Method and apparatus for wireless communication

Abstract

A method and apparatus for wireless communication are provided. The method includes: a terminal device receiving a CSI-RS sent by a network device; the terminal device determining a first PMI according to a first codebook and the CSI-RS; wherein the first PMI is associated with a first port subset, the first codebook is used to determine a PMI corresponding to a port in the first port subset, and the first port subset is one of: an effective port subset selected from all ports corresponding to the CSI-RS; the first port subset is one of a plurality of port subsets divided from all ports corresponding to the CSI-RS.

Description

Technical Field

[0001] This application relates to the field of communication technology, and more specifically, to a method and apparatus for wireless communication. Background Technology

[0002] Terminal devices can report CSI by measuring the Channel State Information (CSI) reference signal (CSI-RS) to enable network devices to perform precoding selection, layer configuration, and resource allocation. However, with the continuous increase in the number of antenna ports and bandwidth, and the gradual popularization of multi-beam / multi-point coordination, traditional CSI-RS configuration and CSI reporting mechanisms face significant challenges. For scenarios with massive MIMO and high bandwidth, how to reduce CSI-RS reporting overhead while ensuring CSI acquisition accuracy has become a technical problem that needs to be solved. Summary of the Invention

[0003] This application provides a method and apparatus for wireless communication. The various aspects of this application will be described below.

[0004] In a first aspect, a method for wireless communication is provided, comprising: a terminal device receiving a CSI-RS transmitted by a network device; the terminal device determining a first pre-coding matrix indication (PMI) based on a first codebook and the CSI-RS; wherein the first PMI is associated with a first port subset, the first codebook is used to determine the PMI corresponding to a port in the first port subset, and the first port subset is one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; or the first port subset is one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0005] In a second aspect, a method for wireless communication is provided, comprising: a network device transmitting a CSI-RS; wherein the CSI-RS is used by a terminal device to determine a first PMI based on a first codebook, the first PMI being associated with a first port subset, the first codebook being used to determine the PMI corresponding to a port in the first port subset, the first port subset being one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; the first port subset being one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0006] Thirdly, an apparatus for wireless communication is provided, the apparatus being a terminal device, the apparatus comprising: a receiving unit for receiving CSI-RS transmitted by a network device; and a processing unit for determining a first PMI based on a first codebook and the CSI-RS; wherein the first PMI is associated with a first port subset, the first codebook being used to determine the PMI corresponding to a port in the first port subset, and the first port subset being one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; or the first port subset being one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0007] Fourthly, an apparatus for wireless communication is provided, the apparatus being a network device, the apparatus comprising: a transmitting unit for transmitting CSI-RS; wherein the CSI-RS is used by a terminal device to determine a first PMI based on a first codebook, the first PMI being associated with a first port subset, the first codebook being used to determine the PMI corresponding to a port in the first port subset, the first port subset being one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; the first port subset being one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0008] Fifthly, a communication device is provided, including a memory and a processor, the memory for storing a program, and the processor for calling the program in the memory to perform the method as described in the first or second aspect.

[0009] A sixth aspect provides an apparatus including a processor for calling a program from memory to perform the method as described in the first or second aspect.

[0010] A seventh aspect provides a chip including a processor for calling a program from memory, causing a device having the chip mounted to perform the method as described in the first or second aspect.

[0011] Eighthly, a computer-readable storage medium is provided having a program stored thereon that causes a computer to perform the method as described in the first or second aspect.

[0012] Ninth aspect, a computer program product is provided, including a program that causes a computer to perform the method as described in the first or second aspect.

[0013] In a tenth aspect, a computer program is provided that causes a computer to perform the method as described in the first or second aspect.

[0014] In this embodiment, after receiving the CSI-RS, the terminal device can determine the first PMI based on the first codebook to send a CSI report. The first codebook is used to determine the PMI corresponding to a first port subset. The first port subset is a valid port subset selected from all ports, or any port subset from multiple port subsets. When the first port subset is a valid port subset, the first codebook is only used to determine the fine-grained PMI corresponding to the valid ports, which helps reduce the overhead when the number of ports is large. When all ports are divided into multiple port subsets, it helps reduce the resource overhead of a single CSI report. Attached Figure Description

[0015] Figure 1 This is a system architecture example diagram of a wireless communication system to which embodiments of this application can be applied.

[0016] Figure 2 This is a schematic diagram of a network architecture applicable to embodiments of this application.

[0017] Figure 3A and Figure 3B This is a schematic diagram of a wireless protocol stack structure applicable to embodiments of this application.

[0018] Figure 4 This is a flowchart illustrating a method for wireless communication proposed in an embodiment of this application.

[0019] Figure 5 for Figure 4 The flowchart illustrates one possible implementation of the method shown.

[0020] Figure 6 for Figure 4 A flowchart illustrating another possible implementation of the method shown.

[0021] Figure 7 This is a schematic diagram of a device for wireless communication provided in an embodiment of this application.

[0022] Figure 8 This is a schematic diagram of another device for wireless communication provided in an embodiment of this application.

[0023] Figure 9 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0025] Figure 1This is a system architecture example diagram of a wireless communication system 100 applicable to embodiments of this application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographical area and may communicate with the terminal device 120 located within that coverage area.

[0026] Figure 1 An exemplary network device and multiple terminal devices are illustrated, such as terminal devices 120a to 120j in the figure. Optionally, the wireless communication system 100 may include multiple network devices, and each network device may include other numbers of terminal devices within its coverage area; this application embodiment does not limit this.

[0027] Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, which is not limited in this embodiment.

[0028] It should be understood that the technical solutions of the embodiments of this application can be applied to various communication systems, such as: 5th-generation (5G) systems or new radio (NR) systems, long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, advanced long-term evolution (LTE-A) systems, enhanced 5G (5G advanced) systems, etc. The technical solutions provided in this application can also be applied to future communication systems, such as 6th-generation (6G) mobile communication systems, satellite communication systems, and so on.

[0029] The communication system in this application embodiment can be applied to carrier aggregation (CA) scenarios, dual connectivity (DC) scenarios, and standalone (SA) network deployment scenarios.

[0030] The embodiments of this application can be applied to non-terrestrial network (NTN) systems. As an example, the NTN system can be an NR-based NTN system, a 6G-based NTN system, an Internet of Things (IoT)-based NTN system, or a narrowband Internet of Things (NB-IoT)-based NTN system.

[0031] The terminal device in this application embodiment can also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device in this application embodiment can be a device that provides voice and / or data connectivity to a user, and can be used to connect people, objects, and machines, such as a handheld device with wireless connectivity, vehicle-mounted device, etc. The terminal device in the embodiments of this application may be a mobile phone, tablet computer, laptop computer, handheld computer, camera equipment, mobile internet device (MID), wearable device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, etc. Optionally, the terminal device may be used to act as a base station. For example, the terminal device may act as a scheduling entity, providing sidelink signals between UEs in vehicle-to-everything (V2X) or device-to-device (D2D) connections. For example, cellular phones and cars communicate with each other using sidelink signals. Cellular phones and smart home devices can communicate without relaying communication signals through base stations.

[0032] The network device in this application embodiment can be a device for communicating with a terminal device. This network device can also be called an access network device or a radio access network device, such as a base station (BS). In this application embodiment, the network device can refer to a radio access network (RAN) node or a next-generation RAN (NG-RAN) node (or device) that connects the terminal device to the wireless network. A base station can broadly encompass, or be replaced by, various names including: NodeB, evolved NodeB (eNB), next-generation NodeB (gNB), relay station, transmitting and receiving point (TRP), transmitting point (TP), master station (MeNB), secondary station (SeNB), multi-mode radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, micro base station, relay node, donor node, or similar, or a combination thereof. A base station can also refer to a communication module, modem, or chip installed within the aforementioned equipment or apparatus. Base stations can also be mobile switching centers, devices that perform base station functions in D2D, V2X, and machine-to-machine (M2M) communications, network-side devices in 6G networks, and devices that perform base station functions in future communication systems. Base stations can support networks using the same or different access technologies. The embodiments of this application do not limit the specific technologies or device forms used in the network equipment.

[0033] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move depending on the location of the mobile base station. In other examples, a helicopter or drone can be configured as a device to communicate with another base station.

[0034] In some deployments, the network device in this application embodiment may refer to a CU or a DU, or the network device may include both a CU and a DU. The gNB may also include an AAU.

[0035] Network devices and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can also be deployed in the air on airplanes, balloons, and satellites. This application does not limit the scenario in which the network devices and terminal devices are located.

[0036] In this embodiment of the application, the network device can provide services for a cell. The terminal device communicates with the network device through the transmission resources (e.g., frequency domain resources, or spectrum resources) used by the cell. The cell can be the cell corresponding to the network device (e.g., a base station). The cell can belong to a macro base station or to a base station corresponding to a small cell. The small cell here can include: metro cell, micro cell, pico cell, femto cell, etc. These small cells have the characteristics of small coverage area and low transmission power, and are suitable for providing high-speed data transmission services.

[0037] It should be understood that all or part of the functions of the communication device in this application can also be implemented by software functions running on hardware, or by virtualization functions instantiated on a platform (such as a cloud platform).

[0038] Figure 2 A schematic diagram of a network architecture 200 according to an embodiment of this application is illustrated. This network architecture 200 describes the network architecture of a 5G NR / LTE / LTE-A system, which can also be referred to as a 5G system (5GS) / evolved packet system (EPS) network architecture. The network architecture 200 includes at least one of the following: network device 110, terminal device 120, 5G core network (5GC) / evolved packet core (EPC) 210, home subscriber server (HSS) / unified data management (UDM) 220, and Internet service 230. Figure 2 The network devices and terminal devices in the diagram are illustrated using RAN and UE as examples, respectively.

