WO2020244368A1 - 一种信道测量方法和通信装置 - Google Patents

一种信道测量方法和通信装置 Download PDF

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Publication number
WO2020244368A1
WO2020244368A1 PCT/CN2020/090551 CN2020090551W WO2020244368A1 WO 2020244368 A1 WO2020244368 A1 WO 2020244368A1 CN 2020090551 W CN2020090551 W CN 2020090551W WO 2020244368 A1 WO2020244368 A1 WO 2020244368A1
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time
space
frequency
vector
component
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PCT/CN2020/090551
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English (en)
French (fr)
Inventor
任翔
王潇涵
金黄平
毕晓艳
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华为技术有限公司
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Priority to EP20817844.2A priority Critical patent/EP3968533A4/en
Publication of WO2020244368A1 publication Critical patent/WO2020244368A1/zh
Priority to US17/541,997 priority patent/US20220094412A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0621—Feedback content
    • H04B7/0626—Channel coefficients, e.g. channel state information [CSI]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • H04B7/0478—Special codebook structures directed to feedback optimisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0636—Feedback format
    • H04B7/0639—Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0222—Estimation of channel variability, e.g. coherence bandwidth, coherence time, fading frequency
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03891—Spatial equalizers
    • H04L25/03898—Spatial equalizers codebook-based design
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
    • H04L5/0057—Physical resource allocation for CQI
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0078—Timing of allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
    • H04L5/0055—Physical resource allocation for ACK/NACK

Definitions

  • This application relates to the field of communication, and more specifically, to a channel measurement method and communication device.
  • Massive MIMO massive multiple-input multiple output
  • network equipment can reduce interference between multiple users and interference between multiple signal streams of the same user through precoding technology. Thereby improving signal quality, realizing space division multiplexing, and improving spectrum utilization.
  • the present application provides a channel measurement method and communication device, in order to feed back the time-varying characteristics of the channel, so as to feed back the channel state more comprehensively.
  • a channel measurement method includes: the terminal device generates first indication information, the first indication information is used to indicate one or more component features of the time-varying feature and the weighting coefficient of each component feature, the one or more component features and each component The weighting coefficient of the feature is used to characterize the time-varying feature of the channel; the terminal device sends the first indication information to the network device.
  • this method may be executed by a terminal device, or may also be executed by a chip configured in the terminal device.
  • a channel measurement method includes: a network device receives first indication information, the first indication information is used to indicate one or more component features of the time-varying feature and a weighting coefficient of each component feature, the one or more component features and each component The weighting coefficient of the characteristic is used to characterize the time-varying characteristic of the channel; the network device determines one or more component characteristics and the weighting coefficient of each component characteristic according to the first indication information.
  • the terminal device can quantize the time-varying characteristics of the channel through one or more component characteristics and one or more weighting coefficients, and feed back the quantization information of the component characteristics and the weighting coefficients to the network device. Therefore, the network device can determine the change of the channel in the time domain, and can also understand the state of the channel more comprehensively, so as to make more reasonable decisions for downlink scheduling.
  • the weighted sum of the one or more component features is used to characterize the time-varying feature of the channel.
  • the time-varying characteristic of the channel may be a weighted sum of the aforementioned one or more component characteristics.
  • the first indication information when used to indicate a component feature of a time-varying feature, it specifically indicates that the time domain vector corresponding to each component feature is in a predefined Index in the codebook.
  • the time domain vector may be an expression form of the component feature of the time-varying feature.
  • Each component feature can correspond to a time domain vector.
  • the time domain vector can be used to represent the change of the channel in the time domain.
  • Each time domain vector in the codebook can be used to represent a changing law of the channel over time.
  • the terminal device can determine the time-varying characteristics of the channel based on the received reference signal, and then quantize the time-varying characteristics by one or more time-domain vectors and one or more weighting coefficients, so as to quantify the quantized channel
  • the time-varying characteristics are fed back to the network equipment.
  • At least two component features are determined based on different codebooks.
  • At least two component features and their corresponding weighting coefficients are determined based on different codebooks.
  • the terminal device may determine the time domain vector based on different codebooks. In other words, the terminal device can determine component features based on different codebooks.
  • the terminal device may determine a plurality of space-frequency vector pairs based on a feedback manner of dual-domain compression, and the plurality of space-frequency vector pairs are space-frequency vector pairs used to construct a precoding matrix.
  • the terminal device may select some or all of the space-frequency vector pair corresponding weighting coefficients to determine the one or more component features and the weighting coefficient of each component feature.
  • the space-frequency vector pair corresponding to the weighting coefficient with larger amplitude can be selected by using a codebook with larger dimension to select the time domain vector; the space-frequency vector pair corresponding to the weighting coefficient with smaller amplitude can be selected with a smaller dimension.
  • the codebook to select the time domain vector can be used to select the time domain vector.
  • the one or more component features are determined based on one or more predefined codebooks, and the one or more codebooks are taken from the predefined codebooks Set, each codebook in the codebook set corresponds to one or more of the following values: measurement duration, pilot time domain density, pilot transmission times, and pilot transmission period.
  • the one or more component features are determined based on one or more predefined codebooks, and can also be replaced with: the one or more component features and the weighting coefficient of each component feature are based on one or more predefined codes This is ok.
  • the component feature of the time-varying feature is a Doppler frequency shift
  • the weighting coefficient of the component feature is a Doppler coefficient
  • the Doppler frequency shift can correspond to the time domain vector.
  • different time-domain vectors may represent the change rule of the channel in the time domain caused by the Doppler frequency shift of different transmission paths.
  • a mathematical expression of Doppler frequency shift can be a time domain vector.
  • a communication device including a processor.
  • the processor is coupled with the memory and can be used to execute instructions in the memory to implement the foregoing first aspect and the method in any one of the possible implementation manners of the first aspect.
  • the communication device further includes a memory.
  • the communication device further includes a communication interface, and the processor is coupled with the communication interface.
  • the communication device is a terminal device.
  • the communication interface may be a transceiver, or an input/output interface.
  • the communication device is a chip configured in a terminal device.
  • the communication interface may be an input/output interface.
  • the transceiver may be a transceiver circuit.
  • the input/output interface may be an input/output circuit.
  • a communication device which includes modules or units for executing the second aspect and the method in any one of the possible implementation manners of the second aspect.
  • the communication device is a network device.
  • the communication interface may be a transceiver, or an input/output interface.
  • the communication device is a chip configured in a network device.
  • the communication interface may be an input/output interface.
  • the transceiver may be a transceiver circuit.
  • the input/output interface may be an input/output circuit.
  • a processor including: an input circuit, an output circuit, and a processing circuit.
  • the processing circuit is configured to receive a signal through the input circuit and transmit a signal through the output circuit, so that the processor executes any one of the first aspect to the second aspect and the first aspect to the second aspect. The method in the way.
  • the above-mentioned processor can be one or more chips
  • the input circuit can be an input pin
  • the output circuit can be an output pin
  • the processing circuit can be a transistor, a gate circuit, a flip-flop, and various logic circuits, etc.
  • the input signal received by the input circuit may be received and input by, for example, but not limited to, a receiver
  • the signal output by the output circuit may be, for example, but not limited to, output to and transmitted by the transmitter
  • the circuit can be the same circuit, which is used as an input circuit and an output circuit at different times.
  • the embodiments of the present application do not limit the specific implementation manners of the processor and various circuits.
  • a processing device including a processor and a memory.
  • the processor is used to read instructions stored in the memory, receive signals through a receiver, and transmit signals through a transmitter to execute any one of the first aspect to the second aspect and the first aspect to the second aspect.
  • processors there are one or more processors and one or more memories.
  • the memory may be integrated with the processor, or the memory and the processor may be provided separately.
  • the memory can be a non-transitory (non-transitory) memory, such as a read only memory (ROM), which can be integrated with the processor on the same chip, or can be set in different On the chip, the embodiment of the present application does not limit the type of memory and the setting mode of the memory and the processor.
  • ROM read only memory
  • sending instruction information may be a process of outputting instruction information from the processor
  • receiving capability information may be a process of the processor receiving input capability information.
  • the data output by the processor can be output to the transmitter, and the input data received by the processor can come from the receiver.
  • the transmitter and receiver can be collectively referred to as a transceiver.
  • the processing device in the above eighth aspect may be one or more chips.
  • the processor in the processing device can be implemented by hardware or software.
  • the processor may be a logic circuit, integrated circuit, etc.; when implemented by software, the processor may be a general-purpose processor, which is implemented by reading software codes stored in the memory, and the memory may Integrated in the processor, can be located outside of the processor, and exist independently.
  • a computer program product includes: a computer program (also called code, or instruction), which when the computer program is executed, causes the computer to execute the first aspect to the first aspect.
  • a computer program also called code, or instruction
  • a computer-readable medium stores a computer program (also called code, or instruction) when it runs on a computer, so that the computer executes the first aspect to the first aspect.
  • a computer program also called code, or instruction
  • a communication system including the aforementioned network equipment and terminal equipment.
  • FIG. 1 is a schematic diagram of a communication system suitable for the method provided by the embodiment of the present application
  • FIG. 2 is a schematic diagram of the principle of a channel measurement method provided by an embodiment of the present application.
  • FIG. 4 is a schematic flowchart of CSI feedback based on the existing channel state information (CSI) feedback process
  • Figure 5 is an effect simulation diagram provided by an embodiment of the present application.
  • FIG. 6 is a schematic block diagram of a communication device provided by an embodiment of the present application.
  • FIG. 7 is a schematic structural diagram of a terminal device provided by an embodiment of the present application.
  • Fig. 8 is a schematic structural diagram of a network device provided by an embodiment of the present application.
  • GSM global system for mobile communications
  • CDMA code division multiple access
  • WCDMA broadband code division multiple access
  • GPRS general packet radio service
  • LTE long term evolution
  • FDD frequency division duplex
  • TDD LTE Time division duplex
  • UMTS universal mobile telecommunication system
  • WiMAX worldwide interoperability for microwave access
  • FIG. 1 is a schematic diagram of a communication system 100 applicable to the channel measurement method of the embodiment of the present application.
  • the communication system 100 may include at least one network device, such as the network device 110 shown in FIG. 1; the communication system 100 may also include at least one terminal device, such as the terminal device 120 shown in FIG. 1.
  • the network device 110 and the terminal device 120 may communicate through a wireless link.
  • Each communication device, such as the network device 110 or the terminal device 120 can be equipped with multiple antennas.
  • the configured multiple antennas may include at least one transmitting antenna for transmitting signals and at least one receiving antenna for receiving signals. Therefore, each communication device in the communication system 100, and between the network device 110 and the terminal device 120, can communicate through multi-antenna technology.
  • the network device in the communication system may be any device with a wireless transceiver function.
  • the network equipment includes but not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC) ), base transceiver station (base transceiver station, BTS), home base station (home evolved NodeB, or home NodeB, HNB), baseband unit (BBU), wireless fidelity (wireless fidelity, WiFi) system connection Access point (AP), wireless relay node, wireless backhaul node, transmission point (TP) or transmission and reception point (TRP), etc.
  • eNB evolved Node B
  • RNC radio network controller
  • NB Node B
  • BSC base station controller
  • BTS base transceiver station
  • BTS home base station
  • home evolved NodeB, or home NodeB, HNB baseband unit
  • BBU wireless fidelity (wireless fidelity, WiFi) system connection Access point (AP), wireless relay node, wireless backhaul node, transmission point (
  • the gNB may include a centralized unit (CU) and a DU.
  • the gNB may also include an active antenna unit (AAU).
  • CU implements some functions of gNB
  • DU implements some functions of gNB.
  • CU is responsible for processing non-real-time protocols and services, implementing radio resource control (RRC), and packet data convergence protocol (PDCP) The function of the layer.
  • RRC radio resource control
  • PDCP packet data convergence protocol
  • the DU is responsible for processing physical layer protocols and real-time services, and realizes the functions of the radio link control (RLC) layer, media access control (MAC) layer, and physical (PHY) layer.
  • RLC radio link control
  • MAC media access control
  • PHY physical
  • the network device may be a device that includes one or more of a CU node, a DU node, and an AAU node.
  • the CU can be divided into network equipment in an access network (radio access network, RAN), or the CU can be divided into network equipment in a core network (core network, CN), which is not limited in this application.
  • terminal equipment in the wireless communication system may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile equipment, User terminal, terminal, wireless communication device, user agent or user device.
  • UE user equipment
  • the terminal device in the embodiment of the present application may be a mobile phone (mobile phone), a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, and an augmented reality (AR) terminal Equipment, wireless terminals in industrial control, wireless terminals in unmanned driving (self-driving), wireless terminals in remote medical, wireless terminals in smart grid, transportation safety ( Wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, mobile terminals configured in transportation, and so on.
  • the embodiment of this application does not limit the application scenario.
  • FIG. 1 is only a simplified schematic diagram of an example for ease of understanding, and the communication system 100 may also include other network devices or other terminal devices, which are not shown in FIG. 1.
  • the processing procedure of the downlink signal at the physical layer before transmission may be executed by a network device, or may be executed by a chip configured in the network device.
  • the following are collectively referred to as network devices.
  • the codeword may be coded bits that have been coded (for example, including channel coding).
  • the codeword is scrambling to generate scrambled bits.
  • the scrambled bits undergo modulation mapping (modulation mapping) to obtain modulation symbols.
  • Modulation symbols are mapped to multiple layers, or transmission layers, through layer mapping.
  • the modulation symbols after layer mapping are precoding (precoding) to obtain a precoded signal.
  • the precoded signal is mapped to multiple REs after resource element (resource element, RE) mapping. These REs are then modulated by orthogonal frequency division multiplexing (OFDM) and then transmitted through an antenna port (antenna port).
  • OFDM orthogonal frequency division multiplexing
  • the sending device (such as network equipment) can process the signal to be sent by using a precoding matrix that matches the channel state when the channel state is known, so that the precoded signal to be sent and the channel Adaptation, thereby reducing the complexity of the receiving device (such as the terminal device) to eliminate the influence between channels. Therefore, through the precoding processing of the signal to be transmitted, the quality of the received signal (for example, the signal to interference plus noise ratio (SINR), etc.) can be improved. Therefore, the use of precoding technology can realize transmission on the same time-frequency resource between the sending device and multiple receiving devices, that is, realizing multiple user multiple input multiple output (MU-MIMO).
  • MU-MIMO multiple user multiple input multiple output
  • the sending device may also perform precoding in other ways. For example, when channel information (such as but not limited to a channel matrix) cannot be obtained, precoding is performed using a preset precoding matrix or a weighting processing method. For the sake of brevity, its specific content will not be repeated in this article.
  • Reference signal reference signal
  • RS reference signal
  • the reference signal may include a non-precoded reference signal (non-precoded RS) and a precoded reference signal.
  • the precoded reference signal may also be referred to as a beamformed reference signal (beamformed RS), or may also be referred to as a precoding reference signal for short.
  • beamformed RS beamformed reference signal
  • the meanings expressed by the precoded reference signal, the precoded reference signal, and the beamformed reference signal are the same.
  • reference signals when referring to reference signals in the following, sometimes only refers to reference signals that have not been precoded, sometimes only refers to precoded reference signals, and sometimes includes reference signals that have not been precoded and precoded reference signals. Those skilled in the art can understand its meaning in different scenarios.
  • the reference signal without precoding processing may be similar to the Class A reference signal defined in the LTE or NR protocol.
  • the beamforming reference signal can be similar to the Class B reference signal in the LTE protocol.
  • the reference signal involved in the embodiment of the present application may be a reference signal used for channel measurement.
  • the reference signal may be a channel state information reference signal (CSI-RS) or a sounding reference signal (sounding reference signal, SRS).
  • CSI-RS channel state information reference signal
  • SRS sounding reference signal
  • Antenna port referred to as port. It can be understood as a virtual antenna recognized by the receiving device. Or transmit antennas that can be distinguished in space. One antenna port can be configured for each virtual antenna, and each virtual antenna can be a weighted combination of multiple physical antennas.
  • the antenna port may refer to the transmitting antenna port.
  • the transmitting antenna port may refer to an actual independent transceiver unit (transceiver unit, TxRU).
  • TxRU transceiver unit
  • the number of antenna ports (that is, the number of transmitting antenna ports) may be equal to the number of TxRUs.
  • the reference signal of each port may be a reference signal that has not been precoded.
  • the antenna port may refer to a reference signal port after precoding.
  • the reference signal of each port may be a precoding reference signal obtained by precoding the reference signal based on a precoding vector.
  • the signal of each port can be transmitted through one or more resource blocks (RB). It is understandable that if the reference signal is pre-coded, the number of reference signal ports may be less than the number of transmit antenna ports before pre-coding. Therefore, by precoding the reference signal, the dimensionality of the transmitting antenna port can be reduced, thereby achieving the purpose of reducing pilot overhead.
  • Time domain vector It can be used to indicate the change of the channel in the time domain. Each time domain vector can represent a change law of the channel over time.
  • the wireless channel is a time-varying channel and will suffer from attenuation loss from different channels.
  • the frequency-selective fading caused by multipath delay spread and the time-frequency dual-selective fading channel that is jointly affected by the time-selective fading caused by Doppler frequency shift is a typical time-varying channel.
  • Doppler shift can refer to the frequency shift between the transmitting frequency and the receiving frequency caused by the relative movement between the terminal equipment and the network equipment.
  • the difference between the receiving frequency and the transmitting frequency is called Doppler Frequency shift.
  • v is the moving speed of the terminal device
  • f c is the carrier frequency
  • ⁇ the incident angle of the multipath signal
  • c is the speed of light.
  • the angle of incidence of different transmission paths can be considered for ⁇ . Since the ⁇ of the multipath is different, different transmission paths will correspond to different Doppler shifts, which will cause Doppler spread.
  • the size of the Doppler frequency shift indicates the influence of the moving speed on the speed of the channel time domain change.
  • each time domain vector may correspond to a Doppler frequency shift. Therefore, different time-domain vectors can be used to represent the change law of the channel in the time domain caused by the Doppler shift of different transmission paths. Generally speaking, in order to facilitate the description of the channel time domain change, the time domain channel can be projected into the Doppler domain and expressed by the weighted exponential function of several slowly varying Doppler frequency shifts.
  • time domain vector is only defined to facilitate the distinction from the space domain vector and the frequency domain vector described later, and should not constitute any limitation to this application.
  • This application does not exclude the possibility of defining other names for time domain vectors in future agreements to express the same or similar meanings. For example, it can also be called a Doppler vector.
  • the time-domain vector is one or more of a Discrete Fourier Transform (DFT) vector, an oversampled DFT vector, a wavelet transform (wavelet transform, WT) vector, or an oversampled WT vector.
  • DFT Discrete Fourier Transform
  • WT wavelet transform
  • WT oversampled WT vector
  • the codebook involved in the embodiments of this application may refer to a collection of time domain vectors. Multiple time-domain vectors in the same codebook may be vectors of the same dimension. For example, if the time-domain vectors in the same codebook are all N-dimensional vectors, the codebook is an N-dimensional codebook.
  • the time domain vectors in the same codebook are all DFT vectors.
  • the codebook may include N time domain vectors, and the N time domain vectors may be orthogonal to each other. In other words, the codebook is an orthogonal codebook.
  • the N time-domain vectors in the codebook can construct a DFT matrix. In other words, the aforementioned time-domain vector may be a vector taken from the DFT matrix.
  • the N time-domain vectors in the N-dimensional codebook may be vectors taken from a DFT matrix with a dimension of N ⁇ N.
  • the N-dimensional codebook can be understood as dividing the maximum Doppler frequency shift into N parts, and the N time domain vectors in the N-dimensional codebook correspond to the N Doppler frequency shifts.
  • n different Doppler shifts can be determined.
  • the ratio of the Doppler frequency shift to the maximum Doppler frequency shift corresponding to the nth vector in the N-dimensional codebook is n/N. Therefore, based on a time domain vector, the corresponding Doppler shift can be determined. In other words, each time domain vector corresponds to a Doppler shift.
  • the time domain vectors in the same codebook are all oversampled DFT vectors.
  • the foregoing orthogonal codebook composed of DFT vectors can be expanded into multiple subsets by an oversampling factor O t (O t is a positive integer greater than 1). Each subset may include N time-domain vectors, and the N time-domain vectors are orthogonal to each other. Multiple time domain vectors in the codebook can construct an oversampled DFT matrix.
  • the codebook can be defined as a non-orthogonal codebook.
  • the aforementioned time-domain vector may be a vector taken from a non-orthogonal codebook, or a vector taken from a certain subset of multiple orthogonal subsets.
  • the time domain vectors in the same codebook are all WT vectors.
  • the codebook may include N time-domain vectors, and the N time-domain vectors are orthogonal to each other.
  • the codebook is an orthogonal codebook.
  • the N time-domain vectors in the codebook can construct a WT matrix.
  • the aforementioned time-domain vector may be a vector taken from the DFT matrix.
  • the time domain vectors in the same codebook are all oversampled WT vectors.
  • the foregoing orthogonal codebook composed of WT vectors can be expanded into multiple subsets by an oversampling factor. Each subset may include N time-domain vectors, and the N time-domain vectors are orthogonal to each other. Multiple time-domain vectors in the codebook can construct an oversampled WT matrix.
  • the codebook can be defined as a non-orthogonal codebook.
  • the above-mentioned time-domain vector can be a vector from a non-orthogonal codebook, or a vector from a certain subset of multiple orthogonal subsets
  • the multiple orthogonal subsets may also be defined as multiple codebooks. This application does not limit this.
  • Multiple codebooks can form a codebook set.
  • the multiple codebooks in the codebook set may be codebooks of different dimensions. In other words, the dimensions of time-domain vectors taken from different codebooks can be different.
  • each codebook in the codebook set corresponds to one or more of the following values: measurement duration, pilot time domain density, pilot transmission times, and pilot transmission period.
  • the relevant description of the measurement duration the pilot frequency time domain density, the number of pilot transmissions, and the pilot transmission period, please refer to the relevant descriptions below.
  • the number of pilot transmission When the number of pilot transmission is large, it can correspond to a codebook with a larger dimension; when the number of pilot transmissions is small, it can correspond to a codebook with a smaller dimension.
  • the terminal device receives more reference signals, which can correspond to a codebook with a larger dimension; when the measurement duration is shorter, The reference signal received by the terminal device is also less frequent and can correspond to a codebook with a smaller dimension.
  • the terminal device receives more reference signals in a period of time (such as the measurement duration), which can correspond to a codebook with a larger dimension;
  • the terminal device receives fewer reference signals in the same period of time, and can correspond to a codebook with a smaller dimension.
  • the terminal device receives less reference signals in a period of time (such as the measurement duration), which can correspond to a codebook with a smaller dimension; pilot transmission period When it is smaller, the terminal device receives more reference signals in the same period of time, and can correspond to a codebook with a larger dimension.
  • the dimension of the codebook may correspond to the measurement duration and the pilot transmission period, or the dimension of the codebook may correspond to the measurement duration and the pilot time domain density. For the sake of brevity, I will not illustrate them one by one.
  • Spatial domain vector or beam vector, angle vector, etc.
  • Each element in the spatial vector may represent the weight of each antenna port (antenna port). Based on the weight of each antenna port represented by each element in the space vector, the signals of each antenna port are linearly superimposed to form an area with a strong signal in a certain direction in space.
  • Precoding the reference signal based on the spatial vector can make the transmitted reference signal have a certain spatial directivity. Therefore, the process of precoding the reference signal based on the spatial domain vector can also be regarded as the process of spatial domain (or simply, spatial domain) precoding.
  • the airspace vector is denoted as u.
  • the length of the space vector u may be the number of transmitting antenna ports N s in a polarization direction, and N s ⁇ 1 and an integer.
  • the spatial vector can be, for example, a column vector or a row vector with a length of N s . This application does not limit this.
  • the spatial vector is taken from the DFT matrix.
  • Each column vector in the DFT matrix can be called a DFT vector.
  • the spatial vector can be a DFT vector.
  • the spatial vector can also be, for example, the two-dimensional (2dimensions, 2D)-discrete Fourier Transform (DFT) defined in the type II (type II) codebook in the NR protocol TS 38.214 version 15 (release 15, R15). ) Vector or oversampled 2D-DFT vector.
  • DFT two-dimensional (2dimensions, 2D)-discrete Fourier Transform
  • Frequency domain vector (frequency domain vector): or delay vector, etc.
  • Each frequency domain vector can represent a change law. Since the signal is transmitted through the wireless channel, it can reach the receiving antenna through multiple paths from the transmitting antenna. Multipath time delay causes frequency selective fading, which is the change of frequency domain channel. Therefore, different frequency domain vectors can be used to represent the changing law of channels in the frequency domain caused by delays on different transmission paths. Since the phase change of the channel in each frequency domain unit is related to the time delay, it can be known from the Fourier transform that the time delay of the signal in the time domain can be equivalent to the phase gradual change in the frequency domain. Therefore, the frequency domain vector can also be called a delay vector. In other words, the frequency domain vector can also be used to express the delay characteristics of the channel.
  • Precoding the reference signal based on the frequency domain vector can essentially refer to the phase rotation of each frequency domain unit in the frequency domain based on the elements in the frequency domain vector to precode the reference signal to pre-encode the frequency domain caused by the multipath delay. Select features for pre-compensation. Therefore, the process of precoding the reference signal based on the frequency domain vector can be regarded as the process of frequency domain precoding.
  • the frequency domain vector may be used to construct a combination of multiple space domain vectors and frequency domain vectors, or simply a space-frequency vector pair, with the above-mentioned spatial domain vector to construct a precoding vector.
  • the frequency domain vector is denoted as v.
  • the length of the frequency domain vector can be denoted as N 3 , N 3 ⁇ 1, and it is an integer.
  • Space-frequency vector pair A space-domain vector and a frequency-domain vector can be combined to obtain a space-frequency vector pair.
  • a space-frequency vector pair can include a space-domain vector and a frequency-domain vector.
  • a space-frequency component matrix can be obtained from the space-frequency vector and the frequency-domain vector in a space-frequency vector pair. For example, a space-frequency vector can be multiplied by the conjugate transpose of a frequency-domain vector to obtain a space-frequency component matrix.
  • At least one of the space vector and the frequency vector included in any two space-frequency vector pairs is different.
  • the space-frequency component matrix constructed by any two space-frequency vector pairs is also different.
  • Space frequency matrix It can be understood as an intermediate quantity used to determine the precoding matrix corresponding to each frequency domain unit.
  • the space-frequency matrix can be determined by the precoding matrix or the channel matrix corresponding to each frequency domain unit.
  • the space-frequency matrix may be obtained by the weighted sum of multiple space-frequency component matrices, so as to recover the downlink channel or precoding matrix.
  • the space frequency matrix can be denoted as H, Where w 1 to Is N 3 column vectors corresponding to N 3 frequency domain units, each column vector may be a precoding matrix corresponding to each frequency domain unit, and the length of each column vector may be N s .
  • the N 3 column vectors respectively correspond to precoding vectors of N 3 frequency domain units. That is, the space-frequency matrix can be regarded as a joint matrix formed by combining the precoding vectors corresponding to N 3 frequency domain units.
  • the space frequency matrix may correspond to the transmission layer.
  • the precoding vector of each frequency domain unit on the same transmission layer can construct the space-frequency matrix corresponding to the transmission layer.
  • the precoding vector of each frequency domain unit on the zth (1 ⁇ z ⁇ Z, z is a positive integer) transmission layer can be used to construct the space-frequency matrix corresponding to the zth transmission layer.
  • Z represents the number of transmission layers, and Z is a positive integer.
  • the space-frequency matrix is only an expression form used to determine the intermediate quantity of the precoding matrix, and should not constitute any limitation in this application.
  • a vector of length N s ⁇ N 3 can also be obtained, which can be called Space frequency vector.
  • the dimensions of the space-frequency matrix and the space-frequency vector shown above are only examples, and should not constitute any limitation to this application.
  • the space-frequency matrix may also be a matrix with a dimension of N 3 ⁇ N s .
  • each row vector may correspond to a frequency domain unit for determining the precoding vector of the corresponding frequency domain unit.
  • the dimension of the space-frequency matrix can be further expanded.
  • the dimension of the space-frequency matrix may be 2N s ⁇ N 3 or N 3 ⁇ 2N s . It should be understood that this application does not limit the number of polarization directions of the transmitting antenna.
  • Dual-domain compression It can include compression in the two dimensions of space-domain compression and frequency-domain compression.
  • Spatial compression may specifically refer to selecting one or more spatial vectors from the set of spatial vectors as the vector for constructing the precoding vector.
  • Frequency domain compression may refer to selecting one or more frequency domain vectors from a set of frequency domain vectors as a vector for constructing a precoding vector.
  • the matrix constructed by a spatial domain vector and a frequency domain vector may be called a spatial frequency component matrix, for example.
  • the selected one or more spatial vectors and one or more frequency domain vectors can construct one or more spatial frequency component matrices.
  • the weighted sum of the one or more space-frequency component matrices can be used to construct a space-frequency matrix corresponding to one transmission layer.
  • the space-frequency matrix can be approximated as a weighted sum of the space-frequency component matrix constructed from the selected one or more space-domain vectors and one or more frequency-domain vectors. Based on the space-frequency matrix corresponding to a transmission layer, the precoding vector corresponding to each frequency domain unit on the transmission layer can be determined.
