WO2019157757A1 - 通信方法、通信装置和系统 - Google Patents

通信方法、通信装置和系统 Download PDF

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Publication number
WO2019157757A1
WO2019157757A1 PCT/CN2018/076904 CN2018076904W WO2019157757A1 WO 2019157757 A1 WO2019157757 A1 WO 2019157757A1 CN 2018076904 W CN2018076904 W CN 2018076904W WO 2019157757 A1 WO2019157757 A1 WO 2019157757A1
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WIPO (PCT)
Prior art keywords
vectors
base vectors
matrix
base
vector
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PCT/CN2018/076904
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English (en)
French (fr)
Inventor
任海豹
祝慧颖
李元杰
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to EP18906647.5A priority Critical patent/EP3751768A4/en
Priority to PCT/CN2018/076904 priority patent/WO2019157757A1/zh
Priority to CN201880089204.3A priority patent/CN111713054B/zh
Publication of WO2019157757A1 publication Critical patent/WO2019157757A1/zh
Priority to US16/991,590 priority patent/US11184208B2/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
    • H04B7/0413—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
    • H04B17/00—Monitoring; Testing
    • H04B17/30—Monitoring; Testing of propagation channels
    • H04B17/309—Measuring or estimating channel quality parameters
    • 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
    • H04B7/0634—Antenna weights or vector/matrix coefficients
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
    • H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H04L27/2613—Structure of the reference signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2634—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2626—Arrangements specific to the transmitter only
    • H04L27/2627—Modulators
    • H04L27/2634—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
    • H04L27/2636—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation with FFT or DFT modulators, e.g. standard single-carrier frequency-division multiple access [SC-FDMA] transmitter or DFT spread orthogonal frequency division multiplexing [DFT-SOFDM]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2649—Demodulators
    • H04L27/26524—Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation

Definitions

  • the present application relates to the field of wireless communications and, more particularly, to communication methods, communication devices and systems.
  • pre-coding can reduce interference between multiple users and interference between multiple signal streams of the same user, which is beneficial to improve Signal quality, space division multiplexing, and improved spectrum utilization.
  • a method for determining a precoding matrix is known.
  • the receiving device feeds back channel state information (CSI) according to the received reference signal, and the transmitting device can determine the pre-determination according to the two-level feedback of the receiving device.
  • Encoding matrix In the first-level feedback, the receiving end device may determine a preferred one or more beam vectors by traversing multiple orthogonal beam vectors in the first-level codebook. In the first-level feedback, the same selection may be performed on each sub-band.
  • One or more beam vectors that is, the first level feedback may be wideband feedback; in the second level feedback, the receiving end device may independently feedback the amplitude and phase on each subband, which may be separately performed on each subband The amplitude and phase in the second level codebook are traversed to determine that the amplitude and phase selected on the different subbands may be different, so the second level feedback may be subband feedback.
  • the present application provides a communication method, a communication apparatus, and a system, which can reduce the complexity of measurement of a receiving end device.
  • a communication method comprising:
  • the CSI is used to indicate a set of measurement values, the set of measured values is used to determine a precoding matrix, or the set of measured values is the precoding matrix, and the set of measured values includes one or Multiple measured values;
  • the measured value is related to the first set of base vectors and the second set of base vectors, or the measured values are related to the Kronecker product of the first set of base vectors and the second set of base vectors
  • the first set of basis vectors comprises an inverse discrete Fourier transform IDFT vector or a Kronecker product of two IDFT vectors, the second base vector comprising a discrete Fourier transform DFT vector.
  • the set of measured values may include one or more measured values, each measured value corresponding to one antenna port group, so the number of measured values included in the set of measured values may be the number of antenna port groups.
  • the measured value includes R columns, each of which has a dimension of (N T ⁇ N SB ) ⁇ 1; or, the measured value includes R matrices, and each matrix has a dimension of N.
  • T ⁇ N SB N T is the number of antennas in one antenna port group
  • N SB is the number of frequency domain units transmitting the reference signal
  • R is determined by the number of antennas receiving the reference signal or the rank of the channel matrix
  • p ⁇ 1, N T ⁇ 1, N SB ⁇ 1, R ⁇ 1, N T , N SB , R are positive integers.
  • the measured value is related to the first set of base vectors and the second set of base vectors, or the measured values are related to the first set of base vectors and the second set of base vectors
  • the Kronecker product correlation may be implemented by the measurement matrix set based on the first set of base vectors and the second set of base vectors on the channel matrix processing, or may be based on the first set of basis vectors and the second set of basis vector pairs Precoding matrix processing is implemented. This is equivalent to mathematically transforming the channel matrix or the precoding matrix and transmitting it to the network device through the CSI.
  • the network device can determine the precoding matrix from the set of measurements according to the received CSI indication.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may determine the measurement based on the CSI.
  • the value determines the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the method further comprises:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the network device may configure the first set of base vectors, the second set of base vectors, or the Kronecker product of the two sets of base vectors for the terminal device.
  • the method further comprises:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the terminal device feeds back the first set of base vectors, the second set of base vectors, or the Kronecker product of the two sets of base vectors to the network device.
  • a communication method including:
  • the CSI is used to indicate a set of measurement values, the set of measured values is used to determine a precoding matrix, or the set of measured values is the precoding matrix, and the set of measured values includes one or a plurality of measurements; wherein the measurements are related to the first set of base vectors and the second set of base vectors, or the measurements are related to the first set of base vectors and the second set of base vectors Necker product correlation; wherein the first set of basis vectors comprises an inverse discrete Fourier transform IDFT vector or a Kronecker product of two IDFT vectors, the second base vector comprising a discrete Fourier transform DFT Vector
  • the signal is precoded according to a precoding matrix determined by the measured value, and the precoded signal is transmitted.
  • the set of measured values may include one or more measured values, each measured value corresponding to one antenna port group, so the number of measured values included in the set of measured values may be the number of antenna port groups.
  • the measured value includes R columns, each column has a dimension of (N T ⁇ N SB ) ⁇ 1; or, the measured value includes (N SB ⁇ R) columns, each The dimension of the column is N T ⁇ 1; N T is the number of antennas in one antenna port group, N SB is the number of frequency domain units transmitting the reference signal, and R is the number of antennas receiving the reference signal or the rank of the channel matrix It is determined that p ⁇ 1, N T ⁇ 1, N SB ⁇ 1, R ⁇ 1, N T , N SB , and R are positive integers.
  • the measured value is related to the first set of base vectors and the second set of base vectors, or the measured values are related to the first set of base vectors and the second set of base vectors.
  • the Kronecker product correlation can be achieved by processing the channel matrix based on the first set of basis vectors and the second set of basis vectors, or by precoding the matrix based on the first set of basis vectors and the second set of basis vectors. Processing to achieve. This is equivalent to mathematically transforming the channel matrix or the precoding matrix and transmitting it to the network device through the CSI. Therefore, the network device can determine the precoding matrix from the measured values according to the received CSI indication.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may determine the measurement based on the CSI.
  • the value determines the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the method further includes:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the network device may configure the first set of base vectors, the second set of base vectors, or the Kronecker product of the two sets of base vectors for the terminal device.
  • the method further includes:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the terminal device feeds back the first set of base vectors, the second set of base vectors, or the Kronecker product of the two sets of base vectors to the network device.
  • the first set of base vectors is defined by a protocol
  • the second set of basis vectors are defined by a protocol; or,
  • the first set of base vectors and the second set of base vectors are defined by a protocol
  • the Kronecker product of the first set of base vectors and the second set of base vectors is defined by a protocol.
  • the Kronecker product of the first set of basis vectors, the second set of basis vectors, or two sets of basis vectors can also be defined by a protocol.
  • the specific method for the terminal device to obtain the first set of base vectors, the second set of base vectors, or the Kronecker product of the two sets of base vectors is not limited, for example, may be defined by a network device or may be Definitions, such as protocol definitions, can also be fed back by the terminal device.
  • the measured value includes R columns, and the nth column y n of the R columns satisfies:
  • ⁇ is a normalization coefficient
  • M is the number of base vectors
  • M base vectors are M columns in the Kronecker product of the first set of base vectors and the second set of base vectors
  • I the i-th column vector of the M base vectors
  • the dimension is N T ⁇ N SB ⁇ 1, for Linear superposition coefficient, for Amplitude factor, for The phase coefficient
  • N T is the number of transmitting antenna ports of the reference signal
  • N SB is the number of frequency domain units included in the frequency domain resource for transmitting the reference signal
  • R is the number of receiving antenna ports or channels of the reference signal
  • the rank of the matrix is determined, 1 ⁇ i ⁇ M, 1 ⁇ R, i, M, and R are integers.
  • the nth column vector may be any one of R column vectors.
  • any nth column vector of the R column vectors satisfies the above formula (condition), ie, Since the dimensions of each column in a measurement are based on an antenna port group.
  • the M base vectors in each column vector, the M amplitude coefficients corresponding to the M base vectors, and the M phase coefficients corresponding to the M base vectors may be indicated by CSI. That is, the CSI may include R group indication information, and each group indication information indicates one or more of the following: M base vectors, M amplitude coefficients corresponding to M base vectors, or M phase coefficients corresponding to M base vectors .
  • the R group indication information corresponding to the R columns may be fed back independently of each other, or may be fed back in a differential manner.
  • the M base vectors, the M amplitude coefficients corresponding to the M base vectors, and the M phase coefficients corresponding to the M base vectors are all fed back by the terminal device, for the R columns
  • a column can be indicated by M basis vectors, M absolute amplitudes, and M absolute phases
  • the remaining (R-1) columns can be indicated by M basis vectors, M relative amplitudes, and M relative phases. This application does not limit this.
  • the CSI includes one or more of the following:
  • Indication information of M base vectors corresponding to the rth column of the R columns indication information of M amplitude coefficients corresponding to the M base vectors, or M corresponding to the M base vectors The indication of the phase coefficient.
  • the CSI is used to indicate one or more of the following:
  • one column vector can be constructed by one or more of the enumerated above.
  • a precoding matrix of dimension N T ⁇ (N SB ⁇ R) can be obtained.
  • the indication information of the M base vectors corresponding to the rth column includes: the M base vectors corresponding to the rth column The position of each base vector in a pre-configured matrix, the pre-configured matrix being the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the M basis vectors corresponding to the rth column may be indicated by positions in the Kronecker product of the first set of base vectors and the second set of base vectors (that is, the pre-configured matrix described above).
  • the M column vectors determined by the pre-configured matrix are also the M basis vectors used to construct the above measured values.
  • the indication information of the M base vectors corresponding to the rth column includes: the M column vectors corresponding to the rth column The position of each column vector in the first set of base vectors and the position in the second set of base vectors.
  • the M base vectors corresponding to the rth column may be determined by a position in the first set of base vectors and a position indication in the second set of base vectors, and a column vector sum determined by the first set of base vectors
  • a column vector determined from the second set of basis vectors obtains a basis vector for constructing the above measured values by the Kronecker product.
  • the value of M is indicated by the network device or by a protocol.
  • the measured value includes R matrices, and the nth matrix Y n of the R matrices satisfies:
  • ⁇ is a normalization coefficient
  • M B is the number of first base vectors
  • M T is the number of second base vectors
  • M B first base vectors are M B columns in the first set of base vectors
  • M T second basis vectors are M T columns in the second set of base vectors
  • Dimension is a t- th second base vector of the M T second base vectors corresponding to the n-th matrix
  • the dimension is N SB ⁇ 1, For linear superposition coefficients, For the amplitude coefficient, Is the phase coefficient.
  • the nth matrix described above may be any one of R matrices.
  • any nth matrix of the R matrices satisfies the above formula (condition), ie, Since one measurement is based on one antenna port, the dimension of each matrix Y can be N T ⁇ N SB .
  • the M B first base vectors, M T second base vectors, M B ⁇ M T amplitude coefficients, and M B ⁇ M T phase coefficients in each matrix may be indicated by CSI. That is, the CSI may include R group indication information, and each group indication information indicates one or more of the following: M B first basis vectors, M T second basis vectors, M B ⁇ M T amplitude coefficients, or M B ⁇ M T phase coefficients.
  • the R group indication information corresponding to the R matrices may be fed back independently of each other, or may be fed back in a differential manner, which is not limited in this application.
  • the CSI includes one or more of the following:
  • the first column indicates the number M B of the information vector includes a number M B of the first row first column vector of each vector position in said first set of column vectors
  • the second M T The indication information of the column vector includes the position of each of the M T second column vectors in the second set of column vectors.
  • a terminal device having the function of implementing the terminal device in the method design of the above first aspect. These functions can be implemented in hardware or in software by executing the corresponding software.
  • the hardware or software includes one or more units corresponding to the functions described above.
  • a network device having the function of implementing the network device in the method design of the second aspect above.
  • These functions can be implemented in hardware or in software by executing the corresponding software.