[0039] like Figure 2As shown, network device 110 provides user plane and control plane protocol termination to terminal device 120. Network device 110 is connected to 5GC / EPC210 via an S1 / NG interface. 5GC / EPC210 includes a mobility management entity (MME) / authentication management field (AMF) / session management function (SMF) 211, other MMEs / AMFs / SMFs 214, a service gateway (S-GW) / user plane function (UPF) 212, and a packet data network gateway (P-GW) / UPF 213. MME / AMF / SMF 211 is the control node that handles signaling between terminal device 120 and 5GC / EPC210. ​​Generally, MME / AMF / SMF 211 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the S-GW / UPF212, which is itself connected to the P-GW / UPF213. The P-GW provides UE IP address allocation and other functions. The P-GW / UPF213 is connected to Internet service 230. Internet service 230 includes operator-compliant Internet Protocol services, specifically including the Internet, intranet, IP multimedia subsystem (IMS), and packet-switched streaming services. It is evident that network architecture 200 provides packet-switched services; however, those skilled in the art will readily understand that the various concepts presented herein can be extended to networks providing circuit-switched services or other cellular networks.

[0040] Figure 3A and Figure 3B The following are schematic diagrams of the wireless protocol stack structure of one embodiment of this application. Figure 3A and Figure 3B This introduction uses the 5G wireless protocol stack as an example. The 5G wireless protocol stack is divided into two planes: the user plane (UP) protocol stack and the control plane (CP) protocol stack. The user plane protocol stack contains the protocol suite used for user data transmission, while the control plane protocol stack contains the protocol suite used for control signaling transmission in the 5G system. The specific names of each protocol stack layer are as follows: like Figure 3AAs shown, the user plane protocol stack, from top to bottom, includes: the Service Data Adaptation Protocol (SDAP) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, the Medium Access Control (MAC) layer, and the Physical (PHY) layer.

[0041] like Figure 3B As shown, the control plane protocol stack, from top to bottom, includes: non-access stratum (NAS); radio resource control (RRC) layer, PDCP layer, RLC layer, MAC layer, and PHY layer.

[0042] It should be understood that the different layers in the above protocol stack have different functions, and they work together through inter-layer interaction to achieve communication between terminal devices and network devices. With the development of artificial intelligence technology, AI-assisted computing has permeated the processing implementation methods of the above protocol stack. For example, the scheduling algorithm of the MAC layer and the encoding / decoding algorithm of the PHY layer can apply artificial intelligence algorithms to improve the performance of communication algorithms.

[0043] As an example, Figure 3A and Figure 3B The wireless protocol architecture described herein is applicable to the terminal device described in this application.

[0044] As an example, Figure 3A and Figure 3B The wireless protocol architecture described herein is applicable to the network devices described in this application.

[0045] It should be understood that the interpretation of the terminology in the embodiments of this application may refer to the TS36, TS37 and TS38 series of specifications of the 3rd generation partnership project (3GPP), but may also refer to the specifications of the Institute of Electrical and Electronics Engineers (IEEE).

[0046] To facilitate understanding, some related technical knowledge involved in the embodiments of this application is first introduced. The following related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0047] With the development of communication technologies, the requirements for system performance and capacity are becoming increasingly stringent. For example, as 5G NR has evolved from early versions to enhanced 5G, and then to subsequent 6G and above versions, cellular systems are constantly improving spectrum efficiency, edge coverage, and capacity. To improve spectrum efficiency, edge coverage, and capacity, communication systems are increasingly relying on massive multi-antenna (such as multiple-input multiple-output, MIMO), multi-TRP / multi-beam transmission, and fine beamforming at higher frequency bands.

[0048] In communication systems, CSI feedback is a crucial component. CSI feedback from terminal devices helps network equipment accurately understand the wireless channel state, thereby optimizing transmission parameters to improve system performance. The transmission of CSI-RS can be used by terminal devices to determine the CSI for feedback. For example, in NR systems, to support downlink adaptive scheduling and beamforming, the network side transmits CSI-RS. Terminal devices measure and report the CSI, enabling network equipment to perform precoding selection, layer configuration, and resource allocation.

[0049] Taking 5G NR as an example, 5G NR defines two types of codebooks: Type 1 and Type 2, and uses a set of precoding matrices to describe CSI. These precoding matrices are based on CSI-RS measurements. The Type 1 codebook is a regular-precision codebook that can support single-user MIMO transmission; the Type 2 codebook is a high-precision codebook that can support multi-user MIMO transmission to improve system spectral efficiency. Terminal devices transmit CSI to network devices through a feedback mechanism so that network devices can perform scheduling and precoding.

[0050] As an example, CSI parameters may include the channel quality indicator (CQI), PMI, and rank indicator (RI), which will be explained in detail below.

[0051] CQI is a quantized value reported by the terminal device to the network device to indicate the channel quality of the downlink (DL). CQI reflects the maximum modulation and coding scheme that the terminal device can receive under the current channel conditions to ensure a certain bit error rate.

[0052] The Precoding Interface (PMI) is a feedback from the terminal device regarding the downlink channel state, instructing the network device which precoding matrix to select for signal transmission. The precoding matrix is ​​a linear transformation matrix used to process signals in a multi-antenna system. The network device determines the transmit precoding for the Physical Downlink Shared Channel (PDSCH), Physical Downlink Shared Channel (PDCCH), and CSI-RS, etc., based on the PMI reported by the terminal device.

[0053] RI represents the number of parallel data streams transmitted in a MIMO system. RI reflects the multipath propagation characteristics of the channel and the rank of the channel matrix, and is usually related to the spatial degrees of freedom of the channel.

[0054] Terminal devices can receive CSI-RS, determine CSI, and provide CSI feedback based on CSI-RS configuration and CSI reporting mechanisms. However, with the continuous increase in the number of antenna ports, bandwidth, and the growing popularity of multi-beam / multi-point collaboration, traditional CSI-RS configuration and CSI reporting mechanisms face significant challenges: on the one hand, to maintain sufficient accuracy, CSI-RS and CSI feedback often need to cover a wider frequency range and have higher spatial resolution; on the other hand, this directly leads to increased pilot resource consumption, increased computational complexity of terminal device measurement and reporting, increased power consumption, and implementation pressure under strict timing (measurement-processing-reporting) constraints.

[0055] To improve CSI accuracy, various solutions have been implemented, such as increasing pilot density, adding CSI-RS resources, or shortening the configuration cycle. However, these methods often lead to increased pilot resource element (RE) usage, more measurements by terminal devices, and significantly longer processing times in high-bandwidth and high-port scenarios. Furthermore, different terminal devices support varying CSI-RS density, port counts, and codebook / report types, resulting in configuration limitations and efficiency losses for cross-generational terminal devices.

[0056] Furthermore, the vision for 6G (such as International Mobile Telecommunications for 2030 and beyond, IMT-2030) emphasizes enhanced immersive experiences, improved ubiquitous coverage, and other capability expansions, and will support richer new scenarios and capabilities. These goals typically imply higher peak data rates and more stringent end-to-end experience metrics, stronger edge coverage, more frequent beam tracking and link adaptation, and potentially larger-scale arrays and higher-dimensional CSI acquisition requirements.

[0057] Therefore, for scenarios such as massive MIMO and high bandwidth, how to allocate CSI-RS resources more flexibly and how to reduce the feedback dimension have become technical issues that need to be considered. For example, how to significantly reduce CSI-RS resource overhead and the computational / latency burden of terminal devices while ensuring CSI acquisition / tracking accuracy, and how to maintain backward compatibility with the capabilities of existing terminal devices in network deployment, have become important technical challenges in the development of communication technology and the evolution of 6G.

[0058] To address the aforementioned issues, this application proposes a method for wireless communication. Using this method, after receiving CSI-RS, a terminal device can determine a first PMI based on a first codebook to send a CSI report. The first codebook is used to determine the PMI corresponding to a first port subset. The first port subset is a valid subset of ports selected from all ports, or any port subset from multiple port subsets. When the first port subset is a valid port subset, the first codebook is only used to determine the fine-grained PMI corresponding to the valid ports, which helps reduce overhead when the number of ports is large. When all ports are divided into multiple port subsets, it helps reduce the resource overhead of a single CSI report. In this method, the first codebook is associated with the first port subset, and resource overhead can be reduced through the design of the first port subset.

[0059] To facilitate understanding, the following will be combined with... Figure 4 The present application provides an exemplary description of the method for wireless communication proposed in its embodiments. Figure 4 The method described is explained from the perspective of the interaction between the terminal device and the network device. The terminal device can be any of the communication terminals mentioned above, such as a UE. The network device can be any network-side device that communicates with the terminal device, such as a base station.

[0060] As one example, the terminal device may be Figure 1 Any of the terminal devices 120a to 120j shown.

[0061] As an example, the terminal device can be a relay, such as a relay terminal or a network control relay.

[0062] As one example, the terminal device can be any one of the multiple TRPs. The network device can be any one of the multiple TRPs that communicates with the terminal device.

[0063] The terminal device can be either a traditional terminal device or a new type of terminal device. A traditional terminal device can refer to one that only supports existing CSI-RS frequency density (or frequency domain density) or port configurations. Existing CSI-RS frequency density is, for example, 1 or 1 / 2. Existing port configuration is, for example, a configuration with 32 or fewer ports. A new type of terminal device can refer to one that supports a larger number of ports, a lower CSI-RS frequency density, and / or CSI-RS resource aggregation. Here, a larger number of ports and a lower CSI-RS frequency density can be relative to existing parameters. For example, a larger number of ports can refer to a number of ports greater than 32.

[0064] As an example, a traditional terminal device can be a first type of terminal device, and a novel terminal device can be a second type of terminal device.

[0065] As an example, a conventional terminal device can receive CSI-RS with 32 ports and 1 / 2 frequency density, while a new terminal device can receive CSI-RS with 128 ports and 1 / 8 frequency density.

[0066] In some embodiments, the terminal device may receive a downlink reference signal sent by the network device to perform channel estimation of the downlink channel. For example, the terminal device may receive a CSI-RS to determine the CSI of the downlink channel.