  • the selected one or more spatial vectors can form a matrix W 1 , where each column vector in W 1 corresponds to a selected spatial vector.
  • the selected one or more frequency domain vectors may form a matrix W 3 , where each column vector in W 3 corresponds to a selected frequency domain vector.
  • L space vectors can be selected for each polarization direction, and the dimension of W 1 can be 2N s ⁇ 2L.
  • the dimension of W 3 H can be M ⁇ N 3 .
  • Each column vector in W 3 can be a frequency domain vector.
  • each space vector in W 1 and each frequency vector in W 3 can form a space-frequency vector pair, and each space-frequency vector pair can correspond to a weighting coefficient, so there are 2L space-domain vectors and M frequency vectors.
  • the 2L ⁇ M space-frequency vector pairs constructed by the domain vector can correspond to the 2L ⁇ M weighting coefficients one-to-one.
  • the C is a coefficient matrix composed of the 2L ⁇ M weighting coefficients, and the dimension may be 2L ⁇ M.
  • the lth row in the coefficient matrix C can correspond to the lth space vector in the first polarization direction in the 2L space vectors, and the L+1 row in the coefficient matrix C can correspond to the second pole in the 2L space vectors
  • the l-th spatial vector in the direction of transformation may correspond to the m-th frequency-domain vector in the M frequency-domain vectors.
  • the space-frequency matrix H and W 1 and W 3 shown above is only an example, and should not constitute any limitation to the application. Based on the same concept, those skilled in the art can perform mathematical transformations on the above-mentioned relationship to obtain other calculation formulas for representing the relationship between the space-frequency matrix H and W 1 , W 3 .
  • the terminal device can feed back the selected one or more spatial vectors and one or more frequency domain vectors to the network device during feedback, instead of being based on Each frequency domain unit (such as a subband) feeds back the weighting coefficient (such as amplitude and phase) of the subband respectively. Therefore, the feedback overhead can be greatly reduced.
  • the frequency domain vector can represent the change rule of the channel in the frequency
  • the linear superposition of one or more frequency domain vectors is used to simulate the channel change in the frequency domain. Therefore, high feedback accuracy can still be maintained, so that the precoding matrix recovered by the network device based on the feedback of the terminal device can still better adapt to the channel.
  • the specific process for the terminal device to determine the precoding matrix indicator (PMI) is the internal implementation behavior of the terminal device, and this application does not limit the specific process for the terminal device to determine the PMI.
  • the specific process for the network device to determine the precoding matrix according to the PMI is an internal implementation behavior of the network device, and this application does not limit the specific process for the network device to determine the precoding matrix according to the PMI.
  • the terminal device and the network device can use different algorithms to generate PMI and restore the precoding matrix.
  • Weighting coefficients In the embodiments of this application, two types of weighting coefficients are mainly involved.
  • weighting coefficient is a weighting coefficient determined based on the feedback method of dual-domain compression.
  • the weighting coefficient may also be called a space-frequency combination coefficient, a space-frequency coefficient, and so on.
  • Each weighting coefficient may correspond to a space vector and a frequency vector selected for constructing a precoding vector, or, in other words, a matrix of space-frequency components, or a pair of space-frequency vectors.
  • the weighting coefficient can be used to express the weight of the space-frequency component matrix constructed by constructing the precoding vector to a space-domain vector and a frequency-domain vector.
  • weighting coefficient corresponding to the time domain vector is the weighting coefficient corresponding to the time domain vector.
  • This weighting coefficient may also be called a time domain coefficient.
  • Each weighting coefficient may correspond to a time domain vector selected to construct the precoding matrix, or in other words, correspond to a Doppler frequency shift, and may be used to represent the weight of each time domain vector used to construct the channel.
  • the time domain vector can also be called a Doppler vector.
  • the weighting coefficient may also be called a Doppler coefficient.
  • the weighting coefficient corresponding to the space-frequency vector pair is recorded as the space-frequency coefficient
  • the weighting coefficient corresponding to the time-domain vector is recorded as the time-domain coefficient
  • Pilot transmission period the interval between two adjacent pilot transmissions.
  • Pilot frequency time domain density the number of times the reference signal is transmitted in a predefined time unit, or the ratio of the time domain resource used for this transmission of the reference signal to the time unit.
  • One time unit may include, for example, one or more pilot transmission periods, and the corresponding pilot time domain density may be, for example, 1 or greater than 1.
  • the terminal device can perform channel measurement within a certain period of time according to the instructions of the network device. This period can be referred to as the measurement duration.
  • the length of this period of time may be indicated by the network equipment through signaling, for example, through high-level signaling (such as radio resource control (Radio Resource Control, RRC) messages, etc.).
  • the measurement duration can also be predefined, such as protocol definition. This application does not limit this.
  • the network device can notify the terminal device to start channel measurement through signaling. For example, the network device may notify the terminal device of the start time and/or duration of the period through signaling, or the network device may trigger the terminal device to start channel measurement through signaling.
  • the terminal device can receive multiple reference signals used for channel measurement within the measurement duration, and can perform channel measurement based on the multiple received reference signals to feed back the time-varying characteristics of the channel to the network device.
  • the network device notifies the terminal device to start channel measurement through signaling, but it does not mean that the terminal device has been performing channel measurement since the start time or trigger time indicated by the network device.
  • the network device only informs the terminal device that it can perform channel measurement through signaling, and the terminal device can perform channel measurement based on the received reference signal within a time window from the start time or trigger time. The size of the time window is also the measurement time.
  • the feedback mentioned here refers to the feedback of the terminal equipment to the time-varying characteristics of the channel, but it does not mean that the terminal equipment does not provide other feedback.
  • the terminal device may feedback based on the feedback mode of dual-domain compression during this time period, or based on the feedback mode of type II codebook during this time period, and so on.
  • the other feedback made by the terminal device during this time period and the feedback on the time-varying characteristics of the channel described in this application are independent processes.
  • the terminal device can receive the reference signal multiple times during the measurement period.
  • the number of times the terminal device receives the reference signal during the measurement period may be the product of the ratio of the measurement period and the aforementioned time unit multiplied by the pilot frequency in the time domain.
  • the number of pilot transmissions may refer to the total number of times the network device sends reference signals used for channel measurement, or in other words, the total number of reference signals received by terminal equipment for channel measurement. frequency.
  • the number of pilot transmissions may specifically refer to the total number of pilot transmissions in a period of time. When the number of pilot transmissions is greater than 1, the multiple pilot transmissions may be multiple transmissions distributed within this period of time. In other words, the multiple pilot transmissions are transmissions at multiple times.
  • the number of pilot transmissions can be indicated by the network device through signaling, such as high-level signaling (such as RRC messages); the number of pilot transmissions can also be predefined, such as protocol definitions. This application does not limit this.
  • each codebook in the codebook set corresponds to one or more of the following values: measurement duration, pilot time domain density, number of pilot transmissions, and pilot transmission cycle. This application does not limit the specific manner in which the terminal device determines the value of the measurement duration, the pilot time domain density, the number of pilot transmissions, and the pilot transmission period.
  • the network device can directly indicate the value of the measurement duration, the pilot time domain density, the number of pilot transmissions, or the pilot transmission period through signaling.
  • the network device may also indicate the configuration related to the value of the measurement duration, the pilot time domain density, the number of pilot transmissions, or the pilot transmission period through signaling.
  • the protocol may predefine the correspondence between multiple configurations and multiple values, and the correspondence may be embodied in a table or other ways, for example.
  • the network device can indicate the value of the measurement duration, the pilot time domain density, the number of pilot transmissions, or the pilot transmission period by indicating the configuration or the index of the configuration corresponding to a certain value.
  • “each codebook in the codebook set corresponds to the value of one or more of the following: measurement duration, pilot time domain density, number of pilot transmissions, and pilot transmission period" mentioned above. It can be replaced by "Each codebook in the codebook set corresponds to one or more of the following configurations: measurement duration, pilot time domain density, pilot transmission times, and pilot transmission period.”
  • the value of the measurement duration, the pilot time domain density, the number of pilot transmissions, or the pilot transmission period may be predefined, as defined by the protocol.
  • the terminal device can feed back CSI based on the reference signal received each time.
  • the terminal device can perform channel measurement based on each received reference signal, and feed back at least one spatial vector, at least one frequency domain vector and at least one weighting coefficient, so that the network device can construct a pre- Encoding matrix.
  • this kind of feedback method may bring greater feedback overhead. For example, if the network device sends the reference signal intensively, the terminal device will frequently feed back the CSI to the network device.
  • this application provides a channel measurement method.
  • the channel measurement method provided in the present application performs channel measurement based on multiple received reference signals, and feeds back the time-varying characteristics based on the results of the channel measurement, and approximates the channel over time by the weighted sum of one or more component characteristics of the time-varying characteristics The trend of change.
  • the results obtained from multiple measurements within a period of time (such as the measurement duration) are compressed by the time-varying feature and then fed back to the network device.
  • P the number of time-domain vectors fed back by the terminal device, P ⁇ 1 and an integer.
  • the terminal device determines one or more time-domain vectors based on each of the multiple space-frequency vector pairs, and the time-domain vectors determined based on at least two space-frequency vector pairs are different, the time-domain vector fed back by the terminal device
  • the number P can satisfy: Among them, P k represents the number of time-domain vectors fed back based on the k-th space-frequency vector pair, and P k ⁇ 1 and is an integer.
  • P the number of time-domain vectors fed back by the terminal device is only one possible definition.
  • P can also be defined as the number of time-domain vectors fed back by a transmission layer, or the number of time-domain vectors fed back by a receiving antenna. This application does not limit this.
  • K the total number of space-frequency vector pairs used to determine the time domain vector, K ⁇ 1 and an integer
  • k can take any value from 1 to K, and k is an integer.
  • the k-th space-frequency vector pair may be one of the K space-frequency vector pairs;
  • K’ the number of space-frequency vector pairs used to construct the precoding matrix in dual-domain compression, K’ ⁇ K, and K’ is an integer;
  • L the number of space-domain vectors (or angle vectors), the combination of the L space-domain vectors (or angle vectors) and the M frequency-domain vectors (delay vectors) described below can obtain K space-frequency vector pairs, L ⁇ 1 And is an integer;
  • M the number of frequency domain vectors (or delay vectors). Combining the M frequency domain vectors (or delay vectors) with the L spatial vectors (or angle vectors) described above can obtain K spatial frequency vector pairs , M ⁇ 1 and an integer.
  • the weighted sum of one or more component features, the weighted sum of one or more time domain vectors, and the weighted sum of one or more Doppler shift exponential functions are mentioned in multiple places. And other descriptions.
  • the "weighted sum of one or more component features” mentioned here may refer to only one component feature.
  • the “weighted sum of one or more component features” mentioned here can mean that the multiple component features are weighted based on the weight (or weighting coefficient) of each component feature. result. For brevity, the description of the same or similar situations is omitted below.
  • the network device may determine the precoding matrix according to the feedback of the terminal device.
  • the precoding matrix may also be in the form of a vector, such as a precoding vector.
  • This application does not limit the specific form of the precoding matrix. For example, it can be a matrix or a vector.
  • used to indicate may include used for direct indication and used for indirect indication.
  • the indication information may directly indicate I or indirectly indicate I, but it does not mean that I must be carried in the indication information.
  • the information indicated by the instruction information is called the information to be indicated.
  • the information to be indicated can be directly indicated, such as the information to be indicated or the Indicates the index of the information, etc.
  • the information to be indicated can also be indicated indirectly by indicating other information, where there is an association relationship between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, and other parts of the information to be indicated are known or agreed in advance. For example, it is also possible to realize the indication of specific information by means of the pre-arranged order (for example, stipulated in the agreement) of various information, thereby reducing the indication overhead to a certain extent.
  • the precoding matrix is composed of precoding vectors, and each precoding vector in the precoding matrix may have the same parts in terms of composition or other attributes.
  • the specific indication manner may also be various existing indication manners, such as, but not limited to, the foregoing indication manner and various combinations thereof.
  • the specific details of the various indication modes can be referred to the prior art, which will not be repeated here. It can be seen from the above that, for example, when multiple pieces of information of the same type need to be indicated, a situation where different information is indicated in different ways may occur.
  • the required instruction method can be selected according to specific needs.
  • the embodiment of the application does not limit the selected instruction method.
  • the instruction method involved in the embodiment of the application should be understood as covering the instructions to be Various methods for obtaining information to be indicated.
  • a row vector can be expressed as a column vector
  • a matrix can be expressed by the transposed matrix of the matrix
  • a matrix can also be expressed in the form of a vector or an array. It can be formed by connecting each row vector or column vector of the matrix, and the Kronecker product of two vectors can also be expressed in the form of the product of one vector and the transposed vector of another vector.
  • the information to be instructed can be sent together as a whole, or divided into multiple sub-information to be sent separately, and the sending period and/or sending timing of these sub-information can be the same or different.
  • the specific sending method is not limited in this application.
  • the sending period and/or sending timing of these sub-information may be pre-defined, for example, pre-defined according to a protocol, or configured by the transmitting end device by sending configuration information to the receiving end device.
  • the configuration information may include, but is not limited to, radio resource control signaling, such as RRC signaling, MAC layer signaling, such as MAC-CE signaling and physical layer signaling, such as downlink control information (DCI) One or a combination of at least two of them.
  • radio resource control signaling such as RRC signaling
  • MAC layer signaling such as MAC-CE signaling
  • DCI downlink control information
  • the "protocols" involved in the embodiments of the present application may refer to standard protocols in the communication field, for example, may include LTE protocol, NR protocol, and related protocols applied to future communication systems, which are not limited in this application.
  • At least one refers to one or more, and “multiple” refers to two or more.
  • And/or describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and/or B, which can mean: A alone exists, both A and B exist, and B exists alone, where A, B can be singular or plural.
  • the character “/” generally indicates that the associated objects are in an “or” relationship.
  • "The following at least one item (a)” or similar expressions refers to any combination of these items, including any combination of a single item (a) or plural items (a).
  • At least one of a, b, and c can mean: a, or, b, or, c, or, a and b, or, a and c, or, b and c, or, a , B, and c.
  • a, b, and c can be single or multiple.
  • the method provided in the embodiments of the present application can be applied to a system that communicates through multi-antenna technology.
  • the communication system 100 shown in FIG. 1. The communication system may include at least one network device and at least one terminal device. Multi-antenna technology can be used to communicate between network equipment and terminal equipment.
  • the method provided in the embodiments of the present application is not limited to the communication between the network device and the terminal device, and can also be applied to the communication between the terminal device and the terminal device.
  • the application does not limit the application scenarios of the method. In the embodiments shown below, only for ease of understanding and description, the interaction between a network device and a terminal device is taken as an example to describe in detail the method provided in the embodiment of the present application.
  • the embodiments shown below do not particularly limit the specific structure of the execution body of the method provided by the embodiments of the present application, as long as the program that records the code of the method provided by the embodiments of the present application can be run according to the present application.
  • the method provided in the application embodiment only needs to communicate.
  • the execution subject of the method provided in the embodiment of the application may be a terminal device or a network device, or a functional module in the terminal device or network device that can call and execute the program.
  • Fig. 2 schematically shows the process of the terminal device converting the channel change in the time domain to the Doppler domain through a), b), c) and d).
  • the terminal device in the plane composed of the space domain and the frequency domain, can determine multiple space-frequency vector pairs.
  • the figure shows three space-frequency vector pairs (that is, the three space-frequency vector pairs shown in the figure). Small squares).
  • the terminal device can determine the change over time of the space-frequency coefficients of the three space-frequency vector pairs based on the reference signal received each time, and the change can be represented by a curve, as shown in b) in Figure 2.
  • the channel change in the time domain can be represented by the weighted sum of the exponential function of several slowly varying Doppler frequency shifts. Therefore, the channel change in the time domain can be converted to the Doppler domain. Obtain several fixed Doppler shifts, as shown in c) in Figure 2.
  • Figure 2 c) shows three Doppler frequency shifts.
  • the coordinates of the three Doppler frequency shifts on the horizontal axis correspond to the positions of the three Doppler frequency shifts.
  • the coordinate on the vertical axis corresponds to the amplitude of the three Doppler shifts.
  • the embodiments shown below are based on one of the one or more transmission layers and one of the one or more polarization directions corresponding to the transmission layer.
  • the embodiments of the present application are described in detail. Provide the specific process of the channel measurement method. It should be understood that this application does not limit the number of transmission layers and the number of polarization directions of the transmitting antenna.
  • One transmission layer illustrated below may be any one of the one or more transmission layers, and one polarization direction may be any one of the one or more polarization directions.
  • FIG. 3 is a schematic flowchart of a channel measurement method 300 according to an embodiment of the present application, shown from the perspective of device interaction. As shown in FIG. 3, the method 300 may include step 310 to step 350. The steps in the method 300 are described in detail below.
  • step 310 the terminal device generates first indication information, which is used to indicate one or more component features of the time-varying feature and a weighting coefficient of each component feature.
  • the time-varying characteristics of the channel can be characterized by a weighted sum of one or more component characteristics. That is, the time-varying characteristics of the channel may be characterized by one component characteristic, or may be characterized by a weighted sum of multiple component characteristics.
  • the time-varying characteristics of the channel can be approximately characterized by the weighted sum of one or more fixed Doppler shift exponential functions.
  • the correspondence between the Doppler frequency shift and the time domain vector has been described in detail above, and each time domain vector in the codebook can correspond to a Doppler frequency shift. Therefore, the time-varying characteristics of the channel can be approximately characterized by the weighted sum of one or more time-domain vectors.
  • the one or more component features described in the embodiment of the present application may be one or more time-domain vectors selected from a predefined codebook. Each component feature corresponds to a time domain vector, and each time domain vector can be used to determine a Doppler shift.
  • the time-domain vector can be considered as an expression form of the component feature of the time-varying feature.
  • the terminal device may perform channel measurement based on the received reference signal to determine one or more time domain vectors and the time domain coefficient corresponding to each time domain vector from a predefined codebook.
  • weighted sum of one or more component features to approximately represent the time-varying feature of the channel is only a possible implementation manner, and should not constitute any limitation in this application.
  • the relationship between the one or more component features and the weighting coefficient of each component feature and the time-varying feature of the channel is not limited to this.
  • the method 300 further includes: step 320, the terminal device receives a reference signal.
  • the network device sends a reference signal.
  • the terminal device can perform channel measurement based on reference signals received at multiple different moments.
  • the above-mentioned time-varying feature is determined by the terminal device based on reference signals received at multiple times.
  • the aforementioned time-varying feature is determined by the terminal device based on the reference signal received multiple times.
  • the terminal device may generate the first indication information based on the reference signal received during the measurement period.
  • the measurement duration may be relatively short, for example, it may be defined in units of time slots (slot) or milliseconds (ms).
  • the measurement duration is 20 time slots or 5ms or 10ms or 20ms.
  • the measurement duration can also be longer, for example, it can be defined in seconds.
  • the measurement duration is 10 seconds.
  • the measurement duration can be predefined, such as protocol definition.
  • the measurement duration may also be pre-configured by the network device, for example, the network device indicates the start time and the measurement duration of the measurement through signaling. This application does not limit this.
  • the terminal device may receive the reference signal based on the number of pilot transmissions, and generate the first indication information based on the received reference signal.
  • the number of pilot transmissions can be predefined, such as protocol definition.
  • the number of pilot transmission times may also be pre-configured by the network equipment, for example, the network equipment indicates the number of pilot transmission times through signaling. This application does not limit this.
  • the terminal device may receive the reference signal based on the measurement duration or the number of pilot transmissions to perform channel measurement. Regardless of whether the terminal device receives the reference signal based on the measurement duration or the number of pilot transmissions, the terminal device can perform channel measurement based on the reference signal received multiple times to determine one or more of the time-varying characteristics of the channel. Time domain vectors and their corresponding time domain coefficients.
  • N times may be the number of received reference signals within the measurement duration, or the number of pilot transmissions. This application does not limit this.
  • the following takes dual-domain compression as an example to describe in detail the specific process of the terminal device determining one or more time-domain vectors and their corresponding time-domain coefficients.
  • the terminal device determines the channel based on the reference signal received each of the N times, and then approximates the change of the channel over time through the weighted sum of one or more time domain vectors. Specifically, the terminal device performs channel measurement based on the reference signal received for the nth (1 ⁇ n ⁇ N, n is an integer) of the N times, and the space-frequency matrix H n can be obtained.
  • the space-frequency matrix can be understood as a way to characterize the channel.
  • the space-frequency matrix obtained from each channel measurement can be approximated by the weighted sum of multiple space-frequency vector pairs.
  • the channel can be changed over time.
  • the change of is approximately expressed by the weighted sum of one or more time domain vectors.
  • the multiple space-frequency vector pairs used to approximate the space-frequency matrix may be determined by the terminal device based on the feedback mode of dual-domain compression.
  • the multiple space-frequency vector pairs can be used to construct a precoding matrix.
  • the multiple space-frequency vector pairs may be determined by, for example, the first measurement in multiple measurements, the last channel measurement in multiple measurements, or any one of multiple measurements. This application does not limit this.
  • the terminal device may perform channel measurement after receiving N reference signals, or may perform channel measurement every time a reference signal is received. It should be understood that channel measurement is an internal implementation behavior of the terminal device, which is not limited in this application.
  • the terminal device can determine one or more time domain vectors that can be used for weighting and the time domain coefficient of each time domain vector based on some or all of the multiple space-frequency vector pairs, so as to pass the one or more time domain vectors.
  • the weighted sum of the time-domain vectors approximates the time-varying characteristics of the channel. For the convenience of description, suppose that the number of time-domain vectors fed back by the terminal device to the network device is P, P ⁇ 1 and is an integer.
  • the method 300 further includes: the terminal device receives second indication information, where the second indication information is used to indicate the P value.
  • the network device sends the second indication information, and the second indication information is used to indicate the P value.
  • the P value may be indicated by the network device to the terminal device through signaling.
  • the terminal device can select a corresponding number of space-frequency vector pairs to report and determine the time domain vector according to the P value indicated by the network device.
  • the network device can configure the number of time domain vectors that need to be reported for the terminal device through signaling in advance.
  • the second indication information may be carried in high-layer signaling, for example.
  • the high-level signaling may be, for example, a radio resource control (radio resource control, RRC) message. This application does not limit the specific signaling used to carry the second indication information.
  • the method 300 further includes: the terminal device sends third indication information, where the third indication information is used to indicate the P value.
  • the network device receives the third indication information, which is used to indicate the P value.
  • the P value can be determined by the terminal device itself and reported to the network device through signaling.
  • the terminal device may, for example, the maximum value of P P network device that may be used to determine P values indicated by 0, where P ⁇ P 0, P 0 is a positive integer.
  • the method 300 further includes: the terminal device receives fourth indication information, where the fourth indication information is used to indicate the maximum value P 0 of P.
  • the network device sends fourth indication information, which is used to indicate the maximum value P 0 of P.
  • the network device can configure the number of time domain vectors that need to be reported for the terminal device through signaling in advance.
  • the number of time domain vectors actually reported by the terminal device may be equal to or less than the number of time domain vectors that need to be reported pre-configured by the network device.
  • the fourth indication information may be carried in high-layer signaling, for example.
  • the high-level signaling may be, for example, an RRC message. This application does not limit the specific signaling used to carry the fourth indication information.
  • the above-mentioned third indication information may be carried in the same signaling as the first indication information, such as a CSI report; or may be carried in different signaling, such as existing or newly-added signaling. This application does not limit this.
  • the P value is predefined, as defined by the protocol.
  • This application does not limit the specific determination method and specific value of the P value.
  • the P value can also be the number of time-domain vectors determined based on one or more (such as K) space-frequency vector pairs, or it can also be based on The number of time-domain vectors determined by a transport layer.
  • the P value has been described in detail above in combination with different situations. For brevity, it will not be repeated here.
  • the P value can also be the number of time-domain vectors determined based on one beam vector, or it can be determined based on multiple beam vectors The number of time domain vectors, or, may also be based on the number of time domain vectors determined by a transport layer.
  • the terminal device may determine P time domain vectors and the time domain coefficients corresponding to each time domain vector based on a predefined codebook, so as to approximate the time-varying characteristics of the channel.
  • a predefined codebook a predefined codebook
  • the terminal device can determine P time-domain vectors and their corresponding time-domain coefficients based on changes over time of the space-frequency coefficients corresponding to the K space-frequency vector pairs.
  • K ⁇ 1 and is an integer.
  • the first indication information is used to indicate P time domain vectors and their corresponding P time domain coefficients.
  • the weighted sum of the P time-domain vectors can be used to approximately represent the change over time of the space-frequency coefficient of the aforementioned space-frequency vector pair.
  • the terminal device may jointly determine P time domain vectors and their corresponding P time domain coefficients based on K space-frequency vector pairs.
  • the K space-frequency vector pairs used to determine the time-domain vector may be K space-frequency vector pairs determined based on the feedback mode of dual-domain compression.
  • the terminal device can determine based on one of the K space-frequency vector pairs, for example, The strongest space-frequency vector pair among the K space-frequency vector pairs; or, the terminal device can also determine based on the K space-frequency vector pairs, for example, the weighted average of the K space-frequency vector pairs; or the terminal device can also determine It can be determined based on some of the K space-frequency vector pairs, which is not limited in this application.
  • the terminal device only selects one space-frequency vector pair or only selects K space-frequency vector pairs to construct the precoding matrix when the PMI is fed back based on dual-domain compression.
  • the precoding matrix can be constructed based on more (K' as described below, K' ⁇ K and K'is an integer) space-frequency vector pairs.
  • the P time domain vectors and the corresponding P time domain coefficients may be jointly determined based on the above K space-frequency vector pairs.
  • the network device described later constructs a precoding matrix based on K'space-frequency vector pairs and their space-frequency coefficients
  • the P time-domain vectors and their corresponding P time-domain coefficients can be combined by the K space-frequency vector pairs. Shared.
  • the space-frequency coefficients corresponding to any two space-frequency vector pairs are the same.
  • the terminal device jointly determines P time-domain vectors and P time-domain coefficients based on K space-frequency vector pairs, it can be considered that the number of time-domain vectors corresponding to each space-frequency vector pair is P, and each space-frequency vector The number of time domain coefficients for the corresponding time domain vector is P.
  • the time domain vector and time domain coefficient corresponding to each space-frequency vector pair can be used to determine the space-frequency coefficient of this space-frequency vector pair.
  • the terminal device can indicate P time domain vectors and P time domain coefficients through the first indication information.
  • the terminal device only indicates the P time domain vectors and their corresponding time domain coefficients once.
  • the terminal device can use the same field to indicate the P time-domain vectors fed back for each of the K space-frequency vector pairs, or use the same field to indicate that each of the K space-frequency vector pairs is P time-domain coefficients fed back by the space-frequency vector pair.
  • the indication field used to indicate P time domain vectors is common to K space-frequency vector pairs, and the indication field used to indicate P time domain coefficients is also common to K space-frequency vector pairs. of.
  • the same field mentioned here specifically refers to the indication field for the K space-frequency vector pairs to the time domain vector without repetition, and for the K space-frequency vector pairs to indicate the time domain coefficients of the time domain vector The fields are not repeated. It is not intended to limit the number of fields used to indicate time domain vectors and time domain coefficients.
  • the first indication information is used to indicate P time domain vectors and K ⁇ P time domain coefficients.
  • the weighted sum of every P time-domain vectors can be used to approximately represent the space-frequency coefficient of a space-frequency vector pair over time.
  • the terminal device may jointly determine P time domain vectors based on the K space-frequency vector pairs, and may determine the time domain coefficient of each time domain vector based on each of the K space-frequency vector pairs.
  • the related description of the K space-frequency vector pairs and the terminal device jointly determining the P time-domain vectors based on the K space-frequency vector pairs has been described in detail above, and for brevity, it will not be repeated here.
  • the terminal device since the terminal device jointly determines P time-domain vectors based on K space-frequency vector pairs, the time domain of each time-domain vector can be determined based on each space-frequency vector pair in the K space-frequency vector pairs. Domain coefficient. At least two space-frequency vector pairs correspond to different space-frequency coefficients. Therefore, when the network device described later constructs a precoding matrix based on K'space-frequency vector pairs and their corresponding space-frequency coefficients, the space-frequency coefficients corresponding to at least two space-frequency vector pairs in the K space-frequency vector pairs are different.
  • the terminal device Since the terminal device jointly determines P time-domain vectors based on K space-frequency vector pairs, it can be considered that the number of time-domain vectors corresponding to each space-frequency vector pair is P. In addition, the terminal device determines P time-domain vectors based on each of the K space-frequency vector pairs, and the total number of time-domain vectors determined by the terminal device based on the K space-frequency vector pairs is K ⁇ P. In this case, the number of time domain coefficients corresponding to each space-frequency vector pair is P, but the time domain coefficients corresponding to at least two space-frequency vector pairs are different.
  • the terminal device when the terminal device indicates the above-mentioned K ⁇ P time domain coefficients through the first indication information, it may indicate separately for each space-frequency vector.
  • the time-domain coefficients respectively indicated for each space-frequency vector pair and the P time-domain vectors described above can be used to determine the space-frequency coefficient of this space-frequency vector pair.
  • the first indication information may be used to indicate Time domain vectors and their corresponding Time domain coefficients.
  • 1 ⁇ k ⁇ K, P k ⁇ 1, k and P k are both integers.