  • the hardware or software includes one or more units corresponding to the functions described above.
  • a terminal device including a transceiver, a processor, and a memory.
  • the processor is configured to control a transceiver transceiver signal for storing a computer program, the processor for calling and running the computer program from the memory, such that the terminal device performs any one of the first aspect or the first aspect described above The method in the implementation.
  • a network device including a transceiver, a processor, and a memory.
  • the processor is configured to control a transceiver transceiver signal for storing a computer program, the processor for calling and running the computer program from the memory, such that the network device performs any one of the second aspect or the second aspect described above The method in the implementation.
  • a communication device which may be a terminal device in the above method design, or a chip disposed in the terminal device.
  • the communication device includes a processor coupled to the memory for executing instructions in the memory to implement the method performed by the terminal device in any of the possible implementations of the first aspect or the first aspect.
  • the communication device further comprises a memory.
  • the communication device further includes a communication interface, the processor being coupled to the communication interface.
  • a communication device which may be a network device in the above method design, or a chip disposed in a network device.
  • the communication device includes a processor coupled to the memory for executing instructions in the memory to implement the method performed by the network device in any one of the possible implementations of the second aspect or the second aspect.
  • the communication device further comprises a memory.
  • the communication device further includes a communication interface, the processor being coupled to the communication interface.
  • a computer program product comprising: computer program code, when the computer program code is run on a computer, causing the computer to perform the method of the above aspects.
  • a computer readable medium storing program code for causing a computer to perform the method of the above aspects when the computer program code is run on a computer.
  • a chip system comprising a processor for supporting a terminal device to implement the functions involved in the above aspects, for example, generating, receiving, transmitting, or processing data involved in the above method And / or information.
  • the chip system further comprises a memory for storing necessary program instructions and data of the terminal device.
  • the chip system can be composed of chips, and can also include chips and other discrete devices.
  • a chip system comprising a processor for supporting a network device to implement the functions involved in the above aspects, for example, generating, receiving, transmitting, or processing data involved in the above method And / or information.
  • the chip system further comprises a memory for storing necessary program instructions and data of the terminal device.
  • the chip system can be composed of chips, and can also include chips and other discrete devices.
  • FIG. 1 is a schematic diagram of a communication system suitable for the communication method of the embodiment of the present application.
  • FIG. 2 is a schematic flowchart of a communication method provided by an embodiment of the present application.
  • FIG. 3 is a schematic diagram of a plurality of antenna ports disposed on a plurality of antenna panels
  • FIG. 4 is a schematic block diagram of a communication apparatus according to an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of a terminal device according to an embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of a network device according to an embodiment of the present application.
  • GSM Global System of Mobile communication
  • CDMA Code Division Multiple Access
  • WCDMA Wideband Code Division Multiple Access
  • GPRS General Packet Radio Service
  • LTE Long Term Evolution
  • FDD Frequency Division Duplex
  • TDD Time Division Duplex
  • UMTS Universal Mobile Telecommunication System
  • WiMAX Worldwide Interoperability for Microwave Access
  • 5G fifth generation
  • 5G new radio access technology
  • the communication system 100 includes a network device 102, which may include multiple antennas, such as antennas 104, 106, 108, 110, 112, and 114.
  • the plurality of antennas included in the network device 102 may be divided into multiple antenna groups, and each antenna group may include one or more antennas.
  • one antenna group may include antennas 104 and 106, and another antenna group Antennas 108 and 110 may be included, and yet another antenna group may include antennas 112 and 114.
  • FIG. 1 are only for ease of understanding, and the case where six antennas are divided into three antenna groups is shown. However, this should not constitute any limitation to the present application, and the network device 102 may include more or less. Antennas, antennas included in network device 102 may be divided into more or fewer antenna groups, each antenna group may include more or fewer antennas.
  • network device 102 may additionally include a transmitter chain and a receiver chain, as will be understood by those of ordinary skill in the art, which may include various components related to signal transmission and reception, such as processors, modulators, multiplexers , demodulator, demultiplexer or antenna.
  • the network device in the communication system may be any device with a wireless transceiver function or a chip that can be disposed on the device, including but not limited to: an evolved Node B (eNB), wireless Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), and home base station (for example, Home evolved NodeB) , or Home Node B, HNB), BaseBand Unit (BBU), Access Point (AP) in Wireless Fidelity (WIFI) system, wireless relay node, wireless backhaul node, Transmission point (TP) or transmission and reception point (TRP), etc., can also be 5G, such as NR, gNB in the system, or transmission point (TRP or TP), in 5G system
  • a network node constituting a gNB or transmission point such as a baseband unit (BBU), or a distributed unit (distribute) d unit, DU),
  • the gNB may include a centralized unit (CU) and a DU.
  • the gNB may also include a radio unit (RU).
  • the CU implements some functions of the gNB, and the DU implements some functions of the gNB.
  • the CU implements radio resource control (RRC), the function of the packet data convergence protocol (PDCP) layer, and the DU implements the wireless chain.
  • RRC radio resource control
  • PDCP packet data convergence protocol
  • the DU implements the wireless chain.
  • the functions of the radio link control (RLC), the media access control (MAC), and the physical (PHY) layer Since the information of the RRC layer eventually becomes information of the PHY layer or is transformed by the information of the PHY layer, high-level signaling, such as RRC layer signaling or PHCP layer signaling, can also be used in this architecture.
  • the network device can be a CU node, or a DU node, or a device including a CU node and a DU node.
  • the CU may be divided into network devices in the access network RAN, and the CU may be divided into network devices in the core network, which is not limited in this application.
  • Network device 102 can communicate with a plurality of terminal devices, for example, network device 102 can communicate with terminal device 116 and terminal device 122. It will be appreciated that network device 102 can communicate with any number of terminal devices similar to terminal device 116 or 122.
  • the terminal equipment in the communication system may also be referred to as user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal. , terminal, wireless communication device, user agent or user device.
  • the terminal device in the embodiment of the present application may be a mobile phone, a tablet, a computer with a wireless transceiver function, a virtual reality (VR) terminal device, and an augmented reality (AR) terminal.
  • Equipment wireless terminals in industrial control, wireless terminals in self driving, wireless terminals in remote medical, wireless terminals in smart grid, transportation security ( A wireless terminal in a transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, and the like.
  • the embodiment of the present application does not limit the application scenario.
  • the foregoing terminal device and a chip that can be disposed in the foregoing terminal device are collectively referred to as a terminal device.
  • terminal device 116 is in communication with antennas 112 and 114, wherein antennas 112 and 114 transmit signals to terminal device 116 over forward link 118 and receive signals from terminal device 116 over reverse link 120.
  • terminal device 122 is in communication with antennas 104 and 106, wherein antennas 104 and 106 transmit signals to terminal device 122 over forward link 124 and receive signals from terminal device 122 over reverse link 126.
  • forward link 118 may utilize a different frequency band than reverse link 120
  • forward link 124 may utilize a different frequency band than reverse link 126.
  • the forward link 118 and the reverse link 120 can use a common frequency band, and the forward link 124 and the reverse link 126 can be used in common. frequency band.
  • Each set of antennas and/or regions designed for communication may be referred to as a sector of network device 102.
  • the antenna group can be designed to communicate with terminal devices in sectors of the network device 102 coverage area.
  • the transmit antenna of network device 102 may utilize beamforming to improve the signal to noise ratio of forward links 118 and 124.
  • the network device 102 uses beamforming to transmit signals to the randomly dispersed terminal devices 116 and 122 in the relevant coverage area, the network device 102 uses a single antenna to transmit signals to all of its terminal devices. Mobile devices are subject to less interference.
  • network device 102, terminal device 116, or terminal device 122 may be a wireless communication transmitting device and/or a wireless communication receiving device.
  • the wireless communication transmitting device can encode the data for transmission.
  • the wireless communication transmitting device may acquire a certain number of data bits to be transmitted to the wireless communication receiving device through a channel, for example, the wireless communication transmitting device may generate, receive from another communication device, or save in a memory, etc., to be transmitted through a channel.
  • a certain number of data bits to the wireless communication receiving device may be included in a transport block or a plurality of transport blocks of data, and the transport blocks may be segmented to produce a plurality of code blocks.
  • the communication system 100 may be a public land mobile network PLMN network or a device to device (D2D) network or a machine to machine (M2M) network or other network, and FIG. 1 is merely an example for convenience of understanding.
  • PLMN public land mobile network
  • D2D device to device
  • M2M machine to machine
  • FIG. 1 is merely an example for convenience of understanding.
  • a simplified schematic diagram of the network may include other network devices and more or fewer terminal devices, which are not shown in FIG.
  • the network device 102 and the terminal device 116 or 122 can employ MIMO technology for wireless communication.
  • MIMO technology refers to using a plurality of transmitting antennas and receiving antennas respectively at the transmitting end device and the receiving end device, so that signals are transmitted and received through multiple antennas of the transmitting end device and the receiving end device, thereby improving communication quality. It can make full use of space resources and achieve multiple transmission and reception through multiple antennas. It can multiply the system channel capacity without increasing spectrum resources and antenna transmission power.
  • MIMO can be divided into single-user MIMO (SU-MIMO) and multi-user MIMO (MU-MIMO).
  • SU-MIMO single-user MIMO
  • MU-MIMO multi-user MIMO
  • Massive MIMO arranges hundreds of antennas at the transmitting end, modulates the respective beams for dozens of target receivers, and transmits dozens of signals simultaneously on the same frequency resource through spatial signal isolation. Therefore, Massive MIMO technology can make full use of the spatial freedom brought by large-scale antenna configuration to improve spectrum efficiency.
  • interference between multiple users and interference between multiple layers (or streams) of the same user can be reduced by precoding.
  • the precoding may be performed by pre-processing the signal to be transmitted at the transmitting end device in the case of a known channel state, that is, processing the signal to be transmitted by means of a precoding matrix matching the channel state, so that the pre-coding is performed.
  • the encoded signal to be transmitted is adapted to the channel, so that the complexity of the influence of the inter-channel interference is reduced by the receiving device. Therefore, the received signal quality (for example, signal to interference plus noise ratio (SINR)) is improved by precoding processing of the transmitted signal.
  • SINR signal to interference plus noise ratio
  • the pre-coding can realize that the transmitting end device and the multiple receiving end devices transmit on the same time-frequency resource, that is, MU-MIMO is implemented.
  • precoding may also be performed by other means (for example, if the channel matrix cannot be known)
  • the precoding is performed by using a pre-set precoding matrix or a weighting processing method, and the details are not described herein.
  • the receiving end device may perform channel measurement according to the reference signal sent by the sending end device to determine a precoding matrix that is adapted to the channel state, and feed back to the transmitting device.
  • a method for determining a precoding matrix is known.
  • the receiving device measures and feeds back channel state information (CSI) according to the received reference signal, and the transmitting device can determine the pre-determination according to the feedback of the receiving device.
  • Encoding matrix may be divided into two levels of feedback. In the first level feedback, the receiving end device may determine one or more preferred ones by traversing multiple orthogonal beam vectors in the first level codebook.
  • the beam vector is fed back, that is, the same beam vector can be selected on each sub-band, so the first-stage feedback can be broadband feedback; in the second-stage feedback, the receiving device can independently feedback the amplitude and phase on each sub-band. This can be determined by traversing the amplitude and phase in the second-level codebook on each sub-band separately, that is, the amplitude and phase selected on different sub-bands may be different, so the second-level feedback may be sub- With feedback.
  • the network device can determine the precoding matrix according to the first level feedback and the second level feedback.
  • the present application provides a communication method to reduce the complexity of channel measurement of the receiving end device, thereby reducing the power consumption of the receiving end device.
  • the first, second, third, etc. are merely for facilitating the differentiation of different objects, and should not be construed as limiting the application.
  • different base vectors, different matrices, different indication information, and the like are distinguished.
  • An antenna port can be understood as a transmitting antenna that is recognized by a receiving device or a spatially distinguishable transmitting antenna.
  • One antenna port is configured for each virtual antenna, and each virtual antenna may be a weighted combination of multiple physical antennas, and each antenna port may correspond to one reference signal port.
  • pre-acquisition may include being indicated by network device signaling or predefined, such as a protocol definition.
  • pre-definition may be implemented by pre-storing corresponding codes, tables, or other manners that can be used to indicate related information in the device (for example, including the terminal device and the network device), and the present application does not perform the specific implementation manner. limited.
  • “save” as used in the embodiments of the present application may refer to being stored in one or more memories.
  • the one or more memories may be separate arrangements or integrated in an encoder or decoder, processor, or communication device.
  • the one or more memories may also be partially provided separately, and some of them may be integrated in a decoder, a processor, or a communication device.
  • the type of the memory may be any form of storage medium, which is not limited herein.
  • protocol in the embodiment of the present application may refer to a standard protocol in the field of communication, for example, may include an LTE protocol, an NR protocol, and a related protocol applied in a future communication system, which is not limited in this application.