[0067] As an example, the terminal device can be any UE in RRC connected state.

[0068] In some embodiments, the terminal device and the network device can transmit and receive signals. For example, the terminal device receives signals, and the network device transmits signals. Alternatively, the terminal device transmits signals, and the network device receives signals.

[0069] As an example, data / signaling can be transmitted between the terminal device and the network device.

[0070] Network equipment can provide services to the serving cell where the terminal device is located. The cell where the terminal device is located can be an NTN cell or a terrestrial network cell, without limitation. As one embodiment, the terminal device is a UE in an NTN cell, and the network equipment is a satellite covering the NTN cell. As another embodiment, the terminal device and network equipment are a terminal and base station that interact in a 6G communication system or other future communication systems.

[0071] As an example, the serving cell where the terminal device is located can simultaneously contain both traditional terminal devices and new terminal devices.

[0072] Figure 4 The method shown includes steps S410 and S420, which are described below. It should be noted that the wireless communication method proposed in this application includes, but is not limited to, these steps.

[0073] See Figure 4 In step S410, the terminal device receives CSI-RS sent by the network device. In some embodiments, the terminal device may receive CSI-RS according to the first configuration information. When the terminal device is a traditional terminal device, the terminal device receives any CSI-RS in the first group of CSI-RS; when the terminal device is a new type of terminal device, the terminal device receives any CSI-RS in the second group of CSI-RS.

[0074] In some embodiments, the first configuration information is used to indicate the CSI-RS configuration; therefore, the first configuration information can also be referred to as CSI-RS configuration information. The CSI-RS configuration can also be referred to as CSI configuration. The CSI-RS configuration includes at least one of the following: multiple CSI-RS resources or a set of CSI-RS resources, CSI-RS configuration parameters, CSI reporting configuration information, and aggregation mode of multiple CSI-RS resources. The CSI reporting configuration information may include the period at which the terminal device reports CSI, i.e., the CSI reporting period.

[0075] CSI-RS resources are time-frequency resources used for transmitting CSI-RS. Terminal devices can receive CSI-RS on CSI-RS resources. The time-domain location corresponding to the CSI-RS resource is the time unit for the terminal device to receive CSI-RS, i.e., the CSI-RS timing or CSI-RS reception timing. The frequency-domain location corresponding to the CSI-RS resource is the frequency unit for the terminal device to receive CSI-RS.

[0076] As an example, a CSI-RS resource can be one or more resource blocks (RBs) or one or more REs.

[0077] As an example, the time-domain location corresponding to a CSI-RS resource can be one or more time slots, or one or more symbols. The symbol can be, for example, an orthogonal frequency division multiplexing (OFDM) symbol.

[0078] As an example, the frequency domain location corresponding to the CSI-RS resource can be one or more subcarriers, or one or more carriers.

[0079] As an example, the multiple CSI-RS resources indicated by the first configuration information can be non-zero power (NZP) CSI-RS resources or zero power (ZP) CSI-RS resources, and there is no limitation here.

[0080] As an example, the terminal device can receive multiple CSI-RS to improve the accuracy of channel estimation.

[0081] As one embodiment, the terminal device can receive CSI-RS on the first CSI-RS resource indicated by the first configuration information. When the terminal device is a new type of terminal device, the first CSI-RS resource can be aggregated with other CSI-RS resources.

[0082] As an example, the first configuration information can be used to configure CSI-RS / codebook. For instance, the first configuration information can be used to configure CSI-RS / codebook via the parameter CSI-ReportConfig. The codebook indicated by the first configuration information can be a first codebook, which will be explained in detail below in conjunction with step S420.

[0083] As an example, the first configuration information may also indicate the maximum rank R. max Maximum number of effective ports The maximum number of valid ports is, for example, 16 or 32.

[0084] After receiving the CSI-RS, the terminal device can perform measurements on the CSI-RS, i.e., CSI measurement. Through these measurements, the terminal device can determine multiple channel estimation results for all ports corresponding to the CSI-RS. As an example, the terminal device can perform measurements separately based on groups of all ports. All ports can be grouped based on covered CSI-RS resources or panels. For example, for multiple CSI-RS resource sets or panel groups, the terminal device can measure only one group for each CSI process.

[0085] As one example, network devices can configure multiple CSI-RS resource sets or panel groups via RRC signaling. Terminal devices can perform measurements on multiple CSI-RS resource sets or multiple panels separately and obtain multiple channel estimation results.

[0086] As one example, the total number of ports corresponding to CSI-RS is any value greater than 32. As another implementation, the total number of ports corresponding to CSI-RS is one of the following: 48, 64, 128, or 256. When the number of CSI-RS ports is greater than 32, the current communication scenario is a multi-port or high-port scenario. For example, the first configuration information can configure a CSI-RS resource set containing 64 / 128 ports. This CSI-RS resource set can contain multiple NZP CSI-RS resources that are aggregated.

[0087] As an example, for each NZP CSI-RS reception opportunity within each CSI reporting period, the terminal device can obtain the pilot vector at frequency domain location f (which can be a subcarrier or a set of reference REs within an RB), and construct a pilot matrix based on the known CSI-RS reference sequence / port mapping. The terminal device performs channel estimation at the port dimension to obtain the port vector channel estimate for each frequency domain location.

[0088] After obtaining multiple channel estimation results based on measurements of the CSI-RS, the terminal device needs to report the CSI. To reduce the overhead of CSI reporting, the terminal device can process multiple channel estimation results corresponding to multiple ports.

[0089] In some embodiments, the terminal device can process multiple channel estimation results based on frequency domain aggregation. For example, the frequency domain aggregation can be used to synthesize multiple channel estimation results into an equivalent channel estimation result in the frequency domain. Alternatively, the frequency domain aggregation can be used to synthesize the statistics or correlation features corresponding to multiple channel estimation results into an equivalent statistic in the frequency domain.

[0090] As an example, the statistics or correlation features corresponding to multiple channel estimates can be relevant parameters used to select the PMI. Statistics or correlation features are, for example, a correlation measure between ports or an equivalent power / covariance feature.

[0091] As one example, the equivalent channel estimation result can be for wideband PMI or for subband PMI, and this application embodiment does not limit it in this way.

[0092] As one example, the equivalent statistic can be for broadband PMI or for subband PMI, and this application does not limit this.

[0093] As one embodiment, the terminal device can perform channel estimation based on the received CSI-RS, and then synthesize multiple channel estimation results in the frequency domain into an equivalent channel estimation result to represent the overall channel trend. For example, the terminal device can average or weightedly average multiple channel estimation results to obtain an equivalent channel estimation result.

[0094] Optionally, the terminal device can obtain full-port channel estimation results at each CSI-RS timing and at each frequency domain location. Subsequently, the terminal device can directly perform frequency domain aggregation on these frequency domain channel estimates while maintaining the port dimension unchanged; that is, first estimate the channel, and then synthesize the channel estimation results into an equivalent channel estimation result in the frequency domain. For wideband PMI, the terminal device can average or weightedly average the port channel estimates at all frequency domain locations used for CSI reporting to obtain a wideband equivalent channel vector. This wideband equivalent channel vector represents the overall channel trend across the entire bandwidth. The terminal device can select a wideband PMI based on this wideband equivalent channel vector and generate the corresponding CSI report. For subband PMI, the terminal device can average or weightedly average the port channel estimates at the frequency domain locations included in each CSI subband to obtain the corresponding subband equivalent channel vector. The terminal device can select a subband PMI based on the equivalent channel vector of each subband and output the subband-related PMI information in the CSI report.

[0095] As one embodiment, the terminal device can perform channel estimation based on the received CSI-RS, then determine multiple statistics or correlation features for PMI selection based on multiple channel estimation results, and then synthesize the multiple statistics or correlation features in the frequency domain into an equivalent statistic to evaluate the matching degree of candidate codewords or candidate precoding matrices. For example, the terminal device can average or weighted average the multiple statistics to obtain the equivalent statistic.

[0096] Optionally, after completing port channel estimation at each frequency domain location, the terminal device may not directly average the channel vector itself, but instead first construct statistics for PMI selection based on the channel estimation. Subsequently, the terminal device can aggregate these statistics in the frequency domain; that is, first estimate the channel, then synthesize an equivalent statistic using the statistics / correlation features for PMI selection in the frequency domain. For wideband PMI, the terminal device can average or weightedly average the statistics corresponding to all frequency domain locations to form a wideband equivalent statistic. The terminal device can then evaluate the matching degree of each candidate codeword / precoding matrix within the wideband range based on this wideband equivalent statistic and select the wideband PMI accordingly. For subband PMI, the terminal device can average or weightedly average the statistics corresponding to the frequency domain locations within each CSI subband to form a subband equivalent statistic. The terminal device can then select the subband PMI using the equivalent statistics of each subband and generate a subband-level CSI report.

[0097] In step S420, the terminal device determines the first PMI based on the first codebook and CSI-RS.

[0098] The first PMI can be either a broadband PMI or a subband PMI. To achieve refined PMI and reduce resource overhead, the first codebook can implement a two-order structure based on a subset of the first ports through a two-step design. The two-order structure can include a first order and a second order. The first order can be used to determine the ports / beams, and the second order can determine the PMI based on the ports / beams determined by the first order.

[0099] As an example, in the first stage, the terminal device can determine a first port subset based on all ports corresponding to CSI-RS, and the first PMI is only associated with the first port subset. The following sections will provide a detailed explanation in conjunction with the first port subset.

[0100] In some embodiments, the first codebook is an angle-delay (AD) domain Type 2 codebook (i.e., AD-domain Type 2 (Type-II) codebook). The AD domain Type 2 codebook can also be called an angle-time domain Type 2 codebook. Traditional Type 2 codebooks involve not only RE matching but also overhead and structural issues such as PMI / RI / layer number and port grouping. Therefore, the first codebook improves upon traditional Type 2 codebooks through a two-step design to reduce overhead while refining PMI.

