measurement. A pre-coded CSI-RS.

[0274] Another method is Precoded CSI-RS transmission: When transmitting M [ When pre-encoded CSI-RS, only one precoder is used. When transmitting N CSI-RS cycles At that time, only one precoder is used. This method is less effective than the aforementioned methods because it fails to capture […]. ]and It combines pre-encoders, but does reduce the time required for CSI-RS transmission.

[0275] In non-full-duplex gNB scenarios, Scheme 5 introduces additional complexity through CD precoding capabilities, while simultaneously managing the unique interference patterns of gNB transmissions on band #2. Precoder cyclic operation enables the UE to evaluate different CD precoders. How does it affect cascaded paths? The desired signal enhancement and interference level. Optimization must jointly consider nonlinearity-dependent... CLI item and the pre-encoder that relies on the gNB for band #2 transmission. CCI item .

[0276] The centralized feedback mechanism in Scheme 5, where all feedback is handled through the gNB, simplifies the system architecture and is more efficient than distributed feedback. The gNB receives the UE's suggestions for all precoders and coordinates their selection, including sending downlink indications to the CD (Precoder Center) specifying which precoder should be used. This centralized approach enables better coordination of interference management across all active links within the system.

[0277] Figure 29 Figure 2900 illustrates another communication process between the gNB, CD, and UE, corresponding to Scheme 6 in a downlink non-full-duplex gNB scenario. The process can be followed by the following steps.

[0278] Option 1.b Include Cross-link interference (CLI) and The selection is based on the Channel State Information Reference Signal (CSI-RS) and the estimated covariance matrix. Then report it to gNB.

[0279] The receiver design is similar to the Y1 robust receiver.

[0280] Depend on and The precoded demodulation reference signal (DM-RS) and the robust receiver are both based on the estimated covariance matrix. .

[0281] In this scenario, the precoder $P$ needs to be selected through a user equipment (UE) measurement and feedback mechanism. This selection process follows option 1, whereby the UE performs channel measurements and provides feedback so that the cooperating device (CD) can make the optimal precoder selection.

[0282] Option 1.b requires establishing a direct connection between the CD and UE for control signaling. This requirement introduces additional implementation complexity compared to Option 1.a. Specifically, establishing and maintaining a dedicated communication channel between the CD and UE may be more difficult to implement than the alternative approach in Option 1.a, which only requires adding a downlink field to the control signaling (e.g., the Physical Downlink Control Channel (PDCCH)) to inform the CD which precoder to use. Option 1.a's centralized approach, where all signaling flows through the gNB, avoids the need for direct CD-UE communication infrastructure, making it more suitable for initial deployments.

[0283] Solution 6 extends Solution 3 to support CLI-aware processing while maintaining the distributed reporting architecture. When jointly optimizing all precoders, the UE considers both CLI on band #1 and co-channel interference (CCI) on band #2. In distributed reporting, the UE will... and Report to gNB, and simultaneously index the preferred CD precoder. Reporting directly to the CD requires additional signaling infrastructure, but can reduce the latency of CD precoder updates.

[0284] In non-full-duplex scenarios, the practical implementation challenges of Scheme 6 include establishing and maintaining the UE-CD communication channel when the gNB actively transmits on band #2. The CCI transmitted from the gNB may not only affect data transmission from CD to UE, but also control signaling from UE to CD. Therefore, robust signaling design is required to ensure reliable transmission of precoder feedback.

[0285] Figure 30 Figure 3000 illustrates the management of in-band carriers and CLIs within the same cell. The process can be followed as follows.

[0286] Scheme 7 is specifically designed for the management of CLIs within the same cell and on in-band carriers. This CLI is denoted as... This indicates that another UE (UE') is interfering with the target UE on the same frequency band. This is different from the inter-carrier CLI handled in schemes 4-6. The latter indicates interference between different frequency bands. In-band carrier CLI occurs when the UE transmits to the gNB in ​​frequency band #2, while CD simultaneously transmits to the target UE in the same frequency band #2.

[0287] When managing in-band carrier and intra-cell cross-link interference (CLI), the system implements a CLI robust precoding matrix indicator (PMI) recommendation and restriction mechanism. In this mechanism, the UE' provides the gNodeB (gNB) with information about the precoder at the cooperating device (CD). The recommended selection. UE's goal is to recommend a precoder. To minimize interference items ,in This indicates the channel from CD to UE'. The precoder applied to the CD. This is the channel from gNB to CD.