  • the technical solution of the present application can be applied to a wireless communication system, for example, the communication system 100 shown in FIG. 1, the communication system can include at least one network device and at least one terminal device, and the network device and the terminal device can communicate through the wireless air interface.
  • the network device in the communication system may correspond to the network device 102 shown in FIG. 1
  • the terminal device may correspond to the terminal device 116 or 122 shown in FIG.
  • the terminal device may be any terminal device that has a wireless connection relationship with the network device in the wireless communication system. It should be understood that the network device can communicate with a plurality of terminal devices having a wireless connection relationship in the wireless communication system based on the same technical solution. This application does not limit the number of terminal devices or the number of network devices.
  • FIG. 2 is a schematic flowchart of a communication method 200 according to an embodiment of the present application, which is shown from the perspective of device interaction. As shown in FIG. 2, the method 200 can include steps 210 through 230.
  • step 210 the network device transmits a reference signal.
  • step 210 the terminal device receives the reference signal.
  • the reference signal sent by the network device can be used for downlink channel measurement.
  • the reference signal may include a channel state information-reference signal (CSI-RS).
  • CSI-RS channel state information-reference signal
  • the functions may be, for example, a downlink demodulation reference signal (DMRS), a tracking reference signal (TRS), a phase tracking reference signal (PTRS), and the like.
  • network devices can be configured with multiple antenna ports.
  • the network device can transmit the reference signal through the configured multiple antenna ports, so that the terminal device performs downlink channel measurement and CSI feedback.
  • the plurality of antenna ports may be divided into one or more antenna port groups.
  • one or more antenna ports may be included in each antenna port group.
  • the network device can be configured with one or more antenna panels, each antenna panel can be configured with one or more antenna port groups, each antenna port group including one or more antenna ports.
  • FIG. 3 shows a schematic diagram of a plurality of antenna ports arranged in a plurality of antenna panels. Specifically, a schematic diagram in which a plurality of antenna ports are arranged in two antenna panels is shown in FIG. Each antenna panel is configured with 8 antenna ports, and each of the figures represents two antenna ports of different polarization directions. Therefore, each antenna panel shown in FIG. 3 is configured with four antenna ports.
  • antenna port 0 and antenna port 1 may be antenna ports of the same polarization direction, for example, a horizontal polarization direction, which may correspond to an identical beam vector (or precoding vector), for example, b 1 ; antenna port 4 and antenna port 5 may be antenna ports of the same polarization direction, for example, a vertical polarization direction, which may correspond to another identical beam vector, such as b 2 .
  • antenna port 2 and antenna port 3 may correspond to beam vector b 1
  • antenna port 6 and antenna port 7 may correspond to beam vector b 2 .
  • the b 1 and b 2 may be two orthogonal discrete Fourier Transform (IDFT) vectors, or may be mathematical vectors that characterize the spatial electromagnetic wave characteristics. It is not particularly limited.
  • IDFT discrete Fourier Transform
  • each antenna port can be understood as a transmit antenna recognized by the receiving device or a spatially distinguishable transmit antenna.
  • One antenna port is configured for each virtual antenna, and each virtual antenna may be a weighted combination of multiple physical antennas, and each antenna port corresponds to one reference signal. In the embodiment of the present application, each antenna port may correspond to one reference signal port used for channel measurement.
  • one antenna port may correspond to one CSI-RS port used for downlink channel measurement.
  • the antenna port may also be referred to as a CSI-RS port;
  • one antenna port may also correspond to an SRS port for uplink channel measurement, and the antenna port may also be referred to as an SRS port.
  • FIG. 3 is only a schematic diagram for ease of understanding and should not be construed as limiting the application.
  • the antenna panel may be configured with more antenna ports, or the network device may be configured with fewer or more antenna panels, which is not specifically limited in this embodiment of the present application.
  • grouping the antenna ports based on the antenna panel is only one possible implementation, or a possible grouping rule, and should not constitute any limitation to the present application.
  • the present application is directed to the grouping rules of the antenna port group. Not limited.
  • the network device may send a reference signal to the terminal device through one or more antenna port groups. Since different antenna port groups correspond to different polarization directions, the network device can transmit reference signals based on different polarization directions, so that complete channel measurement results can be obtained.
  • the number of antenna ports may be indicated in an explicit or implicit manner.
  • the method further includes: the information that the network device sends the number of the antenna ports.
  • the method further includes: receiving, by the terminal device, information of the number of antenna ports.
  • the information about the number of antenna ports may be carried in higher layer signaling or physical layer signaling.
  • higher layer signaling may include, for example, an RRC message or a MAC CE.
  • physical layer signaling may include, for example, downlink control information.
  • the downlink control information may be, for example, DCI (downlink control information) in the LTE protocol or the NR protocol, or may be other signaling that can be used to carry downlink control information transmitted in the physical downlink control channel.
  • DCI downlink control information
  • NR NR protocol
  • the physical downlink control channel mentioned herein may be a PDCCH (physical downlink control channel) defined in the LTE protocol or the NR protocol, an enhanced physical downlink control channel (EPDCCH), or an NR.
  • PDCCH physical downlink control channel
  • EPDCCH enhanced physical downlink control channel
  • NR NR
  • the number of antenna ports may be predefined, for example, a protocol definition.
  • the configuration information of the antenna port group may be indicated in an explicit or implicit manner.
  • the method further includes: the network device sends the configuration information of the antenna port group, where the configuration information of the antenna port group can be used to indicate the antenna.
  • the number of port groups is a configurable period of time.
  • the configuration information of the foregoing antenna port group may be carried in high layer signaling or physical layer signaling.
  • the high-level signaling and physical layer signaling are respectively illustrated in the above, and are not described here for brevity.
  • the configuration information of the antenna port group may also be used to indicate information such as a port number, a polarization direction, and the like of an antenna port included in each antenna port group.
  • the number of the antenna ports may be predefined, for example, a protocol definition.
  • the network device and the terminal device may further determine a port number of the antenna port included in each antenna port group according to a predefined grouping rule.
  • the preset grouping rule may include: determining an antenna port with an odd port number as one antenna port group, and determining an antenna port with an even port number as another antenna port group; or, according to the antenna port number ascending or descending order, the antenna ports 2N T N T before the port number corresponding to the antenna port determined to be a group antenna port, the other port is determined as the port number corresponding to N T antennas Antenna port group.
  • the configuration information of the antenna port group can be indicated by an explicit and implicit combination.
  • the network device indicates the number of antenna port groups by signaling, and the terminal device and the network device determine the port number of the antenna port included in each antenna port group based on a predefined grouping rule.
  • the terminal device can know the number of antenna port groups used by the network device to transmit the reference signal and the number of antenna ports included in each antenna port group. It should be understood that the method for indicating the configuration information of the antenna port group is only exemplified, and the present application is not limited to the present application. The specific method for obtaining the configuration information of the antenna port group is not limited.
  • the method further includes:
  • the network device sends the location information of the time-frequency resource of the reference signal.
  • the location information of the time-frequency resource of the reference signal can be determined, for example, by a pilot pattern.
  • the method further includes:
  • the period and subframe offset of the reference signal can be used to determine the time domain location of the reference signal.
  • the method further includes:
  • the network device transmits location information of the start resource block RB of the reference signal and/or information of the number of RBs.
  • the location information of the start RB of the reference signal and/or the quantity information of the RB may be used to determine the frequency domain location of the reference signal and/or the size of the occupied frequency domain resource.
  • the location of the starting RB of the reference signal may be determined, for example, by an offset from a bandwidth portion (BWP) of the terminal device.
  • BWP bandwidth portion
  • the location information of the time-frequency resource of the reference signal enumerated, the configuration information of the period and the subframe offset, the location information of the initial RB, and/or the quantity information of the RB may be referred to as configuration information of the reference signal.
  • the foregoing configuration information is indicated by the high layer signaling or the physical layer signaling, and may also be indicated by a combination of the high layer signaling and the physical layer signaling, and may be indicated by the same signaling or by different signaling instructions.
  • the detailed description of the indication manner of the configuration information is omitted here.
  • the manner of indicating the configuration information is not limited in this application.
  • step 220 the terminal device transmits CSI.
  • step 220 the network device receives the CSI.
  • the CSI can be used to indicate a set of measurement values.
  • the set of measurements can include one or more measurements. Each measurement corresponds to an antenna port group for transmitting a reference signal.
  • the measured value is related to the first set of base vectors and the second set of base vectors, or the measured value and the Kronecker product of the first set of base vectors and the second set of base vectors Correlation may be achieved by processing the channel matrix based on the first set of base vectors and the second set of base vectors, or by precoding matrix processing based on the first set of base vectors and the second set of base vectors.
  • the terminal device may perform channel estimation according to the received reference signal to obtain a channel matrix, and further obtain a precoding matrix based on the channel matrix, for example, perform singular value decomposition (SVD) on the channel matrix. Assuming the channel matrix is H, SVD is obtained for the channel matrix:
  • U and V H are ⁇ matrices
  • S is a diagonal matrix
  • its non-zero elements ie, elements on the diagonal
  • These singular values can usually be in descending order arrangement.
  • the conjugate transpose V of the right chirp matrix V H is a precoding matrix.
  • the precoding matrix is the precoding matrix calculated from the channel matrix H.
  • the method for determining the precoding matrix by the SVD in the above example is only one possible implementation manner, and should not constitute any limitation on the embodiments of the present application.
  • the network device may also determine a precoding matrix by using a minimum mean square error (MMSE), zero-forcing (ZF), maximum ratio combining (MRC) receiver algorithm.
  • MMSE minimum mean square error
  • ZF zero-forcing
  • MRC maximum ratio combining
  • the precoding matrix determined based on the method for determining the precoding matrix enumerated above may be the same as or may be similar to the precoding matrix actually used in the signal processing.
  • the precoding matrix determined based on the methods enumerated above can be understood as an ideal precoding matrix.
  • the channel measurement is performed based on the reference signal to obtain a channel matrix, or a precoding matrix is further obtained. Therefore, the measured value may be related to the channel matrix, or the measured value may be related to the precoding matrix.
  • the terminal device indicates the measured value to the network device through the CSI, so that the network device determines the precoding matrix according to the measured value.
  • the network device may directly use the measured value as a precoding matrix, or may perform transform processing on the measured value to obtain a precoding matrix. The specific process of determining the precoding matrix by the measured value will be described in detail below with reference to specific embodiments.
  • the measurement value is illustrated by taking an antenna port group as an example, and the antenna port group may be one of a plurality of antenna port groups for transmitting a reference signal.
  • the measured value may include R columns, each column having a dimension of (N T ⁇ N SB ) ⁇ 1; or, the measured value includes R matrices, each matrix having a dimension of N T ⁇ N SB .
  • N T is the number of antennas in one antenna port group
  • N SB is the number of frequency domain units transmitting the reference signal
  • R is determined by the number of antennas receiving the reference signal or the rank of the channel matrix
  • p ⁇ 1, N T ⁇ 1, N SB ⁇ 1, R ⁇ 1, N T , N SB , and R are positive integers.
  • the measured value may be related to the first set of base vectors and the second set of base vectors, or the measured values may be related to the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the terminal device may process the channel matrix based on at least the first set of base vectors and the second set of base vectors, or may process the precoding matrix based on the first set of base vectors and the second set of base vectors, or The first set of base vectors and the second set of base vectors can be used to transform the channel matrix or the precoding matrix.
  • the first set of base vectors may include a plurality of column vectors, each of the plurality of column vectors may be an IDFT vector, or may be a Kronecker product of two IDFT vectors;
  • the base vector may include a plurality of discrete Fourier Transform (DFT) vectors.
  • DFT discrete Fourier Transform
  • the first set of base vectors may include a plurality of column vectors, and each of the plurality of column vectors may be any one of the following:
  • an IDFT vector for example, the mth (0 ⁇ m ⁇ N-1) basis vectors included in the set of base vectors may be N (N ⁇ 1 and N is a positive integer) dimensional IDFT vector, the IDFT vector Mathematical expressions can be, for example: or
  • the mathematical expression can be, for example: N-1 remaining elements
  • the mathematical expression can be, for example: or
  • the first N wiki vector in the IDCT vector may be
  • the mth N wiki vector can be or
  • the Kronecker product is a direct product of two matrices, that is, all the elements in one matrix are multiplied by a matrix of another matrix, for example, a matrix A of k ⁇ l dimension and a Kronecker of matrix B of p ⁇ q dimension Find the matrix of kp ⁇ lq dimension by product
  • the terminal device may acquire the first group base vector and the second group base vector in advance.
  • the first group base vector and the second group base vector may be predefined, for example, a protocol definition, or may be configured by the network device to the terminal device, or may be a terminal device to the network device. Feedback. This application does not limit this. If the first set of base vectors and the second set of base vectors are configured by the network device to the terminal device, the first set of base vectors and the second set of base vectors may be indicated by the same signaling, or may be through different letters. The instructions are given, and the application does not limit this.