[0101] As an example, when the first codebook is an AD-domain type 2 codebook, the key to fine-grained PMI based on the first codebook is that for a large-port channel of 64 / 128, directly performing codebook search and quantization in the high-dimensional space of physical port × frequency domain would lead to high complexity and feedback overhead. Therefore, the terminal device can first project the obtained port domain / frequency domain channel estimation results to the angle × time delay domain through a two-dimensional orthogonal transformation, thereby obtaining a set of angle-time domain ports, so as to perform energy concentration assessment and subsequent port subset selection in this domain. During the CSI-RS timing in each CSI reporting period, the terminal device performs channel estimation on all 64 / 128 ports, obtaining port channel estimation results that vary with frequency domain position. This port domain / frequency domain channel estimation result can be regarded as a two-dimensional structure: one dimension is the port dimension (reflecting the array spatial characteristics), and the other dimension is the frequency domain dimension (reflecting the frequency selectivity caused by multipath).

[0102] In the above embodiments, the terminal device performs a two-dimensional discrete Fourier transform (DFT) on the aforementioned two-dimensional channel, or an equivalent two-dimensional orthogonal transform. For example, performing DFT / orthogonal projection in the port dimension can map the physical port / array response to several angles, i.e., the beam / spatial frequency dimension, thereby making the spatial correlation and principal energy direction explicit. Similarly, performing an orthogonal transform in the frequency domain dimension, such as DFT / inverse discrete Fourier transform (IDFT), can map the frequency response to several time delays, thereby making the principal time delay component of the multipath explicit. The output after the two-dimensional transform is not a new physical antenna port, but rather a set of coefficients after expanding the original high-dimensional port channel on a set of predefined orthogonal bases. In other words, an angle-time domain port is an equivalent port / coefficient in the transform domain. In typical propagation environments, channel energy is often concentrated in a few angular directions and a few time delay locations, exhibiting a certain degree of sparsity or energy concentration, thus facilitating the subsequent retention of only a small number of high-energy ports in the fine PMI process. Therefore, it can be seen that the first codebook based on the AD domain can reduce the overhead of refined PMI.

[0103] As an example, the first codebook can be a combined codebook or a hierarchical codebook.

[0104] As an example, the type of the first codebook (codebookType) can be type 2 single-panel / double-panel based on the AD field. This type can be represented as type2-AD-SinglePanel / MultiPanel.

[0105] It should be noted that whether to use the first codebook depends on the capability indication of the terminal device. That is, the network device determines whether to configure the terminal device to determine the first PMI based on the first codebook based on the terminal device's capability indication. The terminal device may indicate at least one of the following in its capability information: support for AD domain Type 2 codebook (“Type-II-AD”); support for Type 2 fine PMI for 48 / 64 / 128 ports (“Type-II fine PMI for 48 / 64 / 128 ports”); maximum number of supported active ports; and maximum number of subbands, etc. When the terminal device's capability information indicates at least one of the above, the first configuration information configures the first codebook for the terminal device.

[0106] In some embodiments, the first codebook is associated with one or more of the following: an initial codebook where channel changes are within a specified range; the codebook corresponding to the PMI reported in the last CSI report; a hierarchical codebook; or a tiered codebook. For the determination of the Type 2 codebook PMI, the greatest resource consumption is codebook search, especially in 128-port and multi-layered scenarios. Associating the first codebook with at least one of the above information helps reduce the resource consumption caused by codebook search.

[0107] As an example, when the first codebook is associated with an initial codebook where the channel changes are within a specified range, the update frequency of the first codebook does not need to be synchronized with each CSI reporting period, thereby reducing resource consumption. The premise that the channel changes are within a specified range may include a fixed set of "main direction / main beam + port subset + initial PMI".

[0108] As an example, when the first codebook is related to the codebook corresponding to the PMI in the previous CSI report, the terminal device can perform only a neighborhood search instead of a global search, thereby reducing resource consumption. This neighborhood can refer to the neighborhood of the previously reported PMI. For example, the terminal device can use the PMI from the previous CSI report as an initial value and search only within its neighborhood (several indices before and after it). For scenarios with low mobility (e.g., fixed wireless access (FWA) or indoor scenarios), where channel direction changes smoothly, this approach can keep the complexity within a certain range. For example, performing a neighborhood search around the vicinity of the previous PMI instead of a global search of the entire codebook.

[0109] As an example, when the first codebook is related to the codebook corresponding to the PMI in the previous CSI report, the terminal device can update only the amplitude or make phase fine adjustments. Specifically, the terminal device can generate ΔPMI based on the PMI in the previous CSI report, instead of requantizing the entire complete PMI, thus reducing resource consumption.

[0110] As an example, when the first codebook is associated with a hierarchical or tiered codebook, the number of candidates for codebook search can be significantly reduced, thereby reducing resource overhead. For instance, the terminal device first selects an optimal direction / beam cluster on the coarse codebook, and then searches only within the fine codebook subset corresponding to that beam cluster, to reduce the number of candidates |C|, for example, from 1024 to 64.

[0111] The first port subset can be one of the following: a subset of valid ports selected from all ports corresponding to CSI-RS; or one of multiple port subsets divided from all ports corresponding to CSI-RS. When the first port subset is a subset of valid ports, the first codebook uses a two-order structure plus the subset of valid ports to achieve refined PMI. When the first port subset is one of multiple port subsets, the first codebook can be a traditional codebook or a codebook based on a two-step design.

[0112] When the first port subset is the effective port subset, the two-order structure of the first codebook can include the first and second orders described above. In the first order, the terminal device can select ports / beams to determine the effective port subset. The effective port subset can be selected based on the energy of the covered ports. The number of ports included in the effective port subset can be expressed as... For example, among the 48 / 64 / 128 physical layer CSI-RS ports, first select one... A subset of valid ports ≤32 is selected, ensuring these ports cover the main power direction of the terminal device. In the second stage, a refined PMI is implemented based on the first codebook on the subset of valid ports.

[0113] When the first subset of ports is a valid subset of ports, the terminal device only performs fine-grained PMI on the valid ports in that subset; other ports are treated as 0 or used only for coarse statistics to reduce complexity and feedback overhead. For example, in the selected... On each port, the first codebook is reused, and the direction (primary / secondary beam) and weight (amplitude / phase) of each layer are finely quantified to obtain the fine PMI.

[0114] As an example, to ensure that a subset of effective ports covers the main energy, a subset of effective ports can be selected based on energy. For instance, the terminal device can first perform a low-precision, low-complexity energy estimation using least squares (LS) and a few subcarriers to determine which groups of ports have high energy. After selecting candidate ports, only ports from the subset of valid ports are included in the subsequent AD field / singular value decomposition (SVD) / type 2 codebook search; other ports are only roughly counted and can even be ignored.

[0115] The valid port subset can be determined by the terminal device, or it can be determined by the network device; there is no limitation here.

[0116] When the subset of valid ports is determined by the terminal device, the terminal device can select valid ports in the energy-based manner described above.

[0117] When the effective port subset is determined by the network device, this subset is also called the network device-side port subset for uplink (UL) assistance. The network side selects and indicates the effective port subset to the end device, which can then use it directly. For example, the network device can use UL sounding reference signal (SRS) / UL CSI (partial reciprocity) for long-term statistics to find the primary energy port subset for each end device / direction offline. Alternatively, the network device can directly assign one or more port subset identifiers (IDs) to the end device through higher-layer configuration; the end device does not need to select dynamically but only performs Type 2 PMI on these subsets.

[0118] As an example, a terminal device or network device can select from multiple physical ports. The most effective port that contributes the most.

[0119] As an example, the energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the AD domain. That is, the terminal device or network device can select effective ports based on the relationship between the port's energy concentration and the first threshold. The first threshold being associated with the AD domain can be understood as a parameter related to the AD domain's energy, such as energy concentration.

[0120] As another embodiment, the effective port subset The port with the highest energy concentration among all ports corresponding to CSI-RS. Ports. For example, terminal devices or network devices can select valid ports based on the AD domain energy on the terminal device side. First, sort by sub-band: within each CSI sub-band b, sort the energy E of all candidate points (i,j) in the AD domain. (i,j) Sort by largest to smallest, and take the first few. Each AD port is then mapped back to a physical port, followed by projection / mapping: these high-energy AD ports are mapped back to their corresponding physical CSI-RS ports or port combinations according to the configured two-dimensional (2D) DFT / mapping relationships; if multiple AD ports are highly correlated, they can be merged into a group (corresponding to a beam group in the codebook). Finally, based on the mapping results, a subset of effective ports is obtained and the output is formed.

[0121] As an example, after the terminal device selects a subset of valid ports from all ports corresponding to CSI-RS, the terminal device reuses the first codebook on all ports of the valid port subset to obtain the first PMI.

[0122] When the first port subset is one of multiple port subsets, the network device can pre-configure one or more sets of port subset IDs, such as different panels / locations. For example, for 64 / 128 ports, the network side can logically split it into 2-8 sub-panels, with each CSI report processing only one of them, thus only one report is sent at a time. ≈16 / 32 ports.

[0123] As an example, multiple port subsets can be determined based on different combinations of panels at different orientations / heights.

[0124] As one embodiment, when the first port subset is one of multiple port subsets, the terminal device sends a first CSI report corresponding to the first port subset. The first CSI report may include a first PMI obtained based on the first port subset. The multiple port subsets may also include a second port subset, and the terminal device may send a second CSI report corresponding to the second port subset after sending the first CSI report. The second CSI report may include a second PMI obtained based on the first port subset. That is, the terminal device may send multiple CSI reports sequentially for multiple port subsets. The multiple CSI reports may include multiple PMIs obtained based on the first port subset. The first CSI report is only one of the multiple CSI reports sent by the terminal device.