[0288] At the UE's receiving end, the received signal can be expressed mathematically. The signal received by UE' on frequency band #2 is... In this expression, This indicates the direct channel from gNB to UE'. This is the signal that gNB sends to UE' on frequency band #2. This represents the noise at UE'. Interference items include... This indicates interference sent by the gNB to the UE via the CD relay path, and This indicates noise amplification through the same interference path. This indicates the signal transmitted by the gNB on frequency band #1. This is noise at the CD.

[0289] This CLI robust PMI recommendation mechanism enables the UE to proactively participate in the interference management process, helping to minimize the interference it experiences from cooperative transmissions targeting the target UE through feedback. The gNB can then use this feedback, along with the recommendation from the target UE, to make decisions regarding the optimal precoder selection at the CD, balancing the performance needs of multiple users in the network.

[0290] The gNB cannot directly obtain the covariance matrix of the interference at the UE, making centralized coordination challenging. Therefore, in practice, option 1.a (centralized reporting via gNB) is preferred over option 1.b (distributed reporting).

[0291] Figure 31 Figure 3100 illustrates another communication process between the gNB, CD, and UE, corresponding to scheme 7.

[0292] In Scheme 7, both the target user equipment (UE) and the potentially interfering user equipment (UE') participate in the precoder selection process. While the target UE measures the concatenated channel and recommends a precoder to maximize its desired signal quality, UE' also monitors the Channel State Information Reference Signal (CSI-RS) transmission and recommends a precoder to minimize its interference to the target UE. This coordinated approach enables the base station (gNB) to make informed decisions, balancing the performance requirements of multiple UEs in the network.

[0293] The processing flow in the downlink non-full-duplex gNB scenario is the same as that in the downlink full-duplex gNB scenario, including the selection of the desired signal and the pre-encoder. The only difference lies in the interference considered.

[0294] In downlink non-full-duplex gNB scenarios, the gNB transmits on frequency band #2, while in downlink full-duplex gNB scenarios, the gNB receives on frequency band #2. This difference explains why, in downlink full-duplex gNB scenarios, interference originates from another UE (UE') affecting the target UE.

[0295] In contrast, in downlink non-full-duplex gNB scenarios, when a gNB transmits, it operates simultaneously on both frequency band #1 and frequency band #2. The gNB's transmission on frequency band #2 can interfere with transmissions from the cooperating device (CD) to the UE. Specifically, while there is CD-to-UE transmission, the gNB is simultaneously transmitting to a potential other UE on frequency band #2, thus interfering with the target UE's signal.

[0296] In this collaborative device scenario, if the goal is to perform measurements, reporting, or feedback to select a pre-encoder, for example... (gNB to CD) (gNB to UE) and (At the CD, and in some cases from the CD to the UE), interference factors such as cross-link interference (CLI) and co-channel interference (CCI) may or may not be considered during the selection process.

[0297] In this disclosure, Scheme 1 involves not selecting a pre-encoder at the CD. And this operation is performed without considering CLI. Similarly, Schemes 2 and 3 involve selecting at CD. The difference lies in that: Option 2 assumes there is no communication between the CD and the UE for reporting. The selection of either the direct communication or control channel must be made through the gNB; however, Scheme 3 assumes a direct communication channel exists between the CD and the UE, allowing the UE to directly report its preferences to the CD. Bypassing gNB.

[0298] Options 4, 5, and 6 correspond to options 1, 2, and 3, respectively, but CLI is considered during the selection process.

[0299] For downlink non-full-duplex gNB scenarios, the only difference from full-duplex scenarios lies in the different interference modes. Schemes 1 to 7 are applicable to two situations: the gNB operates in sub-band full-duplex mode (or full-duplex, such as scenario a.1), and the gNB is non-full-duplex (HD gNB, such as scenario a.2).

[0300] The process involved in Scheme 7 follows option 1.a with CLI, and is performed at the UE as follows: At UE' In this method, the pre-encoder Option 1 must be selected, which pertains to UE measurement and feedback. The process begins with the gNB sending CSI-RS for measurement. The CD then applies N precoders in a loop, for each precoder... , until CSI-RS is used to measure separately , until .