  • the terminal device can determine one or more time domain vectors based on each space-frequency vector pair in K space-frequency vector pairs, and can determine each space-frequency vector pair based on each space-frequency vector pair in the K space-frequency vector pairs. Time domain coefficients corresponding to each time domain vector.
  • the terminal device determines one or more time domain vectors and one or more time domain coefficients based on each space-frequency vector pair. At least two space-frequency vector pairs correspond to different space-frequency coefficients. Therefore, when the network device described below constructs a precoding matrix based on K'space-frequency vector pairs and their space-frequency coefficients, the space-frequency coefficients corresponding to at least two space-frequency vector pairs in the K space-frequency vector pairs are different. .
  • the terminal device is indicating the above When there are two time-domain vectors and their corresponding time-domain coefficients, they can be indicated separately for each pair of space-frequency vectors.
  • the time domain vector and its corresponding time domain coefficient respectively indicated for each space-frequency vector pair can be used to determine the space-frequency coefficient of the space-frequency vector pair.
  • the P k time-domain vectors indicated for the k-th space-frequency vector pair and their corresponding time-domain coefficients can be used to determine the space-frequency coefficients of the k-th space-frequency vector pair.
  • the vector obtained by weighted summation of one or more (for example, P or P k ) time-domain vectors corresponding to a pair of space-frequency vectors is referred to as the space-frequency corresponding to the pair of space-frequency vectors.
  • the estimated value of the coefficient vector is referred to as the space-frequency coefficient vector.
  • the space-frequency coefficient vector will be described in detail later, and the detailed description of the space-frequency coefficient vector will be omitted here.
  • a space-frequency vector pair is taken as an example to explain in detail the specific process of the terminal device determining P time domain vectors and their corresponding time domain coefficients.
  • One space-frequency vector pair in the K space-frequency vector pairs is denoted as (u l , v m ).
  • the space-frequency vector pair (u l , v m ) can be the strongest space-frequency vector pair among the K space-frequency vector pairs. Frequency vector pairs.
  • l (1 ⁇ l ⁇ L and l is an integer) means that the space vector u l is the l-th space vector among the L (L ⁇ 1 and is an integer) space vector
  • m (1 ⁇ m ⁇ M and m Is an integer) means that the frequency domain vector v m is the m- th frequency domain vector among M (M ⁇ 1 and an integer) frequency domain vectors.
  • the L space-domain vectors and the M frequency-domain vectors can be combined to obtain multiple space-frequency vector pairs (K space-frequency vector pairs as described below), and the multiple space-frequency vector pairs can be used to construct a precoding matrix.
  • the strongest space-frequency vector pair mentioned here may specifically refer to: the amplitude of the space-frequency coefficient corresponding to the space-frequency vector pair is greater than or equal to any of the plurality of space-frequency vector pairs except the space-frequency vector pair.
  • the strongest space-frequency vector (u l , v m ) can be determined based on the reference signal received for the first time, or it can be determined based on the reference signal received at any one of the N times, or it can be based on N It is determined after averaging the received reference signals. This application does not limit this.
  • the N space-frequency coefficients corresponding to the space-frequency vector pair (u l , v m ) determined based on the reference signals received N times are recorded as The nth element among the N elements may be determined based on the channel measurement performed on the reference signal received for the nth time.
  • the N space frequency coefficients can form a vector
  • the vector c l,m can also reflect the change trend of N space-frequency matrices determined by the reference signals received N times over time, that is, indirectly reflect the change trend of the channel over time.
  • the vector formed by the space-frequency vector pair corresponding to the space-frequency coefficient determined by the reference signals received multiple times is recorded as the space-frequency coefficient vector.
  • space-frequency coefficient vector with a dimension of N ⁇ 1, but this should not constitute any limitation to the application.
  • the space-frequency coefficient vector may also be a vector with a dimension of 1 ⁇ N.
  • Those skilled in the art can make mathematical transformations or equivalent substitutions to the forms of the above-mentioned space-frequency coefficient vectors based on the same concept, and these mathematical transformations or equivalent substitutions should fall within the protection scope of this application.
  • the dimension of the space-frequency coefficient vector may also be less than N, and the terminal device may determine the space-frequency matrix based on the reference signals received multiple times, and then determine the space-frequency coefficient corresponding thereto.
  • the number of space frequency coefficients thus determined is less than N, so the length of the space frequency coefficient vector is also less than N.
  • the N elements in the space-domain coefficient vector correspond to N measurement times, and can be used to represent the space-frequency coefficient of the space-frequency vector pair at each measurement time in the N measurement times.
  • the n-th element among the N elements in the time-domain coefficient vector can be used to determine the space-frequency matrix at the n-th measurement moment.
  • the space-frequency coefficient vector can be represented by a weighted sum of one or more time-domain vectors.
  • the terminal device may determine one or more time domain vectors from a predefined codebook to approximately represent the above-mentioned space-frequency coefficient vector.
  • the codebook used to determine one or more time-domain vectors can be indicated by the network device to the terminal device through signaling, such as indicating the index of the codebook, or indicating the index and oversampling factor of the codebook; it can also be the terminal device itself.
  • the terminal device may, for example, project the space-frequency coefficient vector to the codebook to select P stronger time-domain vectors to approximate the space-frequency coefficient vector.
  • the dimension of the codebook used to determine the time domain vector corresponds to the dimension of the space-frequency coefficient vector.
  • the dimension of the codebook used to determine the time-domain vector may also be N-dimensional.
  • the dimension of the space-frequency coefficient vector is related to the number of times the reference signal is received. Therefore, the dimension of the codebook can be correlated with the number of times N the reference signal is received.
  • the dimension of the codebook may be the same as the number of times N of receiving the reference signal.
  • the terminal device may generate a space-frequency coefficient vector of length N based on the reference signal received N times.
  • the codebook dimension may be the same as the length of the space-frequency coefficient vector.
  • the terminal device can select P time-domain vectors that can be used to approximate the space-frequency coefficient vector through the N-dimensional codebook.
  • the dimension N of the codebook used to determine the time domain vector is greater than or equal to the number P of the selected time domain vector. That is, N ⁇ P.
  • the codebook dimension may be an oversampling multiple of the space-frequency coefficient vector. For example, if the length of the space-frequency coefficient vector is N and the oversampling factor is O t , the dimension of the codebook used to determine the time domain vector may also be N ⁇ (O t ⁇ N) dimensions. It can be understood that the dimension O t ⁇ N of the codebook used to determine the time domain vector is greater than or equal to the number P of the selected time domain vector. That is, O t ⁇ N ⁇ P.
  • the length of the space-frequency coefficient vector can be pre-appointed by the network device and the terminal device.
  • the two parties can agree that the number of times N of receiving the reference signal is used as the length of the space-frequency coefficient vector, and the length of the space-frequency coefficient vector can also be determined based on N, such as 2N.
  • N such as 2N.
  • the network device may indicate the codebook used to determine the time domain vector to the terminal device in advance, and implicitly indicate the length of the spatial coefficient vector by indicating the codebook.
  • the codebook indicated by the network device to the terminal device in advance is an N-dimensional codebook
  • the length of the spatial coefficient vector is N.
  • the network device may also indicate the length of the spatial coefficient vector to the terminal device through other signaling. For the sake of brevity, I will not illustrate them one by one.
  • the length of the space-frequency coefficient vector is N.
  • the codebook used to determine the time domain vector is an N-dimensional codebook, and the N-dimensional codebook includes N time domain vectors of length N.
  • the N time-domain vectors of length N can be constructed to obtain a matrix with a dimension of N ⁇ N. Suppose this matrix is denoted as U t .
  • U t [d 1 d 2 ...d N ].
  • d 1 , d 2 ,..., d N are N time-domain vectors of length N in the codebook.
  • the projection of the space-frequency coefficient vector to the predefined codebook can be expressed as: U t H c l,m .
  • a vector d l,m with dimension N ⁇ 1 can be obtained.
  • the N elements in the vector d l,m may represent the weight of each time domain vector in the N time domain vectors in the matrix U t .
  • the nth element in the vector d l,m Weight matrix U t represents the n-th time domain weight vector D n. It can be understood that the aforementioned weights may also be referred to as time domain coefficients.
  • the terminal device may be selected from strong P elements of the vector d l, m, the strong position P elements in the vector d l, m corresponding to the time-domain vector position P in the matrix U t. For example, the terminal device may determine the stronger P elements according to the magnitude of the square of the modulus of the N elements in the vector d l,m obtained by the projection. The square of the modulus of any one of the selected P elements is greater than or equal to the square of the modulus of any one of the unselected NP elements. From the stronger P elements, P time-domain vectors can be determined. For example, the positions corresponding to the stronger P elements in the vectors d l,m may also be the positions of the selected P time-domain vectors in the matrix U t .
  • the stronger 3 elements among the N elements are recorded as
  • the subscripts p 1 , p 2 and p 3 respectively represent the index of the element in the vector d l, m .
  • the first vector d 1 , the fourth vector d 4, and the eighth vector d 8 in the matrix U t are three strong time-domain vectors.
  • the terminal device may also determine P time-domain vectors and their corresponding time-domain coefficients based on the space-frequency coefficients corresponding to multiple space-frequency vector pairs.
  • the terminal device determines P time-domain vectors and their corresponding time-domain coefficients based on the K space-frequency coefficient vectors corresponding to the K space-frequency vector pairs.
  • the multiple space-frequency vector pairs correspond to the common P time domain vectors and the common P time domain coefficients; or, The multiple space-frequency vector pairs correspond to the common P time-domain vectors, and each space-frequency vector pair corresponds to P time-domain coefficients; or, the multiple space-frequency vector pairs respectively correspond to one or more time-domain vectors and one Or multiple time domain coefficients.
  • a possible situation is that multiple space-frequency vector pairs correspond to common P time-domain vectors and common P time-domain coefficients, and the terminal device can be based on one of the multiple space-frequency vector pairs. (For example, the strongest space-frequency vector pair), or a weighted average of the multiple space-frequency vector pairs, to determine the common P time domain vectors and the common P time domain coefficients.
  • multiple pairs of space-frequency vectors may each correspond to one or more time domain vectors and one or more time domain coefficients.
  • the terminal device may determine the space-frequency coefficient vector corresponding to each space-frequency vector pair based on the change over time of the space-frequency coefficient corresponding to each space-frequency vector pair in the plurality of space-frequency vector pairs.
  • the terminal device can project the space-frequency coefficient vector corresponding to each space-frequency vector pair onto the codebook to obtain one or more time-domain vectors corresponding to each space-frequency vector pair and the corresponding time-domain vector. Time domain coefficient.
  • the terminal device determines the corresponding K space-frequency coefficient vectors based on the K space-frequency vector pairs.
  • Each of the K space-frequency coefficient vectors can be used to determine one or more time-domain vectors.
  • the k-th space-frequency coefficient vector in the K space-frequency coefficient vectors can be used to determine the P k time-domain vectors and their corresponding time-domain coefficients, P k ⁇ P, and P k is a positive integer.
  • the P k time domain vectors and the corresponding time domain coefficients are the time domain vectors and time domain coefficients corresponding to the k-th space-frequency vector pair.
  • the P k time-domain vectors and their corresponding time-domain coefficients can be used to determine the estimated value of the space-frequency coefficient vector corresponding to the k-th space-frequency vector pair.
  • the terminal device may sequentially determine the time domain vectors and time domain coefficients corresponding to the first to Kth space frequency vector pairs in the manner of projecting a space frequency coefficient vector to the codebook as described above. In this case, the terminal device may sequentially project the space-frequency coefficient vectors corresponding to the K space-frequency vector pairs to the codebook to determine the time domain vector and the time domain coefficient.
  • the terminal device may also construct the corresponding space-frequency coefficient vectors of the K space-frequency vector pairs as a matrix, and the matrix may be, for example, a matrix with a dimension of N ⁇ K.
  • Each column vector of the matrix corresponds to a pair of space-frequency vectors.
  • Each column vector in the matrix obtained after projection corresponds to a space-frequency vector pair.
  • the terminal device can determine the stronger one or more elements in each column as the time domain coefficient based on the elements in each column vector, and the position of the one or more elements in the column vector can be determined to correspond to each space-frequency vector pair One or more time domain vectors of.
  • the method for the terminal device to determine the corresponding time-domain vector and the corresponding time-domain coefficient based on the K space-frequency vector pairs is not limited to the above list, and for the sake of brevity, examples are not described here.
  • the terminal equipment can determine the total K space-frequency coefficient vectors based on the K space-frequency vector pairs.
  • Time domain vectors It can be understood that, among the P time-domain vectors determined based on the K space-frequency coefficient vectors, some of the time-domain vectors may be the same or duplicated. In other words, the P time-domain vectors may be different from each other, or they may partially overlap. However, since these repeated time domain vectors are determined based on different space-frequency coefficient vectors, the corresponding time domain coefficients are not necessarily the same.
  • the number of time-domain vectors determined based on multiple space-frequency vector pairs may be the same or different, which is not limited in this application.
  • the number of time-domain vectors determined based on each pair of space-frequency vectors may be indicated by the network device, may also be determined by the terminal device itself, or may be predefined, which is not limited in this application.
  • the terminal device can determine a larger number of time-domain vectors for the strongest space-frequency vector pair, and determine a smaller number of time-domain vectors for other space-frequency vector pairs.
  • the terminal device may divide the K space-frequency vector pairs into multiple groups, and determine different numbers of time-domain vectors for the space-frequency vector pairs in different groups. For example, the terminal device may divide the K space-frequency vector pairs into two groups, group 1 and group 2, where group 1 includes the stronger one or more of the K space-frequency vector pairs, and group 2 includes the remaining space-frequency vector pairs. One or more space-frequency vector pairs of. Or, when the transmitting antenna has multiple polarization directions, group 1 and group 2 may also include one or more space-frequency vector pairs corresponding to different polarization directions.
  • the space-frequency vector pairs in each group can be used to determine the same number of time-domain vectors, and the number of time-domain vectors determined based on the space-frequency vector pairs in group 1 can be greater than that determined based on the space-frequency vector pairs in group 2.
  • the number of space-frequency vector pairs included in group 1 and the number of space-frequency vector pairs included in group 2, for example, can be predefined, or agreed in advance by both the network device and the terminal device, or can also be based on predefined rules To be sure, for the sake of brevity, I will not illustrate them one by one.
  • the codebook used to determine the time domain vector is determined from a plurality of predefined codebooks.
  • the codebook used to determine the P time-domain vectors may be one or multiple. This application does not limit this.
  • the terminal device may determine P time domain vectors and their corresponding time domain coefficients based on multiple codebooks of different dimensions. Specifically, the terminal device may determine the corresponding time domain vector and time domain coefficient based on the K space-frequency vector pairs. Wherein, when at least two space-frequency vector pairs are used to determine the time domain vector, they may be determined based on two codebooks of different dimensions. For example, the intensity of space-frequency vector pair 1 is higher than the intensity of space-frequency vector pair 2.
  • the terminal device can determine one or more time-domain vectors based on the space-frequency vector pair 1 and the codebook of dimension ⁇ N, and use the space-frequency vector pair 2 and the codebook of dimension N to determine one or more time-domain vectors, where ⁇ >1 and is an integer; or, the terminal device can determine one or more time-domain vectors based on the space-frequency vector pair 1 and the codebook with dimension N, using space-frequency vector pair 2 and dimension as Or [N/ ⁇ ] codebook to determine one or more time domain vectors, where ⁇ >1 and an integer.
  • Means rounding up, Means rounding down, [] means rounding up.
  • the intensity of space-frequency vector pair 1 is higher than that of space-frequency vector pair 2.
  • the space-frequency coefficient corresponding to space-frequency vector pair 1 and the space-frequency coefficient corresponding to space-frequency vector pair 2 can be compared at the same measurement time. The magnitude of the coefficient is determined. This application does not limit this.
  • the terminal device can use different precision codebooks for space-frequency vector pairs of different strengths to determine the time domain vector. For example, for a strong space-frequency vector pair, a codebook with higher precision can be used to determine the time domain vector.
  • One form of expression is to use a larger-dimensional codebook to determine the time domain vector; for a weaker space-frequency vector pair, A codebook with lower accuracy can be used to determine the time domain vector.
  • One form of expression is to use a codebook with a smaller dimension to determine the time domain vector.
  • the terminal device may also determine one or more time domain vectors and their corresponding time domain coefficients based on more codebooks of different dimensions and K space-frequency vector pairs. This application does not limit this.
  • the terminal device can determine the stronger P time domain vectors based on a space-frequency vector pair (for example, the strongest space-frequency vector pair), or can determine the stronger P time domains based on multiple space-frequency vector pairs vector.
  • the terminal device may further determine P time-domain coefficients corresponding to each pair of space-frequency vectors based on the space-frequency coefficient vectors respectively corresponding to the multiple pair of space-frequency vectors.
  • the terminal device also determines the stronger P time-domain vectors based on multiple space-frequency vector pairs. Specifically, the terminal device may project the space-frequency coefficient vectors corresponding to the multiple space-frequency vector pairs to the codebook to obtain multiple vectors. The terminal device may select the stronger P elements according to the multiple vectors, and determine the P time domain vectors with the same position from the codebook according to the positions of the stronger P elements in the vector. The P time-domain vectors thus determined may be P time-domain vectors common to the multiple space-frequency vector pairs.
  • the terminal device may sequentially determine the time domain coefficients corresponding to the first to Kth space-frequency vector pairs in the manner of projecting a space-frequency coefficient vector to the codebook as described above. Take the k-th space-frequency vector pair as an example, project the space-frequency coefficient vector corresponding to the k-th space-frequency vector pair into the vector that can be obtained from the codebook, and choose the position of the P time-domain vectors in the matrix U t The corresponding P elements are used as the P time domain coefficients corresponding to the P time domain vectors.
  • the terminal device may also construct the K space-frequency coefficient vectors corresponding to the K space-frequency vector pairs as a matrix, and the matrix may be, for example, a matrix with a dimension of N ⁇ K.
  • Each column vector of the matrix corresponds to a pair of space-frequency vectors.
  • each column vector corresponds to a space-frequency vector pair.
  • the terminal device may select elements at corresponding positions from each column vector based on the positions of the P time domain vectors in the matrix U t as the P time domain coefficients corresponding to the P time domain vectors. Therefore, P time domain coefficients corresponding to each space-frequency vector pair can be determined.
  • the terminal device may also determine P time-domain vectors and their corresponding time-domain coefficients in other possible ways. For example, the terminal device may combine the two methods described above to determine P time domain vectors and their corresponding time domain coefficients. Alternatively, the terminal device can select P rows with larger total energy or average energy from the above-mentioned matrix with dimensions of N ⁇ K, and their positions in the matrix with dimensions of N ⁇ K correspond to the P time domain vectors The position in the matrix U t .
  • the terminal device may divide the K space-frequency vector pairs into multiple groups, and each group may include one or more space-frequency vector pairs.
  • the terminal device may determine the common one or more time domain vectors and the common one or more time domain coefficients based on the space-frequency vector pairs in each group.
  • the space-frequency vector pairs in the group can share the same one or more time domain vectors and the same one or more time domain coefficients.
  • the terminal device may also determine one or more common time-domain vectors based on the space-frequency vector pairs in each group, and determine respective one or more time-domain coefficients based on each space-frequency vector pair.
  • the terminal device determines the same one or more time domain vectors and the same one or more time domain coefficients based on the space-frequency vector pairs in the group, it can be determined based on a certain space-frequency vector pair in the group, such as the strongest in the group
  • the space-frequency vector pairs of can also be determined based on the weighted average of multiple space-frequency vector pairs in the group. For brevity, we will not list them all here.
  • the method for determining P time-domain vectors and their corresponding time-domain coefficients described above is only an example, and should not constitute any limitation to this application.
  • the terminal device can also use existing estimation algorithms, such as multiple signal classification algorithm (MUSIC), Bartlett algorithm, or rotation invariant subspace algorithm (estimation of signal parameters via rotation invariant technique algorithm). , ESPRIT) and so on to determine the time domain vector and its corresponding time domain coefficients.
  • MUSIC multiple signal classification algorithm
  • Bartlett algorithm or rotation invariant subspace algorithm (estimation of signal parameters via rotation invariant technique algorithm).
  • ESPRIT rotation invariant subspace algorithm
  • the present application does not limit the sequence of determining the time domain vector and the corresponding time domain coefficient.
  • the terminal device may generate first indication information to indicate the P time domain vectors and their corresponding time domain coefficients.
  • the P time-domain vectors are determined based on the same codebook.
  • the codebook may be indicated by the network device or predefined by the protocol.
  • the first indication information when used to indicate the P time domain vectors, it may include the indexes of the P time domain vectors in the codebook, or The index of the combination of the P time domain vectors.
  • the P time-domain vectors are determined based on the same codebook.
  • the codebook can be determined by the terminal device itself.
  • the first indication information is used to indicate the P time domain vectors, it may include an indication of the codebook, and the index of the P time domain vectors in the codebook, or a combination of the P time domain vectors index.
  • the P time-domain vectors are determined based on different codebooks.
  • the first indication information may include an indication for determining the codebook of each time domain vector and the index of each time domain vector in the corresponding codebook.
  • each time domain vector may correspond to a Doppler shift.
  • the component feature of the time-varying feature described above may be a Doppler shift.
  • the multiple time domain vectors are taken from an N-dimensional codebook, it can be understood that the maximum Doppler frequency shift is equally divided into N parts, and the N time domain vectors and N Doppler frequencies in the N-dimensional codebook Shift correspondence.
  • the ratio of the Doppler frequency shift corresponding to the nth time domain vector to the maximum Doppler frequency shift is n/N.
  • the maximum Doppler frequency can be determined by the network equipment, for example, using uplink and downlink reciprocity or according to the moving speed of the terminal device and/or the relative position with the base station, and instruct the terminal device to use the maximum Doppler frequency shift
  • the corresponding codebook is used for channel measurement and feedback.
  • the maximum Doppler frequency shift can be determined by the terminal device and reported to the network device.
  • the maximum Doppler frequency shift can also be predefined, such as defined by a protocol, or bound with a reference signal configuration, etc.
  • the terminal device When the terminal device indicates the P time domain coefficients corresponding to the P time domain vectors through the first indication information, it may be indicated by the quantized value of the P time domain coefficients, or may be indicated by the index of the quantized value, or It can also be indicated in other ways.
  • the present application does not limit the way of indicating the time domain coefficients, as long as the network device can determine the P time domain coefficients according to the first indication information.
  • the information used to indicate the time domain coefficient is referred to as the quantization information of the time domain coefficient.
  • the quantization information may be, for example, a quantization value, an index, or any other information that can be used to indicate time domain coefficients.
  • the terminal device may indicate the P time domain coefficients in a normalized manner. For example, the terminal device may determine the time domain coefficient with the largest modulus from the P time domain coefficients (for example, denoted as the maximum time domain coefficient), and indicate that the maximum time domain coefficient is in the P time domains corresponding to the P time domain coefficients. The position in the vector. The terminal device may further indicate the relative value of the remaining P-1 time domain coefficients with respect to the maximum time domain coefficient. The terminal device may indicate the aforementioned P-1 time domain coefficients through the quantization value index of each relative value.
  • the first indication information when used to indicate P time domain coefficients, it may be indicated in a direct or indirect manner. For example, for the largest time domain coefficient, it may indicate its position in the P time domain coefficients; for another example, for a time domain coefficient with a quantization value of zero, it may also indicate its position in the P time domain coefficients. In other words, the first indication information does not necessarily indicate each coefficient of the P time domain coefficients. As long as the network device can recover P time domain coefficients according to the first indication information.
  • step 330 the terminal device sends the first indication information.
  • the network device receives the first indication information.
  • the terminal device may send the first indication information to the network device through a physical uplink resource, such as a physical uplink share channel (PUSCH) or a physical uplink control channel (PUCCH).
  • a physical uplink resource such as a physical uplink share channel (PUSCH) or a physical uplink control channel (PUCCH).
  • the first indication information may be carried in, for example, a channel state information (CSI) report (CSI for short), or may also be carried in other signaling. This application does not limit this.
  • CSI channel state information
  • the space-frequency vector pairs indicated by the terminal device to the network device may be the aforementioned K space-frequency vector pairs, or may include the aforementioned K space-frequency vector pairs. This application does not limit this.
  • the terminal device based on the dual-domain compression feedback method includes one or more space-frequency vector pairs other than the above-mentioned K space-frequency vector pairs, for example, the terminal device is based on dual-domain compression
  • the feedback method feeds back K'space-frequency vector pairs, K'>K, and K'is an integer.
  • the network device and the terminal device can preset rules to select K space-frequency vector pairs from the K'space-frequency vector pairs to determine P time-domain vectors and their corresponding time-domain coefficients.
  • the K value can be determined by a network device.
  • the K space-frequency vector pairs can be the stronger K space-frequency vector pairs among the K'space-frequency vector pairs.
  • the amplitude of the space-frequency coefficient corresponding to any one of the selected K'-K space-frequency vector pairs is less than or equal to the amplitude of the corresponding space-frequency coefficient of any one of the K space-frequency vector pairs value.
  • the K value can be determined by the terminal device itself.
  • the K space-frequency vector pairs may be space-frequency vector pairs of which the amplitude of the K'space-frequency vector pairs is greater than or equal to a preset threshold.
  • the terminal device can also report the K space-frequency vector pairs to the network device separately.
  • the method further includes: the terminal device sends fifth indication information, where the fifth indication information is used to indicate K space-frequency vector pairs.
  • the network device receives the fifth indication information, which is used to indicate K space-frequency vector pairs.
  • the K space-frequency vector pairs are space-frequency vector pairs used to determine one or more time domain vectors and their corresponding time domain coefficients.
  • the fifth indication information and the first indication information described above can be carried in the same signaling, such as a CSI report; it can also be carried in different signaling, such as existing or newly added Signaling. This application does not limit this.
  • the reference signal sent by the network device may be a reference signal that has not been pre-coded or a pre-coded reference signal. Based on the different reference signals sent by network devices, the processing methods of terminal devices are also slightly different.
  • the fifth indication information specifically indicates the K space-frequency vector pairs.
  • the specific method for the terminal device to indicate the K space-frequency vector pairs may refer to the method for indicating the space-frequency vector pairs in the dual-domain compression feedback manner in the prior art. This application does not limit the specific method for the terminal device to indicate the K space-frequency vector pairs.
  • the fifth indication information specifically indicates ports corresponding to the K space-frequency vector pairs.
  • the precoding reference signal can be obtained by precoding the reference signal based on the spatial vector and the frequency domain vector, or can be obtained by precoding the reference signal based on the angle vector and the delay vector. Precoded.
  • the reference signal obtained by precoding can correspond to K'ports, and the K'ports can correspond to K'space-frequency vectors one-to-one, and can also correspond to K'angle delays one-to-one.
  • the terminal device may determine the space frequency coefficient corresponding to each port based on the received precoding reference signals of the K'ports, and select K ports from the K'ports according to the space frequency coefficient corresponding to each port.
  • the terminal device can measure and record the space-frequency coefficients corresponding to the selected K ports at multiple measurement moments to obtain the K space-frequency coefficient vectors, and then determine the P time-domain vectors and their corresponding time-domain coefficients.
  • the indication of the K ports by the fifth indication information may include the port numbers of the K ports, for example. This application does not limit the specific method for the terminal device to indicate the K ports.
  • step 340 the network device determines the one or more component features and the weighting coefficient of each component feature according to the first indication information.
  • the network device may determine the aforementioned P time domain vectors and their corresponding time domain coefficients according to the first indication information.
  • the process in which the network device interprets the first indication information corresponds to the process in which the terminal device generates the first indication information.
  • the terminal device may generate the first instruction information in a manner that can be agreed in advance by both parties, or in a predefined manner; the network device may also interpret the first instruction information in the same manner.
  • step 310 Since the specific process of generating the first indication information by the terminal device has been described in detail in step 310 above, the specific process of the network device determining P time domain vectors and their corresponding time domain coefficients according to the first indication information corresponds to it, For brevity, I won't repeat them here.
  • the terminal device can approximate the time-varying characteristics of the channel through the weighted sum of one or more component characteristics, and feed back the quantized information of the component characteristics and the weighted coefficients to the network device. Therefore, the network device can determine the change of the channel in the time domain, and can also understand the state of the channel more comprehensively, so as to make more reasonable decisions for downlink scheduling.
  • the network device may determine the precoding matrix for downlink transmission based on the time-varying characteristics fed back by the terminal device.
  • the method further includes step 350.
  • the network device determines a precoding matrix according to the one or more component features and the weighting coefficient of each component feature.
  • the network equipment can recover the space-frequency coefficient vectors of the K space-frequency vector pairs, that is, it can determine that the K space-frequency vector pairs are at N measurement moments. Corresponding to the space frequency coefficient. It can be understood that the space-frequency coefficient vector recovered by the network device according to the P time-domain vectors and their corresponding time-domain coefficients is the estimated value of the space-frequency coefficient vector described above. As mentioned above, the weighted sum of the P time-domain vectors can approximately restore the above-mentioned space-frequency coefficient vector.
  • the estimated value of the space-frequency coefficient vector of the space-frequency vector pair is recovered from the weighted sum of the P time-domain vectors.