  • the network device and the terminal device may pre-store a plurality of sets of column vectors that can be used as the first set of base vectors (for convenience of distinction and description, for example, As a first set) and a plurality of sets of column vectors that can be used as the second set of base vectors (for convenience of distinction and illustration, for example, as a second set).
  • the first set may include a one-to-one correspondence between multiple sets of base vectors and multiple indexes, and each set of base vectors in the multiple sets of base vectors may be a matrix of dimension N T ⁇ N 1 .
  • Each column vector in each set of base vectors may be not completely orthogonal, that is, a non-orthogonal basis vector, or may be completely orthogonal, that is, an orthogonal basis vector.
  • the orthogonal basis vector may be a complete orthogonal basis vector, or may be a non-complete orthogonal basis vector, wherein the complete orthogonal basis vector satisfies: linearly combining the orthogonal basis vectors for any vector of the same dimension Characterization.
  • the second set may include a one-to-one correspondence between the plurality of sets of base vectors and the plurality of indexes, and each set of base vectors in the plurality of sets of base vectors may be a matrix having a dimension of N SB ⁇ N 2 .
  • the method further includes:
  • the network device sends indication information of the first set of base vectors
  • the network device sends indication information of the second set of base vectors.
  • the plurality of sets of base vectors may be in one-to-one correspondence with the plurality of indexes; in the second set, the plurality of sets of base vectors may also correspond to the plurality of indexes one-to-one.
  • the network device may separately send an index of the first set of base vectors and an index of the second set of base vectors to the terminal device by signaling.
  • the method further includes:
  • the network device transmits indication information of the first set of base vectors and the second set of base vectors.
  • the combination of a set of base vectors in the first set and a set of base vectors in the second set may correspond to an index. Therefore, the network device can indicate the first group base vector and the second group base vector through an index by means of joint coding.
  • the network device may indicate the first set of base vectors and the second set of base vectors to the terminal device through the bitmap, and each bit in the bitmap may correspond to a set of base vectors. For example, when the bit position in the bitmap is "0", it indicates that the corresponding set of base vectors is not the first set of base vectors or the second set of base vectors; when the bit position in the bitmap is "1", the corresponding A set of basis vectors is a first set of base vectors or a second set of base vectors.
  • the specific method for the network device to indicate the first group of base vectors and the second group of base vectors to the terminal device may be implemented by a method in the prior art, and details are not described herein for brevity. It should also be understood that the above list is only a few possible implementations and should not be construed as limiting the application.
  • the network device may predetermine the first group base vector and the second group base vector before indicating the first group base vector and the second group base vector to the terminal device.
  • the first group of base vectors is determined based on the SRS or DMRS sent by the terminal device. For example, estimating the reciprocal uplink channel according to SRS or DMRS, and performing feature decomposition to obtain a feature matrix, and finding a base with the smallest distance from the feature matrix from the set of pre-stored sets of base vectors to obtain the first group base Vector; or, by traversing the set of the plurality of sets of basis vectors, determining the first set of basis vectors based on a capacity maximization criterion, a signal to interference and noise ratio (SINR) maximization criterion, or other criteria.
  • SINR signal to interference and noise ratio
  • the terminal device may indicate the first set of base vectors and the second set of base vectors by CSI.
  • the network device and the terminal device may pre-store a plurality of sets of column vectors (ie, the first set) that can be used as the first set of base vectors and multiple sets can be used as the second set of base vectors.
  • the plurality of sets of base vectors of the first set and the sets of base vectors of the second set have been described in detail above, and are not described herein for brevity.
  • the terminal device may determine the first set of base vectors and the second set of base vectors to be fed back by traversing the plurality of sets of base vectors in the first set and the sets of base vectors in the second set.
  • a method for determining the first group base vector and the second group base vector in the following manner will be described in detail in conjunction with the fourth method.
  • a method of network device configuration and terminal device feedback can be used in combination to determine a first set of basis vectors and a second set of basis vectors.
  • the network device configures a first set of base vectors, and the terminal device traverses each set of base vectors in a predefined second set to select a second set of base vectors and feeds back to the network device.
  • the terminal device may also acquire the Kronecker product of the first group base vector and the second group base vector in advance.
  • the Kronecker product of the first group base vector and the second group base vector may be predefined, such as a protocol definition, or may be configured by the network device to the terminal device. This application does not limit this.
  • a specific method of configuring a Kronecker product of a first set of base vectors and a second set of base vectors by a protocol definition or a network device and a specific method of configuring a first set of base vectors and a second set of base vectors by protocol definition or network device Similar, for the sake of brevity, we will not repeat them here.
  • the transform processing of the channel matrix or the ideal precoding matrix can include at least: performing a channel matrix or an ideal precoding matrix. IDFT and DFT.
  • the terminal device may measure and feed back N SB frequency domain units based on a group of antenna ports with the number of antenna ports N T , then the first group base vector may include N 1 dimensions of N T A column vector of ⁇ 1, the second group of base vectors may include N 2 column vectors of dimension N SB ⁇ 1.
  • the first set of basis vectors can be characterized by a matrix of dimensions N T ⁇ N 1 , which can be characterized by a matrix of dimensions N SB ⁇ N 2 .
  • 0 ⁇ N 1 ⁇ N T , 0 ⁇ N 2 ⁇ N SB , N 1 and N 2 are integers, and the values of N 1 and N 2 may be the same or different, which is not limited in the present application.
  • the frequency domain unit may include, for example, a sub-band or a physical resource block (PRB), or may be other units defined in an existing or future protocol for representing a frequency domain resource, which is not limited in this application.
  • the number of the frequency domain units N SB may be predefined by the system or configured by the network device through signaling, which is not limited in this application.
  • the first IDFT can be understood as the projection of the channel matrix or the ideal precoding matrix on the antenna into the beam domain. As the number of antennas increases, the beam becomes narrower, the spatial channel correlation becomes higher, and the signal quality of the terminal device is better. The number of beams is small, and the channel matrix or ideal precoding matrix corresponding to the beam domain becomes sparse, so that further measurement can be performed only for one or several beams that can reach the terminal device and have better signal quality.
  • the same beam may have different amplitudes and/or phases of feedback on different sub-bands due to factors such as frequency selection, fading, etc. on different frequency domain elements (eg, sub-bands or PRBs).
  • the DFT transform can be understood as a beam-frequency-to-beam-time-time domain projection, thereby converting a channel matrix or an ideal precoding matrix in the frequency domain to the time domain, so that the independent feedback in the frequency domain can be
  • a plurality of (eg, N SB ) frequency domain units are correspondingly transformed into a plurality of amplitudes and/or phases that are converted into amplitudes and/or phases of a plurality of (eg, M) points in the time domain. Under normal circumstances, N SB is greater than M.
  • the M points may be beams having a larger power obtained after the above-described transform processing.
  • the value of the M may be predefined, for example, a protocol definition, or may be indicated by the network device, or may be fed back by the terminal device, which is not limited in this application.
  • the terminal device may indicate the measured value to the network device based on the first set of base vectors and the second set of base vectors.
  • the precoding matrix is taken as an object of the transform processing as an example. Assuming that the first set of base vectors is denoted as G 1 , the second set of base vectors is denoted as G 2 , and the precoding matrix is denoted by V, the precoding matrix is transformed based on the first set of base vectors and the second set of base vectors One possible form of getting it can be: For easy differentiation, Recorded as V'. In order to feed back the precoding matrix V, the V' obtained after the transform processing may be further transformed, and a possible form of the obtained measured value may be: G 1 V'G 2 T , Substituting G 1 V'G 2 T for further deformation That is V.
  • the CSI fed back by the terminal device may be a quantized value of the measured value. It should be understood that the transformation process described above is shown for ease of understanding only, and the actual transformation process may not be limited to the steps listed above.
  • the terminal device determines the measurement value based on the channel matrix or the precoding matrix, and the specific quantization manner of the measurement value will be described in detail later with reference to the specific embodiment, and a detailed description of the specific process is omitted here.
  • the method 200 further includes: Step 230, the network device pre-codes the signal to be transmitted based on the pre-coding matrix determined by the measured value indicated by the CSI, and sends the pre-coded signal.
  • the network device may determine the precoding matrix according to the measured value indicated by the CSI, so that the signal to be transmitted according to the determined precoding matrix can be precoded, and the precoded signal is sent.
  • step 230 the terminal device receives the precoded signal.
  • the CSI transmitted by the terminal device in step 220 can be used to determine a channel matrix or a precoding matrix.
  • the network device may further determine, according to the determined channel matrix or precoding matrix, a precoding matrix for precoding the signal to be transmitted, where the precoding matrix is an antenna domain-frequency domain. Precoding matrix.
  • the network device may further perform transform processing on the measured values according to the first group base vector and the second group base vector to determine a precoding matrix of the beam domain-delay domain, and then send the signal. The signal is precoded.
  • the specific processing manner of the signal to be sent by the network device is not limited in this application.
  • the CSI fed back by the terminal device is determined based on a pre-defined codebook and multiple conversion processes. Therefore, the channel matrix (or precoding matrix) determined by the network device according to the CSI and the terminal device are based on the reference signal.
  • the determined channel matrices (or precoding matrices) may be the same or may be close.
  • the precoding matrix determined by the network device can be better adapted to the current channel state, and better reception performance can be obtained.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may be based on the CSI.
  • the measured values are determined to determine the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the terminal device may perform transform processing on the channel matrix based on the first group base vector and the second group base vector, or may also base the ideal precoding matrix on the first group base vector and the second group base vector.
  • the transform processing may be performed, and the measured values obtained by different matrix processing may be different.
  • the process of obtaining the measured values based on the first set of base vectors and the second set of base vectors will be described in detail by taking the channel matrix and the ideal precoding matrix as examples.
  • the network device may send reference signals through multiple transmit antennas (ie, antenna ports), and the multiple antenna ports may belong to the same antenna port group, or the multiple antenna ports may also belong to different antenna ports.
  • the terminal device can receive the reference signal through a plurality of receiving antennas (ie, antenna ports).
  • the dimension of the channel matrix may be: the number of transmitting antennas ⁇ the number of receiving antennas.
  • a transmit antenna group may be configured with N T (N T ⁇ 1, and N T is a positive integer) antenna ports
  • the terminal device may be configured with N R (N R ⁇ 1, and N R is a positive integer) receive antennas.
  • the network device may be configured with a plurality of antenna port groups each port group can comprise antennas N T antenna ports. The number of the transmitting antennas and the number of receiving antennas configured by the network device are not limited in this application.
  • the terminal device can perform channel measurement and feedback on N SB frequency units configured by the system.
  • the N SB may be determined according to a matrix dimension of the second set of base vectors.
  • the second set of base vectors may include N SBs .
  • the N SB may be determined according to at least one of the following parameters: system bandwidth, CSI-RS bandwidth, BWP bandwidth, or feedback bandwidth.
  • system bandwidth CSI-RS bandwidth, BWP bandwidth, carrier frequency or CSI feedback bandwidth, and configured carrier bandwidth, CSI-RS bandwidth, BWP bandwidth Any one of the carrier frequency or the CSI feedback bandwidth determines N SB .
  • N SB frequency for the unit of n sb (1 ⁇ n sb ⁇ N SB) frequency units the channel matrix (for ease of distinction, for example, referred to as H sb) dimension may be N T ⁇ N R .
  • the dimension of the channel matrix in the spatial domain-frequency domain (for ease of differentiation, for example, Hr ) may be N T ⁇ N SB .
  • the nth sb column in the channel matrix is a channel corresponding coefficient of all antenna ports to the receiving antenna on the nth sb frequency unit, and may correspond to a transposition of the H rth line in the channel matrix H sb .
  • the terminal device may perform SVD on the channel matrix corresponding to each receiving antenna to obtain a precoding matrix corresponding to each receiving antenna. Therefore, for the r (1 ⁇ r ⁇ N R ) receiving antennas of the terminal device, or for channels having a rank of A (1 ⁇ A ⁇ min ⁇ N T , N R ⁇ , and R is an integer)
  • the dimension of the precoding matrix for the r (1 ⁇ r ⁇ A) layers, the dimension of the precoding matrix (for convenience of distinction, for example, V r ) may also be N T ⁇ N SB .
  • transmit antennas may be greater than or equal to a terminal device arranged to receive antennas N R, i.e., 1 ⁇ A ⁇ N R, hereinafter, is not made
  • A N R
  • A may also be a positive integer less than N R .
  • the value of the rank can be determined by the RI fed back by the terminal device.
  • the measurements may comprise N R columns, each column dimensions may be (N T ⁇ N SB) ⁇ 1;
  • measurements may comprise N R matrices, each of dimension N T matrix may be ⁇ N SB .