[0301] After completing the measurement, the UE provides CSI feedback to the gNB. The UE then determines its preferred precoder. and compare the corresponding index with the precoder pair Joint report. Alternatively, the UE can decide first. Then confirm This selection is based on CSI-RS measurements and The estimated covariance matrix. Therefore, the feedback includes inputs for the pre-encoder. PMI and for pre-encoder pairs PMI feedback.

[0302] After receiving CSI feedback from the UE, the gNB contains the preferred precoder. and recommended pre-encoders and The gNB sends a downlink instruction to the CD, specifying that the CD should use the selected precoder during its transmission. gNB to The choice may be related to the UE's recommendation. The difference is that the gNB must consider feedback from multiple UEs (including UE') in order to balance the overall system performance.

[0303] For data demodulation, both the direct signal received on band #1 and the relay signal received on band #2 utilize the demodulation reference signal (DM-RS) to detect the transmitted message. The UE is based on... A robust receiver design is implemented based on the estimated noise and interference covariance matrix. This robust receiver employs interference suppression techniques to suppress cross-link interference on frequency band #1. Co-channel interference on band #2 This improves the reception quality of the desired signal.

[0304] While the measurement process is running in parallel with that of the target UE, the UE' also participates in precoder selection by listening to CSI-RS transmissions. The UE' selects each precoder for each CD cycle. Candidate precoders are used to measure the potential interference they may cause to the target UE. Specifically, the UE' applies the first precoder to the CD. Time measurement of interference channel A second pre-encoder is applied to CDs. Time measurement and in turn for all The pre-encoder performs this process, measuring during the final pre-encoder phase in the codebook. These measurements enable the UE to assess the impact of each CD precoder on the level of interference it causes to the target UE's reception on band #2.

[0305] UE' is based on CSI-RS and Given the estimated covariance matrix, the preferred method is... (and report the corresponding index). Therefore, for Recommended PMI feedback.

[0306] UE' based A robust receiver is constructed from the estimated covariance matrix.

[0307] Regarding option 1.b with CLI (UE is...) UE' is If you expect UE' and CD to share recommendations This would be of little significance, because a communication channel would need to be established between them. The central node needs to decide... Since the requests from UE and UE' will be different, option 1.a is likely the optimal choice.

[0308] In option 1.a, the gNB, acting as the central decision node, receives precoder recommendations from both the target UE (which seeks to maximize the desired signal) and UE' (which seeks to minimize its own interference). The gNB then selects the final precoder for the CD. In this case, these potentially conflicting objectives must be balanced. The decision can prioritize the performance of the target UE while ensuring that interference with other UEs remains within acceptable limits.

[0309] While Proposal 7 extends the framework for handling intra-carrier, intra-cell CLI, its actual implementation may be complex due to the need for coordination among multiple UEs. Its process is similar to Proposals 4-6, with the main difference being the types and sources of interference managed.

[0310] Figure 32 A first instance flowchart 3200 illustrates CSI and PMI signaling based on UE measurements and feedback. This process involves the interaction between the network (NW) and the UE (e.g., UE 104) via a base station (e.g., base station 102).

[0311] In block 3202, the UE directly receives the first channel state information reference signal (CSI-RS) from the base station on the first frequency band.

[0312] In block 3204, the UE receives a second CSI-RS from the cooperating device (CD) on the second frequency band. This second CSI-RS is a frequency-converted version of the CSI-RS sent by the base station to the CD on the first frequency band.

[0313] Subsequently, in block 3206, the UE measures the direct channel between the base station and the UE based on the first CSI-RS. ).

[0314] In block 3208, the UE measures the cascaded channel between the base station and the UE via CD based on the second CSI-RS. ). This represents the channel from the base station to the CD. This indicates the channel from CD to UE.

[0315] After completing the measurements of the direct channel and the concatenated channel, in block 3210, the UE generates channel state information (CSI) feedback based on the measured direct channel and the measured concatenated channel. This CSI feedback includes at least: information for the first precoder (…). The first precoder matrix indicator (PMI) is used by the base station for transmission to the CD; and the first precoder is used for the second precoder ( The second PMI, which is a second precoder used by the base station for direct transmission to the UE.

[0316] Subsequently, in block 3212, the UE sends the CSI feedback to the base station.

[0317] In some configurations, the CD-specific precoder is not applied during frequency conversion, thus enabling the effective precoder at the CD location. It is equal to the identity matrix.