[0125] In some scenarios, network devices can merge multiple CSI reports received sequentially to obtain the final CSI. In other scenarios, network devices can select or process multiple CSI reports to determine the final CSI. For example, a network device can process or select multiple PMIs to determine the PMI used for the downlink channel.

[0126] As one example, multiple port subsets are determined based on configuration information indicated by RRC signaling. For instance, for port subsets / groups, network devices can configure multiple CSI-RS resource sets or panel groups via RRC signaling.

[0127] As an example, at least two port subsets within a set of multiple port subsets have different activation times. That is, multiple port subsets can be activated at different times to allow network devices to perform staggered CSI-RS configuration, thereby reducing resource consumption. For instance, for multiple CSI-ReportConfigs of the same terminal device (such as different panels and different beam sets), staggering the CSI-RS periods ensures that the terminal device does not receive multiple high-port-count CSI-RSs in the same time slot. Another example is configuring multiple CSI-RS sets at higher layers, each corresponding to different port subsets. At any given time, the network device only activates 1-2 of these CSI-RS sets; the others are marked as idle and used only for subsequent handover / reconfiguration, without requiring the terminal device to perform measurements in the current period.

[0128] As an example, activation indications for multiple port subsets are carried in higher-layer signaling. Higher-layer signaling could be, for example, RRC signaling.

[0129] As an example, multiple port subsets correspond to multiple CSI-RS sets. CSI-RS within each CSI-RS set are activated synchronously. At least two of the multiple CSI-RS sets have different activation times.

[0130] The first PMI is associated with a first port subset. Since the first PMI is determined based on a first codebook, and the first codebook is related to the first port subset, as an example, the first codebook is used to determine the PMI corresponding to the ports in the first port subset.

[0131] As an example, the first port subset includes a number of ports less than or equal to 32. That is, the first port subset includes a number of ports of 32 or less. For example, the first port subset includes a number of ports of 8, 16, 24 or 32.

[0132] In some embodiments, the number of ports included in the first port subset can be determined based on the actual communication situation. That is, the terminal device can adaptively adjust the number of ports in the first port subset. For example, for low signal-to-noise ratio (SNR) / low rank scenarios, the number of ports included in the first port subset can be set to a smaller number, such as 8 or 16, to reduce feedback overhead. Conversely, for high SNR / high rank scenarios, the number of ports included in the first port subset can be increased to 24 or 32 to support spatial diversity / multistream.

[0133] As an example, the number of ports included in the first port subset can be smoothed using a time dimension. For instance, the selection of the effective port subset can be based on a time average of multiple CSI periods to reduce frequent jitter over time and decrease mismatches.

[0134] As an example, the ID of the first port subset can be reused. Several port subset IDs can be predefined for the same terminal device. The terminal device only returns the currently selected subset ID plus the PMI within the subset, which can save some bits.

[0135] In some embodiments, in order to reduce resource consumption, "the terminal device determines the first PMI according to the first codebook and CSI-RS" may include at least one of the following: the terminal device determines the first sub-PMI according to the first codebook on a portion of the subbands and determines the second sub-PMI according to the second codebook on the remaining subbands, and the first sub-PMI and the second sub-PMI constitute the first PMI; the terminal device determines the multiple sub-PMIs that constitute the first PMI according to the reception timing of multiple CSI-RSs respectively.

[0136] As an example, the period of the CSI-RS corresponding to the first codebook is shorter than the period of the CSI-RS corresponding to the second codebook.

[0137] As an example, the second codebook can be any codebook with less overhead than the first codebook. For example, the second codebook is a type 1 codebook.

[0138] As one embodiment, the terminal device determines a fine-grained PMI based on the first codebook only for selected sub-bands, rather than performing this processing on all sub-bands. For example, the terminal device can determine a fine-grained PMI based on the first codebook, i.e., a first sub-PMI, for several sub-bands with a high signal-to-interference-plus-noise ratio in the frequency domain; for the remaining sub-bands, it only determines a Type 1 codebook PMI or a wideband PMI, i.e., a second sub-PMI. The first sub-PMI can be used for multi-user MIMO (MU-MIMO). In this embodiment, the complexity of the codebook can decrease linearly with the number of sub-bands.

[0139] As an example, when the terminal device determines the multiple sub-PMIs constituting the first PMI according to the reception timing of multiple CSI-RS, the terminal device does not wait to receive all CSI-RSs before performing channel estimation, which can improve processing efficiency. That is, once the terminal device receives CSI-RS on an OFDM symbol, it immediately performs channel estimation and energy accumulation on that symbol. Therefore, the measurements and calculations performed by the terminal device do not have to wait until all CSI-RSs on the entire time slot or frame have been received.

[0140] As an example, for multi-port or highly complex CSI-RS, the CSI period can be reduced. For instance, the period of the CSI-RS corresponding to the first codebook can use a long period or an on-demand CSI-RS. In this case, a lower period (e.g., 40ms / 80ms) can be used for highly complex first codebook-based CSI, while a higher period can be used to cover the less complex second codebook / CQI.

[0141] After determining the first PMI, the terminal device can send a CSI report to the network device. Upon receiving the CSI reported by the terminal device, the network side (e.g., gNB) reconstructs the fine precoding for downlink transmission based on the CSI. The information in the CSI may include: RI, the fine PMI based on the first codebook (first PMI), and optional wideband PMI based on the second codebook (coarse PMI), etc.

[0142] For ease of understanding, the following example illustrates the process of a terminal device receiving configuration information and CSI-RS, and reporting CSI, assuming the first port subset is a valid port subset. This process assumes the number of physical ports is 64 or 128; the network device is configured with a first codebook based on the valid port subset; and the terminal device performs a fine-grained PMI once per CSI reporting period. The process includes six steps, S1 to S6, as detailed below.

[0143] In step S1, the terminal device receives the CSI-RS / codebook configuration.

[0144] In step S2, the terminal device performs channel estimation based on the received CSI-RS and performs frequency domain aggregation on the channel estimation results, such as... Figure 5 As shown. See also Figure 5 In step S510, the terminal device measures the CSI-RS to determine multiple channel estimation results for all ports corresponding to the CSI-RS. In step S520, the terminal device processes the multiple channel estimation results based on frequency domain aggregation. Through step S520, an equivalent channel estimation result or an equivalent statistic can be obtained for all ports.

[0145] In step S3, the terminal device performs angle-to-time transformation and energy statistics. The core of determining the PMI based on the first codebook is the angle-to-time port. The terminal device can perform a 2D DFT transformation to obtain a set of angle-to-time ports.

[0146] For example, projecting the channel in the frequency domain plus port dimension onto the angle × time delay domain: ; In this context, the angle-time domain (AD domain) channel representation is the projected channel matrix (or an equivalent two-dimensional representation), whose elements can be obtained using... or This represents the coefficient at a certain angle index and delay index; The channel representation in the port domain (physical CSI-RS port domain) typically includes estimation results in both the port dimension and the frequency domain dimension (e.g., port × frequency point, or port × subband / PRB). It is a DFT (or predefined orthogonal transformation) matrix in the port dimension, used to project the physical port / array dimension to the angle (beam) dimension; This is a DFT (or predefined orthogonal transform) matrix in the frequency domain, used to project frequency domain samples onto the time delay dimension. It is its conjugate transpose.

[0147] Optionally, In Angle index for the AD domain (can be understood as a beam / angle number); This is the delay index for the AD field (which can be understood as a delay number). It is a frequency domain index (which can correspond to the index of the RB set within the subcarrier, PRB, or CSI subband).

[0148] When performing energy statistics, for broadband PMI: the terminal device can sum across all frequency points; for sub-band PMI, the terminal device can perform individual statistics within each CSI sub-band. The statistical energy on each AD port is: ; in, It is the first One AD port (angle) Delay The energy metric is used to characterize the contribution of the AD port; For the square of the complex amplitude; based on Summation means summing over frequency domain positions (or equivalent weighted summation).

[0149] As mentioned above, the AD port is not a newly added physical antenna port. It refers to a set of transform domain coefficients / equivalent ports obtained by transforming the original physical CSI-RS port domain × frequency domain channel estimation results through angle-time delay two-dimensional transformation.

[0150] The terminal device can target each corner-time domain port. Statistical energy This is used to measure the effect of the angle-time domain port on the overall channel. For broadband PMI scenarios, the terminal device accumulates / sums all frequency domain positions used for broadband CSI to obtain the value for each... Broadband energy measurement (i.e., summation over all frequency points). For sub-band PMI scenarios, the terminal device performs energy statistics separately within each CSI sub-band, i.e., forming a separate set for each sub-band. (That is, statistics are collected separately within each CSI subband). In many scenarios, channel energy is concentrated at a few angles and with a few delays. Terminal devices can collect statistics on each CSI subband in the AD domain. energy We select a small number of AD ports with the highest energy and then map them back to a subset of physical ports for subsequent fine-grained PMI calculations based on the first codebook, thereby reducing complexity and feedback overhead.

[0151] In step S4, the terminal device selects valid ports. After obtaining the set of valid ports, the terminal device can obtain one for each sub-band. A list of valid ports. , For example, it is 32. This list indicates the port index or beam group index.

[0152] The terminal device can output a list of valid ports for this subband. Its number of elements is , denoted as: ; in, This indicates the final number of valid ports (or valid port groups) selected from multiple physical ports; This indicates the maximum allowed number of valid ports.

[0153] In step S5, quantization of the first codebook is performed on the subset of valid ports to obtain the first PMI. The first PMI is a fine-grained PMI. Terminal device determination. Subsequently, the dimensionality of the processing flow based on the first codebook was reduced from 64 / 128 to .

[0154] First, the terminal device performs subset channel matrix extraction. Each port corresponds to a frequency-domain aggregated port channel coefficient (or a small-dimensional vector) in subband b, as follows: ; in, This indicates that the physical port index is on subband b. The port domain channel estimate is typically a complex scalar (the equivalent channel of the port in subband b). This represents the extracted port channel vector, with dimension . ×1.