  • the dimensions of the first set of base vectors may be, for example, N T ⁇ N 1
  • the dimensions of the second set of base vectors may be, for example, N SB ⁇ N 2 .
  • the channel matrix and the precoding matrix are respectively used as the objects of the terminal device transform processing, and the process of the terminal device feeding back CSI and the process of the network device determining the precoding matrix according to the CSI are described in detail.
  • V r may be further transformed to give the measured value y r.
  • the measured value y r can be understood as a measurement corresponding to the rth receiving antenna or a measured value corresponding to the rth layer.
  • one possible form of the measured value y r may be: G 1 V PT G 2 T . will Can be further deformed That is V r . It can be understood that the dimension of the V r can be N T ⁇ N SB .
  • the terminal device can feed back the precoding matrix V r to the network device through CSI.
  • the measured values obtained through the above transformation process may be related to the first set of base vectors and the second set of base vectors, or the measured values may be related to the first set of base vectors and the second set of base vectors.
  • Kronecker is related.
  • the manner in which the terminal device performs the transform processing on the precoding matrix and the network device determine the precoding matrix according to the CSI may include at least one of the following four. The four methods are described in detail below.
  • the first method may include the steps i) to viii), wherein the steps i) to v) may be operations performed by the terminal device, and the steps vi) to vii) may be operations performed by the network device.
  • the terminal device may perform IDFT on the ideal precoding matrix in columns based on the first set of base vectors to obtain a matrix having a dimension of N 1 ⁇ N SB .
  • the terminal device may transpose the precoding matrix V r of dimension N T ⁇ N SB to the conjugate of the first group base vector G 1 of dimension N T ⁇ N 1 .
  • the dimension of V P can be N 1 ⁇ N SB .
  • the terminal device may perform DFT on the basis of the result of the IDFT processing based on the second group basis vector to obtain a matrix having a dimension of N 1 ⁇ N 2 .
  • the terminal device can determine M beams according to the matrix obtained by IDFT.
  • the power of each element in the matrix V P,T obtained by the IDFT processing is sorted in descending order, and the M elements with larger power values are found, and the remaining elements are set. zero.
  • the power can be proportional to the square of the amplitude, so that the elements having the larger absolute values of the M amplitudes can be determined from the N T ⁇ N SB elements included in the matrix obtained by the IDFT.
  • the power of any one of the M power-rich elements is greater than the power of any one of the remaining N 1 ⁇ N 2 -M elements.
  • the terminal device may zero the remaining (N 1 ⁇ N 2 -M) elements to obtain a processed matrix (for convenience of distinction and description, for example, as the first matrix V P, T '), the first matrix
  • the dimension can still be N 1 ⁇ N 2 .
  • the terminal device can convert the first matrix into a column vector of dimension (N 1 ⁇ N 2 ) ⁇ 1.
  • the terminal device may convert the first matrix having a dimension of N 1 ⁇ N 2 into a column vector of dimension (N 1 ⁇ N 2 ) ⁇ 1.
  • a first dimension may be a matrix N 1 ⁇ N 2 in the second column to the N 2 columns of the splice element sequentially under the first column element, to give dimension (N 1 ⁇ N 2) ⁇ 1 column vector of .
  • the first element to the N 1 element in the column vector may correspond to the first column of the matrix, and the N 1 +1 element to the 2N 1 element in the column vector may correspond to the second column of the matrix.
  • the column vector is denoted as u
  • the column vector u may comprise N 1 ⁇ N 2 complex elements, among which there are M non-zero elements.
  • the locations of the M non-zero elements can be used to indicate the location of the M beams.
  • the positions of the M non-zero elements in the N 1 ⁇ N 2 rows in the column vector u may correspond to the M beams in a predefined dimension of (N T ⁇ N SB ) ⁇ (N 1 ⁇ N N 1 ⁇ N 2 in position 2) of the matrix, the N 1 ⁇ N 2 columns of the M row vectors is the beamforming vector of M beams.
  • the predefined matrix of (N T ⁇ N SB ) ⁇ (N 1 ⁇ N 2 ) may be the Kronecker product of the first set of base vectors G 1 and the second set of base vectors G 2 .
  • the signals transmitted by the M beams have better signal reception quality, that is, the selected better M beams.
  • the value of the M may be predefined, for example, a protocol definition, or may be indicated by a network device, which is not limited in this application.
  • the method further includes: the terminal device receiving the indication information of the M.
  • the network device sends an indication message of M.
  • the indication information of the M may be carried in the high layer signaling or may be carried in the physical layer signaling.
  • the high layer signaling includes, for example, an RRC message or a MAC CE or the like.
  • physical layer signaling includes, for example, DCI.
  • the terminal device transmits a CSI, which can be used to indicate the measured value.
  • the terminal device may send N R group indication information to the network device.
  • the CSI may comprise N R group destination directing information
  • indication information may each include one or more of the following:
  • the network device may pre-define any one or two of the above items a) to c), and only need to feedback the remaining two or one item. For example, if the network device pre-defines M beams, the terminal device may only feed back the indication information of the amplitude coefficients corresponding to the M beams and the indication information of the phase coefficients corresponding to the M beams; for example, the network device is predefined. With the amplitude coefficients of the M beams and the M beams, the terminal device can only feed back the phase coefficients of the M beams. For the sake of brevity, we will not list them one by one here.
  • the number N R N R columns corresponding indication information may be set independently of each other feedback, feedback may be a difference in the way of application of the present embodiment.
  • the M base vectors, the M amplitude coefficients corresponding to the M base vectors, and the M phase coefficients corresponding to the M base vectors are all fed back by the terminal device, for the N R columns
  • a certain column can be indicated by M basis vectors, M absolute amplitudes, and M absolute phases
  • the remaining (N R -1) columns can be indicated by M basis vectors, M relative amplitudes, and M relative phases. . This application does not limit this.
  • the indication information of the M beams may be position information of the M-high power elements in the column vector u of dimension (N 1 ⁇ N 2 ) ⁇ 1.
  • the position of the M power elements can be indicated by joint coding, so it may be necessary
  • the overhead of bits In another possible design, the position of each of the more powerful elements may be indicated by a bitmap, each bit corresponding to one element in the first matrix, so N 1 ⁇ N 2 bits may be required. Overhead.
  • the M beams can correspond to M beam vectors, or M basis vectors. Therefore, in a possible implementation manner, the positions of the M beams in the column vector u of the above dimension (N 1 ⁇ N 2 ) ⁇ 1, that is, the M base vectors are in the first group base vector G 1 And the Kronecker product of the second set of basis vectors G 2 The location in .
  • the dimension may be (N T ⁇ N SB ) ⁇ (N 1 ⁇ N 2 ). That is, the M dimension beams (N 1 ⁇ N 2) 1 ⁇ N 2 N rows ⁇ 1 column vector u in the location corresponding to N M basis vectors. 1 in W ⁇ N 2 positions in the column.
  • the above M base vectors can be from The M columns determined in the N 1 ⁇ N 2 columns, each column contains N T ⁇ N SB elements.
  • the indication information of the M beams may include a position of the M base vectors in a pre-configured matrix, and the matrix is configured by The resulting matrix.
  • each base vector may satisfy: Where v i may be the i-th base vector of the M base vectors, 1 ⁇ i ⁇ M and i is a positive integer, and g i,1 may be a column vector of dimension N T ⁇ 1, which can be understood as the i-th
  • the first component of the basis vector can be determined from the first set of base vectors G 1
  • g i, 2 can be a column vector of dimension N SB ⁇ 1, which can be understood as the second component of the i-th base vector. Determined from the second set of basis vectors G 2 .
  • each base vector satisfies
  • each base vector may include N T ⁇ N SB elements.
  • the indication information of the M beams may include a position of the first component of each of the M base vectors in the first group base vector and a second component of each base vector in the second group base vector The location in .
  • the M amplitude coefficients corresponding to the M beams may correspond to the modes of the M power-rich complex elements in the first matrix.
  • the terminal device may send the quantized value of the modulus of the M complex elements to the network device.
  • the network device and the terminal device may pre-store a plurality of amplitude coefficients and a plurality of indexes, and the corresponding relationship between the plurality of amplitude coefficients and the plurality of indexes may be referred to as an amplitude codebook.
  • the terminal device may transmit an index of the M amplitude coefficients closest to the real part of the M complex elements in the amplitude codebook to the network device, so that the network device determines M amplitude coefficients based on the M indexes.
  • the network device and the terminal device may pre-store a correspondence between multiple amplitude coefficients and multiple indexes and a correspondence between multiple amplitude difference values and multiple indexes, and the multiple amplitude coefficients and multiple
  • the correspondence relationship of the index may be referred to as a first amplitude codebook, for example, and the correspondence between the plurality of amplitude difference values and the plurality of indexes may be referred to as a second amplitude codebook, for example.
  • the terminal device can feed back in a differential manner to reduce feedback overhead.
  • the absolute value of the maximum amplitude of the M complex elements may be indicated to the network device, for example, an index of the amplitude coefficient closest to the maximum amplitude in the first amplitude codebook is sent to the network device, and the remaining (M-1) a difference value of the complex elements relative to the maximum amplitude described above is indicated to the network device, such as (M-1) which is closest to the difference between the amplitudes of the remaining (M-1) complex elements with respect to the maximum amplitude described above.
  • the index of the differential values is sent to the network device.
  • the bit overhead for indicating the maximum amplitude may be greater than the bit overhead for indicating the remaining (M-1) relative amplitudes, for example, the maximum amplitude bit overhead is b bits, and the bit overhead of each relative amplitude is c.
  • the number of bits, b>c the network device can determine the codebook corresponding to the index carried in each field according to the number of bits of each field in the received CSI.
  • the amplitude of each complex element can be uniformly quantized by a bits, respectively, or the maximum amplitude can be quantized by b bits, by (M-1)
  • the c bits quantize the relative amplitude, which is not limited in this application.
  • the M phase coefficients corresponding to the M beams may be determined by the real and imaginary parts of the M power-rich complex elements in the first matrix described above.
  • the terminal device may determine the corresponding M phase coefficients according to the real part and the imaginary part of the M complex elements, and send the quantized value of the phase coefficient to the network device.
  • the network device and the terminal device may pre-store a correspondence between a plurality of phase coefficients and a plurality of indexes, and the correspondence between the plurality of phase coefficients and the plurality of indexes may be referred to as a phase codebook.
  • the terminal device may send an index of the M phase coefficients closest to the M phase coefficients of the M complex elements in the phase codebook to the network device, so that the network device determines M phase coefficients based on the M indexes.
  • the network device may pre-store a correspondence between multiple phase coefficients and multiple indexes and a correspondence between multiple phase difference values and multiple indexes, and the corresponding multiple phase coefficients correspond to multiple indexes.
  • the relationship may be referred to as a first phase codebook, for example, and the correspondence between the plurality of phase difference values and the plurality of indices may be referred to as a second phase codebook, for example.
  • the terminal device can feed back in a differential manner to reduce feedback overhead.
  • the phase coefficient of the first complex element of the M complex elements may be indicated to the network device, such as sending an index of the phase coefficient closest to the phase coefficient of the first complex element in the first phase codebook to the network.
  • the device indicates to the network device the difference value of the phase coefficients of the remaining (M-1) complex elements relative to the phase coefficients of the first complex element, such as the phase coefficients of the remaining (M-1) complex elements
  • An index of the (M-1) differential values closest to the difference value of the phase coefficients of the first complex element is transmitted to the network device.
  • the bit overhead for indicating the phase coefficient of the first complex element may be greater than the bit overhead for indicating the remaining (M-1) difference values, for example, the bit overhead of the phase coefficient of the first complex element is j
  • the bit cost of each difference value is k bits, j>k
  • the network device can determine the codebook corresponding to the index carried in each field according to the difference in the number of bits of each field in the received CSI.
  • the phase of each complex element can be uniformly quantized by 1 bit, or the phase of the first complex element can be quantized by j bits. (M-1) k bits quantize relative amplitude, which is not limited in this application.
  • a combination of uniform quantization of amplitude coefficients and uniform quantization of phase coefficients may be used, or a combination of non-uniform quantization of amplitude coefficients and uniform quantization of phase coefficients may be used.
  • the amplitude coefficient non-uniform quantization and the phase coefficient uniform quantization may be used in combination, or the amplitude phase non-uniform quantization and the phase coefficient non-uniform quantization may be combined, which is not limited in the present application.
  • the CSI is information indicating the group N R N R can be used to indicate the column vectors, the N R columns form a measurement value Z.
  • the measurement value Z may include N R column vectors, the column vectors appreciated N R N R Z th component of the measured value. It will be appreciated that the number N R components may also be understood as a measured value, i.e., corresponding to a receiving antenna or a measured value of a corresponding layer.
  • the measured value Z and the measured value y n alternately appear, as will be understood by those skilled in the art, the dimensions of the two are different, and the measured value y n may be the nth column vector in the measured value Z.