[0318] In some configurations, the UE may further include: receiving a first demodulation reference signal (DM-RS) directly from a base station on a first frequency band, the first DM-RS being generated by a second precoder ( Precoding is performed; a second DM-RS is received from the CD on the second frequency band, which is transmitted from the base station to the CD and precoded by the first precoder. The DM-RS is pre-coded and frequency-converted; and the data stream is demodulated based on the received first and second DM-RS.

[0319] In some configurations, CSI feedback may further include at least one of a rank indicator (RI) or a channel quality indicator (CQI).

[0320] In some configurations, the CD can perform amplified forwarding operations with frequency conversion, and the processing delay at the CD remains below the duration of the cyclic prefix.

[0321] In some configurations, the first frequency band provides wide-area coverage, while the second frequency band provides limited geographic coverage.

[0322] In some configurations, the first and second frequency bands can be different carriers within the same frequency band used for in-band multicarrier operation.

[0323] Figure 33 A second instance flowchart 3300 illustrates CSI and PMI signaling based on UE measurements and feedback. This process involves the interaction between the network (NW) and the UE (e.g., UE 104) through a base station (e.g., base station 102).

[0324] In block 3302, the UE directly receives the first channel state information reference signal (CSI-RS) from the base station on the first frequency band.

[0325] In block 3304, the User Equipment (UE) receives multiple N precoded Channel State Information Reference Signal (CSI-RS) instances from the Cooperative Equipment (CD) on the second frequency band. Each of these N precoded CSI-RS instances can be encoded by the CD using different candidate precoders from a predefined codebook before frequency conversion. (in It is generated by applying the CSI-RS received from the base station on the first frequency band.

[0326] In block 3306, the UE measures the direct channel between the base station and the UE based on this first CSI-RS. ).

[0327] In block 3308, the UE measures N precoded concatenated channels based on these N precoded CSI-RS instances. ) example. This represents the channel from the base station to the CD. This indicates the channel from CD to UE.

[0328] In block 3310, the UE selects the optimal CD-dedicated precoder from the N candidate precoders based on the measured direct channel and the N precoded concatenated channel instances. .

[0329] In block 3312, the UE generates Channel State Information (CSI) feedback, which includes an indication of the selected optimal CD-dedicated precoder. For the first pre-encoder ( The first precoder matrix indicator (PMI) is used by the base station for transmission to the CD, and is used for the second precoder ( The second PMI, which is a second precoder used by the base station for direct transmission to the UE.

[0330] In block 3314, the UE sends the CSI feedback to the base station.

[0331] In some configurations, the base station can send a downlink control instruction to the CD to instruct the CD to use the selected optimal CD-specific precoder in subsequent data transmissions. .

[0332] In some configurations, the CD can store CSI-RS received from the base station and apply the N candidate precoders sequentially to the stored CSI-RS to generate the N precoded CSI-RS instances.

[0333] In some configurations, selecting the optimal CD-specific precoder and generating CSI feedback may also include: estimating the covariance matrix of noise and interference; and jointly optimizing the optimal CD-specific precoder based on the estimated covariance matrix. and the first and second pre-encoders ( , The choice of ) . This interference may include cross-link interference (CLI) caused by CD transmission on the second band to UE reception on the first band.

[0334] In some configurations, the CLI can be represented as ,in It's interfering with the channel. It is a function of the signal received at the CD, the CD-specific pre-encoder, the frequency offset between the first and second frequency bands, and the modulation scheme.

[0335] In some configurations, the base station can operate in full-duplex mode, and the estimated covariance matrix may also include interference from another UE transmitting on the second frequency band, denoted as... .

[0336] In some configurations, the base station can operate in non-full-duplex mode and transmit on a second frequency band, and the estimated covariance matrix may also include co-channel interference (CCI) from the base station's transmissions on the second frequency band, denoted as... .

[0337] In some configurations, the base station can use a third precoder on the second frequency band. The process may also include: taking into account the CCI from the third precoder in the precoder selection.

[0338] In some configurations, the UE may also include: during data demodulation, employing interference suppression combining to achieve a robust receiver based on the estimated covariance matrix of noise and interference.

[0339] In some configurations, the base station can use a third precoder on the second frequency band. The process may also include: taking into account the CCI from the third precoder in the precoder selection.