[0155] This formula represents the set of valid ports of the terminal device based on the b-th sub-band. Only the channel components corresponding to these ports are retained from the full-port channel to form a low-dimensional channel. This is used for subsequent search / PMI quantization of the first codebook to reduce the processing dimension from 64 / 128 to ≤16 / 32.

[0156] The choice of the first codebook is related to the choice of rank and the number of layers. For each possible rank r=1,…,R max Calculate a performance metric and select the best performing r' as the RI. This step is consistent with the coarse PMI in Type 1 codebooks or the RI decision in standard Type 2 codebooks, except that it is based on h. eff .

[0157] The first codebook can be decomposed based on primary / secondary beams and weights. Following the standard type 2 codebook structure, the refined PMI can be broken down into multiple parts based on mode 1 / 2 / 3: primary beam / sub-band direction index, several selected beam group indices for each layer, and complex weights (or amplitude + phase quantization indexes) for each layer. Within the 2D port space, the terminal device can select a precoding vector / matrix from the type 2 codebook set C, such that the precoding is consistent with... The matching degree (e.g., equivalent SNR or capacity metric) is the highest, as follows: ; in, It is the codebook entry that the terminal device ultimately selects, which is the mathematical object of the fine PMI, and its discrete index will be encoded into PMI bits; It is the set containing the first codebook; It is a signal-to-interference-plus-noise ratio / capacity metric.

[0158] Optionally, when r'=1, a candidate precoding vector / beam vector, dimension r'=1 indicates that the terminal device determines "layer 1 is best", so the subsequent PMI only needs to select one precoding vector. When r'>1, a candidate precoding matrix needs to be selected, with dimensions... Each column can correspond to a precoding vector of one layer.

[0159] For PMI bit generation, each selection in the first codebook (main beam ID, beam group ID, weight index, etc.) corresponds to a certain number of bits. These bits are then concatenated to obtain the refined PMI bit field, which is then filled into the CSI message of the physical uplink control channel (PUCCH) / physical uplink shared channel (PUSCH). Therefore, step S5 involves refining the PMI bit field... The dimensional port space defines a standard PMI based on the first codebook, thereby focusing the resolution on the direction where there is a real signal, achieving a fine PMI.

[0160] Steps S4 and S5 can be as follows Figure 6 As shown. See also Figure 6 In step S610, the terminal device selects a subset of valid ports from all ports corresponding to CSI-RS. In step S620, the first codebook is multiplexed on all ports of the subset of valid ports.

[0161] In step S6, the network side can complete the precoding reconstruction and application in the following manner.

[0162] First, the network side reconstructs or determines the set of valid ports corresponding to each CSI subband b. . The network side can pre-determine the candidate port subset and indexing rules in the higher-layer configuration (e.g., by determining the candidate port subset and indexing rules through RRC / semi-static parameters), and can further combine the subset-related information carried by the terminal device in the PMI (if it exists) to recover the final effective port set of the subband. Thus, the network side can determine the set of port locations participating in the downlink precoding of the terminal device in the full port dimension P, while unselected ports will not participate in the fine precoding of the terminal device.

[0163] As an example, the set of valid ports for subband b The determination method can be any of the following or a combination thereof: Method 1, Fixed / Semi-Static Determination on the Network Side: The network side configures a set of candidate valid ports or a set of candidate port groups for the terminal device in the RRC configuration, and defines the mapping relationship between the port subset index and the port / port group. The network device can then directly recover based on this. ; Method 2, dynamic indication on the terminal device side: The terminal device explicitly carries subset-related information (such as subset ID or port group ID) in the CSI report, and the network device restores the network based on the subset information and the configured mapping relationship. ; Method 3, combined approach: The network side configures multiple candidate subsets, and the terminal device only returns the index of one subset, thus balancing flexibility and feedback overhead.

[0164] Secondly, based on the PMI bit field reported by the terminal device, the network side determines the corresponding precoding entry from the set containing the predefined first codebook, and obtains the low-dimensional precoding matrix on subband b. .in, The dimension is , The number of valid ports. The optimal rank (i.e., the number of layers) reported by the terminal device.

[0165] For example, the PMI bit field consists of the main beam / coarse direction index, beam group index, and complex weights (or amplitude and phase quantization index), which allows the network to completely reconstruct the precoding vector (single layer) or precoding matrix (multi-layer) in the codebook.

[0166] Furthermore, to enable low-dimensional precoding to be used directly in the full-port transmit space of network devices, the network side will... Embedded into the full-port dimension P, constructing a full-dimensional precoding matrix. For example, the network side can construct a selection / embedding matrix. This matrix is ​​used to... The effective port space is mapped to the P-dimensional full port space, and zeros are filled in the unselected port positions.

[0167] For the full-port dimension, network devices can construct the final precoding matrix in P-dimensional space: ; in, It is a selection matrix, which... 1-dimensional mapping to P-dimensional (fill in 0 for invalid ports), for example, .

[0168] For low-dimensional precoding It is the precoding matrix (within the effective port subspace) retrieved by the network device from the codebook set based on the first codebook PMI reported by the terminal device. Each column corresponds to a precoding vector of layer l (the beam of layer l). For the selection / embedding matrix, It is a selection matrix, used to select... 1D vectors / matrices are embedded back into the P-dimensional port space.

[0169] Optionally, It can be a 0 / 1 matrix: each column corresponds to a valid port position; the row corresponding to that port is set to 1, and the other rows are set to 0. The l-th row is placed into the full-port matrix by p l For the specified location, enter 0 for other unselected port rows.

[0170] For full-dimensional precoding . It is the final precoding matrix in the full-port dimension, with a dimension of P× For those who are not in For ports in the set, the corresponding row element is 0 (equivalent to the port not participating in the precoding of the terminal device). For ports in the set, the corresponding row is... The corresponding decision is made in the middle.

[0171] thus, Inherit on the row corresponding to the valid port The precoding coefficients are set to zero in the rows corresponding to ineffective ports, thus achieving the goal of "using only a subset of effective ports for fine precoding". Finally, during multi-user scheduling and resource allocation, the network side can comprehensively determine the user set, layer allocation, and power allocation strategy on the same time-frequency resource by integrating the CSI of multiple terminal devices (including the RI of each terminal device, the first codebook PMI, and the optional second codebook wideband PMI), and based on each terminal device... MU-MIMO joint precoding is performed to generate a precoded transmit signal for downlink transmission. In this way, the network side can effectively map the low-dimensional fine-grained CSI feedback from the terminal device side to the full-port transmit dimension while maintaining backward compatibility, thus enabling the reconstruction and application of sub-band fine-grained precoding.

[0172] As an example, joint precoding includes zero-forcible, regularized zero-forcible, or minimum mean square error (MMSE) class precoding.

[0173] As an example, for precoding in multi-user scheduling, the network device obtains information from each terminal device. After RI and optional broadband PMI, multi-user scheduling and resource allocation can be performed on each subband, and MU-MIMO joint precoding can be performed based on the full-dimensional precoding matrix of multiple terminal devices. At the same time, the final downlink transmission signal is generated by combining power allocation and other strategies.

[0174] As can be seen from steps S1 to S6 above, the fine PMI first uses angle-time domain energy / UL reciprocity to perform port subset selection (reducing the 64 / 128 ports to...) (≤32 valid ports), and then the first codebook can be reused on this subset, concentrating the limited PMI bits on the truly energetic directions and ports.

[0175] The above text combined Figures 1 to 6 The method embodiments of this application are described in detail below. Figures 7 to 9 The present application provides a detailed description of the apparatus embodiments. It should be understood that the descriptions of the apparatus embodiments correspond to the descriptions of the method embodiments; therefore, any parts not described in detail can be found in the foregoing method embodiments.

[0176] Figure 7 This is a schematic block diagram of a device for wireless communication according to an embodiment of this application. The device 700 can be any of the terminal devices described above. Figure 7 The apparatus 700 shown includes a receiving unit 710 and a processing unit 720.

[0177] The receiving unit 710 can be used to receive CSI-RS.

[0178] Processing unit 720 can be used to determine a first PMI based on a first codebook and the CSI-RS; wherein the first PMI is associated with a first port subset, the first codebook is used to determine the PMI corresponding to the ports in the first port subset, and the first port subset is one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; or the first port subset is one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0179] Optionally, the energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the AD domain.

[0180] Optionally, the subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

[0181] Optionally, the processing unit 720 is further configured to: select the subset of valid ports from all ports corresponding to the CSI-RS; and multiplex the first codebook on all ports of the subset of valid ports to obtain the first PMI.

[0182] Optionally, the device 700 further includes a sending unit, which can be used to send a first CSI report; wherein the first port subset corresponds to the first CSI report, the first CSI report is one of a plurality of CSI reports sent by the terminal device, and the plurality of CSI reports respectively correspond to the plurality of port subsets.

[0183] Optionally, the plurality of port subsets are determined based on configuration information indicated by RRC signaling.

[0184] Optionally, at least two port subsets in the plurality of port subsets have different activation times, and the activation indications of the plurality of port subsets are carried in higher-layer signaling.

[0185] Optionally, the processing unit 720 is further configured to measure the CSI-RS to determine multiple channel estimation results for all ports corresponding to the CSI-RS; and to process the multiple channel estimation results based on frequency domain aggregation.

[0186] Optionally, the frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

[0187] Optionally, the frequency domain aggregation is used to synthesize an equivalent statistic in the frequency domain by combining the statistics or correlation features corresponding to the multiple channel estimation results.

[0188] Optionally, the number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

[0189] Optionally, the first port subset includes a number of ports less than or equal to 32.