  • N R number of columns n (1 ⁇ n ⁇ N R, n is an integer) row can be expressed as y n, y n satisfying:
  • ⁇ is a normalization coefficient
  • M is the number of base vectors
  • M base vectors are M columns in the Kronecker product of the first set of base vectors G 1 and the second set of base vectors G 2 , Is the i-th column vector of the M base vectors
  • the dimension is N T ⁇ N SB ⁇ 1, for Linear superposition coefficient, for Amplitude factor, for Phase coefficient.
  • N T is the number of antenna ports transmitting the reference signal
  • N SB is the number of frequency domain units included in the frequency domain resource for transmitting the reference signal
  • 1 ⁇ i ⁇ M, and i and M are integers.
  • each of the N R columns can satisfy the above The structure, or rather, has the same dimensions.
  • one or more of the M base vectors, M amplitude coefficients, or M phase coefficients used to construct the column vector may be different, and therefore, any of the N R columns The two columns may be different or the same. This application does not limit this.
  • the measured value y n may be equivalent to Then, the measured value y n may be a column vector having a dimension of (N T ⁇ N SB ) ⁇ 1.
  • the measured value y r of the dimension (N T ⁇ N SB ) ⁇ 1 is further converted into a matrix of dimension N T ⁇ N SB , which is a matrix approximating the precoding matrix V r .
  • the measured value y n may be equivalent to a column vector converted by G 1 V P, T 'G 2 T. Since G 1 V P, T 'G 2 T is a matrix of dimension N 1 ⁇ N 2 , the dimension of the transformed column vector is (N 1 ⁇ N 2 ) ⁇ 1.
  • the dimension of the above measured value Z may be (N T ⁇ N SB ) ⁇ N R .
  • the terminal device may directly feed back the CSI to the network device to indicate the foregoing measurement value, so that the network device determines the precoding matrix.
  • the process of the transform processing is similar for a plurality of receiving antennas or a plurality of layers of the terminal device. Therefore, for a plurality of receiving antennas or layers of the terminal device, the measured values corresponding to the plurality of receiving antennas or layers may constitute the measured value Z.
  • the measured value Z can be obtained by taking a value for n traversal in [1, N].
  • the rank of the channel matrix is equal to the number of receiving antennas.
  • the value of the rank is not limited in this application.
  • the rank may also be an integer value smaller than the number of receiving antennas.
  • the network device can determine the measured value based on the received CSI.
  • the network device may obtain a measurement value corresponding to one receiving antenna or one layer according to each group of indication information in the received CSI, and the dimension of the measurement value may be (N T ⁇ N SB ) ⁇ 1.
  • the network device can be based on a predefined matrix (ie, Corresponding relationship between the plurality of column vectors and the plurality of indexes determines the M beam vectors, or according to the correspondence between the plurality of column vectors and the plurality of indexes in the first group of base vectors defined in advance and the plurality of base vectors in the second group The correspondence between the column vectors and the plurality of indices determines M beam vectors.
  • the network device may further determine M amplitude coefficients corresponding to the M beams according to the correspondence between the plurality of quantized values and the plurality of amplitude coefficients stored in advance, and/or the correspondence between the plurality of quantized values and the plurality of phase coefficients, And/or M phase coefficients corresponding to M beams.
  • the measured value y r can be obtained from a set of indication information in the CSI.
  • the network device can further convert the measured value y r into a matrix of dimension N T ⁇ N SB .
  • the network device may line (N T ⁇ N SB - N T +1) of the measured value y r to the (N T ⁇ N SB ) row as the N SB column of the second matrix, and measure y r
  • the (N T ⁇ N SB -2N T +1 ) line to the (N T ⁇ N SB -N T ) line serves as the Nth SB column of the second matrix, and so on.
  • the matrix of the dimension N T ⁇ N SB recovered from the measured value y r can be recorded as the third matrix V P,T ′′.
  • the third matrix V P,T ′′ is the same as or close to the first matrix V P,T ′ in step iii), that is , the same as the precoding matrix V r measured by the terminal device based on the reference signal or Therefore, the third matrix V P,T ′′′ is a precoding matrix corresponding to one receiving antenna or one layer determined by the network device according to the CSI.
  • the network device can obtain the measured value Z' by taking a value for n traversal in [1, N R ].
  • the dimension of the measured value Z' may be (N T ⁇ N SB ) ⁇ N R .
  • a matrix of N R dimensions of N T ⁇ N SB can be obtained. Maintaining the number of rows in the same premise, the number N R N T ⁇ N SB splicing sequentially obtained a matrix of dimension N T ⁇ (N R ⁇ N SB) matrix.
  • the matrix whose dimension is N T ⁇ (N R ⁇ N SB ) can be understood as a precoding matrix corresponding to one antenna port group.
  • the measured value Z′ calculated by the network device according to the CSI may be the same or close to the measured value Z obtained by performing the above transformation processing on the precoding matrix V r by the terminal device. That is to say, the precoding matrix determined by the network device based on the CSI may be the same as or close to the precoding matrix determined based on the reference signal.
  • the network device may further perform inverse transformation of the IDFT and the DFT by using a matrix of N R dimensions of N T ⁇ N SB obtained by the measured value conversion.
  • the network device performs inverse transformation of IDFT and DFT on the third matrix V PT ′′ converted from the rth column in the measured value Z′, DFT and IDFT is performed according to the inverse transform of each column N R dimensions measured value converter Z 'is obtained for the N T ⁇ N SB matrix dimensions is obtained N R N T ⁇ N SB matrix, holding the line Under the premise of constant number, the matrix of N R N T ⁇ N SBs is sequentially spliced to obtain a matrix of dimension N T ⁇ (N R ⁇ N SB ).
  • the matrix whose dimension is N T ⁇ (N R ⁇ N SB ) can be understood as a precoding matrix corresponding to one antenna port group.
  • the terminal device and the network device can perform the above operations for each antenna port group respectively, and obtain p dimensions of N T ⁇ (N R ⁇ N SB ) matrix. Then, the matrix with the dimension N T ⁇ (N R ⁇ N SB ) is sequentially spliced to obtain a matrix of dimension (p ⁇ N T ) ⁇ (N R ⁇ N SB ) while keeping the number of columns unchanged.
  • the matrix of (p ⁇ N T ) ⁇ (N R ⁇ N SB ) is a precoding matrix corresponding to p antenna port groups.
  • the terminal device may feed back multiple sets of indication information corresponding to the multiple antenna port groups to the network device based on the same indication manner.
  • M beams, M amplitude coefficients corresponding to M beams, and M phase coefficients corresponding to M beams may be indicated according to different antenna port groups, or may be based on One antenna port group (for example, referred to as antenna port group #1), indicating M beams corresponding to antenna port group #1, M amplitude coefficients corresponding to the M beams, and the manner as described above M phase coefficients corresponding to the M beams, based on the remaining one or more antenna port groups (for example, referred to as antenna port group #2), and feedback M beams corresponding to antenna port group #2, and the M beams
  • a plurality of antenna ports based on the CSI fed back group may include N R groups corresponding to the plurality of antenna ports group indication information corresponding to the plurality of antenna ports N R groups may be used to group destination directing information indicating a plurality of measurement values A set of measured values.
  • the terminal device may be based on a plurality of antenna port groups, for each of the M beams corresponding to each antenna port group, the M amplitude coefficients corresponding to the M beams, and the M phase coefficients corresponding to the M beams.
  • One or more feedbacks this application does not limit this.
  • the terminal device can obtain the measurement value to be fed back through the fast operation of the FFT and the IFFT, and send the quantized value of the measured value to the network device through the CSI, and the network device can determine the pre-determination by the inverse operation of the FFT and the IFFT according to the CSI.
  • Encoding matrix Compared with the process of determining the precoding matrix by using the codewords in the codebook in the prior art, the computational complexity of the terminal device can be greatly reduced, and the power consumption of the terminal device is reduced.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission. In other words, under the premise of ensuring the reliability of data transmission, the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the second method may include the steps i) to vx), wherein the steps i) to v) may be performed by the terminal device, and the steps vi) to vx) may be performed by the network device.
  • the terminal device may perform IDFT on the precoding matrix based on the first set of base vectors to obtain a matrix having a dimension of N 1 ⁇ N SB .
  • the terminal device may perform DFT on the result of the IDFT processing based on the second set of base vectors to obtain a matrix having a dimension of N 1 ⁇ N 2 .
  • the matrix can be obtained through step i) and step ii)
  • the matrix V P,T whose dimension is N 1 ⁇ N 2 is denoted as the fourth matrix.
  • the terminal device converts the matrix obtained by the DFT into a column vector.
  • the second column to the Nth SB column element of the matrix V P with the dimension obtained by IDFT and having the dimension N 1 ⁇ N 2 may be sequentially spliced under the first column element to obtain a dimension of N 1 ⁇ N 2 ⁇ 1 column vector.
  • the column vector of the dimension is denoted by x.
  • the first element to the N 1 element in the column vector may correspond to the first column of the matrix, and the N 1 +1 element to the 2N 1 element in the column vector may correspond to the second column of the matrix. And so on.
  • the terminal device may perform compression transformation on the column vector of dimension N 1 ⁇ N 2 ⁇ 1 to obtain a column vector having a dimension of M ⁇ 1.
  • the column vector x of N 1 ⁇ N 2 ⁇ 1 is compression-converted based on the compression transformation matrix ⁇ obtained in advance. For example, by compressing the transformation matrix ⁇ by the column vector x left, the ⁇ x is obtained.
  • the dimension of the compression transformation matrix may be, for example, M ⁇ (N 1 ⁇ N 2 ), and the column vector x with the above dimension (N 1 ⁇ N 2 ) ⁇ 1 is multiplied by the compression transformation matrix, and the dimension is M ⁇ 1.
  • the compressed vector obtained by compressing the M x 1 column vector can be understood as the measured value y r measured by the terminal device based on the reference signal.
  • the above-mentioned compression transformation matrix may be defined in advance, for example, a protocol definition, and may also be indicated by a network device, which is not limited in this application.
  • the terminal device may send a CSI to the network device, the CSI being used to indicate the measured value.
  • the terminal device can respectively feed back the quantized values of the real and imaginary parts of the M complex elements in the measured value y r of the dimension M ⁇ 1 to the network device, so that the network device can receive the CSI according to the received CSI. Determine the measured value.
  • each complex element is quantized using a predefined number of bits, such as quantizing a complex element using 20 bits, using 10 bits for the real part and 10 bits for the imaginary part.
  • the first 6 bits of the 10 bits can be used to quantize the integer part, and the last 4 bits can be used to quantize the fractional part.
  • the CSI sent by the terminal device to the network device may carry the quantized values of the M complex elements.
  • the terminal device may separately encode and feed the quantized values of the M complex elements to the network device, and jointly encode and quantize the quantized values of the M complex elements to the network device, which is not limited in this application.
  • the terminal device and the network device pre-store a plurality of mappings between the plurality of quantized values and the plurality of values, and the terminal device may quantize each complex element based on the correspondence, and the network device may also determine, according to the corresponding relationship, the quantized value.
  • Each plural element may be stored in the terminal device and the network device.
  • the measured value may be denoted as Z, and Z may include a plurality of columns.
  • the number of receiving antennas or the rank may be N R
  • each column vector in the measured value Z corresponds to a measured value y n (1 ⁇ n ⁇ N R and n is a positive integer).
  • the number of columns included in the measured value Z is the number of measured value components included in the measured value Z. That is, n traverses the value in [1, N R ], and n is a positive integer.
  • the dimension of the above measured value Z may be M ⁇ N R .
  • the network device can determine the measured value based on the CSI.
  • the network device may determine M complex elements according to the quantized values in the CSI according to the correspondence between the plurality of quantized values pre-stored and the plurality of values, thereby obtaining a column vector having a dimension of M ⁇ 1, that is, the measured value y r '. It can be understood that the measured value y r ' obtained by the network device according to the CSI may be the same as or close to the measured value y r obtained by the terminal device based on the precoding matrix transform process.
  • the network device can restore the measured value to a column vector of dimension (N 1 ⁇ N 2 ) ⁇ 1 based on the compression transformation matrix.
  • the network device can convert the column vector of dimension M ⁇ 1 into a column vector of dimension (N 1 ⁇ N 2 ) ⁇ 1 by inverse transformation of the compression transformation.
  • the column vector of the dimension (N 1 ⁇ N 2 ) ⁇ 1 obtained by the inverse transformation of the compression transformation is denoted as x′.
  • the column vector x' obtained by inverse transformation of the network device by the compression transformation of the measured value y r ' may be the same as or close to the column vector x converted by the terminal device according to the precoding matrix V r .
  • the network device may further convert the column vector of dimension M ⁇ 1 into a matrix of dimension N 1 ⁇ N 2 .