[0340] Figure 34 A third example flowchart 3400 illustrates CSI and PMI signaling based on UE measurements and feedback. This process involves the interaction between the network (NW) and the UE (e.g., UE 104) through a base station (e.g., base station 102).

[0341] In block 3402, the UE directly receives the first channel state information reference signal (CSI-RS) from the base station on the first frequency band.

[0342] In block 3404, the UE receives multiple N precoded CSI-RS instances from the cooperating device (CD) on the second frequency band.

[0343] In block 3406, the UE measures the direct channel and N precoded concatenated channel instances based on the received CSI-RS instances.

[0344] In block 3408, the UE selects the optimal CD-specific precoder from N candidate precoders.

[0345] In block 3410, the UE generates a first feedback portion for the base station, the first feedback portion including a first precoding matrix indicator (PMI) for a first precoder for transmission to the CD by the base station, and a second PMI for a second precoder for direct transmission to the UE by the base station.

[0346] In block 3412, the UE generates a second feedback section for CD, which contains an indication of the selected optimal CD-specific precoder.

[0347] In block 3414, the UE sends the first feedback part to the base station.

[0348] In block 3416, the UE sends the second feedback part directly to the CD via the communication channel established between the UE and the CD.

[0349] In some configurations, the UE can jointly optimize the selection of the optimal CD-dedicated precoder and the first and second precoders based on maximizing the effective channel capacity across both the first and second frequency bands.

[0350] Figure 35 A fourth example flowchart 3500 illustrates CSI and PMI signaling based on UE measurements and feedback. This process involves the interaction between the network (NW) and the UE (e.g., UE 104) through a base station (e.g., base station 102).

[0351] In block 3502, the UE listens for N precoded Channel State Information Reference Signal (CSI-RS) instances transmitted by the cooperating device (CD) on the second frequency band. These N precoded CSI-RS instances can be sent to another UE.

[0352] In block 3504, UE targets Measure interference channel ,in This indicates the interference channel from CD to UE. Indicates a CD-specific pre-coder. This indicates the channel from the base station to the CD.

[0353] In block 3506, the UE determines the recommended CD-specific precoder index based on minimizing interference to the UE.

[0354] In block 3508, the UE sends the recommended CD-specific precoder index to the base station.

[0355] In block 3510, the UE implements a robust receiver for subsequent data reception based on the estimated covariance matrix of the interference.

[0356] In some configurations, the base station can determine the final CD-specific precoder based on channel state information (CSI) feedback from another user equipment (UE) and a recommended CD-specific precoder index from that UE.

[0357] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is merely exemplary. Depending on design preferences, the specific order or hierarchy of the blocks in the process / flowchart may be rearranged. Furthermore, some blocks may be combined or omitted. The appended method claims present the block elements in an exemplary order and are not limited to the specific order or hierarchy shown.

[0358] The foregoing description is intended to enable those skilled in the art to implement the aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to limit the aspects shown herein, but rather to provide a full scope consistent with the language of the claims, wherein a singular reference to an element does not mean “only one” unless explicitly stated otherwise, but rather “one or more.” The term “exemplary” herein means “as an example, instance, or illustration.” Any aspect described as “exemplary” is not necessarily to be construed as preferred or superior to other aspects. Unless otherwise explicitly stated, the term “some” means one or more. Combinations such as “at least one A, B, or C,” “one or more A, B, or C,” “at least one A, B, and C,” “one or more A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as "at least one A, B, or C", "one or more A, B, or C", "at least one A, B, and C", "one or more A, B, and C", and "A, B, C, or any combination thereof" can be only A, only B, only C, A and B, A and C, B and C, or A, B, and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the elements of the aspects described herein, whether known or hereafter known to those skilled in the art, are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, the disclosures herein are not intended for public disclosure, whether or not such disclosures are expressly stated in the claims. The terms "module," "mechanism," "element," "device," etc., are not substitutes for the word "means." Therefore, no element of a claim should be construed as means plus function unless the element is expressly stated in the phrase "means for..."

Claims

1. A wireless communication method for a user equipment (UE), comprising: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive a second CSI-RS from a cooperating device (CD) on a second frequency band, wherein the second CSI-RS is a frequency-converted version of the CSI-RS sent by the base station to the CD on the first frequency band; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on this second CSI-RS, the cascaded channel (H) between the base station and the UE via the CD is measured. s ·H1), where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Channel state information (CSI) feedback is generated based on the measured direct channel and the measured concatenated channel, wherein the CSI feedback includes at least: a first precoding matrix indicator (PMI) for a first precoder (P1), the first precoder being used by the base station for transmission to the CD; and a second PMI for a second precoder (P2), the second precoder being used by the base station for direct transmission to the UE; as well as The CSI feedback is sent to the base station.