  • the weighted sum of the P time-domain vectors is which is, Alternatively, the weighted sum of the P time-domain vectors can also be represented by matrix operations, such as: or Or other equivalent mathematical transformations. This application does not limit this. among them, Represents c l, m of the estimated value, and the terminal device to determine the actual measured frequency space coefficient vector c l, m distinguish.
  • the network device may also determine the estimated values of the space-frequency coefficient vectors of multiple space-frequency vector pairs based on the P time-domain vectors and their corresponding time-domain coefficients. That is, K>1.
  • the network device can first determine one or more time domain vectors and one or more time domains corresponding to each space-frequency vector pair among the P time domain vectors and their corresponding time domain coefficients. coefficient. For example, for the k-th space-frequency vector pair, the network device may determine P k time-domain vectors and their corresponding time-domain coefficients. The P k time-domain vectors and their corresponding time-domain coefficients determined based on the k-th space-frequency vector pair can be used to determine the estimated value of the k-th space-frequency vector to the corresponding space-frequency coefficient vector.
  • the network device can determine that the K space-frequency vector pairs are at each of the N measurement moments.
  • the space frequency coefficient corresponding to the measurement moment can further construct the space-frequency matrix at each measurement moment based on the K space-frequency vector pairs and the space-frequency coefficient vector corresponding to each space-frequency vector pair.
  • the space-frequency matrix thus determined is the estimated value of the space-frequency matrix. In order to distinguish it from the space-frequency matrix H determined by the terminal device based on the channel measurement described above, the estimated value of the space-frequency matrix is used here Said.
  • the network device may determine the space-frequency matrix at any one of the N measurement times based on the K space-frequency vector pairs and the space-frequency coefficient vector of each space-frequency vector pair.
  • the space-frequency matrix at the nth measurement time can be expressed as among them, Represents the space-frequency coefficient vector corresponding to the space-frequency vector pair obtained by combining the l-th space-domain vector u l and the m-th frequency-domain vector v m.
  • the network device may determine a precoding matrix for downlink data transmission based on the space-frequency matrix after the Nth measurement moment.
  • the specific method for the network device to determine the precoding matrix according to the space-frequency matrix has been briefly explained above, and the specific method can refer to the prior art. For brevity, I won't repeat them here.
  • the network device is not limited to determining the space-frequency matrix, or in other words, the precoding matrix, at the N measurement moments based on the P time domain vectors and their corresponding time domain coefficients. Based on the P time-domain vectors and their corresponding time-domain coefficients determined above, the network device can further predict the space-frequency matrix or the precoding matrix at a future time.
  • the network device may predict the space-frequency coefficient vector at a future time according to the space-frequency coefficient vectors of the K space-frequency vector pairs, and then determine the space-frequency matrix at the future time according to the predicted space-frequency coefficient vector.
  • the network device can first determine the space-frequency matrix of N measurement moments based on the space-frequency coefficient vectors of the K space-frequency vector pairs, and then predict the future time based on the space-frequency matrix of the N measurement moments. Space frequency matrix.
  • the network device may use an autoregressive model (AR) model for channel prediction.
  • AR autoregressive model
  • the historical channel of the time-varying channel is correlated with the subsequent channel, and the correlation can be characterized by several slowly changing or constant coefficients. That is, the channel at any time can be expressed as the weighting coefficient of the specific coefficient of the channel at the previous time (for example, ⁇ 1 , ⁇ 2 ,..., ⁇ E in the following formula).
  • the network device can predict the future space-frequency coefficient through the known space-frequency coefficient, and then predict the subsequent channel.
  • N time-domain coefficients corresponding to the space-frequency vector pair (u l , v m ) For example, Where 1 ⁇ E ⁇ N, and E is an integer.
  • the network device can predict the channel at any time after the N measurement time. E.g among them, It is the space-frequency coefficient of the space-frequency vector pair (u l , v m ) matched by the channel at a certain time in the future.
  • the network device can determine the precoding matrix used for downlink transmission at that time.
  • the precoding matrix thus determined takes into account the time-varying characteristics of the channel and can be well adapted to the downlink channel.
  • the terminal device determines the precoding matrix for downlink transmission based on the feedback mode of dual domain compression, it may face the problem of CSI expiration.
  • the process of CSI feedback based on the existing CSI feedback process and the CSI expiration problem faced are described in detail here with reference to FIG. 4.
  • FIG. 4 is a schematic flowchart of CSI feedback based on a dual-domain compression feedback method provided by an embodiment of the present application.
  • the network device sends a reference signal at time 1, and the terminal device can perform channel measurement and feedback at time 2 after receiving the reference signal. Since the reference signal sent by the network device may be periodic, aperiodic or semi-continuous, that is, there may be a period of time between the last time the network device sends the reference signal and the next time the reference signal is sent. As shown in FIG. 4, the network device transmits the next reference signal at time 3, and the terminal device performs channel measurement and feedback based on the reference signal transmitted next time at time 4.
  • a time interval t1 has passed, and from time 2 to time 4, a time interval t2 has passed.
  • the precoding matrix used by the network device for downlink transmission is determined based on the feedback received at time 2.
  • the channel may have changed during the time interval t2.
  • the precoding matrix determined based on the feedback at time 2 is directly used to precode the subsequent downlink transmission, the precoding matrix may no longer be compatible with the downlink channel.
  • Ground adaptation which may cause a decrease in transmission performance.
  • This situation in which the precoding matrix determined based on feedback cannot match the real channel due to changes in the channel over time is called CSI expiration. In other words, when the channel changes rapidly over time, the CSI expiration may cause a significant decrease in transmission performance.
  • the terminal device performs channel measurement based on the reference signals sent by the network device at multiple different times, and feeds the channel changes over time to the network after being weighted and quantized by the time domain vector. equipment.
  • the network device can predict the channel at a future time based on the change of the channel over time, and then determine the precoding matrix adapted to it. Therefore, the problem of transmission performance degradation caused by CSI expiration is alleviated, which is beneficial to improve system performance.
  • FIG. 5 shows the correlation between the precoding matrix corresponding to the channel at different moments and the precoding matrix corresponding to the real channel constructed based on different feedback methods.
  • Fig. 5 is an effect simulation diagram provided by an embodiment of the present application.
  • Figure 5 is simulated based on the following assumptions: the number of transmitting antennas of the network device is 64, the number of receiving antennas of the terminal device is 1, the carrier frequency is 3.5GHz, the subcarrier spacing is 30kHz, and the bandwidth is 50 resource blocks (RB) , The moving speed of the terminal equipment is 30 kilometers per hour (km/h).
  • the horizontal axis in the figure represents the time interval, and the unit is a time slot; the vertical axis in the figure represents the correlation coefficient, which is used to characterize the correlation between the precoding matrix corresponding to the channel constructed based on different feedback methods and the precoding matrix corresponding to the real channel Sex.
  • the curve formed by connecting triangles in the figure is the correlation coefficient of the precoding matrix corresponding to the real channel and the precoding matrix corresponding to the real channel. It can be understood that the correlation coefficient is always 1.
  • the curve formed by connecting diamonds in the figure is based on the channel measurement method provided by the embodiment of the present application, and is constructed (or predicted) to obtain the correlation between the precoding matrix corresponding to the channel at different times and the precoding matrix corresponding to the real channel Coefficient (for easy distinction, for example, recorded as correlation coefficient 1).
  • the curve formed by star connection in the figure is based on the correlation coefficient between the precoding matrix corresponding to the channel and the precoding matrix corresponding to the real channel constructed based on the previous feedback of the terminal equipment in the prior art (for easy distinction, for example, it is recorded as Correlation coefficient 2). It can be seen that as time goes on, the correlation coefficient 1 shows a tendency to be higher than the correlation coefficient 2. That is to say, compared to the precoding matrix determined by the terminal device in the previous feedback, the precoding matrix determined based on the method provided by the embodiment of the present application to predict the future channel and then determine the precoding matrix can be more consistent with the real channel. Match, thereby alleviating the problem of performance transmission degradation caused by CSI expiration, which is beneficial to improving system performance.
  • the terminal device may also determine the component characteristics of the time-varying characteristics and their weighting coefficients based on the feedback mode of the type II codebook.
  • the terminal device can assume that the beam vector used to restore the precoding matrix remains unchanged, and determine the P component characteristics of the channel's time-varying characteristics and their corresponding correspondence based on the broadband amplitude coefficient or subband coefficient of the beam vector over time.
  • the weighting factor Based on the P component features and their corresponding weighting coefficients determined by the terminal device, the network device can approximately restore the precoding matrix.
  • this application will not give examples in detail.
  • the terminal device determines P component features and their corresponding weighting coefficients based on one polarization direction and one transmission layer. But this should not constitute any limitation to this application.
  • the terminal device may determine one or more based on the same method described above. Component features and their corresponding weighting coefficients.
  • the network device can also restore the channel based on the same method described above to determine the precoding matrix.
  • Fig. 6 is a schematic block diagram of a communication device provided by an embodiment of the present application.
  • the communication device 1000 may include a processing unit 1100 and a transceiving unit 1200.
  • the communication device 1000 may correspond to the terminal device in the above method embodiment, for example, it may be a terminal device or a chip configured in the terminal device.
  • the communication device 1000 may correspond to the terminal device in the method 300 according to the embodiment of the present application, and the communication device 1000 may include a unit for executing the method executed by the terminal device in the method 300 in FIG. 3.
  • each unit in the communication device 1000 and other operations and/or functions described above are used to implement the corresponding process of the method 300 in FIG. 3.
  • the processing unit 1100 can be used to execute step 310 in the method 300
  • the transceiver unit 1200 can be used to execute step 320 and step 330 in the method 300. It should be understood that the specific process for each unit to execute the foregoing corresponding steps has been described in detail in the foregoing method embodiment, and is not repeated here for brevity.
  • the transceiver unit 1200 in the communication device 1000 may correspond to the transceiver 2020 in the terminal device 2000 shown in FIG. 7, and the processing unit 1100 in the communication device 1000 may It corresponds to the processor 2010 in the terminal device 2000 shown in FIG. 7.
  • the transceiver unit 1200 in the communication device 1000 may be an input/output interface.
  • the communication device 1000 may correspond to the network device in the above method embodiment, for example, it may be a network device or a chip configured in the network device.
  • the communication device 1000 may correspond to the network device in the method 300 according to the embodiment of the present application, and the communication device 1000 may include a unit for executing the method executed by the network device in the method 300 in FIG. 3.
  • each unit in the communication device 1000 and other operations and/or functions described above are used to implement the corresponding process of the method 300 in FIG. 3.
  • the processing unit 1100 can be used to execute steps 340 and 350 in the method 300, and the transceiver unit 1200 can be used to execute steps 320 and 330 in the method 300. It should be understood that the specific process for each unit to execute the foregoing corresponding steps has been described in detail in the foregoing method embodiment, and is not repeated here for brevity.
  • the transceiver unit in the communication device 1000 may correspond to the RRU 3100 in the base station 3000 shown in FIG. 8, and the processing unit 1100 in the communication device 1000 may correspond to The BBU 3200 or the processor 3202 in the base station 3000 shown in FIG. 8.
  • the transceiver unit 1200 in the communication device 1000 may be an input/output interface.
  • FIG. 7 is a schematic structural diagram of a terminal device 2000 provided by an embodiment of the present application.
  • the terminal device 2000 can be applied to the system shown in FIG. 1 to perform the functions of the terminal device in the foregoing method embodiment.
  • the terminal device 2000 includes a processor 2010 and a transceiver 2020.
  • the terminal device 2000 further includes a memory 2030.
  • the processor 2010, the transceiver 2020, and the memory 2030 can communicate with each other through internal connection paths to transfer control and/or data signals.
  • the memory 2030 is used for storing computer programs, and the processor 2010 is used for downloading from the memory 2030. Call and run the computer program to control the transceiver 2020 to send and receive signals.
  • the terminal device 2000 may further include an antenna 2040 for transmitting the uplink data or uplink control signaling output by the transceiver 2020 through a wireless signal.
  • the aforementioned processor 2010 and the memory 2030 can be combined into a processing device, and the processor 2010 is configured to execute the program code stored in the memory 2030 to implement the aforementioned functions.
  • the memory 2030 may also be integrated in the processor 2010 or independent of the processor 2010.
  • the processor 2010 may correspond to the processing unit 1100 in FIG. 6.
  • the above-mentioned transceiver 2020 may correspond to the transceiver unit 1200 in FIG. 6, and may also be referred to as a transceiver unit.
  • the transceiver 2020 may include a receiver (or called receiver, receiving circuit) and a transmitter (or called transmitter, transmitting circuit). Among them, the receiver is used to receive signals, and the transmitter is used to transmit signals.
  • the terminal device 2000 shown in FIG. 7 can implement various processes involving the terminal device in the method embodiment shown in FIG. 3.
  • the operations and/or functions of each module in the terminal device 2000 are respectively for implementing the corresponding processes in the foregoing method embodiments.
  • the above-mentioned processor 2010 can be used to execute the actions described in the previous method embodiments implemented by the terminal device, and the transceiver 2020 can be used to execute the terminal device described in the previous method embodiments to send or receive from the network device action.
  • the transceiver 2020 can be used to execute the terminal device described in the previous method embodiments to send or receive from the network device action.
  • the aforementioned terminal device 2000 may further include a power supply 2050 for providing power to various devices or circuits in the terminal device.
  • the terminal device 2000 may also include one or more of an input unit 2060, a display unit 2070, an audio circuit 2080, a camera 2090, and a sensor 2100.
  • the audio circuit A speaker 2082, a microphone 2084, etc. may also be included.
  • FIG. 8 is a schematic structural diagram of a network device provided by an embodiment of the present application, for example, may be a schematic structural diagram of a base station.
  • the base station 3000 can be applied to the system shown in FIG. 1 to perform the functions of the network device in the foregoing method embodiment.
  • the base station 3000 may include one or more radio frequency units, such as a remote radio unit (RRU) 3100 and one or more baseband units (BBU) (also known as distributed unit (DU) )) 3200.
  • RRU 3100 may be referred to as a transceiver unit, which corresponds to the transceiver unit 1200 in FIG. 6.
  • the transceiver unit may also be called a transceiver, a transceiver circuit, or a transceiver, etc., and it may include at least one antenna 3101 and a radio frequency unit 3102.
  • the transceiving unit may include a receiving unit and a transmitting unit, the receiving unit may correspond to a receiver (or receiver, receiving circuit), and the transmitting unit may correspond to a transmitter (or transmitter, transmitting circuit).
  • the RRU 3100 part is mainly used for sending and receiving of radio frequency signals and conversion of radio frequency signals and baseband signals, for example, for sending instruction information to terminal equipment.
  • the 3200 part of the BBU is mainly used for baseband processing and control of the base station.
  • the RRU 3100 and the BBU 3200 may be physically set together, or may be physically separated, that is, a distributed base station.
  • the BBU 3200 is the control center of the base station, and may also be called a processing unit, which may correspond to the processing unit 1100 in FIG. 6, and is mainly used to complete baseband processing functions, such as channel coding, multiplexing, modulation, and spreading.
  • the BBU processing unit
  • the BBU may be used to control the base station to execute the operation procedure of the network device in the foregoing method embodiment, for example, to generate the foregoing indication information.
  • the BBU 3200 may be composed of one or more single boards, and multiple single boards may jointly support a radio access network with a single access standard (such as an LTE network), or support different access standards. Wireless access network (such as LTE network, 5G network or other networks).
  • the BBU 3200 also includes a memory 3201 and a processor 3202.
  • the memory 3201 is used to store necessary instructions and data.
  • the processor 3202 is configured to control the base station to perform necessary actions, for example, to control the base station to execute the operation procedure of the network device in the foregoing method embodiment.
  • the memory 3201 and the processor 3202 may serve one or more single boards. In other words, the memory and the processor can be set separately on each board. It can also be that multiple boards share the same memory and processor. In addition, necessary circuits can be provided on each board.
  • the base station 3000 shown in FIG. 8 can implement various processes involving network devices in the method embodiment shown in FIG. 3.
  • the operations and/or functions of the various modules in the base station 3000 are used to implement the corresponding processes in the foregoing method embodiments.
  • the above-mentioned BBU 3200 can be used to perform the actions described in the previous method embodiments implemented by the network device, and the RRU 3100 can be used to perform the actions described in the previous method embodiments that the network device sends to or receives from the terminal device.
  • the RRU 3100 can be used to perform the actions described in the previous method embodiments that the network device sends to or receives from the terminal device.
  • the base station 3000 shown in FIG. 8 is only a possible architecture of the network device, and should not constitute any limitation in this application.
  • the method provided in this application can be applied to network devices of other architectures.
  • network equipment including CU, DU, and active antenna unit (AAU). This application does not limit the specific architecture of the network device.
  • An embodiment of the present application also provides a processing device, including a processor and an interface; the processor is configured to execute the method in the foregoing method embodiment.
  • the aforementioned processing device may be one or more chips.
  • the processing device may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a system on chip (SoC), or It is a central processor unit (CPU), it can also be a network processor (NP), it can also be a digital signal processing circuit (digital signal processor, DSP), or it can be a microcontroller (microcontroller unit). , MCU), it can also be a programmable logic device (PLD) or other integrated chips.
  • FPGA field programmable gate array
  • ASIC application specific integrated circuit
  • SoC system on chip
  • CPU central processor unit
  • NP network processor
  • DSP digital signal processing circuit
  • microcontroller unit microcontroller unit
  • MCU programmable logic device
  • PLD programmable logic device
  • the steps of the above method can be completed by hardware integrated logic circuits in the processor or instructions in the form of software.
  • the steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed and completed by a hardware processor, or executed and completed by a combination of hardware and software modules in the processor.
  • the software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers.
  • the storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it will not be described in detail here.
  • the processor in the embodiment of the present application may be an integrated circuit chip with signal processing capability.
  • the steps of the foregoing method embodiments can be completed by hardware integrated logic circuits in the processor or instructions in the form of software.
  • the above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components .
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • the methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed.
  • the general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.
  • the steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor.
  • the software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers.
  • the storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.
  • the memory in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory.
  • the non-volatile memory can be read-only memory (ROM), programmable read-only memory (programmable ROM, PROM), erasable programmable read-only memory (erasable PROM, EPROM), and electronic Erase programmable read-only memory (electrically EPROM, EEPROM) or flash memory.
  • the volatile memory may be random access memory (RAM), which is used as an external cache.
  • RAM random access memory
  • static random access memory static random access memory
  • dynamic RAM dynamic random access memory
  • DRAM dynamic random access memory
  • SDRAM synchronous dynamic random access memory
  • double data rate synchronous dynamic random access memory double data rate SDRAM, DDR SDRAM
  • enhanced synchronous dynamic random access memory enhanced SDRAM, ESDRAM
  • serial link DRAM SLDRAM
  • direct rambus RAM direct rambus RAM
  • the present application also provides a computer program product, the computer program product includes: computer program code, when the computer program code runs on a computer, the computer executes the embodiment shown in FIG. 3 Method in.
  • the present application also provides a computer-readable medium storing program code, which when the program code runs on a computer, causes the computer to execute the embodiment shown in FIG. 3 Method in.
  • the present application also provides a system, which includes the aforementioned one or more terminal devices and one or more network devices.
  • the network equipment in the above-mentioned device embodiments completely corresponds to the network equipment or terminal equipment in the terminal equipment and method embodiments, and the corresponding modules or units execute the corresponding steps.
  • the communication unit transmits the receiving or In the sending step, other steps except sending and receiving can be executed by the processing unit (processor).
  • the processing unit processor
  • component used in this specification are used to denote computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution.
  • the component may be, but is not limited to, a process, a processor, an object, an executable file, an execution thread, a program, and/or a computer running on a processor.
  • the application running on the computing device and the computing device can be components.
  • One or more components may reside in processes and/or threads of execution, and components may be located on one computer and/or distributed among two or more computers.
  • these components can be executed from various computer readable media having various data structures stored thereon.
  • the component may be based on, for example, a signal having one or more data packets (such as data from two components interacting with another component in a local system, a distributed system, and/or a network, such as the Internet that interacts with other systems through signals) Communicate through local and/or remote processes.
  • a signal having one or more data packets (such as data from two components interacting with another component in a local system, a distributed system, and/or a network, such as the Internet that interacts with other systems through signals) Communicate through local and/or remote processes.
  • the disclosed system, device, and method may be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.
  • each unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • each functional unit may be implemented in whole or in part by software, hardware, firmware, or any combination thereof.
  • software When implemented by software, it can be implemented in the form of a computer program product in whole or in part.
  • the computer program product includes one or more computer instructions (programs).
  • programs When the computer program instructions (programs) are loaded and executed on the computer, the processes or functions described in the embodiments of the present application are generated in whole or in part.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.
  • the computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium.
  • the computer instructions may be transmitted from a website, computer, server, or data center. Transmission to another website, computer, server or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.).
  • the computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center integrated with one or more available media.
  • the usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, and a magnetic tape), an optical medium (for example, a high-density digital video disc (digital video disc, DVD)), or a semiconductor medium (for example, a solid state disk, SSD)) etc.
  • the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium.
  • the technical solution of this application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other media that can store program code .