  • the network device may further convert the column vector x' of dimension M x 1 into a matrix V P,T ' with a dimension of N 1 ⁇ N 2 .
  • the matrix V P,T ' with the dimension N 1 ⁇ N 2 is denoted as the fifth matrix. It can be understood that the fifth matrix V P,T ' is converted according to the measured value y r ' determined by the CSI fed back by the terminal device, so the fifth matrix V P,T ' and the terminal device are converted according to the precoding matrix V r .
  • the resulting fourth matrix V P,T is the same or close.
  • the network device converts the column vector x' of the dimension M ⁇ 1 into the fifth matrix of the dimension N 1 ⁇ N 2 and the specific process of the method of the first method in the step vii) to convert the column vector into the third matrix.
  • the process is similar, for the sake of brevity, it will not be repeated here.
  • the network device can determine the precoding matrix according to the fifth matrix.
  • the fifth matrix V P,T ' is the same as or close to the fourth matrix V P,T , and therefore, V r ' can be approximately equal to G 1 V P,T (G 2 ) T , will Substitution can get V r 'approximate Simplified to get V r 'is approximately equal to V r . Therefore, the precoding matrix V r ' obtained by the network device according to the fifth matrix is the same as or close to the precoding matrix V r determined by the terminal device based on the reference signal.
  • the network device can obtain the measured value Z' by taking a value for n traversal in [1, N R ].
  • the dimension of the measured value Z' may be M x N R .
  • the terminal device and the network device can perform the above operations for each antenna port group separately, and then, while keeping the number of columns unchanged,
  • the obtained matrix of dimension N T ⁇ (N R ⁇ N SB ) is sequentially spliced to obtain a matrix of dimensions (p ⁇ N T ) ⁇ (N R ⁇ N SB ).
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may determine the measurement based on the CSI.
  • the value determines the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the third method may include the steps i) to v), wherein the steps i) to v) may be operations performed by the terminal device, and the step vi) may be an operation performed by the network device.
  • the terminal device may perform IDFT on the precoding matrix based on the first set of base vectors to obtain a matrix having a dimension of N 1 ⁇ N SB .
  • the terminal device may multiply the precoding matrix V r by the conjugate of the first group base vector G 1 to obtain a matrix having a dimension of N 1 ⁇ N SB .
  • the terminal device can determine the M B beam vectors according to the matrix obtained by IDFT.
  • the terminal device may determine the M with a larger power in the matrix of the dimension N 1 ⁇ N SB obtained from the IDFT processing based on the previously acquired M B (1 ⁇ M B ⁇ N 1 and the M B is a positive integer).
  • B lines For example, the power of each row element in the matrix obtained by the IDFT process is summed and arranged in descending order to find M B rows with large power values, and the elements in the M B rows are kept unchanged. Zero the elements of the remaining rows.
  • the dimensions of the matrix obtained after the above processing are still N 1 ⁇ N SB .
  • the matrix subjected to the above processing is referred to as a sixth matrix U P .
  • the locations of the M B rows in which the non-zero elements in the sixth matrix are located may be used to indicate the beam vectors of the M B beams that are more powerful in the beam domain-frequency domain. That is, the positions of the M B rows in the sixth matrix may correspond to the positions of the M B beam vectors in the N 1 columns of the first group base vector G 1 having the dimension N T ⁇ N 1 .
  • the value of the M B may be defined in advance, for example, a protocol definition, and may also be indicated by a network device, which is not limited in this application.
  • the method further includes: the terminal device receiving the indication information of the M B.
  • the network device sends the indication information of the M B .
  • the indication information of the M B may be carried in the high layer signaling or may be carried in the physical layer signaling.
  • the high layer signaling includes, for example, an RRC message or a MAC CE or the like.
  • physical layer signaling includes, for example, DCI.
  • the terminal device can perform DFT on the sixth matrix to obtain a matrix having a dimension of N 1 ⁇ N 2 .
  • the terminal device may multiply the transposition of the conjugate transpose of the sixth matrix U P by the second set of base vectors G 2 to obtain a matrix of dimension N 1 ⁇ N 2 .
  • step iii) in the third method is similar to the specific process of the step ii) in the first method, except that the dimensions of the matrix are different, and for brevity, no further details are provided herein.
  • the terminal device can determine M T beam vectors for the matrix obtained by the DFT.
  • the terminal device may calculate the power of each column element in the matrix of the dimension N 1 ⁇ N 2 obtained by the DFT processing based on the pre-acquired M T (1 ⁇ M T ⁇ N 2 and the M T is a positive integer) After summing, the data is sorted in descending order, and the M T columns with larger power values are found, the elements in the M T columns are kept unchanged, and the elements of the remaining columns are set to zero.
  • the dimensions of the matrix obtained after the above processing are still N 1 ⁇ N 2 .
  • the matrix processed as described above is referred to as the seventh matrix U P,T '.
  • the locations of the M T columns in which the non-zero elements are located in the seventh matrix can be used to indicate the beam vectors of the M T beams that are more powerful in the beam domain-time domain. That is, the positions of the M T columns in the seventh matrix may correspond to the positions of the M T beam vectors in N 2 columns of the second group base vector G 2 of dimension N SB ⁇ N 2 .
  • the value of the M T may be defined in advance, for example, a protocol definition, and may also be indicated by a network device, which is not limited in this application.
  • the method further includes: the network device sending the indication information of the M T . Accordingly, the terminal device receives the indication information of the M T .
  • the indication information of the M T may be carried in the high layer signaling or may be carried in the physical layer signaling.
  • the high layer signaling includes, for example, an RRC message or a MAC CE or the like.
  • physical layer signaling includes, for example, DCI.
  • the indication information of the M B and the indication information of the M T may be carried in the same signaling, or carried in different signaling, which is not limited in this application.
  • the terminal device transmits a CSI, which can be used to indicate the measured value.
  • the terminal device may send N R group indication information to the network device.
  • the CSI may comprise N R group destination directing information, each set of instructions includes one or more of:
  • the network device and the terminal device may pre-define any one or more of the above items d) to g), and only need the terminal device to feed back one or more of the remaining ones.
  • the network device may predefine M beams, that is, pre-defining the foregoing M B first base vectors and the M T second base vectors, and the terminal device may only feed back indication information of the amplitude coefficients corresponding to the M beams.
  • indication information of a phase coefficient corresponding to the M beams for example, the network device may predefine amplitude coefficients of the M beams and the M beams, and the terminal device may only feed back the phase coefficients of the M beams.
  • the number M B of the first indication information may be the above-described base vectors M B th row matrix of dimensions for the location information of the sixth N 1 ⁇ N SB in.
  • the position of the M B rows in the sixth matrix of dimension N 1 ⁇ N SB also corresponds to the position of the M B beam vectors in the N 1 columns of the first set of base vectors.
  • the position of the M B lines can be indicated by joint coding, so it may be necessary The overhead of bits.
  • the M B row vectors of the N 1 row vectors can be indicated by a bitmap, and each bit in the bitmap can correspond to N 1 row vectors. One, therefore requires an overhead of N 1 bit.
  • Information indicating the second base vector M T may be the above column vectors of M T in the dimension for the location information of the seventh matrix of N 1 ⁇ N 2 in.
  • the position of the M T column vectors in the seventh matrix of dimension N 1 ⁇ N 2 also corresponds to the position of the M T beam vectors in the N 2 columns of the second set of base vectors.
  • the location of the M T column vectors can be indicated by joint coding, so it may be necessary The overhead of bits.
  • the M B first basis vectors and the M T second basis vectors are determined.
  • the Kronecker product of the M T second basis vectors is the beam vector of the M beams.
  • the M amplitude coefficients corresponding to the M beam vectors may correspond to the magnitudes of M B ⁇ M T non-zero elements in the seventh matrix.
  • the M B ⁇ M T non-zero elements in the seventh matrix may be extracted to form a matrix of dimensions M B ⁇ M T non-zero elements, and the relative between the non-zero elements The position is unchanged. Then, the number of rows and the number of columns of each element in the dimension M B ⁇ M T may correspond to the lower corners b and t in P b,t , respectively.
  • the M phase coefficients corresponding to the M beam vectors may be determined by the real and imaginary parts of M B ⁇ M T non-zero elements in the seventh matrix.
  • the M B ⁇ M T non-zero elements in the seventh matrix may be extracted to form a matrix of dimensions M B ⁇ M T non-zero elements, and the relative between the non-zero elements The position is unchanged. Then, the number of rows and the number of columns of each element in the dimension M B ⁇ M T may correspond to the lower corners b and t in C b,t , respectively.
  • any Two or more items may be indicated by means of joint coding, which is not limited in this application.
  • a set of indication information in the CSI is described from the perspective of a receiving antenna or a layer.
  • the manner of indicating the measured value by using multiple sets of indication information in the CSI is similar.
  • the measured value N R Z include column vectors, and correspondence information indicating the group N R.
  • the number of columns N R included in the measured value Z is also the number of measured values indicated by the measured value Z. That is, n can traverse the value in [1, N R ], and n is a positive integer.
  • the measured value can be expressed by at least the two forms of Form 1 and Form 2 listed below.
  • the specific process of determining the measured value based on CSI is described in detail below in combination with Form 1 and Form 2, respectively.
  • Z may comprise measurement value N R measurements, the measured value of each column vector Z corresponding to a measured value of the n-th column of the columns in the N R can be represented as y n, y n satisfying:
  • ⁇ is a normalization coefficient
  • M is the number of base vectors
  • M base vectors are M columns in the Kronecker product of the first set of base vectors G 1 and the second set of base vectors G 2 , An i-th column vector among the M base vectors corresponding to the nth column, and
  • the dimension is N T ⁇ N SB ⁇ 1, for Linear superposition coefficient, for Amplitude factor, for Phase coefficient.
  • the protocol may define values of at least two of M, M B and M T , or the network device may only transmit indication information of at least two of M, M B and M T .
  • the measured value can be equivalent to
  • u is a column vector of (N 1 ⁇ N 2 ) ⁇ 1 having a dimension converted from a seventh matrix having a dimension of N 1 ⁇ N 2 .
  • the seventh column to the matrix in the second column of N 2 under the first row are sequentially splicing element can be obtained dimension (N 1 ⁇ N 2) ⁇ 1 column vector of u.
  • the first element to the N 1 element in the column vector u may correspond to the first column of the matrix, and the N 1 +1 element to the 2N 1 element in the column vector may correspond to the second column of the matrix And so on.
  • the column vector of the dimension (N T ⁇ N SB ) ⁇ 1 can be understood as the measured value y r corresponding to the rth receiving antenna or the rth layer.
  • the measured value may be equivalent to the column vector resulting from the conversion of G 1 U P, T 'G 2 T.
  • the matrix of the dimension N T ⁇ N SB is further converted into a column vector of dimension (N T ⁇ N SB ) ⁇ 1.
  • the terminal device may directly feed back the CSI to the network device to indicate the foregoing measurement value, so that the network device determines the precoding matrix.
  • a set of indication information in the CSI is described from the perspective of a receiving antenna or a layer.
  • the manner of indicating the measured value by using multiple sets of indication information in the CSI is similar.
  • the measured value N R Z include column vectors, and correspondence information indicating the group N R.
  • the number of columns N R included in the measured value Z is also the number of measured values indicated by the measured value Z. That is, n can traverse the value in [1, N R ], and n is a positive integer.
  • the dimension of the measured value Z is (N T ⁇ N SB ) ⁇ N R .
  • the NR group indication information in the CSI can be used to indicate the matrix R of N R dimensions of N T ⁇ N SB .
  • the N R matrix may constitute a measured value Z.
  • the measured value N R matrix the matrix appreciated N R N R Z th component of the measured value.
  • the number N R components may also be understood as a measured value, i.e., corresponding to a receiving antenna or a measured value of a corresponding layer.
  • the measured value Z and the measured value Y n alternately appear, and it will be understood by those skilled in the art that the dimensions of the two are different, and the measured value Y n may be the nth column vector of the measured value Z.
  • the measured value Z may be a spliced matrix of N R dimensions of N T ⁇ N SB without changing the number of rows, and the dimension of the measured value Z obtained by the splicing may be N T ⁇ (N R ⁇ N SB ).
  • nth matrix Y n of the R matrices satisfies:
  • ⁇ is a normalization coefficient
  • M B is the number of first base vectors
  • M T is the number of second base vectors
  • M B first base vectors are M B columns in the first set of base vectors
  • M T second basis vectors are M T columns in the second set of base vectors
  • the dimension is N T ⁇ 1, a t- th second base vector of the M T second base vectors corresponding to the n-th matrix
  • Dimension is For linear superposition coefficients,
  • Is a phase factor, 1 ⁇ b ⁇ M B, 1 ⁇ t ⁇ M T, b , t, M B, M T are positive integers.
  • the protocol may define values of at least two of M, M B and M T , or the network device may only transmit indication information of at least two of M, M B and M T .