2. The method of claim 1, wherein the CD does not apply a CD-specific precoder during the frequency conversion, such that the effective precoder P at the CD is equal to the identity matrix.

3. The method of claim 1, further comprising: The first demodulation reference signal (DM-RS) is received directly from the base station on the first frequency band, wherein the first DM-RS is precoded by the second precoder (P2); The second DM-RS is received from the CD on the second frequency band, wherein the second DM-RS is a frequency-converted version of the DM-RS sent by the base station to the CD and precoded by the first precoder (P1); as well as The data stream is demodulated based on the received first DM-RS and second DM-RS.

4. A wireless communication method for a user equipment (UE), comprising: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. N precoded CSI-RS instances are received from the cooperating device (CD) in the second frequency band, wherein each of the N precoded CSI-RS instances is generated by the CD applying different candidate precoders P(k) from a predefined codebook to the CSI-RS received from the base station in the first frequency band before frequency conversion, where k=1,2,…,N; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on these N precoded CSI-RS instances, measurements were taken on N precoded concatenated channels (H). s ·P(k)·H1) instance, where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Based on the measured direct channel and the N precoded concatenated channel instances, the optimal CD-specific precoder P is selected from the N candidate precoders. ); Generate Channel State Information (CSI) feedback, which includes: the selected optimal CD-dedicated precoder P( The first precoder (P1) is used by the base station for transmission to the CD, and the second precoder (P2) is used by the base station for direct transmission to the UE. as well as The CSI feedback is sent to the base station.

5. The method of claim 4, wherein the base station sends a downlink control indication to the CD to instruct the CD to use the selected optimal CD-specific precoder P in subsequent data transmission. ).

6. The method of claim 4, wherein the CD stores the CSI-RS received from the base station and sequentially applies the N candidate precoders to the stored CSI-RS to generate the N precoded CSI-RS instances.

7. The method of claim 4, wherein selecting the optimal CD-specific precoder and generating the CSI feedback further comprises: Estimate the covariance matrix of noise and interference, where the interference includes cross-link interference (CLI) caused by the CD's transmission on the second frequency band to the UE's reception on the first frequency band; and Based on the estimated covariance matrix, the optimal CD-specific precoder P is jointly optimized. The selection of the first precoder and the second precoder (P1, P2).

8. The method of claim 7, wherein the CLI is represented as H cli ·ibe, where H cli It is the interference channel, and ibe is a function of the signal received at the CD, the CD's dedicated pre-encoder, the frequency offset between the first and second frequency bands, and the modulation scheme.

9. The method of claim 7, wherein the base station operates in full-duplex mode, and the estimated covariance matrix further includes interference from another UE transmitting on the second frequency band, the interference being denoted as H. cli '·ue'.

10. The method of claim 7, wherein the base station operates in non-full-duplex mode and transmits on the second frequency band, and the estimated covariance matrix further includes co-channel interference (CCI) from the base station's transmissions on the second frequency band, the interference being denoted as H. cci ·X o_gnb .

11. A wireless communication method for a user equipment (UE), comprising: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive N precoded CSI-RS instances from the cooperating device (CD) on the second frequency band; Based on the received CSI-RS instance, measure the direct channel and N precoded concatenated channel instances; Select the optimal CD-specific precoder from N candidate precoders; Generate a first feedback portion for the base station, the first feedback portion including: a first precoding matrix indicator (PMI) for a first precoder, the first precoder being used by the base station for transmission to the CD, and a second PMI for a second precoder, the second precoder being used by the base station for direct transmission to the UE; A second feedback section is generated for the CD, which includes an indication of the selected optimal CD-specific pre-encoder; Send the first feedback portion to the base station; and The second feedback portion is sent directly to the CD via the communication channel established between the UE and the CD.

12. The method of claim 11, wherein the UE jointly optimizes the selection of the optimal CD-dedicated precoder and the first and second precoders based on maximizing the effective channel capacity across both the first and second frequency bands.