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Abstract

本申请提供了一种信道测量方法和通信装置。该方法包括：终端设备生成第一指示信息，并向网络设备发送该第一指示信息。该第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，该一个或多个分量特征以及每个分量特征的加权系数可用于表征信道的时变特征。其中，该时变特征可以基于终端设备多次接收到的参考信号确定。通过基于多次接收到的参考信号，终端设备可以确定信道随时间的变化，进而将该时变信道通过分量特征和加权系数来量化，并将量化的信道的时变特征反馈给网络设备，以便于网络设备更加全面地了解信道的状态。

Description

一种信道测量方法和通信装置
本申请要求于2019年6月6日提交中国专利局、申请号为201910493700.1、申请名称为“一种信道测量方法和通信装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信领域，并且更具体地，涉及一种信道测量方法和通信装置。
背景技术
在大规模多输入多输出(massive multiple-input multiple output，Massive MIMO)技术中，网络设备可以通过预编码技术减小多用户之间的干扰以及同一用户的多个信号流之间的干扰。从而提高信号质量，实现空分复用，提高频谱利用率。
目前，已知一种信道测量和反馈的方法，终端设备可以根据接收到的参考信号进行信道测量，确定待反馈的预编码向量，并将每一次测量所确定的待反馈的预编码向量通过一个或多个波束向量的加权和来表示，以反馈波束向量和各波束向量的加权系数。
然而，对于时变信道来说，上述反馈并不能够全面地反馈信道的状态。
发明内容
本申请提供一种信道测量方法和通信装置，以期反馈信道的时变特征，从而更加全面地反馈信道状态。
第一方面，提供了一种信道测量方法。该方法包括：终端设备生成第一指示信息，该第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，该一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；该终端设备向网络设备发送该第一指示信息。
应理解，该方法可以由终端设备执行，或者，也可以由配置在终端设备中的芯片执行。
第二方面，提供了一种信道测量方法。该方法包括：网络设备接收第一指示信息，该第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，该一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；该网络设备根据该第一指示信息确定一个或多个分量特征以及每个分量特征的加权系数。
应理解，该方法可以由网络设备执行，或者，也可以由配置在网络设备中的芯片执行。
因此，基于上述方案，终端设备可以将信道的时变特征通过一个或多个分量特征以及一个或多个加权系数来量化，并将分量特征和加权系数的量化信息反馈给网络设备。因此，网络设备可以确定信道在时域的变化，也就能够更全面地了解信道的状态，从而为下行调度做出更合理的决策。
结合第一方面或第二方面，在某些实现方式中，所述一个或多个分量特征以及每个分 量特征的加权系数由终端设备基于多次接收到的参考信号确定。
由于该一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征。故该一个或多个分量特征以及每个分量特征的加权系数可以基于多次接收到的参考信号确定。该多次接收到的参考信号可以是终端设备在多个不同的时刻接收到的参考信号。通过基于不同时刻接收到的参考信号进行信道测量，终端设备可以确定信道的时变特征，进而将该时变特征用一个或多个分量特征以及一个或多个加权系数来量化。
结合第一方面或第二方面，在某些实现方式中，所述一个或多个分量特征的加权和用于表征信道的时变特征。
在一种实现方式中，信道的时变特征可以是上述一个或多个分量特征的加权和。
结合第一方面或第二方面，在某些实现方式中，该第一指示信息在用于指示时变特征的一个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
在本申请实施例中，时域向量可以是时变特征的分量特征的一种表现形式。每个分量特征可以对应一个时域向量。该时域向量可用于表示信道在时域的变化。码本中的每个时域向量可用于表示信道随时间的一种变化规律。
因此，该终端设备可以基于接收到的参考信号确定信道的时变特征，然后将该时变特征通过一个或多个时域向量以及一个或多个加权系数来量化，以便将量化后的信道的时变特征反馈给网络设备。
结合第一方面或第二方面，在某些实现方式中，至少两个分量特征基于不同的码本确定。
或者说，至少两个分量特征及其对应的加权系数基于不同的码本确定。
为了获得终端设备更加精准的反馈，终端设备可以基于不同的码本来确定时域向量。换句话说，终端设备可以基于不同的码本来确定分量特征。在一种实现方式中，终端设备可以基于双域压缩的反馈方式确定多个空频向量对，该多个空频向量对是用于构建预编码矩阵的空频向量对。终端设备可以选择其中的部分或全部空频向量对对应的加权系数来确定上述一个或多个分量特征以及每个分量特征的加权系数。其中，对应于幅值较大的加权系数的空频向量对，可以采用维度较大的码本来选择时域向量；对应于幅值较小的加权系数的空频向量对，可以采用维度较小的码本来选择时域向量。
结合第一方面或第二方面，在某些实现方式中，所述一个或多个分量特征基于预定义的一个或多个码本确定，该一个或多个码本取自预定义的码本集合，该码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
所述一个或多个分量特征基于预定义的一个或多个码本确定，也可以替换为：所述一个或多个分量特征以及每个分量特征的加权系数基于预定义的一个或多个码本确定。
为了获得终端设备更加精准的反馈，可以定义多种不同维度的码本。维度较高的码本相比于维度较低的码本而言，更加精准。终端设备可以采用不同精度的码本来进行信道测量，以获得不同精度的反馈。
结合第一方面或第二方面，在某些实现方式中，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
无线信道是一种时变信道。信道在时域的变化可以通过若干个缓变的多普勒频移的指 示函数的加权和来表示。因此在一种实现方式中，时变特征的分量特征为多普勒频移，分量特征的加权系数为多普勒系数。
其中，多普勒频移可以与时域向量对应。在本申请实施例中，不同的时域向量可以表示不同传输路径的多普勒频移造成的信道在时域上的变化规律。换言之，多普勒频移的一种数学表达方式可以是时域向量。
第三方面，提供了一种通信装置，包括用于执行第一方面以及第一方面中任一种可能实现方式中的方法的各个模块或单元。
第四方面，提供了一种通信装置，包括处理器。该处理器与存储器耦合，可用于执行存储器中的指令，以实现上述第一方面以及第一方面中任一种可能实现方式中的方法。可选地，该通信装置还包括存储器。可选地，该通信装置还包括通信接口，处理器与通信接口耦合。
在一种实现方式中，该通信装置为终端设备。当该通信装置为终端设备时，该通信接口可以是收发器，或，输入/输出接口。
在另一种实现方式中，该通信装置为配置于终端设备中的芯片。当该通信装置为配置于终端设备中的芯片时，该通信接口可以是输入/输出接口。
可选地，该收发器可以为收发电路。可选地，该输入/输出接口可以为输入/输出电路。
第五方面，提供了一种通信装置，包括用于执行第二方面以及第二方面中任一种可能实现方式中的方法的各个模块或单元。
第六方面，提供了一种通信装置，包括处理器。该处理器与存储器耦合，可用于执行存储器中的指令，以实现上述第二方面以及第二方面中任一种可能实现方式中的方法。可选地，该通信装置还包括存储器。可选地，该通信装置还包括通信接口，处理器与通信接口耦合。
在一种实现方式中，该通信装置为网络设备。当该通信装置为网络设备时，所述通信接口可以是收发器，或，输入/输出接口。
在另一种实现方式中，该通信装置为配置于网络设备中的芯片。当该通信装置为配置于网络设备中的芯片时，所述通信接口可以是输入/输出接口。
可选地，所述收发器可以为收发电路。可选地，所述输入/输出接口可以为输入/输出电路。
第七方面，提供了一种处理器，包括：输入电路、输出电路和处理电路。所述处理电路用于通过所述输入电路接收信号，并通过所述输出电路发射信号，使得所述处理器执行第一方面至第二方面以及第一方面至第二方面中任一种可能实现方式中的方法。
在具体实现过程中，上述处理器可以为一个或多个芯片，输入电路可以为输入管脚，输出电路可以为输出管脚，处理电路可以为晶体管、门电路、触发器和各种逻辑电路等。输入电路所接收的输入的信号可以是由例如但不限于接收器接收并输入的，输出电路所输出的信号可以是例如但不限于输出给发射器并由发射器发射的，且输入电路和输出电路可以是同一电路，该电路在不同的时刻分别用作输入电路和输出电路。本申请实施例对处理器及各种电路的具体实现方式不做限定。
第八方面，提供了一种处理装置，包括处理器和存储器。该处理器用于读取存储器中存储的指令，并可通过接收器接收信号，通过发射器发射信号，以执行第一方面至第二方 面以及第一方面至第二方面中任一种可能实现方式中的方法。
可选地，所述处理器为一个或多个，所述存储器为一个或多个。
可选地，所述存储器可以与所述处理器集成在一起，或者所述存储器与处理器分离设置。
在具体实现过程中，存储器可以为非瞬时性(non-transitory)存储器，例如只读存储器(read only memory，ROM)，其可以与处理器集成在同一块芯片上，也可以分别设置在不同的芯片上，本申请实施例对存储器的类型以及存储器与处理器的设置方式不做限定。
应理解，相关的数据交互过程例如发送指示信息可以为从处理器输出指示信息的过程，接收能力信息可以为处理器接收输入能力信息的过程。具体地，处理器输出的数据可以输出给发射器，处理器接收的输入数据可以来自接收器。其中，发射器和接收器可以统称为收发器。
上述第八方面中的处理装置可以是一个或多个芯片。该处理装置中的处理器可以通过硬件来实现也可以通过软件来实现。当通过硬件实现时，该处理器可以是逻辑电路、集成电路等；当通过软件来实现时，该处理器可以是一个通用处理器，通过读取存储器中存储的软件代码来实现，该存储器可以集成在处理器中，可以位于该处理器之外，独立存在。
第九方面，提供了一种计算机程序产品，所述计算机程序产品包括：计算机程序(也可以称为代码，或指令)，当所述计算机程序被运行时，使得计算机执行上述第一方面至第二方面以及第一方面至第二方面中任一种可能实现方式中的方法。
第十方面，提供了一种计算机可读介质，所述计算机可读介质存储有计算机程序(也可以称为代码，或指令)当其在计算机上运行时，使得计算机执行上述第一方面至第二方面以及第一方面至第二方面中任一种可能实现方式中的方法。
第十一方面，提供了一种通信系统，包括前述的网络设备和终端设备。
附图说明
图1是适用于本申请实施例提供的方法的通信系统的示意图；
图2是本申请实施例提供的信道测量方法的原理的示意图；
图3是本申请实施例提供的信道测量方法的示意性流程图；
图4是基于现有的信道状态信息(channel state information，CSI)反馈流程进行CSI反馈的示意性流程图；
图5是本申请实施例提供的效果仿真图；
图6是本申请实施例提供的通信装置的示意性框图；
图7是本申请实施例提供的终端设备的结构示意图；
图8是本申请实施例提供的网络设备的结构示意图。
具体实施方式
下面将结合附图，对本申请中的技术方案进行描述。
本申请实施例的技术方案可以应用于各种通信系统，例如：全球移动通信(global system for mobile communications，GSM)系统、码分多址(code division multiple access， CDMA)系统、宽带码分多址(wideband code division multiple access，WCDMA)系统、通用分组无线业务(general packet radio service，GPRS)、长期演进(long term evolution，LTE)系统、LTE频分双工(frequency division duplex，FDD)系统、LTE时分双工(time division duplex，TDD)、通用移动通信系统(universal mobile telecommunication system，UMTS)、全球互联微波接入(worldwide interoperability for microwave access，WiMAX)通信系统、未来的第五代(5th generation，5G)系统或新无线(new radio，NR)等。
为便于理解本申请实施例，首先以图1中示出的通信系统为例详细说明适用于本申请实施例的通信系统。图1是适用于本申请实施例的信道测量方法的通信系统100的示意图。如图1所示，该通信系统100可以包括至少一个网络设备，例如图1所示的网络设备110；该通信系统100还可以包括至少一个终端设备，例如图1所示的终端设备120。网络设备110与终端设备120可通过无线链路通信。各通信设备，如网络设备110或终端设备120，均可以配置多个天线。对于该通信系统100中的每一个通信设备而言，所配置的多个天线可以包括至少一个用于发送信号的发射天线和至少一个用于接收信号的接收天线。因此，该通信系统100中的各通信设备之间，网络设备110与终端设备120之间，可通过多天线技术通信。
应理解，该通信系统中的网络设备可以是任意一种具有无线收发功能的设备。该网络设备包括但不限于：演进型节点B(evolved Node B，eNB)、无线网络控制器(radio network controller，RNC)、节点B(Node B，NB)、基站控制器(base station controller，BSC)、基站收发台(base transceiver station，BTS)、家庭基站(home evolved NodeB，或home Node B，HNB)、基带单元(baseband unit，BBU)，无线保真(wireless fidelity，WiFi)系统中的接入点(access point，AP)、无线中继节点、无线回传节点、传输点(transmission point，TP)或者发送接收点(transmission and reception point，TRP)等，还可以为5G，如，NR，系统中的gNB，或，传输点(TRP或TP)，5G系统中的基站的一个或一组(包括多个天线面板)天线面板，或者，还可以为构成gNB或传输点的网络节点，如基带单元(BBU)，或，分布式单元(distributed unit，DU)等。
在一些部署中，gNB可以包括集中式单元(centralized unit，CU)和DU。gNB还可以包括有源天线单元(active antenna unit，AAU)。CU实现gNB的部分功能，DU实现gNB的部分功能，比如，CU负责处理非实时协议和服务，实现无线资源控制(radio resource control，RRC)，分组数据汇聚层协议(packet data convergence protocol，PDCP)层的功能。DU负责处理物理层协议和实时服务，实现无线链路控制(radio link control，RLC)层、媒体接入控制(media access control，MAC)层和物理(physical，PHY)层的功能。AAU实现部分物理层处理功能、射频处理及有源天线的相关功能。由于RRC层的信息最终会变成PHY层的信息，或者，由PHY层的信息转变而来，因而，在这种架构下，高层信令，如RRC层信令，也可以认为是由DU发送的，或者，由DU+AAU发送的。可以理解的是，网络设备可以为包括CU节点、DU节点、AAU节点中一项或多项的设备。此外，可以将CU划分为接入网(radio access network，RAN)中的网络设备，也可以将CU划分为核心网(core network，CN)中的网络设备，本申请对此不做限定。
还应理解，该无线通信系统中的终端设备也可以称为用户设备(user equipment，UE)、接入终端、用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、用户终 端、终端、无线通信设备、用户代理或用户装置。本申请的实施例中的终端设备可以是手机(mobile phone)、平板电脑(pad)、带无线收发功能的电脑、虚拟现实(virtual reality，VR)终端设备、增强现实(augmented reality，AR)终端设备、工业控制(industrial control)中的无线终端、无人驾驶(self driving)中的无线终端、远程医疗(remote medical)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端、配置在交通工具中的移动终端等等。本申请的实施例对应用场景不做限定。
还应理解，图1仅为便于理解而示例的简化示意图，该通信系统100中还可以包括其他网络设备或者还可以包括其他终端设备，图1中未予以画出。
为了便于理解本申请实施例，下面简单说明下行信号在发送之前在物理层的处理过程。应理解，下文所描述的对下行信号的处理过程可以由网络设备执行，也可以由配置于网络设备中的芯片执行。为方便说明，下文统称为网络设备。
网络设备在物理信道可对码字(code word)进行处理。其中，码字可以为经过编码(例如包括信道编码)的编码比特。码字经过加扰(scrambling)，生成加扰比特。加扰比特经过调制映射(modulation mapping)，得到调制符号。调制符号经过层映射(layer mapping)，被映射到多个层(layer)，或者称，传输层。经过层映射后的调制符号经过预编码(precoding)，得到预编码后的信号。预编码后的信号经过资源元素(resource element，RE)映射后，被映射到多个RE上。这些RE随后经过正交复用(orthogonal frequency division multiplexing，OFDM)调制后通过天线端口(antenna port)发射出去。
应理解，上文所描述的对下行信号的处理过程仅为示例性描述，不应对本申请构成任何限定。对下行信号的处理过程具体可以参考现有技术，为了简洁，这里省略对其具体过程的详细说明。
为了便于理解本申请实施例，下面先对本申请实施例中涉及的术语做简单说明。
1、预编码技术：发送设备(如网络设备)可以在已知信道状态的情况下，借助与信道状态相匹配的预编码矩阵来对待发送信号进行处理，使得经过预编码的待发送信号与信道相适配，从而使得接收设备(如终端设备)消除信道间影响的复杂度降低。因此，通过对待发送信号的预编码处理，接收信号质量(例如信号与干扰加噪声比(signal to interference plus noise ratio，SINR)等)得以提升。因此，采用预编码技术，可以实现发送设备与多个接收设备在相同的时频资源上传输，也就是实现了多用户多输入多输出(multiple user multiple input multiple output，MU-MIMO)。
应理解，有关预编码技术的相关描述仅为便于理解而示例，并非用于限制本申请实施例的保护范围。在具体实现过程中，发送设备还可以通过其他方式进行预编码。例如，在无法获知信道信息(例如但不限于信道矩阵)的情况下，采用预先设置的预编码矩阵或者加权处理方式进行预编码等。为了简洁，其具体内容本文不再赘述。
2、参考信号(reference signal，RS)：也可以称为导频(pilot)、参考序列等。在本申请实施例中，参考信号可以包括未经过预编码的参考信号(non-precoded RS)和经过预编码的参考信号。其中，经过预编码的参考信号也可以称为波束赋形的参考信号(beamformed RS)，或者，也可以简称为预编码参考信号。下文实施例中，经过预编码的参考信号、预编码参考信号以及波束赋形的参考信号所表达的含义是一致的。
另外，下文中在提及参考信号时，有时仅指未经过预编码的参考信号，有时仅指预编码参考信号，有时包括未经过预编码的参考信号和预编码参考信号。本领域的技术人员可以理解其在不同场景下所表达的含义。
未经过预编码处理的参考信号可以类似于LTE或NR协议中定义的A类(Class A)参考信号。波束赋形的参考信号可以类似于LTE协议中的B类(Class B)参考信号。
应理解，本申请实施例中涉及的参考信号可以是用于信道测量的参考信号。例如，该参考信号可以是信道状态信息参考信号(channel state information reference signal，CSI-RS)或探测参考信号(sounding reference signal，SRS)。但应理解，上文列举仅为示例，不应对本申请构成任何限定，本申请并不排除在未来的协议中定义其他参考信号以实现相同或相似功能的可能。
3、天线端口(antenna port)：简称端口。可以理解为被接收设备所识别的虚拟天线。或者在空间上可以区分的发射天线。针对每个虚拟天线可以配置一个天线端口，每个虚拟天线可以为多个物理天线的加权组合。
在一种可能的设计中，天线端口可以指发射天线端口。发射天线端口可以是指实际的独立的收发单元(transceiver unit，TxRU)。天线端口数(也即发射天线端口数)可以等于TxRU数。每个端口的参考信号可以是未经过预编码的参考信号。
在另一种可能的设计中，天线端口可以是指经过预编码之后的参考信号端口。例如，每个端口的参考信号可以是基于一个预编码向量对参考信号做预编码得到的预编码参考信号。每个端口的信号可以通过一个或多个资源块(resource block，RB)传输。可以理解的是，若对参考信号做了预编码，则该参考信号端口数可以小于做预编码之前的发射天线端口数。因此，通过对参考信号做预编码，可以实现对发射天线端口的降维，从而达到减小导频开销的目的。
4、时域向量：可用于表示信道在时域的变化。每个时域向量可以表示信道随时间的一种变化规律。无线信道是一种时变信道，会遭遇来自不同途径的衰减损耗。比如，由多径时延扩展造成的频率选择性衰落和由多普勒频移造成时间选择性衰落共同影响的时间-频率双选择性衰落信道即为一种典型的时变信道。
多普勒频移(Doppler shift)可以是指由于终端设备和网络设备之间的相对移动而引发的发射频率和接收频率之间的频率偏移，接收频率与发射频率之差称为多普勒频移。通常来说，多普勒频移可f d可以定义为f d＝v×f c×cosθ/c。其中，v为终端设备的移动速度，f c为为载波频率，θ为多径信号的入射角，c为光速。具体实现时，θ可以考虑不同传输路径的入射角，由于多径的θ不同，则不同传输路径会对应不同的多普勒频移，从而引起多普勒扩展(Doppler spread)。一般来说，多普勒频移的大小表示了移动速度对于信道时域变化快慢的影响。
在本申请实施例中，每个时域向量可以对应一个多普勒频移。因此，可以通过不同的时域向量来表示不同传输路径的多普勒频移导致的信道在时域上的变化规律。通常来说，为了便于描述信道时域的变化，可以将时域信道投影到多普勒域，并通过若干个缓变的多普勒频移的指数函数的加权表示。
应理解，时域向量仅为便于与后文所述的空域向量、频域向量区分而定义，不应对本申请构成任何限定。本申请并不排除在未来的协议中对时域向量定义其他的名称以表示与 其相同或相似含义的可能。例如，也可以称为多普勒向量。
可选地，时域向量是离散傅里叶变换(Discrete Fourier Transform，DFT)向量、过采样DFT向量、小波变换(wavelet transform，WT)向量或过采样WT向量中的一种或多种。本申请对此不作限定。
5、码本：本申请实施例中所涉及的码本可以是指时域向量的集合。同一个码本中的多个时域向量可以是相同维度的向量。例如，同一码本中的时域向量均为N维向量，则该码本为N维码本。
可选地，同一码本中的时域向量均为DFT向量。该码本中可以包括N个时域向量，且该N个时域向量之间可以两两相互正交。换句话说，该码本为正交码本。该码本中的N个时域向量可以构造DFT矩阵。或者说，上述时域向量可以是取自DFT矩阵的向量。
例如，N维码本中的N个时域向量可以是取自维度为N×N的DFT矩阵的向量。该N维码本中的第n(n＝0，1，……，N-1)个向量例如可以是：
[e -j2π×0×n/N e -j2π×1×n/N … e -j2π×(N-1)×n/N] T。
应理解，上文示出的向量仅为示例，不应对本申请构成任何限定。本申请对于时域向量的具体形式不作限定。
一种实现方式中，该N维码本可以理解为，将最大多普勒频移等分为N份，该N维码本中的N个时域向量与N个多普勒频移对应。对于n的不同取值，可以确定不同的多普勒频移。例如，该N维码本中的第n个向量所对应的多普勒频移与最大多普勒频移的比值为n/N。因此，基于一个时域向量可以确定其所对应的多普勒频移。换言之，每个时域向量对应一个多普勒频移。
其中，最大多普勒频移可以按照上文所示的多普勒频移的计算公式f d＝v×f c×cosθ/c来确定。假设终端设备的移动速度v不变，载波频率f c不变，则该最大多普勒频移可以是f d＝v×f c×/c，即，cosθ为1。或者，该最大多普勒频移也可以是f d＝v×f c×cosθ 0/c，其中θ 0为基站与终端设备的直射径的角度。
可选地，同一码本中的时域向量均为过采样DFT向量。上述由DFT向量构成的正交码本可以通过过采样因子O t(O t为大于1的正整数)扩展为多个子集。每个子集中可以包括N个时域向量，且该N个时域向量之间两两相互正交。该码本中的多个时域向量可以构造过采样DFT矩阵。该码本可以被定义为非正交码本。上述时域向量可以是取自非正交码本中的向量，也可以是取自多个正交子集中某一子集的向量。
应理解，当上述由DFT向量构成的正交码本通过过采样因子扩展为多个正交子集时，该多个正交子集也可以被定义为多个码本。本申请对此不作限定。
可选地，同一码本中的时域向量均为WT向量。该码本可以包括N个时域向量，且该N个时域向量之间两两相互正交。换句话说，该码本为正交码本。该码本中的N个时域向量可以构造WT矩阵。或者说，上述时域向量可以是取自DFT矩阵的向量。
可选地，同一码本中的时域向量均为过采样WT向量。上述由WT向量构成的正交码本可以通过过采样因子扩展为多个子集。每个子集中可以包括N个时域向量，且该N个时域向量之间两两相互正交。该码本中的多个时域向量可以构造过采样WT矩阵。该码本可以被定义为非正交码本。上述时域向量可以是取自非正交码本中的向量，也可以是取自多个正交子集中某一子集的向量
应理解，当上述由WT向量构成的正交码本通过过采样因子扩展为多个正交子集时，该多个正交子集也可以被定义为多个码本。本申请对此不作限定。
多个码本可以构成码本集合。码本集合中的多个码本可以是不同维度的码本。换句话说，取自不同码本的时域向量的维度可以是不同的。
可选地，该码本集合中的每个码本与以下中的一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
其中，关于测量时长、导频时域密度、导频传输次数和导频传输周期的相关说明可以参考下文中的相关描述。
导频传输次数较多时，可以对应维度较大的码本；导频传输次数较小时，可以对应维度较小的码本。
在导频传输周期或导频时域密度一定的情况下，测量时长较长时，终端设备接收到的参考信号的次数也较多，可以对应维度较大的码本；测量时长较短时，终端设备接收到的参考信号的次数也较少，可以对应维度较小的码本。
在测量时长一定的情况下，导频时域密度较大时，终端设备在一段时间内(如测量时长)接收到的参考信号的次数也较多，可以对应维度较大的码本；导频时域密度较小时，终端设备在同一段时间内接收到的参考信号的次数也较少，可以对应维度较小的码本。
在测量时长一定的情况下，导频传输周期较大时，终端设备在一段时间内(如测量时长)接收到的参考信号的次数较少，可以对应维度较小的码本；导频传输周期较小时，终端设备在同一段时间内接收到的参考信号的次数较多，可以对应维度较大的码本。
当然，上述各项因素也可以结合。例如，码本的维度可以与测量时长和导频传输周期对应，或者，码本的维度可以与测量时长和导频时域密度对应等。为了简洁，这里不一一举例说明。
应理解，上文列举的与码本维度相关的各项因素仅为示例，不应对本申请构成任何限定。基于相同的构思，本领域的技术人员可以对上述因素做出等价替换，但这些等价变换均应落入本申请的保护范围内。
6、空域向量(spatial domain vector)：或者称波束(beam)向量、角度向量等。空域向量中的各个元素可以表示各个天线端口(antenna port)的权重。基于空域向量中各个元素所表示的各个天线端口的权重，将各个天线端口的信号做线性叠加，可以在空间某一方向上形成信号较强的区域。基于空域向量对参考信号做预编码，可以使得发射出来的参考信号具有一定的空间指向性。因此，基于空域向量对参考信号做预编码的过程也可以视为是空间域(或简称，空域)预编码的过程。
下文中为方便说明，假设空域向量记作u。空域向量u的长度可以为一个极化方向上的发射天线端口数N s，N s≥1且为整数。空域向量例如可以为长度为N s的列向量或行向量。本申请对此不作限定。
可选地，空域向量取自DFT矩阵。该DFT矩阵中的每个列向量可以称为一个DFT向量。换句话说，空域向量可以为DFT向量。该空域向量例如也可以是NR协议TS 38.214版本15(release 15，R15)中类型II(type II)码本中定义的二维(2dimensions，2D)-离散傅里叶变换(Discrete Fourier Transform，DFT)向量或过采样2D-DFT向量。这里为了简洁，不再赘述。
7、频域向量：(frequency domain vector)：或者称时延向量等。可用于表示信道在频域的变化规律的向量。每个频域向量可以表示一种变化规律。由于信号在经过无线信道传输时，从发射天线可以经过多个路径到达接收天线。多径时延导致频率选择性衰落，就是频域信道的变化。因此，可以通过不同的频域向量来表示不同传输路径上时延导致的信道在频域上的变化规律。而由于信道在各频域单元的相位变化与时延相关，由傅里叶变换可知，信号在时域上的时间延迟，可以等效到频域的相位渐变。故频域向量也可以称为时延向量。换句话说，该频域向量也可用于表示信道的时延特性。
基于频域向量对参考信号进行预编码，实质上可以是指基于频域向量中的元素对频域上各个频域单元进行相位旋转，以通过预编码参考信号来对多径时延造成的频选特性进行预补偿。因此，基于频域向量对参考信号进行预编码的过程可以视为频域预编码的过程。
在本申请实施例中，频域向量可用于和上述空域向量构建多个空域向量和频域向量的组合，或者简称空频向量对，以用于构建预编码向量。
下文中为方便说明，假设频域向量记作v。频域向量的长度可以记作N 3，N 3≥1，且为整数。
8、空频向量对：一个空域向量和一个频域向量可以组合得到一个空频向量对。一个空频向量对可以包括一个空域向量和一个频域向量。由一个空频向量对中的空域向量和频域向量可以得到一个空频分量矩阵，如，将一个空频向量与一个频域向量的共轭转置相乘，可以得到一个空频分量矩阵。
在本申请实施例中，任意两个空频向量对中包含的空域向量和频域向量中至少有一项不同。换句话说，任意两个空频向量对所构建的空频分量矩阵也不同。
9、空频矩阵：可以理解为用于确定每个频域单元对应的预编码矩阵的一个中间量。对于终端设备来说，空频矩阵可以由每个频域单元对应的预编码矩阵或信道矩阵确定。对于网络设备来说，空频矩阵可以是由多个空频分量矩阵的加权和得到，以用于恢复下行信道或预编码矩阵。
例如，空频矩阵可以记作H，
Figure PCTCN2020090551-appb-000001
其中，w 1至
Figure PCTCN2020090551-appb-000002
是与N 3个频域单元对应的N 3个列向量，每个列向量可以是每个频域单元对应的预编码矩阵，各列向量的长度均可以为N s。该N 3个列向量分别对应N 3个频域单元的预编码向量。即空频矩阵可以视为将N 3个频域单元对应的预编码向量组合构成的联合矩阵。
此外，空频矩阵可以与传输层对应。同一传输层上各频域单元的预编码向量可以构建该传输层对应的空频矩阵。例如，将第z(1≤z≤Z，z为正整数)个传输层上各频域单元的预编码向量可以构建第z个传输层对应的空频矩阵。其中，Z表示传输层数，Z为正整数。
应理解，空频矩阵仅为用于确定预编码矩阵的中间量的一种表现形式，不应对本申请构成任何限定。例如，将空频矩阵中的各列向量按从左至右的顺序依次首位相接，或者按照其他预定义的规则排列，也可以得到长度为N s×N 3的向量，该向量可以称为空频向量。
还应理解，上文所示的空频矩阵和空频向量的维度仅为示例，不应对本申请构成任何限定。例如，该空频矩阵也可以是维度为N 3×N s的的矩阵。其中，每个行向量可对应于一个频域单元，以用于确定所对应的频域单元的预编码向量。