[0190] Optionally, determining the first PMI based on the first codebook and the CSI-RS includes at least one of the following: determining a first sub-PMI based on the first codebook in a portion of the subbands, and determining a second sub-PMI based on the second codebook in the remaining subbands, wherein the first sub-PMI and the second sub-PMI constitute the first PMI; determining multiple sub-PMIs constituting the first PMI according to the reception timing of multiple CSI-RSs; wherein the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

[0191] Optionally, the first codebook is associated with one or more of the following: an initial codebook where channel changes are within a specified range; a codebook corresponding to the PMI reported in the last Channel State Information (CSI) report; a hierarchical codebook or a graded codebook.

[0192] Optionally, the first codebook is an AD field type 2 codebook.

[0193] Optionally, the processing unit 720 in the device 700 can be a processor 910, the receiving unit 710 can be a transceiver 930, and the device 700 may also include a memory 920, specifically as follows: Figure 9 As shown.

[0194] Figure 8 This is a schematic block diagram of another device for wireless communication according to an embodiment of this application. The device 800 can be any of the network devices described above. Figure 8The device 800 shown includes a transmitting unit 810.

[0195] The transmitting unit 810 can be used to transmit CSI-RS; wherein, the CSI-RS is used by the terminal device to determine a first PMI according to a first codebook, the first PMI is associated with a first port subset, the first codebook is used to determine the PMI corresponding to the port in the first port subset, and the first port subset is one of the following: a valid port subset selected from all ports corresponding to the CSI-RS; or the first port subset is one of multiple port subsets divided from all ports corresponding to the CSI-RS.

[0196] Optionally, the energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the angle delay AD domain.

[0197] Optionally, the subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

[0198] Optionally, all ports corresponding to the CSI-RS are used by the terminal device to select the subset of valid ports; the first PMI is obtained by multiplexing the first codebook on all ports of the subset of valid ports.

[0199] Optionally, the device 800 further includes a receiving unit, which can be used to receive a first CSI report; wherein the first port subset corresponds to the first CSI report, the first CSI report is one of a plurality of CSI reports sent by the terminal device, and the plurality of CSI reports respectively correspond to the plurality of port subsets.

[0200] Optionally, the plurality of port subsets are determined based on configuration information indicated by Radio Resource Control (RRC) signaling.

[0201] Optionally, at least two port subsets in the plurality of port subsets have different activation times, and the activation indications of the plurality of port subsets are carried in higher-layer signaling.

[0202] Optionally, the CSI-RS is used by the terminal device to perform measurements to determine multiple channel estimation results for all ports corresponding to the CSI-RS; the multiple channel estimation results are processed by the terminal device based on frequency domain aggregation.

[0203] Optionally, the frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

[0204] Optionally, the frequency domain aggregation is used to synthesize an equivalent statistic in the frequency domain by combining the statistics or correlation features corresponding to the multiple channel estimation results.

[0205] Optionally, the number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

[0206] Optionally, the first port subset includes a number of ports less than or equal to 32.

[0207] Optionally, determining the first PMI based on the first codebook includes at least one of the following: determining a first sub-PMI based on the first codebook in a portion of the subbands, and determining a second sub-PMI based on the second codebook in the remaining subbands, wherein the first sub-PMI and the second sub-PMI constitute the first PMI; or determining multiple sub-PMIs constituting the first PMI according to the reception timing of multiple CSI-RSs respectively. Wherein, the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

[0208] Optionally, the first codebook is associated with one or more of the following: an initial codebook where channel changes are within a specified range; a codebook corresponding to the PMI reported in the last Channel State Information (CSI) report; a hierarchical codebook or a graded codebook.

[0209] Optionally, the first codebook is an AD field type 2 codebook.

[0210] Optionally, the transmitting unit 810 in device 800 can be a transceiver 930, and device 800 may further include a processor 910 and a memory 920, specifically as follows: Figure 9 As shown.

[0211] Figure 9 The diagram shown is a structural schematic of a communication device according to an embodiment of this application. Figure 9 The dashed lines indicate that the unit or module is optional. The device 900 can be used to implement the methods described in the above method embodiments. The device 900 can be a chip, a terminal device, or a network device.

[0212] The apparatus 900 may include one or more processors 910. The processor 910 may support the apparatus 900 in implementing the methods described in the preceding method embodiments. The processor 910 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0213] The apparatus 900 may further include one or more memories 920. The memories 920 store a program that can be executed by the processor 910, causing the processor 910 to perform the methods described in the preceding method embodiments. The memories 920 may be independent of the processor 910 or integrated within the processor 910.

[0214] The device 900 may also include a transceiver 930. The processor 910 can communicate with other devices or chips via the transceiver 930. For example, the processor 910 can send and receive data with other devices or chips via the transceiver 930.

[0215] This application also provides a computer-readable storage medium for storing a program. This computer-readable storage medium can be applied to a terminal device or network device provided in this application embodiment, and the program causes a computer to execute the methods performed by the terminal device or network device in the various embodiments of this application.

[0216] The computer-readable storage medium can be any available medium that a computer can read, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state disks (SSDs)).

[0217] This application also provides a computer program product. The computer program product includes a program. This computer program product can be applied to a terminal device or network device provided in the embodiments of this application, and the program causes a computer to execute the methods performed by the terminal device or network device in the various embodiments of this application.

[0218] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0219] This application also provides a computer program. This computer program can be applied to the terminal device or network device provided in this application, and the computer program causes the computer to execute the methods performed by the terminal device or network device in various embodiments of this application.

[0220] In this application, the terms "system" and "network" are used interchangeably. Furthermore, the terminology used in this application is only for explaining specific embodiments of the application and is not intended to limit the application. The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0221] In the embodiments of this application, the term "instruction" can be a direct instruction, an indirect instruction, or an indication of a relationship. For example, A instructing B can mean that A directly instructs B, such as B being able to obtain information through A; it can also mean that A indirectly instructs B, such as A instructing C, so B can obtain information through C; or it can mean that there is a relationship between A and B.

[0222] In the embodiments of this application, the term "correspondence" may indicate a direct or indirect correspondence between two things, or an association between two things, or a relationship such as instruction and being instructed, configuration and being configured.

[0223] In the embodiments of this application, "predefined" or "preconfigured" can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices). This application does not limit the specific implementation method. For example, predefined can refer to what is defined in the protocol.

[0224] In the embodiments of this application, the term "protocol" may refer to standard protocols in the field of communications, such as LTE protocols, NR protocols, and related protocols applied in future communication systems. This application does not limit the scope of these protocols.

[0225] In the embodiments of this application, determining B based on A does not mean determining B solely based on A; B can also be determined based on A and / or other information.

[0226] In the embodiments of this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0227] In the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0228] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0229] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0230] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0231] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for wireless communication, characterized in that, include: The terminal device receives the Channel State Information Reference Signal (CSI-RS) sent by the network device; The terminal device determines the first precoding matrix indicator PMI based on the first codebook and the CSI-RS; The first PMI is associated with a first port subset, and the first codebook is used to determine the PMI corresponding to the ports in the first port subset. The first port subset is one of the following: A subset of valid ports selected from all ports corresponding to the CSI-RS; The first port subset is one of the multiple port subsets divided among all ports corresponding to the CSI-RS.

2. The method according to claim 1, characterized in that, The energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the angle delay AD domain.

3. The method according to claim 2, characterized in that, The subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

4. The method according to claim 2 or 3, characterized in that, The method further includes: The terminal device selects the subset of valid ports from all ports corresponding to the CSI-RS; The terminal device multiplexes the first codebook on all ports of the valid port subset to obtain the first PMI.

5. The method according to claim 1, characterized in that, The method further includes: The terminal device sends a first CSI report; Wherein, the first port subset corresponds to the first CSI report, and the first CSI report is one of multiple CSI reports sent by the terminal device, and the multiple CSI reports respectively correspond to the multiple port subsets.

6. The method according to claim 5, characterized in that, The multiple port subsets are determined based on the configuration information indicated by the Radio Resource Control (RRC) signaling.

7. The method according to claim 5 or 6, characterized in that, At least two of the multiple port subsets have different activation times, and the activation indications of the multiple port subsets are carried in higher-layer signaling.

8. The method according to any one of claims 1-7, characterized in that, The method further includes: The terminal device measures the CSI-RS to determine multiple channel estimation results for all ports corresponding to the CSI-RS; The terminal device processes the multiple channel estimation results based on frequency domain aggregation.

9. The method according to claim 8, characterized in that, The frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

10. The method according to claim 8, characterized in that, The frequency domain aggregation is used to synthesize the statistics or correlation features corresponding to the multiple channel estimation results into an equivalent statistic in the frequency domain.

11. The method according to any one of claims 1-10, characterized in that, The number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

12. The method according to any one of claims 1-11, characterized in that, The first port subset includes 32 or fewer ports.

13. The method according to any one of claims 1-12, characterized in that, The terminal device determines the first PMI based on the first codebook and the CSI-RS, including at least one of the following: The terminal device determines a first sub-PMI based on a first codebook in some sub-bands and a second sub-PMI based on a second codebook in the remaining sub-bands. The first sub-PMI and the second sub-PMI together constitute the first PMI. The terminal device determines multiple sub-PMIs that make up the first PMI according to the reception timing of multiple CSI-RS; Wherein, the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

14. The method according to any one of claims 1-13, characterized in that, The first codebook is associated with one or more of the following: An initial codebook within a specified range for channel variations; The codebook corresponding to the PMI in the last Channel State Information (CSI) report; Hierarchical codebook or graded codebook.

15. The method according to any one of claims 1-14, characterized in that, The first codebook is an AD field type 2 codebook.

16. A method for wireless communication, characterized in that, include: Network devices transmit Channel State Information Reference Signal (CSI-RS); The CSI-RS is used by the terminal device to determine a first precoding matrix indicator PMI based on a first codebook. The first PMI is associated with a first port subset. The first codebook is used to determine the PMI corresponding to the ports in the first port subset. The first port subset is one of the following: A subset of valid ports selected from all ports corresponding to the CSI-RS; The first port subset is one of the multiple port subsets divided among all ports corresponding to the CSI-RS.