13. The method of claim 1, wherein the CSI feedback further includes at least one of a rank indicator (RI) or a channel quality indicator (CQI).

14. The method of claim 1, wherein the CD performs an amplified forwarding operation with frequency conversion, and the processing delay at the CD remains below the duration of the cyclic prefix.

15. The method of claim 7, further comprising: During data demodulation, a robust receiver is achieved by using interference suppression combining based on the estimated noise and interference covariance matrix.

16. A wireless communication method for a user equipment (UE) in a multi-UE coordination scenario, comprising: Listen for N precoded Channel State Information Reference Signal (CSI-RS) instances transmitted by the cooperating device (CD) on the second frequency band, wherein the N precoded CSI-RS instances are sent to another UE; For k=1,2,…,N, measure the interference channel H cli '·P(k)·H1, where H cli ' represents the interference channel from the CD to the UE, P(k) represents the CD-specific precoder, and H1 represents the channel from the base station to the CD; Based on minimizing interference with the UE, a recommended CD-specific precoder index is determined; Send the recommended CD-specific precoder index to the base station; and Based on the estimated covariance matrix of the interference, a robust receiver is implemented for subsequent data reception.

17. The method of claim 16, wherein the base station determines the final CD-specific precoder based on CSI feedback from the other UE and the recommended CD-specific precoder index from the UE.

18. The method of claim 10, wherein the base station transmits a data stream to the UE using a third precoder (P3) on the second frequency band, and the method further includes taking into account the CCI from the third precoder in the precoder selection.

19. The method of claim 1, wherein the first frequency band provides wide-area coverage and the second frequency band provides limited geographical coverage.

20. The method of claim 1, wherein the first frequency band and the second frequency band are different carriers within the same frequency band for in-band multicarrier operation.

21. An apparatus for wireless communication, the apparatus being a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory is configured as follows: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive a second CSI-RS from a cooperating device (CD) on a second frequency band, wherein the second CSI-RS is a frequency-converted version of the CSI-RS sent by the base station to the CD on the first frequency band; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on this second CSI-RS, the cascaded channel (H) between the base station and the UE via the CD is measured. s ·H1), where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Channel state information (CSI) feedback is generated based on the measured direct channel and the measured concatenated channel, wherein the CSI feedback includes at least: a first precoding matrix indicator (PMI) for a first precoder (P1), the first precoder being used by the base station for transmission to the CD; and a second PMI for a second precoder (P2), the second precoder being used by the base station for direct transmission to the UE; as well as The CSI feedback is sent to the base station.

22. A computer-readable medium storing computer-executable code for wireless communication of a user equipment (UE), comprising code for: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive a second CSI-RS from a cooperating device (CD) on a second frequency band, wherein the second CSI-RS is a frequency-converted version of the CSI-RS sent by the base station to the CD on the first frequency band; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on this second CSI-RS, the cascaded channel (H) between the base station and the UE via the CD is measured. s ·H1), where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Channel state information (CSI) feedback is generated based on the measured direct channel and the measured cascaded channel, wherein the CSI feedback includes at least: A first precoding matrix indicator (PMI) for a first precoder (P1), the first precoder being used by the base station for transmission to the CD; and a second PMI for a second precoder (P2), the second precoder being used by the base station for direct transmission to the UE; as well as The CSI feedback is sent to the base station.

23. An apparatus for wireless communication, the apparatus being a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory is configured as follows: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. N precoded CSI-RS instances are received from the cooperating device (CD) in the second frequency band, wherein each of the N precoded CSI-RS instances is generated by the CD applying different candidate precoders P(k) from a predefined codebook to the CSI-RS received from the base station in the first frequency band before frequency conversion, where k=1,2,…,N; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on these N precoded CSI-RS instances, measurements were taken on N precoded concatenated channels (H). s ·P(k)·H1) instance, where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Based on the measured direct channel and the N precoded concatenated channel instances, the optimal CD-specific precoder P is selected from the N candidate precoders. ); Generate Channel State Information (CSI) feedback, which includes: the selected optimal CD-dedicated precoder P( The instructions include a first precoding matrix indicator (PMI) for a first precoder (P1), which is used by the base station for transmission to the CD, and a second PMI for a second precoder (P2), which is used by the base station for direct transmission to the UE. as well as The CSI feedback is sent to the base station.