此外，当发射天线配置有多个极化方向时，该空频矩阵的维度还可以进一步扩展。如， 对于双极化方向的发射天线，该空频矩阵的维度可以为2N s×N 3或N 3×2N s。应理解，本申请对于发射天线的极化方向数不作限定。
10、双域压缩：可以包括空域压缩和频域压缩这两个维度的压缩。空域压缩具体可以是指空域向量集合中选择一个或多个空域向量来作为构建预编码向量的向量。频域压缩可以是指在频域向量集合中选择一个或多个频域向量来作为构建预编码向量的向量。如前所述，一个空域向量和一个频域向量所构建的矩阵例如可以称为空频分量矩阵。被选择的一个或多个空域向量和一个或多个频域向量可以构建一个或多个空频分量矩阵。该一个或多个空频分量矩阵的加权和可用于构建与一个传输层对应的空频矩阵。换句话说，空频矩阵可以近似为由上述被选择的一个或多个空域向量和一个或多个频域向量所构建的空频分量矩阵的加权和。基于一个传输层对应的空频矩阵，进而可以确定该传输层上各频域单元对应的预编码向量。
具体地，选择的一个或多个空域向量可以构成矩阵W 1，其中W 1中的每一个列向量对应选择的一个空域向量。选择的一个或多个频域向量可以构成矩阵W 3，其中W 3中的每一个列向量对应选择的一个频域向量。空频矩阵H可以表示为选择的一个或多个空域向量与选择的一个或多个频域向量线性合并的结果H＝W 1CW 3 H。
以一个传输层为例，该传输层对应的空频矩阵为H＝W 1CW 3 H。
若采用双极化方向天线，每个极化方向可以选择L个空域向量，W 1的维度可以是2N s×2L。在一种可能的实现方式中，两个极化方向可以采用相同的L个空域向量
Figure PCTCN2020090551-appb-000003
其中，
Figure PCTCN2020090551-appb-000004
例如可以是从上文所述的空域向量集合中选择的L个空域向量。此时，W 1可以表示为
Figure PCTCN2020090551-appb-000005
其中
Figure PCTCN2020090551-appb-000006
表示选择的L个空域向量中的第l个空域向量，l＝1，2，…，L。
若选择M个频域向量，则W 3 H的维度可以为M×N 3。W 3中的每一个列向量可以是一个频域向量。此时W 1中的每个空域向量和W 3中的每个频域向量可以构成一个空频向量对，每个空频向量对可以对应一个加权系数，则有2L个空域向量和M个频域向量所构建的2L×M个空频向量对可以与2L×M个加权系数一一对应。
C为由该2L×M个加权系数构成的系数矩阵，维度可以为2L×M。该系数矩阵C中的第l行可以对应2L个空域向量中第一极化方向上的第l个空域向量，该系数矩阵C中的第L+l行可以对应2L个空域向量中第二极化方向上的第l个空域向量。该系数矩阵C中的第m列可以对应M个频域向量中的第m个频域向量。
应理解，上文中所示的空频矩阵H与W 1、W 3的关系仅为示例，不应对本申请构成任何限定。本领域的技术人员基于相同的构思，可以对上述关系进行数学变换，而得到其他用于表征空频矩阵H与W 1、W 3关系的计算式。例如，空频矩阵H也可以表示为H＝W 1CW 3，此时W 3中的每一个行向量对应选择的一个频域向量。
由于双域压缩在空域和频域都分别进行了压缩，终端设备在反馈时，可以将被选择的一个或多个空域向量和一个或多个频域向量反馈给网络设备，而不再需要基于每个频域单元(如子带)分别反馈子带的加权系数(如包括幅度和相位)。因此，可以大大减小反馈开销。同时，由于频域向量能够表示信道在频率的变化规律，通过一个或多个频域向量的线性叠加来模拟信道在频域上的变化。因此，仍能够保持较高的反馈精度，使得网络设备 基于终端设备的反馈恢复出来的预编码矩阵仍然能够较好地与信道适配。
应理解，上文中为了便于理解双域压缩，分别定义了空频矩阵、空频向量对等术语，但这不应对本申请构成任何限定。终端设备确定预编码矩阵指示(precoding matrix indicator，PMI)的具体过程为终端设备的内部实现行为，本申请对于终端设备确定PMI的具体过程并不作限定。网络设备根据PMI确定预编码矩阵的具体过程为网络设备的内部实现行为，本申请对于网络设备根据PMI确定预编码矩阵的具体过程也不作限定。终端设备和网络设备分别可以采用不同的算法来生成PMI和恢复预编码矩阵。
11、加权系数：在本申请实施例中，主要涉及两类加权系数。
其中一类加权系数是基于双域压缩的反馈方式确定的加权系数。该加权系数也可以称为空频合并系数、空频系数等。每个加权系数可以与被选择用于构建预编码向量的一个空域向量和一个频域向量对应，或者说，与一个空频分量矩阵对应，或者说，与一个空频向量对对应。加权系数可以用于表示构建预编码向量对一个空域向量和频域向量所构建的空频分量矩阵的权重。
另一类加权系数是与时域向量对应的加权系数。该加权系数也可以称为时域系数。每个加权系数可以与被选择用于构建预编码矩阵的一个时域向量对应，或者说，与一个多普勒频移对应，可用于表示构建信道的每个时域向量的权重。如前所述，时域向量也可以称为多普勒向量。与之对应地，该加权系数也可以称为多普勒系数。
下文中为便于区分和理解，将与空频向量对对应的加权系数记作空频系数，与时域向量对应的加权系数记作时域系数。
应理解，上文列举的命名仅为便于区分而定义，不应对本申请构成任何限定。本申请对于系数的具体命名不做限定。
12、导频传输周期：相邻的两次导频传输之间间隔的时间。
13、导频时域密度：在预定义的一个时间单元内传输参考信号的次数，或者，用于本次传输参考信号的时域资源相对于该时间单元的比值。一个时间单元例如可以包括一个或多个导频传输周期，所对应的导频时域密度例如可以为1或大于1。
14、测量时长：本申请实施例中，终端设备可以根据网络设备的指示，在某一时段内进行信道测量。该时段可以称为测量时长。该时段的时间长度可以由网络设备通过信令指示，如，通过高层信令(如无线资源控制(radio resource control，RRC)消息等)通知。该测量时长也可以是预定义的，如协议定义。本申请对此不作限定。
网络设备可以通过信令通知终端设备开始进行信道测量。例如，网络设备可以通过信令通知终端设备该时段的起始时间和/或持续时间，或者，网络设备可以通过信令触发终端设备开始进行信道测量。终端设备在测量时长内可以接收多次用作信道测量的参考信号，并可以基于多次接收到的参考信号进行信道测量，以将信道的时变特征反馈给网络设备。
应理解，网络设备通过信令通知终端设备开始进行信道测量，并不代表终端设备在网络设备所指示的起始时间或触发时间开始就一直在做信道测量。网络设备只是通过信令通知终端设备可以进行信道测量，终端设备可以在由该起始时间或触发时间往后的一个时间窗内，基于接收到的参考信号进行信道测量。该时间窗的大小也即测量时长。
还应理解，这里所说的反馈是指终端设备对信道的时变特征的反馈，但并不表示终端 设备除此之外不作其他的反馈。例如，终端设备可以在该时段内基于双域压缩的反馈方式来反馈，也可以在该时段内基于type II码本的反馈方式来反馈等等。为了简洁，这里不一一列举。需要注意的是，终端设备在此时段内所做的其他反馈与本申请中所述的对信道的时变特征的反馈是相互独立的过程。
在测量时长内终端设备可以多次接收到参考信号。终端设备在测量时长内接收到参考信号的次数可以是测量时长与上述时间单元的比值乘以导频时域密度之积。
15、导频传输次数：本申请实施例中，导频传输次数可以是指，网络设备发送用作信道测量的参考信号的总次数，或者说，终端设备接收用作信道测量的参考信号的总次数。该导频传输次数具体可以是指一段时间内导频传输的总次数。当导频传输次数大于1时，多次导频传输可以是分布在这段时间内的多次传输。或者说，该多次导频传输是多个时刻的传输。
导频传输次数可以由网络设备通过信令指示，如高层信令(如RRC消息)；该导频传输次数也可以是预定义的，如协议定义。本申请对此不作限定。
需要说明的是，在本申请实施例中，码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。本申请对于终端设备确定测量时长、导频时域密度、导频传输次数和导频传输周期的取值的具体方式不作限定。
在一种实现方式中，网络设备可以通过信令直接指示测量时长、导频时域密度、导频传输次数或导频传输周期的取值。
在另一种实现方式中，网络设备也可以通过信令指示与测量时长、导频时域密度、导频传输次数或导频传输周期的取值相关的配置。例如，协议可以预定义多种配置与多种取值的对应关系，该对应关系例如可以通过表格或其他方式来体现。网络设备可以通过指示与某一取值对应的配置或配置的索引来指示测量时长、导频时域密度、导频传输次数或导频传输周期的取值。在此情况下，上文所述“码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期”可以替换为“码本集合中的每个码本与以下一项或多项的配置对应：测量时长，导频时域密度，导频传输次数和导频传输周期”。
在又一种实现方式中，测量时长、导频时域密度、导频传输次数或导频传输周期的取值可以是预定义的，如协议定义。
上文列举了几种确定测量时长、导频时域密度、导频传输次数或导频传输周期的取值的具体实现方式，但这不应对本申请构成任何限定。只要码本集合中的每个码本与测量时长、导频时域密度、导频传输次数和导频传输周期中的一项或多项存在对应关系，均应落入本申请的保护范围内。
终端设备可以基于每一次接收到的参考信号反馈CSI。以双域压缩的码本反馈方式为例，终端设备可以基于每一次接收到的参考信号进行信道测量，并反馈至少一个空域向量，至少一个频域向量和至少一个加权系数，以便网络设备构建预编码矩阵。然而，这种反馈方式可能会带来较大的反馈开销。例如，如果网络设备对参考信号的发送较为密集，那么终端设备就会频繁地向网络设备反馈CSI。
有鉴于此，本申请提供一种信道测量方法。本申请提供的信道测量方法基于多次接收到的参考信号进行信道测量，并基于信道测量的结果反馈时变特征，通过时变特征的一个 或多个分量特征的加权和来近似表示信道随时间的变化趋势。从而将一段时间(如测量时长)内的多次测量得到的结果通过时变特征压缩后反馈给网络设备。相比于上述基于每一次接收到的参考信号反馈CSI的反馈方式而言，有利于减少反馈开销。
下面结合图2至图5详细说明本申请实施例提供的信道测量方法。
为了便于理解本申请实施例，在介绍本申请实施例之前，先作出以下几点说明。
第一，为方便理解和说明，首先对本申请中涉及到的主要参数分别说明如下：
P：终端设备反馈的时域向量的数量，P≥1且为整数。
当终端设备基于双域压缩的码本反馈方式进行信道测量时，若终端设备基于一个空频向量对确定一个或多个时域向量，或者，若终端设备基于多个空频向量对确定共同的一个或多个时域向量，则终端设备反馈的时域向量的数量为P，该P个时域向量之间彼此互不相同。
若终端设备基于多个空频向量对中的每个空频向量对确定一个或多个时域向量，且基于至少两个空频向量对确定的时域向量不同，终端设备反馈的时域向量的数量P可以满足：
Figure PCTCN2020090551-appb-000007
其中，P k表示基于第k个空频向量对反馈的时域向量的数量，P k≥1且为整数。
应理解，上文将P定义为终端设备反馈的时域向量的数量仅为一种可能的定义方式。例如，P也可以定义为基于一个传输层反馈的时域向量的数量，或者，基于一个接收天线反馈的时域向量的数量等。本申请对此不作限定。
K：用于确定时域向量的空频向量对的总数量，K≥1且为整数；
k：k可以在1至K中任意取值，且k为整数。第k个空频向量对可以是K个空频向量对中的一个空频向量对；
K’：双域压缩中用于构建预编码矩阵的空频向量对的数量，K’≥K，且K’为整数；
L：空域向量(或者角度向量)的数量，该L个空域向量(或者角度向量)与下文所述的M个频域向量(时延向量)组合可以得到K个空频向量对，L≥1且为整数；
M：频域向量(或者时延向量)的数量，该M个频域向量(或者时延向量)与上文所述的L个空域向量(或者角度向量)组合可以得到K个空频向量对，M≥1且为整数。
第二，在本申请实施例中，为便于描述，在涉及编号时，可以从1开始连续编号。例如，P个时域向量包括第1个时域向量至第P个时域向量。以此类推，这里不再一一举例说明。当然，具体实现时不限于此，例如，也可以从0开始连续编号。应理解，上文所述均为便于描述本申请实施例提供的技术方案而进行的设置，而并非用于限制本申请的范围。
第三，在本申请实施例中，多处涉及矩阵和向量的变换。为便于理解，这里做统一说明。上角标T表示转置，如A T表示矩阵(或向量)A的转置；上角标H表示共轭转置，如，A H表示矩阵(或向量)A的共轭转置。后文中为了简洁，省略对相同或相似情况的说明。
第四，在本申请实施例中，多处提及一个或多个分量特征的加权和、一个或多个时域向量的加权和、一个或多个多普勒频移的指数函数的加权和等描述。
以分量特征为例，当分量特征仅为一个时，这里所说的“一个或多个分量特征的加权和”可以仅指一个分量特征。当分量特征为多个时，这里所说的“一个或多个分量特征的 加权和”可以表示，基于每个分量特征的权重(或者说加权系数)对该多个分量特征进行加权而得到的结果。为了简洁，下文中省略对相同或相似情况的说明。
第五，在本申请实施例中，网络设备可以根据终端设备的反馈确定预编码矩阵。当该预编码矩阵对应于一个传输层或一个极化方向时，该预编码矩阵也可以是向量的形式，如预编码向量。本申请对于该预编码矩阵的具体形式不作限定。例如可以为矩阵，也可以为向量。
第六，在本申请实施例中，“用于指示”可以包括用于直接指示和用于间接指示。例如，当描述某一指示信息用于指示信息I时，可以包括该指示信息直接指示I或间接指示I，而并不代表该指示信息中一定携带有I。
将指示信息所指示的信息称为待指示信息，则具体实现过程中，对待指示信息进行指示的方式有很多种，例如但不限于，可以直接指示待指示信息，如待指示信息本身或者该待指示信息的索引等。也可以通过指示其他信息来间接指示待指示信息，其中该其他信息与待指示信息之间存在关联关系。还可以仅仅指示待指示信息的一部分，而待指示信息的其他部分则是已知的或者提前约定的。例如，还可以借助预先约定(例如协议规定)的各个信息的排列顺序来实现对特定信息的指示，从而在一定程度上降低指示开销。同时，还可以识别各个信息的通用部分并统一指示，以降低单独指示同样的信息而带来的指示开销。例如，本领域的技术人员应当明白，预编码矩阵是由预编码向量组成的，预编码矩阵中的各个预编码向量，在组成或者其他属性方面，可能存在相同的部分。
此外，具体的指示方式还可以是现有各种指示方式，例如但不限于，上述指示方式及其各种组合等。各种指示方式的具体细节可以参考现有技术，本文不再赘述。由上文所述可知，举例来说，当需要指示相同类型的多个信息时，可能会出现不同信息的指示方式不相同的情形。具体实现过程中，可以根据具体的需要选择所需的指示方式，本申请实施例对选择的指示方式不做限定，如此一来，本申请实施例涉及的指示方式应理解为涵盖可以使得待指示方获知待指示信息的各种方法。
此外，待指示信息可能存在其他等价形式，例如行向量可以表现为列向量，一个矩阵可以通过该矩阵的转置矩阵来表示，一个矩阵也可以表现为向量或者数组的形式，该向量或者数组可以由该矩阵的各个行向量或者列向量相互连接而成，两个向量的克罗内克尔积也可以通过一个向量与另一个向量的转置向量的乘积等形式来表现等。本申请实施例提供的技术方案应理解为涵盖各种形式。举例来说，本申请实施例涉及的部分或者全部特性，应理解为涵盖该特性的各种表现形式。
待指示信息可以作为一个整体一起发送，也可以分成多个子信息分开发送，而且这些子信息的发送周期和/或发送时机可以相同，也可以不同。具体发送方法本申请不进行限定。其中，这些子信息的发送周期和/或发送时机可以是预先定义的，例如根据协议预先定义的，也可以是发射端设备通过向接收端设备发送配置信息来配置的。其中，该配置信息可以例如但不限于包括无线资源控制信令，例如RRC信令、MAC层信令，例如MAC-CE信令和物理层信令，例如下行控制信息(downlink control information，DCI)中的一种或者至少两种的组合。
第七，在下文示出的实施例中，第一、第二以及各种数字编号仅为描述方便进行的区分，并不用来限制本申请实施例的范围。例如，区分不同的指示信息等。
第八，“预先定义”或“预先配置”可以通过在设备(例如，包括终端设备和网络设备)中预先保存相应的代码、表格或其他可用于指示相关信息的方式来实现，本申请对于其具体的实现方式不做限定。其中，“保存”可以是指，保存在一个或者多个存储器中。所述一个或者多个存储器可以是单独的设置，也可以是集成在编码器或者译码器，处理器、或通信装置中。所述一个或者多个存储器也可以是一部分单独设置，一部分集成在译码器、处理器、或通信装置中。存储器的类型可以是任意形式的存储介质，本申请并不对此限定。
第九，本申请实施例中涉及的“协议”可以是指通信领域的标准协议，例如可以包括LTE协议、NR协议以及应用于未来的通信系统中的相关协议，本申请对此不做限定。
第十，“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A，B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a、b和c中的至少一项(个)，可以表示：a，或，b，或，c，或，a和b，或，a和c，或，b和c，或，a、b和c。其中a、b和c分别可以是单个，也可以是多个。
第十一，在本申请实施例中，“当……时”、“在……的情况下”、“若”以及“如果”等描述均指在某种客观情况下设备(如，终端设备或者网络设备)会做出相应的处理，并非是限定时间，且也不要求设备(如，终端设备或者网络设备)在实现时一定要有判断的动作，也不意味着存在其它限定。
下面结合附图详细说明本申请实施例提供的方法。
本申请实施例提供的方法可以应用于通过多天线技术通信的系统。例如，图1中所示的通信系统100。该通信系统可以包括至少一个网络设备和至少一个终端设备。网络设备和终端设备之间可通过多天线技术通信。
应理解，本申请实施例提供的方法并不仅限于在网络设备与终端设备之间的通信，还可应用于终端设备与终端设备之间的通信等。本申请对于该方法所应用的场景并不做限定。下文示出的实施例中，仅为便于理解和说明，以网络设备与终端设备之间的交互为例详细说明本申请实施例提供的方法。
还应理解，下文示出的实施例并未对本申请实施例提供的方法的执行主体的具体结构特别限定，只要能够通过运行记录有本申请实施例的提供的方法的代码的程序，以根据本申请实施例提供的方法进行通信即可，例如，本申请实施例提供的方法的执行主体可以是终端设备或网络设备，或者，是终端设备或网络设备中能够调用程序并执行程序的功能模块。
还应理解，下文中为便于理解，以双域压缩的反馈方式为例，详细说明本申请所提供的方法。但这不应对本申请提供的方法所适用的场景构成任何限定。本申请所提供的方法可应用于其他通过反馈波束向量和加权系数来指示预编码矩阵的反馈方式。例如，type II码本反馈方式等。下面首先结合图2简单说明本申请实施例所提供的信道测量方法的大致思想。图2通过a)、b)、c)和d)示意性地示出了终端设备将信道在时域的变化转换到多普勒域的过程。如图2中的a)所示，在空域和频域组成的平面内，终端设备可以确定多个空频向量对，图中示出了3个空频向量对(即图中示出的三个小方块)。终端设备 可以基于每一次接收到的参考信号确定该3个空频向量对的空频系数随时间的变化，将该变化通过曲线表示可以参看图2中的b)所示。如前所述，信道在时域的变化可以通过若干个缓变的多普勒频移的指数函数的加权和来表示，因此将该信道在时域的变化转换到多普勒域，便可以得到若干个固定不变的多普勒频移，如图2中的c)所示。图2中的c)示出了3个多普勒频移，该3个多普勒频移在横轴的坐标对应了该3个多普勒频移的位置，该3个多普勒频率在纵轴的坐标对应了该3个多普勒频移的幅值。若将该信道在时域的变化通过该3个多普勒频移的指数函数的加权和来表示，可以对信道在时域的变化进行时域的压缩(或者说，进行多普勒域的压缩)。并且，基于对信道在时域的变化，还可以进一步预测信道在未来时刻的变化，如图2中的d)所示。图2中的d)中虚线方框内的曲线是对未来时刻的信道的预测。
基于上述思想，下面将结合图3，更加详细地说明本申请实施例提供的信道测量方法。
为便于理解，下文示出的实施例是基于一个或多个传输层中的一个传输层、该传输层对应的一个或多个极化方向中的一个极化方向，详细说明了本申请实施例提供的信道测量方法的具体过程。应理解，本申请对于传输层数以及发射天线的极化方向数并不做限定。下文所示例说明的一个传输层可以为一个或多个传输层中的任意一个传输层，一个极化方向可以为一个或多个极化方向中的任意一个极化方向。
图3是从设备交互的角度示出的本申请一实施例提供的信道测量方法300的示意性流程图。如图3所示，该方法300可以包括步骤310至步骤350。下面详细说明方法300中的各步骤。
在步骤310中，终端设备生成第一指示信息，该第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数。
具体地，信道的时变特征可以通过一个或多个分量特征的加权和来表征。即，信道的时变特征可以通过一个分量特征来表征，或者，可以通过多个分量特征的加权和来表征。
在一种可能的实现方式中，信道的时变特征可以通过一个或多个固定不变的多普勒频移的指数函数的加权和来近似地表征。多普勒频移与时域向量的对应关系在上文已经做了详细说明，码本中每个时域向量可以对应一个多普勒频移。因此，信道的时变特征可以通过一个或多个时域向量的加权和来近似地表征。换句话说，本申请实施例中所述的一个或多个分量特征可以是从预定义的码本中选择的一个或多个时域向量。每个分量特征对应于一个时域向量，每个时域向量可用于确定一个多普勒频移。
因此，在本申请实施例中，时域向量可以认为是时变特征的分量特征的一种表现形式。终端设备可以基于接收到的参考信号进行信道测量，以从预定义的码本中确定一个或多个时域向量以及每个时域向量对应的时域系数。
应理解，将一个或多个分量特征的加权和用来近似地表示信道的时变特征仅为一种可能的实现方式，不应对本申请构成任何限定。该一个或多个分量特征以及每个分量特征的加权系数与信道的时变特征之间的关系并不限于此。
可选地，在步骤310之前，该方法300还包括：步骤320，终端设备接收参考信号。相对应地，在步骤320中，网络设备发送参考信号。
由于信道的时变特性，终端设备可以基于在多个不同的时刻接收到的参考信号进行信道测量。换句话说，上述时变特征是终端设备基于多个时刻接收到的参考信号确定的。或 者说，上述时变特征是终端设备基于多次接收到的参考信号确定。
在一种实现方式中，终端设备可以基于测量时长内接收到的参考信号生成第一指示信息。应理解，该测量时长可以较短，例如可以以时隙(slot)或者毫秒(ms)为单位来定义。如，该测量时长为20个时隙或者5ms或10ms或20ms。或者，该测量时长也可以较长，例如可以以秒为单位来定义。如，该测量时长为10秒。
该测量时长可以是预定义的，如协议定义。该测量时长也可以是网络设备预配置的，如网络设备通过信令指示测量的起始时间和测量时长。本申请对此不作限定。
在另一种实现方式中，终端设备可以基于导频传输次数接收参考信号，并基于接收到的参考信号生成第一指示信息。
该导频传输次数可以是预定义的，如协议定义。该导频传输次数也可以是网络设备预配置的，如网络设备通过信令指示导频传输次数。本申请对此不做限定。
由于上文中已经详细说明了测量时长和导频传输次数，为了简洁，这里不再赘述。
需要说明的是，在本申请实施例中，终端设备可以基于测量时长或导频传输次数接收参考信号，以进行信道测量。无论终端设备是基于测量时长接收参考信号，还是基于导频传输次数接收参考信号，终端设备均可以基于多次接收到的参考信号进行信道测量，以确定用于表征信道时变特征的一个或多个时域向量及其对应的时域系数。
下文中为方便说明，假设终端设备基于N次接收到的参考信号确定上述一个或多个时域向量及其对应的时域系数，进而生成第一指示信息。其中，N次可以是在测量时长内接收到的参考信号的次数，也可以是导频传输次数。本申请对此不作限定。
为方便理解和说明，下文以双域压缩为例详细说明终端设备确定一个或多个时域向量及其对应的时域系数的具体过程。
终端设备基于N次中的每一次接收到的参考信号确定信道，然后通过一个或多个时域向量的加权和来近似地表征该信道随时间的变化。具体地，终端设备基于N次中的第n(1≤n≤N，n为整数)次接收到的参考信号进行信道测量，可以得到空频矩阵H n。空频矩阵可以理解是对信道的一种表征方式。每一次信道测量所得到的空频矩阵均可以通过多个空频向量对的加权和来近似表示。通常在一定测量时长内，在用来构建预编码矩阵的多个空频向量对不变的情况下，基于该多个空频向量对的空频系数随时间的变化，便可将信道随时间的变化通过一个或多个时域向量的加权和近似地表示出来。
其中，用于近似表示空频矩阵的多个空频向量对可以是由终端设备基于双域压缩的反馈方式而确定。该多个空频向量对可以用来构建预编码矩阵。该多个空频向量对例如可以由多次测量中的第一次测量确定，也可以由多次测量中的最后一次信道测量确定，还可以由多次测量中的任意一次测量确定。本申请对此不作限定。也就是说，终端设备可以在接收到N次参考信号之后再进行信道测量，也可以在每接收到一次参考信号就进行一次信道测量。应理解，信道测量是终端设备的内部实现行为，本申请对此不作限定。
终端设备可以基于多个空频向量对中的部分或全部空频向量对，确定可以用来加权的一个或多个时域向量以及每个时域向量的时域系数，从而通过该一个或多个时域向量的加权和来近似地表示信道的时变特征。为方便说明，假设终端设备向网络设备反馈的时域向量的数量为P，P≥1且为整数。
可选地，该方法300还包括：终端设备接收第二指示信息，该第二指示信息用于指示 P值。相应地，网络设备发送该第二指示信息，该第二指示信息用于指示P值。
即，P值可以是网络设备通过信令向终端设备指示的。终端设备可以根据网络设备指示的P值，选择相应数量的空频向量对上报并确定时域向量。换句话说，网络设备可以预先通过信令为终端设备配置需要上报的时域向量的数量。
该第二指示信息例如可以携带在高层信令中。该高层信令例如可以是无线资源控制(radio resource control，RRC)消息等。本申请对用于携带该第二指示信息的具体信令不作限定。
可选地，该方法300还包括：终端设备发送第三指示信息，该第三指示信息用于指示P值。相应地，网络设备接收第三指示信息，该第三指示信息用于指示P值。
即，P值可以由终端设备自行确定，并通过信令上报给网络设备。
终端设备例如可以根据网络设备指示的可使用的P值的最大值P 0确定P值，其中P≤P 0，P 0为正整数。可选地，该方法300还包括：终端设备接收第四指示信息，该第四指示信息用于指示P的最大值P 0。相应地，网络设备发送第四指示信息，该第四指示信息用于指示P的最大值P 0。
换句话说，网络设备可以预先通过信令为终端设备配置需要上报的时域向量的数量。终端设备实际上报的时域向量的数量可以等于或小于网络设备预配置的需要上报的时域向量的数量。该第四指示信息例如可以携带在高层信令中。该高层信令例如可以是RRC消息等。本申请对用于携带该第四指示信息的具体信令不作限定。
应理解，上述第三指示信息可以与第一指示信息携带在相同的信令中，如CSI报告；也可以携带在不同的信令中，例如可以是已有或新增的信令。本申请对此不作限定。
可选地，P值是预定义的，如协议定义。
本申请对P值的具体确定方法和具体数值均不作限定。
当终端设备基于双域压缩的码本反馈方式进行信道测量时，P值也可以是基于一个或多个(如K个)空频向量对确定的时域向量的数量，或者，也可以是基于一个传输层确定的时域向量的数量。上文中已经结合不同的情况对P值做了详细说明，为了简洁，这里不再赘述。
当终端设备基于其它反馈方式，如type II码本的反馈方式，进行信道测量时，P值也可以是基于一个波束向量确定的时域向量的数量，或者，也可以是基于多个波束向量确定的时域向量的数量，或者，还可以是基于一个传输层确定的时域向量的数量。
应理解，上文中对P值的定义仅为示例，不应对本申请构成任何限定。本申请对于P的具体定义不作限定。本领域的技术人员基于相同的发明构思，可以对P的定义做出等价替换，这些等价替换均应落入本申请的保护范围内。
在本申请实施例中，终端设备可以基于预定义的码本确定P个时域向量以及每个时域向量对应的时域系数，以用于近似地表示信道的时变特征。下面详细说明终端设备确定P个时域向量以及每个时域向量的时域系数的具体过程。
仍以双域压缩为例，终端设备可以基于K个空频向量对对应的空频系数随时间的变化来确定P个时域向量及其对应的时域系数。其中，K≥1且为整数。
作为一个实施例，该第一指示信息用于指示P个时域向量及其对应的P个时域系数。该P个时域向量的加权和可用于近似地表示上述空频向量对的空频系数随时间的变化。
也就是说，终端设备可以基于K个空频向量对共同确定P个时域向量及其对应的P个时域系数。
其中，用来确定时域向量的K个空频向量对可以是基于双域压缩的反馈方式而确定的K个空频向量对。当终端设备基于K个空频向量对共同确定了P个时域向量和P个时域系数时，终端设备可以基于该K个空频向量对中的某一个空频向量对来确定，如，K个空频向量对中最强的一个空频向量对；或者，终端设备也可以基于该K个空频向量对来确定，如，K个空频向量对的加权平均；或者，终端设备也可以基于该K个空频向量对中的部分空频向量对来确定，本申请对此不作限定。但应理解，这并不表示终端设备在基于双域压缩反馈PMI时，只选择了一个空频向量对或者只选择了K个空频向量对来构建预编码矩阵。当终端设备基于双域压缩反馈PMI时，可以基于更多个(如下文所述的K’个，K’≥K且K’为整数)空频向量对来构建预编码矩阵。
在本实施例中，由于该P个时域向量及其对应的P个时域系数可以是基于上述K个空频向量对共同确定的。在后文所述网络设备基于K’个空频向量对及其空频系数构建预编码矩阵时，该P个时域向量及其对应的P个时域系数可以被上述K个空频向量对共用。或者说，该K个空频向量对在用于构建预编码矩阵时，任意两个空频向量对对应的空频系数是相同的。
由于终端设备基于K个空频向量对共同确定了P个时域向量和P个时域系数，则可以认为每个空频向量对对应的时域向量的数量为P，且每个空频向量对对应的时域向量的时域系数的数量为P。每个空频向量对对应的时域向量和时域系数可用于确定这个空频向量对的空频系数。
可以理解的是，由于任意两个空频向量对对应的P个时域向量是相同的，任意两个空频向量对对应的P个时域系数也是相同的。因此，终端设备可以通过第一指示信息指示P个时域向量和P个时域系数。或者说，终端设备对于该P个时域向量及其对应的时域系数仅指示一次。或者说，终端设备可以通过同一字段来指示针对K个空频向量对中每个空频向量对反馈的P个时域向量，也可以通过同一字段来指示针对K个空频向量对中每个空频向量对反馈的P个时域系数。换句话说，用于指示P个时域向量的指示字段对于K个空频向量对来说是共同的，用于指示P个时域系数的指示字段对于K个空频向量对来说也是共同的。
应理解，这里所说的同一字段，具体是指，针对K个空频向量对对时域向量的指示字段没有重复，以及，针对K个空频向量对对时域向量的时域系数的指示字段没有重复。而并非要限制用来指示时域向量和时域系数的字段个数。
作为另一个实施例，该第一指示信息用于指示P个时域向量以及K×P个时域系数。每P个时域向量的加权和可用于近似地表示一个空频向量对的空频系数随时间的变化。
也就是说，终端设备可以基于K个空频向量对共同确定P个时域向量，并可以基于K个空频向量对中的每个空频向量对确定每个时域向量的时域系数。其中关于K个空频向量对以及终端设备基于K个空频向量对共同确定P个时域向量的相关说明在上文已经做了详细说明，为了简洁，这里不再赘述。
在本实施例中，由于终端设备基于K个空频向量对共同确定了P个时域向量，又可以基于K个空频向量对中的每个空频向量对确定每个时域向量的时域系数。至少两个空频 向量对对应的空频系数不同。因此，在后文所述网络设备基于K’个空频向量对及其对应的空频系数构建预编码矩阵时，K个空频向量对中至少两个空频向量对对应的空频系数是不同的。
由于终端设备基于K个空频向量对共同确定了P个时域向量，则可以认为每个空频向量对对应的时域向量的数量为P。此外，终端设备基于K个空频向量对中的每个空频向量对确定P个时域向量，则终端设备基于K个空频向量对确定的时域向量的总数量为K×P。此情况下，每个空频向量对对应的时域系数的数量为P，但至少两个空频向量对对应的时域系数不同。
可以理解的是，任意两个空频向量对对应的P个时域向量是相同的，因此终端设备可以通过第一指示信息指示P个时域向量。或者说，终端设备对于该P个时域向量仅指示一次。或者说，终端设备可以通过同一字段来指示针对K个空频向量对中的每个空频向量对反馈的P个时域向量。换句话说，用于指示P个时域向量的指示字段对于K个空频向量对来说是共同的。
应理解，这里所述的同一字段具体是指针对K个空频向量对对时域向量的指示字段没有重复，而并非要限制用来指示时域向量的字段个数。
此外，终端设备在通过第一指示信息指示上述K×P个时域系数时，可以针对每个空频向量分别指示。针对每个空频向量对分别指示的时域系数和上文所述的P个时域向量可用于确定这个空频向量对的空频系数。
作为又一个实施例，该第一指示信息可用于指示