17. The method according to claim 16, characterized in that, The energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the angle delay AD domain.

18. The method according to claim 17, characterized in that, The subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

19. The method according to claim 17 or 18, characterized in that, The method further includes: The terminal device selects the subset of valid ports from all ports corresponding to the CSI-RS; The terminal device multiplexes the first codebook on all ports of the valid port subset to obtain the first PMI.

20. The method according to claim 16, characterized in that, The method further includes: The network device receives the first CSI report; Wherein, the first port subset corresponds to the first CSI report, and the first CSI report is one of multiple CSI reports sent by the terminal device, and the multiple CSI reports respectively correspond to the multiple port subsets.

21. The method according to claim 20, characterized in that, The multiple port subsets are determined based on the configuration information indicated by the Radio Resource Control (RRC) signaling.

22. The method according to claim 20 or 21, characterized in that, At least two of the multiple port subsets have different activation times, and the activation indications of the multiple port subsets are carried in higher-layer signaling.

23. The method according to any one of claims 16-22, characterized in that, The CSI-RS is used by the terminal device to perform measurements to determine multiple channel estimation results for all ports corresponding to the CSI-RS; the multiple channel estimation results are processed by the terminal device based on frequency domain aggregation.

24. The method according to claim 23, characterized in that, The frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

25. The method according to claim 23, characterized in that, The frequency domain aggregation is used to synthesize the statistics or correlation features corresponding to the multiple channel estimation results into an equivalent statistic in the frequency domain.

26. The method according to any one of claims 16-25, characterized in that, The number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

27. The method according to any one of claims 16-26, characterized in that, The first port subset includes 32 or fewer ports.

28. The method according to any one of claims 16-27, characterized in that, The CSI-RS is used by the terminal device to determine the first precoding matrix indicator PMI based on the first codebook, including at least one of the following: The first sub-PMI is determined based on the first codebook in some sub-bands, and the second sub-PMI is determined based on the second codebook in the remaining sub-bands. The first sub-PMI and the second sub-PMI constitute the first PMI. The multiple sub-PMIs that make up the first PMI are determined according to the reception timing of multiple CSI-RS; Wherein, the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

29. The method according to any one of claims 16-28, characterized in that, The first codebook is associated with one or more of the following: An initial codebook within a specified range for channel variations; The codebook corresponding to the PMI in the last Channel State Information (CSI) report; Hierarchical codebook or graded codebook.

30. The method according to any one of claims 16-29, characterized in that, The first codebook is an AD field type 2 codebook.

31. A device for wireless communication, characterized in that, The device is a terminal device, and the device includes: The receiving unit is used to receive the Channel State Information Reference Signal (CSI-RS) sent by the network device. Processing unit, configured to determine first precoding matrix indicator PMI based on first codebook and CSI-RS; The first PMI is associated with a first port subset, and the first codebook is used to determine the PMI corresponding to the ports in the first port subset. The first port subset is one of the following: A subset of valid ports selected from all ports corresponding to the CSI-RS; The first port subset is one of the multiple port subsets divided among all ports corresponding to the CSI-RS.

32. The apparatus according to claim 31, characterized in that, The energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the angle delay AD domain.

33. The apparatus according to claim 32, characterized in that, The subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

34. The apparatus according to claim 32 or 33, characterized in that, The processing unit is also used for: The terminal device selects the subset of valid ports from all ports corresponding to the CSI-RS; The terminal device multiplexes the first codebook on all ports of the valid port subset to obtain the first PMI.

35. The apparatus according to claim 31, characterized in that, The device further includes: The sending unit is used to send the first CSI report; Wherein, the first port subset corresponds to the first CSI report, and the first CSI report is one of multiple CSI reports sent by the terminal device, and the multiple CSI reports respectively correspond to the multiple port subsets.

36. The apparatus according to claim 35, characterized in that, The multiple port subsets are determined based on the configuration information indicated by the Radio Resource Control (RRC) signaling.

37. The apparatus according to claim 35 or 36, characterized in that, At least two of the multiple port subsets have different activation times, and the activation indications of the multiple port subsets are carried in higher-layer signaling.

38. The apparatus according to any one of claims 31-37, characterized in that, The processing unit is also used for: The CSI-RS is measured to determine multiple channel estimation results for all ports corresponding to the CSI-RS; The multiple channel estimation results are processed using a frequency domain aggregation method.

39. The apparatus according to claim 38, characterized in that, The frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

40. The apparatus according to claim 38, characterized in that, The frequency domain aggregation is used to synthesize the statistics or correlation features corresponding to the multiple channel estimation results into an equivalent statistic in the frequency domain.

41. The apparatus according to any one of claims 31-40, characterized in that, The number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

42. The apparatus according to any one of claims 31-41, characterized in that, The first port subset includes 32 or fewer ports.

43. The apparatus according to any one of claims 31-42, characterized in that, Determining the first PMI based on the first codebook and the CSI-RS includes at least one of the following: The first sub-PMI is determined based on the first codebook in some sub-bands, and the second sub-PMI is determined based on the second codebook in the remaining sub-bands. The first sub-PMI and the second sub-PMI constitute the first PMI. The multiple sub-PMIs that make up the first PMI are determined according to the reception timing of multiple CSI-RS; Wherein, the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

44. The apparatus according to any one of claims 31-43, characterized in that, The first codebook is associated with one or more of the following: An initial codebook within a specified range for channel variations; The codebook corresponding to the PMI in the last Channel State Information (CSI) report; Hierarchical codebook or graded codebook.

45. The apparatus according to claim 44, characterized in that, The first codebook is an AD field type 2 codebook.

46. ​​A device for wireless communication, characterized in that, The device is a network device, and the device includes: The transmitting unit is used to transmit the Channel State Information Reference Signal (CSI-RS). The CSI-RS is used by the terminal device to determine a first precoding matrix indicator PMI based on a first codebook. The first PMI is associated with a first port subset. The first codebook is used to determine the PMI corresponding to the ports in the first port subset. The first port subset is one of the following: A subset of valid ports selected from all ports corresponding to the CSI-RS; The first port subset is one of the multiple port subsets divided among all ports corresponding to the CSI-RS.

47. The apparatus according to claim 46, characterized in that, The energy concentration of all ports in the effective port subset is greater than a first threshold, which is associated with the angle delay AD domain.

48. The apparatus according to claim 47, characterized in that, The subset of valid ports is determined by the terminal device, or the subset of valid ports is determined by the network device.

49. The apparatus according to claim 47 or 48, characterized in that, All ports corresponding to the CSI-RS are used by the terminal device to select the effective port subset; the first PMI is obtained by multiplexing the first codebook on all ports of the effective port subset.

50. The apparatus according to claim 46, characterized in that, The device further includes: The receiving unit is used to receive the first CSI report; Wherein, the first port subset corresponds to the first CSI report, and the first CSI report is one of multiple CSI reports sent by the terminal device, and the multiple CSI reports respectively correspond to the multiple port subsets.

51. The apparatus according to claim 50, characterized in that, The multiple port subsets are determined based on the configuration information indicated by the Radio Resource Control (RRC) signaling.

52. The apparatus according to claim 50 or 51, characterized in that, At least two of the multiple port subsets have different activation times, and the activation indications of the multiple port subsets are carried in higher-layer signaling.

53. The apparatus according to any one of claims 46-52, characterized in that, The CSI-RS is used by the terminal device to perform measurements to determine multiple channel estimation results for all ports corresponding to the CSI-RS; the multiple channel estimation results are processed by the terminal device based on frequency domain aggregation.

54. The apparatus according to claim 53, characterized in that, The frequency domain aggregation is used to synthesize the multiple channel estimation results into an equivalent channel estimation result in the frequency domain.

55. The apparatus according to claim 53, characterized in that, The frequency domain aggregation is used to synthesize the statistics or correlation features corresponding to the multiple channel estimation results into an equivalent statistic in the frequency domain.

56. The apparatus according to any one of claims 46-55, characterized in that, The number of all ports corresponding to the CSI-RS is one of the following: 48, 64, 128, or 256.

57. The apparatus according to any one of claims 46-56, characterized in that, The first port subset includes 32 or fewer ports.

58. The apparatus according to any one of claims 46-57, characterized in that, Determining the first precoding matrix indicator PMI based on the first codebook includes at least one of the following: The first sub-PMI is determined based on the first codebook in some sub-bands, and the second sub-PMI is determined based on the second codebook in the remaining sub-bands. The first sub-PMI and the second sub-PMI constitute the first PMI. The multiple sub-PMIs that make up the first PMI are determined according to the reception timing of multiple CSI-RS; Wherein, the period of the CSI-RS corresponding to the first codebook is less than the period of the CSI-RS corresponding to the second codebook.

59. The apparatus according to any one of claims 46-58, characterized in that, The first codebook is associated with one or more of the following: An initial codebook within a specified range for channel variations; The codebook corresponding to the PMI in the last Channel State Information (CSI) report; Hierarchical codebook or graded codebook.

60. The apparatus according to claim 59, characterized in that, The first codebook is an AD field type 2 codebook.

61. A communication device, characterized in that, It includes a memory and a processor, the memory being used to store a program, and the processor being used to invoke the program in the memory to perform the method as described in any one of claims 1-30.

62. An apparatus, characterized in that, Includes a processor for calling a program from memory to perform the method as described in any one of claims 1-30.

63. A chip, characterized in that, Includes a processor for calling a program from memory, causing a device on which the chip is mounted to perform the method as described in any one of claims 1-30.

64. A computer-readable storage medium, characterized in that, It contains a program that causes a computer to perform the method as described in any one of claims 1-30.

65. A computer program product, characterized in that, Includes a program that causes a computer to perform the method as described in any one of claims 1-30.

66. A computer program, characterized in that, The computer program causes the computer to perform the method as described in any one of claims 1-30.

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