24. A computer-readable medium storing computer-executable code for wireless communication of a user equipment (UE), comprising code for: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. N precoded CSI-RS instances are received from the cooperating device (CD) in the second frequency band, wherein each of the N precoded CSI-RS instances is generated by the CD applying different candidate precoders P(k) from a predefined codebook to the CSI-RS received from the base station in the first frequency band before frequency conversion, where k=1,2,…,N; Based on the first CSI-RS, the direct channel (H2) between the base station and the UE is measured. Based on these N precoded CSI-RS instances, measurements were taken on N precoded concatenated channels (H). s ·P(k)·H1) instance, where H1 represents the channel from the base station to the CD, H s This indicates the channel from the CD to the UE; Based on the measured direct channel and the N precoded concatenated channel instances, the optimal CD-specific precoder P is selected from the N candidate precoders. ); Generate Channel State Information (CSI) feedback, which includes: The selected optimal CD-specific precoder P( The instructions include a first precoding matrix indicator (PMI) for a first precoder (P1), which is used by the base station for transmission to the CD, and a second PMI for a second precoder (P2), which is used by the base station for direct transmission to the UE. as well as The CSI feedback is sent to the base station.

25. An apparatus for wireless communication, the apparatus being a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory is configured as follows: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive N precoded CSI-RS instances from the cooperating device (CD) on the second frequency band; Based on the received CSI-RS instance, measure the direct channel and N precoded concatenated channel instances; Select the optimal CD-specific precoder from N candidate precoders; A first feedback portion is generated for the base station, the first feedback portion including a first precoding matrix indicator (PMI) for a first precoder, the first precoder being used by the base station for transmission to the CD, and a second PMI for a second precoder, the second precoder being used by the base station for direct transmission to the UE; A second feedback section is generated for the CD, which includes an indication of the selected optimal CD-specific pre-encoder; The first feedback portion is sent to the base station; as well as The second feedback portion is sent directly to the CD via the communication channel established between the UE and the CD.

26. A computer-readable medium storing computer-executable code for wireless communication of a user equipment (UE), comprising code for: The first channel state information reference signal (CSI-RS) is received directly from the base station on the first frequency band. Receive N precoded CSI-RS instances from the cooperating device (CD) on the second frequency band; Based on the received CSI-RS instance, measure the direct channel and N precoded concatenated channel instances; Select the optimal CD-specific precoder from N candidate precoders; A first feedback portion is generated for the base station, the first feedback portion including a first precoding matrix indicator (PMI) for a first precoder, the first precoder being used by the base station for transmission to the CD, and a second PMI for a second precoder, the second precoder being used by the base station for direct transmission to the UE; A second feedback section is generated for the CD, which includes an indication of the selected optimal CD-specific pre-encoder; The first feedback portion is sent to the base station; as well as The second feedback portion is sent directly to the CD via the communication channel established between the UE and the CD.

27. An apparatus for wireless communication, the apparatus being a user equipment (UE), comprising: Memory; as well as At least one processor coupled to the memory is configured as follows: Listen for N precoded Channel State Information Reference Signal (CSI-RS) instances transmitted by the cooperating device (CD) on the second frequency band, wherein the N precoded CSI-RS instances are sent to another UE; For k=1,2,…,N, measure the interference channel H cli '·P(k)·H1, where H cli ' represents the interference channel from the CD to the UE, P(k) represents the CD-specific precoder, and H1 represents the channel from the base station to the CD; Based on minimizing interference with the UE, a recommended CD-specific precoder index is determined; Send the recommended CD-specific precoder index to the base station; and Based on the estimated covariance matrix of the interference, a robust receiver is implemented for subsequent data reception.

28. A computer-readable medium storing computer-executable code for wireless communication of a user equipment (UE), comprising code for: Listen for N precoded Channel State Information Reference Signal (CSI-RS) instances transmitted by the cooperating device (CD) on the second frequency band, wherein the N precoded CSI-RS instances are sent to another UE; For k=1,2,…,N, measure the interference channel H cli '·P(k)·H1, where H cli ' represents the interference channel from the CD to the UE, P(k) represents the CD-specific precoder, and H1 represents the channel from the base station to the CD; Based on minimizing interference with the UE, a recommended CD-specific precoder index is determined; Send the recommended CD-specific precoder index to the base station; and Based on the estimated covariance matrix of the interference, a robust receiver is implemented for subsequent data reception.

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