Figure PCTCN2020090551-appb-000008
个时域向量及其对应的
Figure PCTCN2020090551-appb-000009
个时域系数。其中，1≤k≤K，P k≥1，k和P k均为整数。
也就是说，终端设备可以基于K个空频向量对中的每个空频向量对确定一个或多个时域向量，并可以基于K个空频向量对中的每个空频向量对确定每个时域向量对应的时域系数。其中关于K个空频向量对的相关说明在上文中已经做了详细说明，为了简洁，这里不再赘述。
在本实施例中，由于终端设备基于每个空频向量对确定了一个或多个时域向量以及一个或多个时域系数。至少两个空频向量对对应的空频系数不同。因此，在后文所述网络设备基于K’个空频向量对及其空频系数构建预编码矩阵时，K个空频向量对中至少两个空频向量对对应的空频系数是不同的。
终端设备在通过第一指示信息指示上述
Figure PCTCN2020090551-appb-000010
个时域向量及其对应的时域系数时，可以针对每个空频向量对分别指示。针对每个空频向量对分别指示的时域向量及其对应的时域系数可用于确定这个空频向量对的空频系数。例如，针对第k个空频向量对指示的P k个时域向量及其对应的时域系数可用于确定该第k个空频向量对的空频系数。
为方便区分和说明，这里将与一个空频向量对对应的一个或多个(例如P个或P k个)时域向量加权求和得到的向量称为与该空频向量对对应的空频系数向量的估计值。后文中会对空频系数向量做详细说明，这里暂且省略对空频系数向量的详细说明。
为便于理解，首先以一个空频向量对为例详细说明终端设备确定P个时域向量及其对应的时域系数的具体过程。将K个空频向量对中的一个空频向量对记为(u l，v m)，该空频向量对(u l，v m)可以是该K个空频向量对中最强的空频向量对。其中，l(1≤l≤L且 l为整数)表示该空域向量u l为L(L≥1且为整数)个空域向量中的第l个空域向量，m(1≤m≤M且m为整数)表示该频域向量v m为M(M≥1且为整数)个频域向量中的第m个频域向量。该L个空域向量和M个频域向量可以组合得到多个空频向量对(如下文所述的K个空频向量对)，该多个空频向量对可用于构建预编码矩阵。
这里所述的最强的空频向量对具体可以是指：该空频向量对对应的空频系数的幅值大于或等于该多个空频向量对除该空频向量对之外的其他任意一个空频向量对应的空频系数的幅值。该最强的空频向量(u l，v m)可以是基于第一次接收到的参考信号确定的，也可以是基于N次中任意一次接收到的参考信号确定的，也可以是基于N次接收到的参考信号平均后确定的。本申请对此不做限定。
基于N次接收到的参考信号所确定的、与该空频向量对(u l，v m)对应的N个空频系数记为
Figure PCTCN2020090551-appb-000011
该N个元素中的第n个元素可以是基于第n次接收到的参考信号进行信道测量而确定。该N个空频系数可以构成向量
Figure PCTCN2020090551-appb-000012
该向量c l,m也就可以反映出由N次接收到的参考信号而确定的N个空频矩阵随时间的变化趋势，也就是间接地反映了信道随时间的变化趋势。下文中为便于区分和说明，将由多次接收到的参考信号确定的空频向量对对应的空频系数所构成的向量记作空频系数向量。
应理解，上文仅为便于理解，示出了维度为N×1的空频系数向量，但这不应对本申请构成任何限定。该空频系数向量也可以是维度1×N的向量。本领域的技术人员可以基于相同的构思，对上文所列举的空频系数向量的形式作出数学变换或等价替换，这些数学变换或等价替换均应落入本申请的保护范围内。
还应理解，上文仅为便于理解，示出了长度为N的空频系数向量，但这不应对本申请构成任何限定。空频系数向量的维度可以与终端设备接收到参考信号的次数N相同，也可以与之不同。例如，空频系数向量的长度可以大于N，终端设备可以通过插值的方式生成更大长度的空频系数向量，如2N。又例如，空频系数向量的长度也可以小于N，终端设备可以从上述由N次接收到的参考信号所确定的N个空频系数中抽取一部分空频系数来构成更小维度的空频系数向量。再例如，空频系数向量的维度也可以小于N，终端设备可以基于多次接收到的参考信号确定空频矩阵，进而确定与之对应的空频系数。由此而确定的空频系数的个数小于N，故该空频系数向量的长度也小于N。
下文中仅为便于说明，假设该空频系数向量的长度为N。
当空频系数向量的长度为N时，该空域系数向量中的N个元素与N个测量时刻对应，可用于表示该空频向量对在N个测量时刻中每个测量时刻的空频系数。换句话说，该时域系数向量中的N个元素中的第n个元素可用于确定第n个测量时刻的空频矩阵。
如前所述，该空频系数向量可以通过一个或多个时域向量的加权和来表示。在本申请实施例中，终端设备可以从预定义的码本中确定一个或多个时域向量来近似表示上述空频系数向量。用于确定一个或多个时域向量的码本可以是网络设备通过信令向终端设备指示的，如指示码本的索引，或指示码本的索引和过采样因子；也可以是终端设备自行确定，并在上报第一指示信息的同时，上报所使用的码本，如上报所使用的码本的索引，或该码本的索引和过采样因子；还可以是预先定义的，如协议定义。本申请对此不作限定。
在一种实现方式中，终端设备例如可以将该空频系数向量投影至码本，以选择较强的P个时域向量来近似地表示该空频系数向量。
需要说明的是，用于确定时域向量的码本的维度与该空频系数向量的维度相对应。例如，空频系数向量的长度为N，则用于确定时域向量的码本的维度也可以是N维。而空频系数向量的维度与接收到参考信号的次数相关，因此，该码本的维度可以与接收到参考信号的次数N相关。可选地，该码本的维度可以与接收到参考信号的次数N相同。终端设备可以基于N次接收到的参考信号，生成长度为N的空频系数向量。可选地，该码本维度可以与空频系数向量的长度相同。终端设备可以通过N维码本来选择可用来近似表示空频系数向量的P个时域向量。可以理解的是，用于确定时域向量的码本的维度N大于或等于所选择的时域向量的个数P。即，N≥P。可选地，该码本维度可以为空频系数向量的过采样倍数。例如，空频系数向量的长度为N，过采样因子为O t，则用于确定时域向量的码本的维度也可以是N×(O t×N)维。可以理解的是，用于确定时域向量的码本的维度O t×N大于或等于所选择的时域向量的个数P。即，O t×N≥P。
还需要说明的是，空频系数向量的长度可以由网络设备和终端设备预先约定。例如，双方可以约定，将接收到参考信号的次数N作为空频系数向量的长度，也可以基于N确定空频系数向量的长度，如2N等。本申请对此不作限定。在一种可能的实现方式中，网络设备可以预先向终端设备指示用来确定时域向量的码本，通过指示码本来隐式地指示空域系数向量的长度。例如，当网络设备预先向终端设备指示的码本为N维码本，也就是隐式地指示了空域系数向量的长度取N。当然，网络设备还可以通过其他信令向终端设备指示空域系数向量的长度。为了简洁，这里不一一举例说明。
在本实施例中，空频系数向量的长度为N。则用来确定时域向量的码本为N维码本，该N维码本中包括N个长度为N的时域向量。该N个长度为N的时域向量可以构造得到维度为N×N的矩阵。假设该矩阵记作U t。例如U t＝[d 1 d 2…d N]。其中，d 1，d 2，……，d N为该码本中的N个长度为N的时域向量。将该空频系数向量投影至该预定义的码本可以通过计算式表示为：U t Hc l,m。经过投影可以得到维度为N×1的向量d l,m，
Figure PCTCN2020090551-appb-000013
该向量d l,m中的N个元素可以表示矩阵U t中的N个时域向量中每个时域向量的权重。例如，该向量d l,m中的第n个元素
Figure PCTCN2020090551-appb-000014
表示该矩阵U t中的第n个时域向量d n的权重。可以理解的是，上述权重也可以被称作时域系数。
终端设备可以从该向量d l,m中选择较强的P个元素，该较强的P个元素在向量d l,m中的位置与P个时域向量在矩阵U t中的位置对应。终端设备例如可以根据投影所得到的向量d l,m中N个元素的模的平方的大小，确定较强的P个元素。被选择的P个元素中的任意一个元素的模的平方大于或等于未被选择N-P个元素中的任意一个元素的模的平方。由较强的P个元素可以确定P个时域向量。例如，该较强的P个元素在向量d l,m中所对应的位置也就可以是被选择的P个时域向量在矩阵U t中的位置。
假设P＝3，该N个元素中较强的3个元素记作
Figure PCTCN2020090551-appb-000015
下角标p 1、p 2和p 3分别代表元素在向量d l,m中的索引。例如，p 1＝1，p 2＝4，p 3＝8，则表示该向量d l,m中的第1个元素
Figure PCTCN2020090551-appb-000016
第4个元素
Figure PCTCN2020090551-appb-000017
和第8个元素
Figure PCTCN2020090551-appb-000018
为较强的3个元素。与此对应地，矩阵U t中的第1个向量d 1、第4个向量d 4和第8个向量d 8是较强的3个时域向量。
应理解，P＝3以及较强的P个元素的索引仅为便于理解而示例，不应对本申请构成任何限定。本申请对于P的取值以及P个元素的索引均不做限定。
上文仅为便于理解，以基于一个空频向量对对应的空频系数向量为例，详细说明了终端设备确定P个时域向量及其对应的时域系数的具体过程。但这不应对本申请构成任何限定。终端设备也可以基于多个空频向量对对应的空频系数来确定P个时域向量及其对应的时域系数。
可选地，该终端设备基于K个空频向量对对应的K个空频系数向量确定P个时域向量及其对应的时域系数。
如前所述，终端设备基于多个空频向量对确定时域向量和时域系数时，该多个空频向量对对应共同的P个时域向量和共同的P个时域系数；或者，该多个空频向量对对应共同的P个时域向量，每个空频向量对对应P个时域系数；或者，该多个空频相对分别对应各自的一个或多个时域向量以及一个或多个时域系数。
一种可能的情况是，多个空频向量对对应共同的P个时域向量和共同的P个时域系数，该终端设备可以基于该多个空频向量对中的某一个空频向量对(如，最强的空频向量对)，或者，该多个空频向量对的加权平均，确定共同的P个时域向量和共同的P个时域系数。
另一种可能的情况是，多个空频向量对均可以分别对应各自的一个或多个时域向量以及一个或多个时域系数。该终端设备可以基于多个空频向量对中每个空频向量对对应的空频系数随时间的变化，确定与每个空频向量对对应的空频系数向量。终端设备可以基于将每个空频向量对对应的空频系数向量投影到码本上，以得到确定与每个空频向量对对应的一个或多个时域向量以及每个时域向量对应的时域系数。
假设终端设备基于K个空频向量对确定对应的K个空频系数向量。该K个空频系数向量中的每个空频系数向量可用于确定一个或多个时域向量。例如，K个空频系数向量中的第k个空频系数向量可用于确定P k个时域向量及其对应的时域系数，P k＜P，且P k为正整数。简单地说，该P k个时域向量及其对应的时域系数是与第k个空频向量对对应的时域向量和时域系数。该P k个时域向量及其对应的时域系数可用于确定与第k个空频向量对对应的空频系数向量的估计值。
终端设备可以按照如上文所述的将一个空频系数向量投影到码本的方式来依次确定第1个至第K个空频向量对分别对应的时域向量和时域系数。此情况下，终端设备可以依次将K个空频向量对对应的空频系数向量投影到码本来确定时域向量和时域系数。
终端设备也可以将K个空频向量对的对应的空频系数向量构建为矩阵，该矩阵例如可以是维度为N×K的矩阵。该矩阵的每个列向量对应于一个空频向量对。投影后得到的矩阵中的每个列向量也就对应一个空频向量对。终端设备可以基于每个列向量中的元素确定每列中较强的一个或多个元素为时域系数，该一个或多个元素在列向量中的位置可确定与每个空频向量对对应的一个或多个时域向量。
应理解，终端设备基于K个空频向量对确定所对应的时域向量及其对应的时域系数的方法并不限于上文所列举，为了简洁，这里不一一举例说明。
终端设备基于该K个空频向量对对应的K个空频系数向量可以确定共
Figure PCTCN2020090551-appb-000019
个时域向量。可以理解的是，基于K个空频系数向量所确定的P个时域向量中，可能有部分时域向量是相同的，或者说是重复的。换句话说，该P个时域向量有可能是彼此互不相同的，也有可能是部分重复的。但由于这些重复的时域向量是基于不同的空频系数向量确定，所对应的时域系数并不一定相同。
此外，基于多个空频向量对确定的时域向量的个数可以是相同的，也可以是不同的，本申请对此不作限定。基于每个空频向量对确定的时域向量的个数可以由网络设备指示，也可以由终端设备自行确定，还可以预定义，本申请对此不作限定。
在一种可能的设计中，终端设备可以对最强的空频向量对确定更多数量的时域向量，而对其他空频向量对确定较少数量的时域向量。
在另一种可能的设计中，终端设备可以将K个空频向量对分为多个组，对不同的组中的空频向量对确定不同数量的时域向量。例如，终端设备可以将K个空频向量对分为组1和组2两个组，其中组1包括K个空频向量对中较强的一个或多个空频向量对，组2包括剩余的一个或多个空频向量对。又或者，在发射天线为多个极化方向的情况下，组1和组2还可以分别包括与不同极化方向对应的一个或多个空频向量对。每个组中的空频向量对可用于确定相同数量的时域向量，且基于组1中的空频向量对确定的时域向量的个数可以大于基于组2中的空频向量对确定的时域向量的个数。其中组1中包含的空频向量对的个数和组2中包含的空频向量对的个数例如可以预定义，或者由网络设备和终端设备双方预先约定，或者还可以基于预定义的规则来确定，为了简洁，这里不一一举例说明。
应理解，上文列举的针对不同的空频向量对确定的时域向量的数量的分配方式仅为示例，不应对本申请构成任何限定。
此外，用于确定时域向量的码本由预定义的多个码本中确定。用于确定P个时域向量的码本可以是一个，也可以是多个。本申请对此不作限定。
作为一个实施例，终端设备可以基于不同维度的多个码本来确定P个时域向量及其对应的时域系数。具体地，终端设备可以基于K个空频向量对来确定各自对应的时域向量和时域系数。其中，至少两个空频向量对在用于确定时域向量时，可以是基于不同维度的两个码本来确定的。例如，空频向量对1的强度高于空频向量对2的强度。终端设备可以基于空频向量对1和维度为α×N的码本来确定一个或多个时域向量，采用空频向量对2和维度为N的码本来确定一个或多个时域向量，其中α>1且为整数；或者，终端设备可以基于空频向量对1和维度为N的码本来确定一个或多个时域向量，采用空频向量对2和维度为
Figure PCTCN2020090551-appb-000020
或[N/β]的码本来确定一个或多个时域向量，其中β＞1且为整数。为了简洁，这里不再赘述。其中，
Figure PCTCN2020090551-appb-000021
表示向上取整，
Figure PCTCN2020090551-appb-000022
表示向下取整，[]表示四舍五入取整。
上文实施例中，空频向量对1的强度高于空频向量对2的强度，例如可以通过比较同一测量时刻空频向量对1对应的空频系数和空频向量对2对应的空频系数的幅值来确定。本申请对此不作限定。
由上文示例可以看到，终端设备可以对不同强度的空频向量对采用不同精度的码本来确定时域向量。例如，对于较强的空频向量对，可以采用精度较高的码本来确定时域向量，一种表现形式就是采用较大维度的码本来确定时域向量；对于较弱的空频向量对，可以采用精度较低的码本来确定时域向量，一种表现形式就是采用较小维度的码本来确定时域向量。
应理解，上文所示的实施例仅为示例，不应对本申请构成任何限定。终端设备还可以基于更多不同维度的码本和K个空频向量对确定一个或多个时域向量及其对应的时域系数。本申请对此不作限定。
再一种可能的情况是，若多个空频向量对对应共同的P个时域向量，但每个空频向量 对分别对应各自的P个时域系数。该终端设备可以基于一个空频向量对(如，最强的空频向量对)来确定较强的P个时域向量，也可以基于多个空频向量对来确定较强的P个时域向量。
由于上文中已经详细说明了终端设备基于一个空频向量对确定P个时域向量的具体过程，为了简洁，这里不再赘述。在确定了P个时域向量之后，终端设备可以进一步基于多个空频向量对分别对应的空频系数向量，确定与各空频向量对对应的P个时域系数。
若多个空频向量对对应共同的P个时域向量，且多个空频向量对分别对应各自的P个时域系数，该终端设备可以基于一个或多个空频向量对来确定较强的P个时域向量。
终端设备基于一个空频向量对确定较强的P个时域向量的具体过程在上文已经做了详细说明，为了简洁，这里不再赘述。
终端设备也基于多个空频向量对来确定较强的P个时域向量。具体地，终端设备可以将该多个空频向量对所对应的空频系数向量投影到码本，以得到多个向量。终端设备可以根据该多个向量选择较强的P个元素，根据该较强的P个元素在向量中的位置从码本中确定位置相同的P个时域向量。由此确定的P个时域向量可以是该多个空频向量对共同的P个时域向量。
终端设备例如可以按照如上文所述的将一个空频系数向量投影到码本的方式来依次确定第1个至第K个空频向量对分别对应的时域系数。以第k个空频向量对为例，将第k个空频向量对对应的空频系数向量投影到码本可以所得到的向量中，选择与P个时域向量在矩阵U t中的位置对应的P个元素作为该P个时域向量对应的P个时域系数。
终端设备也可以将K个空频向量对所对应的K个空频系数向量构建为矩阵，该矩阵例如可以是维度为N×K的矩阵。该矩阵的每个列向量对应于一个空频向量对。投影后得到的矩阵中，每个列向量也就对应一个空频向量对。终端设备可以基于P个时域向量在矩阵U t中的位置，从每个列向量中选择对应位置的元素作为该P个时域向量对应的P个时域系数。由此可以确定与每个空频向量对对应的P个时域系数。
除了上文列举的方法之外，终端设备还可以通过其他可能的方式来确定P个时域向量及其对应的时域系数。例如，终端设备可以将上文所述的两种方法结合来确定P个时域向量及其对应的时域系数。或者，终端设备可以从上述维度为N×K的矩阵中，选择总能量或平均能量较大的P行，其在维度为N×K的矩阵中的位置也就对应于P个时域向量在矩阵U t中的位置。
具体地，终端设备可以将K个空频向量对分为多个组，每个组可以包括一个或多个空频向量对。终端设备可以基于每个组中的空频向量对确定共同的一个或多个时域向量以及共同的一个或多个时域系数。也就是说，组内的空频向量对可以共用相同的一个或多个时域向量以及相同的一个或多个时域系数。终端设备也可以基于每个组中的空频向量对确定共同的一个或多个时域向量，并基于每个空频向量对确定各自的一个或多个时域系数。也就是说，组内的空频向量对可以共用相同的一个或多个时域向量，但组内的空频向量对对应的时域系数不同。另外，组间的空频向量对所对应的时域向量不同，且组间的空频向量对所对应的时延系数也不同。这里所述的“不同”，可以是部分不同，也可以是全部不同。本申请对此不作限定。
终端设备基于组内的空频向量对确定相同的一个或多个时域向量以及相同的一个或 多个时域系数时，可以基于组内的某一空频向量对来确定，如组内最强的空频向量对，也可以基于组内的多个空频向量对的加权平均来确定，为了简洁，这里不再一一列举。
应理解，上文所述的用于确定P个时域向量及其对应的时域系数的方法仅为示例，不应对本申请构成任何限定。终端设备例如还可以通过现有的估计算法，如多重信号分类算法(multiple signal classification algorithm，MUSIC)、巴特利特(Bartlett)算法或旋转不变子空间算法(estimation of signal parameters via rotation invariant technique algorithm，ESPRIT)等来确定时域向量及其对应的时域系数。为了简洁，这里不再举例说明。此外，本申请对于确定时域向量及其对应的时域系数的先后顺序也不作限定。
在确定了P个时域向量及其对应的时域系数之后，终端设备可以生成第一指示信息，以指示该P个时域向量及其对应的时域系数。
其中，该P个时域向量由码本中选择的。因此，在一种实现方式中，终端设备在通过该第一指示信息指示P个时域向量时，可以通过指示该P个时域向量在码本中的索引的方式来指示。
作为一个实施例，该P个时域向量是基于同一码本确定的。该码本可以是网络设备指示的，或者协议预定义的，该第一指示信息在用于指示该P个时域向量时，可包括该P个时域向量在该码本中的索引，或者该P个时域向量的组合的索引。
例如，上文实施例中终端设备所选择的3(P＝3)个的时域向量为码本中N个时域向量中的第1个、第4个和第8个，则终端设备可以通过第一指示信息指示索引值1、4和8。
作为另一个实施例，该P个时域向量是基于同一码本确定的。该码本可以是终端设备自行确定的。该第一指示信息在用于指示该P个时域向量时，可以包括该码本的指示，以及该P个时域向量在该码本中的索引，或者该P个时域向量的组合的索引。
作为又一个实施例，该P个时域向量是基于不同码本确定的。该第一指示信息在用于指示P个时域向量时，可以包括用于确定每个时域向量的码本的指示以及每个时域向量在所对应的码本中的索引。
在另一种实现方式中，每个时域向量可以对应于一个多普勒频移。换言之，上文所述的时变特征的分量特征可以是多普勒频移。当该多个时域向量取自N维码本时，可以理解为，将最大多普勒频移等分成N份，该N维码本中的N个时域向量与N个多普勒频移对应。一种实现方式中，第n个时域向量所对应的多普勒频移与最大多普勒频移的比值为n/N。
其中，最大多普勒频率可以由网络设备确定，例如利用上下行互易性确定或根据终端设备移动速度和/或与基站的相对位置确定，并指示终端设备使用与该最大多普勒频移所对应的码本来进行信道测量和反馈。或者，最大多普勒频移可以由终端设备确定，并上报给网络设备。或者，最大多普勒频移也可以是预定义的，如协议定义，或与参考信号配置等绑定。
因此，当终端设备通过第一指示信息指示P个多普勒频移时，也就认为该终端设备通过该第一指示了上述被选择的P个时域向量时。换言之，这两种指示方式是等价的。
应理解，上文仅为示例，示出了终端设备指示P个时域向量的几种可能的实现方式，但这不应对本申请构成任何限定。
此外，若K个空频向量对并不是对应相同的P个时域向量，则终端设备在指示该P个时域向量时，可以按照预先约定的顺序来指示。例如，按照K个空频向量对的指示顺序来依次指示所对应的一个或多个时域向量。又例如，按照K个空频向量对的强弱顺序来依次指示所对应的一个或多时域向量。本申请对于终端设备指示P个时域向量的具体顺序和方法不作限定。
终端设备在通过该第一指示信息来指示与该P个时域向量对应的P个时域系数时，可以通过该P个时域系数的量化值指示，也可以通过量化值的索引指示，或者也可以通过其他方式指示，本申请对于时域系数的指示方式不作限定，只要网络设备根据该第一指示信息可以确定该P个时域系数即可。在本申请实施例中，为方便说明，将用于指示时域系数的信息称为时域系数的量化信息。该量化信息例如可以是量化值、索引或者其他任何可用于指示时域系数的信息。
在一种实现方式中，终端设备可以通过归一化方式来指示该P个时域系数。例如，终端设备可以从该P个时域系数中确定模最大的时域系数(例如记作最大时域系数)，并指示该最大时域系数在P个时域系数所对应的P个时域向量中所处的位置。终端设备可进一步指示其余的P-1个时域系数相对于该最大时域系数的相对值。终端设备可以通过各相对值的量化值索引来指示上述P-1个时域系数。例如，网络设备和终端设备可以预先定义多个量化值与多个索引的一一对应关系，终端设备可以基于该一一对应关系，将上述各时域系数相对于最大时域系数的相对值反馈给网络设备。由于终端设备对各时域系数进行了量化，量化值与真实值可能相同或相近，故称为时域系数的量化值。
应理解，上文列举的通过归一化方式来指示各时域系数的方式仅为一种可能的实现方式，而不应对本申请构成任何限定。本申请对于终端设备指示时域系数的具体方式不作限定。
还应理解，该第一指示信息在用于指示P个时域系数时，可通过直接或间接的方式来指示。例如，对于最大时域系数，可以指示其在P个时域系数中的位置；又例如，对于量化值为零的时域系数，也可以指示其在P个时域系数中的位置。换句话说，该第一指示信息并不一定指示了P个时域系数中的每一个系数。只要网络设备可以根据第一指示信息恢复出P个时域系数即可。
在步骤330中，终端设备发送该第一指示信息。相应地，网络设备接收该第一指示信息。
终端设备例如可以通过物理上行资源，如物理上行共享信道(physical uplink share channel，PUSCH)或物理上行控制信道(physical uplink control channel，PUCCH)，向网络设备发送该第一指示信息。该第一指示信息例如可以携带在信道状态信息(channel state information，CSI)报告(简称CSI)中，或者也可以携带在其他信令中。本申请对此不作限定。
终端设备通过物理上行资源向网络设备发送对指示信息的具体方法可以与现有技术相同，为了简洁，这里省略对该具体过程的详细说明。
如前所述，该P个时域向量及其对应的时域系数用于网络设备恢复下行信道。当终端设备基于双域压缩的反馈方式确定与空频向量对对应的空频系数随时间的变化规律时，该终端设备还可以将用于确定时域向量及其对应的时域系数的空频向量对上报给网络设备。
终端设备向网络设备指示的空频向量对可以是上述K个空频向量对，也可以包括上述K个空频向量对。本申请对此不作限定。
若终端设备基于双域压缩的反馈方式向网络设备指示的空频向量对包括了除上述K个空频向量对之外的一个或多个空频向量对，例如，终端设备基于双域压缩的反馈方式反馈了K’个空频向量对，K’＞K，K’为整数。则网络设备和终端设备可以预设规则，从该K’个空频向量对中选择K个空频向量对来确定P个时域向量及其对应的时域系数。例如，K值可以由网络设备确定，该K个空频向量对可以是该K’个空频向量对中较强的K个空频向量对，该K’个空频向量对中，未被选择的K’－K个空频向量对中任意一个空频向量对对应的空频系数的幅值小于或等于该K个空频向量对中任意一个空频向量对对应的空频系数的幅值。又例如，K值可以由终端设备自行确定。该K个空频向量对可以是该K’个空频向量对中幅值大于或等于预设门限的空频向量对。
应理解，上文列举的用于确定K个空频向量对的预设规则仅为示例，不应对本申请构成任何限定。本申请对于K个空频向量对与K’个空频向量对的具体关系不作限定。
当然，终端设备也可以通过另外向网络设备上报上述K个空频向量对。可选地，该方法还包括：终端设备发送第五指示信息，该第五指示信息用于指示K个空频向量对。相应地，网络设备接收该第五指示信息，该第五指示信息用于指示K个空频向量对。应理解，该K个空频向量对是用于确定上述一个或多个时域向量及其对应的时域系数的空频向量对。
还应理解，该第五指示信息与上文所述的第一指示信息可以携带在相同的信令中，如CSI报告；也可以携带在不同的信令中，例如可以是已有或新增的信令。本申请对此不作限定。
当第五指示信息与第一指示信息携带在相同的信令中时，该发送第五指示信息的步骤可以与步骤330合为同一步骤，即，终端设备可以通过发送同一信令，将第一指示信息和第五指示信息发送给网络设备。当第五指示信息与第一指示信息携带在不同的信令中时，该发送第五指示信息与步骤330可以是不同的步骤。
如前所述，网络设备发送的参考信号可以是未经过预编码的参考信号，也可以是预编码参考信号。基于网络设备发送的参考信号的不同，终端设备的处理方式也略有不同。
可选地，该第五指示信息具体指示该K个空频向量对。
如果网络设备发送的参考信号是未经过预编码的参考信号，终端设备可以先基于接收到的参考信号确定K’个空频向量对，该K’个空频向量对的加权和可用于构建空频矩阵。终端设备可以从该K’个空频向量对中选择K个空频向量对，该K个空频向量对可以终端设备确定的K’个空频向量对中的部分或全部空频向量对。终端设备可以在多个测量时刻测量并记录被选择的K个空频向量对对应的空频系数，以得到上述K个空频系数向量，进而确定P个时域向量及其对应的时域系数。
该第五指示信息对该K个空频向量对的指示例如可以包括用于组合得到该K个空频向量对中的空域向量在空域向量集合中的索引以及用于组合得到该K个空频向量对中的频域向量在频域向量集合中的索引；该第五指示信息对该K个空频向量对的指示例如也可以包括用于组合得到该K个空频向量对的多个空域向量的组合在空域向量集合中的索引以及用于组合得到该K个空频向量对的多个频域向量的组合在频域向量集合中的索引。
应理解，该终端设备指示K个空频向量对的具体方法可以参考现有技术对双域压缩反馈方式中对空频向量对的指示方法。本申请对于终端设备指示K个空频向量对的具体方法不作限定。
可选地，该第五指示信息具体指示该K个空频向量对对应的端口。
如果网络设备发送的参考信号是预编码参考信号，该预编码参考信号例如可以是基于空域向量和频域向量对参考信号做预编码得到，也可以是基于角度向量和时延向量对参考信号做预编码得到。经过预编码得到的参考信号可对应K’个端口，该K’个端口可以与K’个空频向量对一一对应，也可以与K’个角度时延对一一对应。终端设备可以基于接收到的K’个端口的预编码参考信号确定与各端口对应的空频系数，并根据各端口对应的空频系数，从该K’个端口中选择K个端口。终端设备可以在多个测量时刻测量并记录被选择的K个端口对应的空频系数，以得到上述K个空频系数向量，进而确定P个时域向量及其对应的时域系数。
应理解，该第五指示信息对该K个端口的指示例如可以包括该K个端口的端口号。本申请对于终端设备指示K个端口的具体方法不作限定。
在步骤340中，网络设备根据该第一指示信息确定该一个或多个分量特征以及每个分量特征的加权系数。
网络设备在接收到该第一指示信息之后，可以根据该第一指示信息确定上文所述的P个时域向量及其对应的时域系数。网络设备解读该第一指示信息的过程与终端设备生成该第一指示信息的过程是相对应的。终端设备可以按照双方可以预先约定的方式，或者按照预定义的方式，生成第一指示信息；网络设备也可以按照相同的方式解读该第一指示信息。
由于上文步骤310中已经详细说明了终端设备生成第一指示信息的具体过程，网络设备根据该第一指示信息确定P个时域向量及其对应的时域系数的具体过程与之相对应，为了简洁，这里不再赘述。
基于上述方案，终端设备可以将信道的时变特征通过一个或多个分量特征的加权和近似地表示，并将分量特征和加权系数的量化信息反馈给网络设备。因此，网络设备可以确定信道在时域的变化，也就能够更全面地了解信道的状态，从而为下行调度做出更合理的决策。
在一个可能的示例中，网络设备可以基于终端设备反馈的时变特征，确定用于下行传输的预编码矩阵。
可选地，该方法还包括步骤350，网络设备根据该一个或多个分量特征以及每个分量特征的加权系数，确定预编码矩阵。
网络设备在确定了P个时域向量及其对应的时域系数之后，便可以恢复出K个空频向量对的空频系数向量，也就是可以确定K个空频向量对在N个测量时刻分别对应的空频系数。可以理解的是，网络设备根据P个时域向量及其对应的时域系数所恢复的空频系数向量是上文所述的空频系数向量的估计值。如前所述，该P个时域向量的加权和可以近似地恢复出上述空频系数向量。
若该P个时域向量及其对应的时域系数是由一个空频向量对对应的空频系数向量确定的，即，K＝1。则由该P个时域向量的加权和恢复出该空频向量对的空频系数向量的估计值。
以步骤310所述的空频向量对(u l，v m)为例，该P个时域向量的加权和为
Figure PCTCN2020090551-appb-000023
即，
Figure PCTCN2020090551-appb-000024
或者，该P个时域向量的加权和也可以通过矩阵运算的方式来表示，如：
Figure PCTCN2020090551-appb-000025
或
Figure PCTCN2020090551-appb-000026
或其他等价的数学变换。本申请对此不作限定。其中，
Figure PCTCN2020090551-appb-000027
表示c l,m的估计值，以与终端设备实际测量确定的空频系数向量c l,m区分。
Figure PCTCN2020090551-appb-000028
表示由上文所述的P个索引(如p 1、p 2和p 3)和向量d l,m确定的时域系数，
Figure PCTCN2020090551-appb-000029
表示由上文所述的P个索引和矩阵U t确定的向量，其中i＝1，2，……，P。
Figure PCTCN2020090551-appb-000030
可以是由上文所述的P个索引和向量d l,m确定的向量，
Figure PCTCN2020090551-appb-000031
可以是由上文所述的P个索引和矩阵U t确定的矩阵。假设P＝3，则：
Figure PCTCN2020090551-appb-000032
以上文所列举的p 1＝1、p 2＝4、p 3＝8为例，可以得到：
Figure PCTCN2020090551-appb-000033
上文以K＝1为例详细说明了网络设备基于P个时域向量及其对应的时域系数确定一个空频向量对的空频系数向量的估计值的具体过程。当然，网络设备也可以基于该P个时域向量及其对应的时域系数确定多个空频向量对的空频系数向量的估计值。即，K＞1。
在K＞1的情况下，网络设备首先可以确定P个时域向量及其对应的时域系数中，与每个空频向量对对应的一个或多个时域向量以及一个或多个时域系数。例如，对于第k个空频向量对，网络设备可以确定P k个时域向量及其对应的时域系数。基于第k个空频向量对确定的P k个时域向量及其对应的时域系数可用于确定第k个空频向量对对应的空频系数向量的估计值。其具体过程与上文所述K＝1的情况下网络设备确定空频系数向量的估计值的具体过程相同，为了简洁，这里不再赘述。
假设网络设备基于P个时域向量及其对应的时域系数所确定的空频系数向量均为长度为N的向量，则网络设备可以确定K个空频向量对在N个测量时刻中每个测量时刻对应的空频系数。网络设备也就可以基于该K个空频向量对以及每个空频向量对对应的空频系数向量，进一步构建每个测量时刻的空频矩阵。应理解，由此而确定的空频矩阵是空频矩阵的估计值，为了与上文所述的终端设备基于信道测量确定的空频矩阵H区分，这里将空频矩阵的估计值用
Figure PCTCN2020090551-appb-000034
表示。
例如，网络设备可以基于该K个空频向量对以及每个空频向量对的空频系数向量，确定N个测量时刻中任意一个测量时刻的空频矩阵。如，第n个测量时刻的空频矩阵可以表示为
Figure PCTCN2020090551-appb-000035
其中，
Figure PCTCN2020090551-appb-000036
表示第l个空域向量u l和第m个频域向量v m组合得到的空频向量对所对应的空频系数向量
Figure PCTCN2020090551-appb-000037
中的第n个元素，且
Figure PCTCN2020090551-appb-000038
网络设备可以在第N个测量时刻之后基于该空频矩阵确定用于下行数据传输的预编码矩阵。网络设备根据该空频矩阵确定预编码矩阵的具体方法在上文中已经做了简单说 明，具体可以参考现有技术。为了简洁，这里不再赘述。
事实上，网络设备基于P个时域向量及其对应的时域系数并不限于确定该N个测量时刻的空频矩阵，或者说，预编码矩阵。基于上文所确定的P个时域向量及其对应的时域系数，网络设备还可以进一步预测未来时刻的空频矩阵或者预编码矩阵。
在一种实现方式中，网络设备可以根据K个空频向量对的空频系数向量预测未来时刻的空频系数向量，然后根据预测的空频系数向量确定未来时刻的空频矩阵。在另一种实现方式中，网络设备可以先通过该K个空频向量对的空频系数向量确定N个测量时刻的空频矩阵，然后基于该N个测量时刻的空频矩阵预测未来时刻的空频矩阵。
在一种可能的实现方式中，网络设备可以使用自回归(autoregressive model，AR)模型进行信道预测。根据NR协议38.901，时变信道的历史信道与后续信道有相关性，其相关性可以表征为几个缓慢变化或不变的系数。即，任意一个时刻的信道可以表示为前几个时刻信道的特定系数(如，下式中的β 1，β 2，……，β E)的加权系数。根据如下公式，网络设备可以通过已知的空频系数预测未来的空频系数，然后预测后续信道。
以空频向量对(u l，v m)对应的N个时域系数
Figure PCTCN2020090551-appb-000039
Figure PCTCN2020090551-appb-000040
为例，
Figure PCTCN2020090551-appb-000041
其中1≤E≤N，且E为整数。
基于上述方法，网络设备可以预测N个测量时刻之后的任意时刻的信道。例如
Figure PCTCN2020090551-appb-000042
其中，
Figure PCTCN2020090551-appb-000043
便是未来某一时刻的信道所匹配的空频向量对(u l，v m)的空频系数。具体实现时，也可以将上式中
Figure PCTCN2020090551-appb-000044
的替换为
Figure PCTCN2020090551-appb-000045
具体实现方式与上文所述相似，为了简洁，这里不再赘述。
应理解，上文仅为便于理解，示出了网络设备预测未来时刻的信道的可能的实现方式，但这不应对本申请构成任何限定。基于相同的构思，本领域的技术人员可以基于不同的算法来预测信道，本申请对于网络设备预测信道的具体实现方式不作限定。
网络设备在预测出未来时刻的空频矩阵之后，便可以确定该时刻用于下行传输的预编码矩阵。由此而确定的预编码矩阵考虑到了信道的时变特性，能够很好地与下行信道相适配。
与此对应，如果终端设备基于双域压缩的反馈方式来确定用于下行传输的预编码矩阵，则可能会面临CSI过期的问题。为便于理解，这里结合图4详细说明基于现有的CSI反馈流程进行CSI反馈的过程以及所面临的CSI过期问题。
图4是本申请实施例提供的基于双域压缩的反馈方式进行CSI反馈的示意性流程图。如图4所示，网络设备在时刻1发送参考信号，终端设备在接收到该参考信号之后，可以在时刻2进行信道测量和反馈。由于网络设备发送参考信号可能是周期性、非周期性或半持续的，也就是说，网络设备上一次发送参考信号与下一次发送参考信号之间可能间隔了一段时间。如图4所示，网络设备在时刻3进行下一次参考信号的发送，终端设备在时刻4基于下一次发送的参考信号进行信道测量和反馈。可以看到，从时刻1至时刻2，经历了时间间隔t1，从时刻2至时刻4，经历了时间间隔t2。在时间间隔t2中，网络设备进行下行传输所使用的预编码矩阵都是基于时刻2接收到的反馈而确定的。然而，信道在时间 间隔t2可能已经发生了变化，如果直接用基于时刻2的反馈而确定的预编码矩阵来对此后的下行传输做预编码，该预编码矩阵可能已经不能够与下行信道很好地适配，由此可能造成传输性能的下降。这种由于信道随时间发生变化导致基于反馈而确定的预编码矩阵无法与真实的信道匹配的情况称为CSI过期。换句话说，当信道随时间变化较快时，CSI过期可能会引起传输性能的显著下降。
与此相对应地，在本申请实施例中，终端设备基于网络设备在多个不同时刻发送的参考信号进行信道测量，并将信道随时间的变化通过时域向量的加权和量化后反馈给网络设备。网络设备可以基于信道随时间的变化，预测未来时刻的信道，进而确定与之相适配的预编码矩阵。因此，缓解了CSI过期带来的传输性能下降的问题，有利于提高系统性能。
为了更好地理解本申请实施例带来的有益效果，图5示出了基于不同的反馈方式而构造的不同时刻的信道对应的预编码矩阵与真实信道对应的预编码矩阵之间的相关性。图5是本申请实施例提供的效果仿真图。图5是基于如下假设仿真得到：网络设备的发射天线数为64、终端设备的接收天线数为1、载波频率为3.5GHz、子载波间隔30kHz、带宽为50个资源块(resource block，RB)、终端设备的移动速度为30千米每小时(km/h)。图中横轴表示时间间隔，单位为时隙；图中纵轴表示相关系数，用于表征基于不同的反馈方式而构造的信道对应的预编码矩阵与真实信道对应的预编码矩阵之间的相关性。
图中三角形连接而成的曲线是真实信道对应的预编码矩阵与真实信道对应的预编码矩阵的相关系数，可以理解，该相关系数始终为1。图中菱形连接而成的曲线是基于本申请实施例所提供的信道测量方法而构造(或者说预测)得到的不同时刻的信道对应的预编码矩阵与真实信道对应的预编码矩阵之间的相关系数(为方便区分，例如记作相关系数1)。图中星形连接而成的曲线是基于现有技术中终端设备上一次反馈而构造的信道对应的预编码矩阵与真实信道对应的预编码矩阵之间的相关系数(为便于区分，例如记作相关系数2)。可以看到，随着时间的延续，相关系数1表现出高于相关系数2的趋势。也就是说，相比于现有技术中终端设备上一次反馈而确定的预编码矩阵而言，基于本申请实施例所提供的方法来预测未来信道进而确定的预编码矩阵能够与真实的信道更加匹配，从而缓解了CSI过期带来的性能传输下降的问题，有利于提高系统性能。
应理解，图5中示出的仿真曲线以及假设条件仅为便于理解本申请实施例而示例，不应对本申请构成任何限定。
还应理解，上文实施例仅为便于理解，以双域压缩为例来说明终端设备确定时变特征的P个分量特征及其对应的时域系数的具体过程以及网络设备根据反馈确定该P个分量特征及其对应的加权系数的具体过程，但这不应对本申请构成任何限定。例如，终端设备也可以基于type II码本的反馈方式来确定时变特征的分量特征及其加权系数。此情况下，终端设备可以假设用来恢复预编码矩阵的波束向量不变，基于波束向量的宽带幅度系数或子带系数随时间的变化来确定信道的时变特征的P个分量特征及其对应的加权系数。基于终端设备所确定的P个分量特征及其对应的加权系数，网络设备可以近似恢复出预编码矩阵。为了简洁，本申请中不一一举例详述。
还应理解，上文仅为示例，仅仅示出了终端设备基于一个极化方向、一个传输层确定P个分量特征及其对应的加权系数的具体过程。但这不应对本申请构成任何限定。当发射天线的极化方向数为多个时，或者，当传输层数大于1时，或者，当接收天线数大于1时， 终端设备可以基于上文所述相同的方法来确定一个或多个分量特征及其对应的加权系数。与此对应，网络设备也可以基于上文所述相同的方法来恢复信道，以确定预编码矩阵。
以上，结合图2至图5详细说明了本申请实施例提供的方法。以下，结合图6至图8详细说明本申请实施例提供的装置。
图6是本申请实施例提供的通信装置的示意性框图。如图6所示，该通信装置1000可以包括处理单元1100和收发单元1200。
在一种可能的设计中，该通信装置1000可对应于上文方法实施例中的终端设备，例如，可以为终端设备，或者配置于终端设备中的芯片。
具体地，该通信装置1000可对应于根据本申请实施例的方法300中的终端设备，该通信装置1000可以包括用于执行图3中的方法300中终端设备执行的方法的单元。并且，该通信装置1000中的各单元和上述其他操作和/或功能分别为了实现图3中的方法300的相应流程。
其中，当该通信装置1000用于执行图3中的方法300时，处理单元1100可用于执行方法300中的步骤310，收发单元1200可用于执行方法300中的步骤320和步骤330。应理解，各单元执行上述相应步骤的具体过程在上述方法实施例中已经详细说明，为了简洁，在此不再赘述。
还应理解，该通信装置1000为终端设备时，该通信装置1000中的收发单元1200可对应于图7中示出的终端设备2000中的收发器2020，该通信装置1000中的处理单元1100可对应于图7中示出的终端设备2000中的处理器2010。
还应理解，该通信装置1000为配置于终端设备中的芯片时，该通信装置1000中的收发单元1200可以为输入/输出接口。
在另一种可能的设计中，该通信装置1000可对应于上文方法实施例中的网络设备，例如，可以为网络设备，或者配置于网络设备中的芯片。
具体地，该通信装置1000可对应于根据本申请实施例的方法300中的网络设备，该通信装置1000可以包括用于执行图3中的方法300中网络设备执行的方法的单元。并且，该通信装置1000中的各单元和上述其他操作和/或功能分别为了实现图3中的方法300的相应流程。
其中，当该通信装置1000用于执行图3中的方法300时，处理单元1100可用于执行方法300中的步骤340和步骤350，收发单元1200可用于执行方法300中的步骤320和步骤330。应理解，各单元执行上述相应步骤的具体过程在上述方法实施例中已经详细说明，为了简洁，在此不再赘述。
还应理解，该通信装置1000为网络设备时，该通信装置1000中的收发单元为可对应于图8中示出的基站3000中的RRU 3100，该通信装置1000中的处理单元1100可对应于图8中示出的基站3000中的BBU 3200或处理器3202。
还应理解，该通信装置1000为配置于网络设备中的芯片时，该通信装置1000中的收发单元1200可以为输入/输出接口。
图7是本申请实施例提供的终端设备2000的结构示意图。该终端设备2000可应用于如图1所示的系统中，执行上述方法实施例中终端设备的功能。如图所示，该终端设备2000包括处理器2010和收发器2020。可选地，该终端设备2000还包括存储器2030。其 中，处理器2010、收发器2020和存储器2030之间可以通过内部连接通路互相通信，传递控制和/或数据信号，该存储器2030用于存储计算机程序，该处理器2010用于从该存储器2030中调用并运行该计算机程序，以控制该收发器2020收发信号。可选地，终端设备2000还可以包括天线2040，用于将收发器2020输出的上行数据或上行控制信令通过无线信号发送出去。
上述处理器2010可以和存储器2030可以合成一个处理装置，处理器2010用于执行存储器2030中存储的程序代码来实现上述功能。具体实现时，该存储器2030也可以集成在处理器2010中，或者独立于处理器2010。该处理器2010可以与图6中的处理单元1100对应。
上述收发器2020可以与图6中的收发单元1200对应，也可以称为收发单元。收发器2020可以包括接收器(或称接收机、接收电路)和发射器(或称发射机、发射电路)。其中，接收器用于接收信号，发射器用于发射信号。
应理解，图7所示的终端设备2000能够实现图3所示方法实施例中涉及终端设备的各个过程。终端设备2000中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详细描述。
上述处理器2010可以用于执行前面方法实施例中描述的由终端设备内部实现的动作，而收发器2020可以用于执行前面方法实施例中描述的终端设备向网络设备发送或从网络设备接收的动作。具体请见前面方法实施例中的描述，此处不再赘述。
可选地，上述终端设备2000还可以包括电源2050，用于给终端设备中的各种器件或电路提供电源。
除此之外，为了使得终端设备的功能更加完善，该终端设备2000还可以包括输入单元2060、显示单元2070、音频电路2080、摄像头2090和传感器2100等中的一个或多个，所述音频电路还可以包括扬声器2082、麦克风2084等。
图8是本申请实施例提供的网络设备的结构示意图，例如可以为基站的结构示意图。该基站3000可应用于如图1所示的系统中，执行上述方法实施例中网络设备的功能。如图所示，该基站3000可以包括一个或多个射频单元，如远端射频单元(remote radio unit，RRU)3100和一个或多个基带单元(BBU)(也可称为分布式单元(DU))3200。所述RRU 3100可以称为收发单元，与图6中的收发单元1200对应。可选地，该收发单元还可以称为收发机、收发电路、或者收发器等等，其可以包括至少一个天线3101和射频单元3102。可选地，收发单元可以包括接收单元和发送单元，接收单元可以对应于接收器(或称接收机、接收电路)，发送单元可以对应于发射器(或称发射机、发射电路)。所述RRU 3100部分主要用于射频信号的收发以及射频信号与基带信号的转换，例如用于向终端设备发送指示信息。所述BBU 3200部分主要用于进行基带处理，对基站进行控制等。所述RRU 3100与BBU 3200可以是物理上设置在一起，也可以物理上分离设置的，即分布式基站。
所述BBU 3200为基站的控制中心，也可以称为处理单元，可以与图6中的处理单元1100对应，主要用于完成基带处理功能，如信道编码，复用，调制，扩频等等。例如所述BBU(处理单元)可以用于控制基站执行上述方法实施例中关于网络设备的操作流程， 例如，生成上述指示信息等。
在一个示例中，所述BBU 3200可以由一个或多个单板构成，多个单板可以共同支持单一接入制式的无线接入网(如LTE网)，也可以分别支持不同接入制式的无线接入网(如LTE网，5G网或其他网)。所述BBU 3200还包括存储器3201和处理器3202。所述存储器3201用以存储必要的指令和数据。所述处理器3202用于控制基站进行必要的动作，例如用于控制基站执行上述方法实施例中关于网络设备的操作流程。所述存储器3201和处理器3202可以服务于一个或多个单板。也就是说，可以每个单板上单独设置存储器和处理器。也可以是多个单板共用相同的存储器和处理器。此外每个单板上还可以设置有必要的电路。
应理解，图8所示的基站3000能够实现图3所示方法实施例中涉及网络设备的各个过程。基站3000中的各个模块的操作和/或功能，分别为了实现上述方法实施例中的相应流程。具体可参见上述方法实施例中的描述，为避免重复，此处适当省略详细描述。
上述BBU 3200可以用于执行前面方法实施例中描述的由网络设备内部实现的动作，而RRU 3100可以用于执行前面方法实施例中描述的网络设备向终端设备发送或从终端设备接收的动作。具体请见前面方法实施例中的描述，此处不再赘述。
应理解，图8所示出的基站3000仅为网络设备的一种可能的架构，而不应对本申请构成任何限定。本申请所提供的方法可适用于其他架构的网络设备。例如，包含CU、DU和有源天线单元(active antenna unit，AAU)的网络设备等。本申请对于网络设备的具体架构不作限定。
本申请实施例还提供了一种处理装置，包括处理器和接口；所述处理器用于执行上述方法实施例中的方法。
应理解，上述处理装置可以是一个或多个芯片。例如，该处理装置可以是现场可编程门阵列(field programmable gate array，FPGA)，可以是专用集成芯片(application specific integrated circuit，ASIC)，还可以是系统芯片(system on chip，SoC)，还可以是中央处理器(central processor unit，CPU)，还可以是网络处理器(network processor，NP)，还可以是数字信号处理电路(digital signal processor，DSP)，还可以是微控制器(micro controller unit，MCU)，还可以是可编程控制器(programmable logic device，PLD)或其他集成芯片。
在实现过程中，上述方法的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。结合本申请实施例所公开的方法的步骤可以直接体现为硬件处理器执行完成，或者用处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。为避免重复，这里不再详细描述。
应注意，本申请实施例中的处理器可以是一种集成电路芯片，具有信号的处理能力。在实现过程中，上述方法实施例的各步骤可以通过处理器中的硬件的集成逻辑电路或者软件形式的指令完成。上述的处理器可以是通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现场可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。可以实现或者执行本申请实施例中的公开的各方法、步骤 及逻辑框图。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器，处理器读取存储器中的信息，结合其硬件完成上述方法的步骤。
可以理解，本申请实施例中的存储器可以是易失性存储器或非易失性存储器，或可包括易失性和非易失性存储器两者。其中，非易失性存储器可以是只读存储器(read-only memory，ROM)、可编程只读存储器(programmable ROM，PROM)、可擦除可编程只读存储器(erasable PROM，EPROM)、电可擦除可编程只读存储器(electrically EPROM，EEPROM)或闪存。易失性存储器可以是随机存取存储器(random access memory，RAM)，其用作外部高速缓存。通过示例性但不是限制性说明，许多形式的RAM可用，例如静态随机存取存储器(static RAM，SRAM)、动态随机存取存储器(dynamic RAM，DRAM)、同步动态随机存取存储器(synchronous DRAM，SDRAM)、双倍数据速率同步动态随机存取存储器(double data rate SDRAM，DDR SDRAM)、增强型同步动态随机存取存储器(enhanced SDRAM，ESDRAM)、同步连接动态随机存取存储器(synchlink DRAM，SLDRAM)和直接内存总线随机存取存储器(direct rambus RAM，DR RAM)。应注意，本文描述的系统和方法的存储器旨在包括但不限于这些和任意其它适合类型的存储器。
根据本申请实施例提供的方法，本申请还提供一种计算机程序产品，该计算机程序产品包括：计算机程序代码，当该计算机程序代码在计算机上运行时，使得该计算机执行图3所示实施例中的方法。
根据本申请实施例提供的方法，本申请还提供一种计算机可读介质，该计算机可读介质存储有程序代码，当该程序代码在计算机上运行时，使得该计算机执行图3所示实施例中的方法。
根据本申请实施例提供的方法，本申请还提供一种系统，其包括前述的一个或多个终端设备以及一个或多个网络设备。
上述各个装置实施例中网络设备与终端设备和方法实施例中的网络设备或终端设备完全对应，由相应的模块或单元执行相应的步骤，例如通信单元(收发器)执行方法实施例中接收或发送的步骤，除发送、接收外的其它步骤可以由处理单元(处理器)执行。具体单元的功能可以参考相应的方法实施例。其中，处理器可以为一个或多个。
在本说明书中使用的术语“部件”、“模块”、“系统”等用于表示计算机相关的实体、硬件、固件、硬件和软件的组合、软件、或执行中的软件。例如，部件可以是但不限于，在处理器上运行的进程、处理器、对象、可执行文件、执行线程、程序和/或计算机。通过图示，在计算设备上运行的应用和计算设备都可以是部件。一个或多个部件可驻留在进程和/或执行线程中，部件可位于一个计算机上和/或分布在2个或更多个计算机之间。此外，这些部件可从在上面存储有各种数据结构的各种计算机可读介质执行。部件可例如根据具有一个或多个数据分组(例如来自与本地系统、分布式系统和/或网络间的另一部件交互的二个部件的数据，例如通过信号与其它系统交互的互联网)的信号通过本地和/或远程进程来通信。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各种说明性逻辑块(illustrative logical block)和步骤(step)，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的系统、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
在上述实施例中，各功能单元的功能可以全部或部分地通过软件、硬件、固件或者其任意组合来实现。当使用软件实现时，可以全部或部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令(程序)。在计算机上加载和执行所述计算机程序指令(程序)时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络、或者其他可编程装置。所述计算机指令可以存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网站站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线(digital subscriber line，DSL))或无线(例如红外、无线、微波等)方式向另一个网站站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质或者是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是磁性介质，(例如，软盘、硬盘、磁带)、光介质(例如，高密度数字视频光盘(digital video disc，DVD))、或者半导体介质(例如固态硬盘(solid state disk，SSD))等。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (46)

  1. 一种信道测量方法，其特征在于，包括：
    终端设备生成第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；
    所述终端设备向网络设备发送所述第一指示信息。
  2. 如权利要求1所述的方法，其特征在于，所述时变特征由所述终端设备基于多次接收到的参考信号确定。
  3. 如权利要求1或2所述的方法，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  4. 如权利要求3所述的方法，其特征在于，至少两个分量特征基于不同的码本确定。
  5. 如权利要求1至4中任一项所述的方法，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  6. 如权利要求1至5中任一项所述的方法，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  7. 一种信道测量方法，其特征在于，包括：
    网络设备接收第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；
    所述网络设备根据所述第一指示信息确定所述一个或多个分量特征以及每个分量特征的加权系数。
  8. 如权利要求7所述的方法，其特征在于，所述时变特征由终端设备基于多次接收到的参考信号确定。
  9. 如权利要求7或8所述的方法，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  10. 如权利要求9所述的方法，其特征在于，至少两个分量特征基于不同的码本确定。
  11. 如权利要求7至10中任一项所述的方法，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下中的一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  12. 如权利要求7至11中任一项所述的方法，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  13. 一种通信装置，其特征在于，包括：
    处理单元，用于生成第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；
    收发单元，用于发送所述第一指示信息。
  14. 如权利要求13所述的装置，其特征在于，所述时变特征由所述处理单元基于多次接收到的参考信号确定。
  15. 如权利要求13或14所述的装置，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  16. 如权利要求15所述的装置，其特征在于，至少两个分量特征基于不同的码本确定。
  17. 如权利要求13至16中任一项所述的装置，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  18. 如权利要求13至17中任一项所述的装置，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  19. 一种通信装置，其特征在于，包括：
    收发单元，用于接收第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；
    处理单元，用于根据所述第一指示信息确定所述一个或多个分量特征以及每个分量特征的加权系数。
  20. 如权利要求19所述的装置，其特征在于，所述时变特征由终端设备基于多次接收到的参考信号确定。
  21. 如权利要求18或19所述的装置，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  22. 如权利要求21所述的装置，其特征在于，至少两个分量特征基于不同的码本确定。
  23. 如权利要求19至22中任一项所述的装置，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下中的一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  24. 如权利要求19至23中任一项所述的装置，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  25. 一种通信装置，其特征在于，包括：
    处理器，用于用于生成第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征 的加权系数用于表征信道的时变特征；
    收发器，用于发送所述第一指示信息。
  26. 如权利要求25所述的装置，其特征在于，所述时变特征由所述处理器基于多次接收到的参考信号确定。
  27. 如权利要求25或26所述的装置，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  28. 如权利要求27所述的装置，其特征在于，至少两个分量特征基于不同的码本确定。
  29. 如权利要求25至28中任一项所述的装置，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  30. 如权利要求25至29中任一项所述的装置，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  31. 一种通信装置，其特征在于，包括：
    收发器，用于接收第一指示信息，所述第一指示信息用于指示时变特征的一个或多个分量特征以及每个分量特征的加权系数，所述一个或多个分量特征以及每个分量特征的加权系数用于表征信道的时变特征；
    处理器，用于根据所述第一指示信息确定所述一个或多个分量特征以及每个分量特征的加权系数。
  32. 如权利要求31所述的装置，其特征在于，所述时变特征由终端设备基于多次接收到的参考信号确定。
  33. 如权利要求31或32所述的装置，其特征在于，所述第一指示信息在用于指示所述时变特征的一个或多个分量特征时，具体指示每个分量特征所对应的时域向量在预定义的码本中的索引。
  34. 如权利要求33所述的装置，其特征在于，至少两个分量特征基于不同的码本确定。
  35. 如权利要求31至34中任一项所述的装置，其特征在于，所述一个或多个分量特征基于预定义的一个或多个码本确定，所述一个或多个码本取自预定义的码本集合，所述码本集合中的每个码本与以下中的一项或多项的取值对应：测量时长，导频时域密度，导频传输次数和导频传输周期。
  36. 如权利要求31至35中任一项所述的装置，其特征在于，所述时变特征的分量特征为多普勒频移，所述分量特征的加权系数为多普勒系数。
  37. 一种处理装置，其特征在于，包括至少一个处理器，所述至少一个处理器用于执行如权利要求1至6中任一项所述的方法。
  38. 一种处理装置，其特征在于，包括至少一个处理器，所述至少一个处理器用于执行如权利要求7至12中任一项所述的方法。
  39. 一种处理装置，其特征在于，包括：
    通信接口，用于输入和/或输出信息；
    处理器，用于执行计算机程序，以使得所述装置实现如权利要求1至6中任一项所述的方法。
  40. 一种处理装置，其特征在于，包括：
    通信接口，用于输入和/或输出信息；
    处理器，用于执行计算机程序，以使得所述装置实现如权利要求7至12中任一项所述的方法。
  41. 一种处理装置，其特征在于，包括：
    存储器，用于存储计算机程序；
    处理器，用于从所述存储器调用并运行所述计算机程序，以使得所述装置实现如权利要求1至6中任一项所述的方法。
  42. 一种处理装置，其特征在于，包括：
    存储器，用于存储计算机程序；
    处理器，用于从所述存储器调用并运行所述计算机程序，以使得所述装置实现如权利要求7至12中任一项所述的方法。
  43. 一种计算机可读存储介质，其特征在于，包括计算机程序，当所述计算机程序在计算机上运行时，使得所述计算机执行如权利要求1至6中任一项所述的方法。
  44. 一种计算机可读存储介质，其特征在于，包括计算机程序，当所述计算机程序在计算机上运行时，使得所述计算机执行如权利要求7至12中任一项所述的方法。
  45. 一种计算机程序产品，所述计算机程序产品包括计算机程序，当所述计算机程序在计算机上运行时，使得计算机执行如权利要求1至6中任一项所述的方法。
  46. 一种计算机程序产品，所述计算机程序产品包括计算机程序，当所述计算机程序在计算机上运行时，使得计算机执行如权利要求7至12中任一项所述的方法。
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CN112054825A (zh) 2020-12-08
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CN112054825B (zh) 2022-05-10
US20220094412A1 (en) 2022-03-24
EP3968533A1 (en) 2022-03-16

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