  • the measured value may be equivalent to G 1 U P, T 'G 2 T .
  • the matrix U P,T ′′ can also be understood as a measurement value Y n corresponding to one transmit antenna port group and corresponding to N r receive antennas or N r layers.
  • the terminal device may directly feed back the CSI to the network device to indicate the above measurement value, so that the network device determines the precoding matrix.
  • the terminal device may perform the operations of step i) to step v) above for the ideal precoding matrix corresponding to each antenna port group, The p measured values Z corresponding to the p antenna port groups are obtained respectively.
  • the terminal device may select one antenna port group from the p antenna port groups, and perform the operations of step i) and step ii) on the precoding matrix corresponding to the antenna port group to obtain M B rows with higher power. , the elements in the M B rows, the remaining elements in the (N 1 -M B ) rows are zeroed.
  • a plurality of antenna ports based on the CSI fed back group may include N R groups corresponding to the plurality of antenna ports group indication information corresponding to the plurality of antenna ports N R groups may be used to group destination directing information indicating a plurality of measurement values
  • a set of measured values can be characterized by a matrix of one or more measured values spliced, the number of rows of the matrix can be the same as the number of rows of each measured value, and the number of columns can be the sum of the number of columns of each measured value.
  • the network device can determine the measured value based on the received CSI.
  • the network device may determine the measurement value based on the received one or the second according to the received CSI.
  • the network device may obtain, according to each group of indication information in the received CSI, a measurement value y n ' corresponding to one receiving antenna or one layer, and the dimension of the measurement value y n ' It can be (N T ⁇ N SB ) ⁇ 1.
  • the measured value y n ' determined by the network device according to the CSI may be the same as or close to the measured value y n obtained by the terminal device after processing based on the precoding matrix.
  • the specific process for the network device to determine the measured value y n ' according to the CSI has been described in detail in the step vii) of the first method. For brevity, no further details are provided herein.
  • the network device can further convert the measured value y n ' into a matrix of dimensions N T ⁇ N SB .
  • the specific process for the network device to convert the measured value of dimension (N T ⁇ N SB ) ⁇ 1 into a matrix of dimension N T ⁇ N SB has been described in detail in step vii) of mode one, for the sake of brevity, here is not Let me repeat.
  • the matrix of the dimension N T ⁇ N SB converted from the measured value y n ' is the same as or close to the precoding matrix V r obtained by the terminal device based on the reference signal. Therefore, the matrix whose dimension is N T ⁇ N SB converted by the measured value y n ' is a precoding matrix corresponding to one receiving antenna or one layer determined by the network device according to the CSI.
  • the network device may obtain a measurement value Y n ' corresponding to one receiving antenna or one layer according to each group of indication information in the received CSI, and the dimension of the measurement value may be N. T ⁇ N SB .
  • the measured value Y n ' determined by the network according to the CSI may be the same as or close to the measured value Y n obtained by the terminal device based on the precoding matrix processing. Since the measured value Y n ' is determined according to the feedback made by the terminal device based on the matrix U P,T ”, and the matrix U P,T ′′ approximates the precoding matrix V r , the measured value is obtained based on the reference signal with the terminal device.
  • the precoding matrices V r are the same or close. That is to say, the measured value is a precoding matrix corresponding to a receiving antenna or a layer determined by the network device according to the CSI.
  • the network device can obtain the measured value Z' by taking a value for n traversal in [1, N R ].
  • the dimension of the measured value Z' may be (N T ⁇ N SB ) ⁇ N R .
  • a matrix of N R dimensions of N T ⁇ N SB can be obtained. Maintaining the number of rows in the same premise, the number N R N T ⁇ N SB splicing sequentially obtained a matrix of dimension N T ⁇ (N R ⁇ N SB) matrix.
  • the matrix whose dimension is N T ⁇ (N R ⁇ N SB ) can be understood as a precoding matrix corresponding to one antenna port group.
  • the terminal device and the network device can perform the above operations for each antenna port group respectively, and obtain p dimensions of N T ⁇ (N R ⁇ N SB ) matrix. Then, the obtained p dimensions of N T ⁇ (N R ⁇ N SB ) are sequentially spliced to obtain a dimension of (p ⁇ N T ) ⁇ (N R ⁇ N SB ) while keeping the number of columns unchanged.
  • the matrix, the matrix of (p ⁇ N T ) ⁇ (N R ⁇ N SB ) is a precoding matrix corresponding to the p antenna port groups.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may determine the measurement based on the CSI.
  • the value determines the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the terminal device may know the first group base vector and the second group base vector in advance, and further determine the M beam vectors according to the first group base vector and the second group base vector.
  • the terminal device may also not know the first group base vector and the second group base vector in advance, based on the pre-stored set of multiple sets of base vectors (ie, the first set) and multiple groups.
  • a collection of base vectors ie, a second set).
  • the first set may include K 1 (K 1 ⁇ 1, and K 1 is a positive integer) group basis vector, for example, denoted as G 1, a , 1 ⁇ a ⁇ K 1 , and each set of base vectors in the first set may For the IDFT vector, or the Kronecker product of two IDFT vectors.
  • each set of base vectors in the first set includes a plurality of column vectors, and each of the plurality of column vectors may be any one of a) to i) listed in step 220. For the sake of brevity, it will not be repeated here.
  • the second set may include K 2 (K 2 ⁇ 1 and K 2 is a positive integer) group basis vector, for example, denoted as G 2,c , 1 ⁇ c ⁇ K 2 , and each set of base vectors in the second set may For the DFT vector.
  • each group base vector in the first set may be N T ⁇ N 1
  • the dimensions of each group base vector in the second set may be N SB ⁇ N 2 .
  • the fourth method may include the steps 1) to 4), wherein the steps 1) to 3) may be performed by the terminal device, and the step 4) may be performed by the network device. Moreover, step 3) and step 4) can be implemented by referring to any one of the above manners 1 to 3.
  • the terminal device may traverse each set of base vectors in the first set and each set of base vectors in the second set, and feed back the selected first set of base vectors and the second set of base vectors to the network device.
  • the terminal device may sequentially take values for a traversal in [1, K 1 ], traverse values for [1, K 2 ] for c, and take values for each of a and c, based on one of the first set.
  • the group basis vector G 1,a and a set of base vectors G 2,c in the second set perform IDFT and DFT processing on the precoding matrix V, for example, A matrix of dimensions N 1 ⁇ N 2 is obtained.
  • the terminal device can obtain a matrix of K 1 ⁇ K 2 dimensions of N 1 ⁇ N 2 .
  • the terminal device determines a matrix having the largest power value from the above K 1 ⁇ K 2 matrix of N 1 ⁇ N 2 .
  • terminal device summing the power K 1 ⁇ K 2 matrices in each matrix contains N 1 ⁇ N 2 elements, the obtained K K 1 ⁇ K 2 matrix corresponding to 1 ⁇ K 2 power sums, from which the maximum sum of power sums is determined from the K 1 ⁇ K 2 power sums, the matrix corresponding to the maximum value of the sum of the power sums can be determined by a set of basis vectors used in the first set For the first set of basis vectors, a set of basis vectors used in the second set can be determined as the second set of basis vectors.
  • the terminal device may respectively feed back the index of the first group base vector in the first set and the index of the second group base vector in the second set to the network device.
  • the dimension of the first group base vector fed back by the terminal device may be N T ⁇ M B
  • the dimension of the second group base vector fed back by the terminal device may be N SB ⁇ M T .
  • the terminal device may pre-code according to the precoding matrix and the first group base vector and the second group base vector pair determined by steps 1) and 2), determine M amplitude coefficients corresponding to the M beams, and correspond to the M beams. M phase coefficients and send CSI.
  • the terminal device may further determine the M amplitude coefficients corresponding to the M beams and the M phase coefficients corresponding to the M beams and send the CSI. It is implemented by any one of the first mode to the third mode. Specifically, the terminal device may perform step i) to step v) in mode one, or step i) to step v) in mode two, or step i) to step v) in mode three, and Send CSI. For the sake of brevity, it will not be repeated here.
  • the network device can determine the precoding matrix based on the received CSI.
  • the specific process of the network device determining the precoding matrix according to the received CSI may be implemented by any one of the foregoing manners 1 to 3. Specifically, the network device may determine the measured value by performing step vi) to step vii) in mode one, or step vi) to step vx) in mode two, or step vi) in mode three. For the sake of brevity, it will not be repeated here.
  • the terminal device may indicate the set of measurement values to the network device by using the CSI, and the network device may determine the set of measurement values according to the CSI, so that the precoding matrix can be determined.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may determine the measurement based on the CSI.
  • the value determines the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art.
  • the computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of data transmission.
  • the complexity of channel measurement is greatly reduced, power consumption is reduced, and thus the performance of the entire communication system is improved.
  • the fourth method in the foregoing is only for ease of understanding, and shows a specific process in which the terminal device feeds back the first group base vector and the second group base vector, but this should not constitute any limitation on the present application.
  • the terminal device may only have one of the first set of base vectors and the second set of base vectors, the other set being indicated by the network device or predefined.
  • a set of basis vector is fed back by the terminal device (e.g., a first set of basis vectors) can be traversed from the first set after the determined first set of basis vectors
  • the vectors may include a first set of groups M B is a
  • the second group base vector may be a pre-defined or network device indication, and may include N 2 column vectors of size N SB ⁇ 1
  • the terminal device may further M T column vectors are selected and fed back in the two sets of basis vectors.
  • the method for obtaining the precoding matrix by SVD decomposition is not limited to the above description, and the terminal device may perform SVD decomposition on the channel matrix corresponding to each frequency unit to obtain a precoding matrix, and the dimension of the precoding matrix thus obtained. It can be N T ⁇ N R .
  • the transformation process and the CSI feedback process of the precoding matrix are similar to the specific processes described above, and are not described herein for brevity.
  • the specific implementation process of the object processed by the channel matrix is substantially similar to the specific implementation process of the object processed by the precoding matrix, and the difference is that the operation of the SVD according to the channel matrix can be performed by the network device, that is, the terminal device.
  • the CSI can be directly fed back by using the channel matrix as the object of the transform processing, and the network device can obtain the measured value according to the CSI in a manner corresponding to the terminal device, and further according to the measurement, by using any one of the foregoing manners 1 to 4.
  • the value determines the channel matrix.
  • the network device may further perform SVD on the converted channel matrix to obtain a precoding matrix.
  • the terminal device may process the channel matrix or the precoding matrix based on the first group base vector and the second group base vector, and feed the processed result to the network device through the CSI, and the network device may be based on the CSI.
  • the measured values are determined to determine the precoding matrix. Since the terminal device can obtain the CSI to be fed back through the fast operation of the FFT and the IFFT, the terminal device can be greatly reduced in comparison with the process of determining the precoding matrix by the terminal code traversing each codeword in the codebook in the prior art. The computational complexity is beneficial to reduce the power consumption of the terminal device.
  • the feedback CSI facilitates the network device to determine a suitable precoding matrix to precode the transmitted signal, thereby improving the reliability of the data transmission and improving the performance of the entire communication system.
  • the embodiment of the present application is described in detail by taking the process of the downlink channel measurement and the feedback between the network device and the terminal device as an example, but the present application should not be limited in any way.
  • the method provided is equally applicable to uplink channel measurement and feedback.
  • the terminal device can transmit a reference signal for uplink channel measurement, for example, SRS.
  • SRS is a reference signal for uplink channel measurement, and is merely illustrative, and should not be construed as limiting the application.
  • This application does not preclude the possibility of defining other reference signals in future protocols to achieve the same or similar functions, such as uplink DMRS and the like.
  • the specific implementation method and process of uplink channel measurement and feedback are similar to the specific implementation methods and processes of downlink channel measurement and feedback. For the sake of brevity, a detailed description of the specific process is omitted here.
  • FIG. 4 is a schematic block diagram of a communication device 400 according to an embodiment of the present application.
  • the communication device 400 can be adapted for use in the communication system illustrated in FIG. As shown in FIG. 3, the communication device 400 includes a receiving unit 410 and a transmitting unit 420.
  • the communication device 400 can be a terminal device or a chip configured in the terminal device.
  • the receiving unit 410 can be configured to receive a reference signal, which is used for channel measurement.
  • the sending unit 420 is configured to send channel state information CSI, where the CSI is used to indicate a set of measurement values, the set of measured values is used to determine a precoding matrix, or the set of measured values is the precoding matrix, where the set of measured values includes One or more measured values; wherein the measured value is related to the first set of base vectors and the second set of base vectors, or the measured value is related to the Kronecker product of the first set of base vectors and the second set of base vectors Related.
  • the first set of base vectors comprises a DFT vector or a Kronecker product of two DFT vectors
  • the second set of base vectors comprises an IDFT vector.
  • the receiving unit 410 is further configured to receive configuration information of one or more of the following:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the sending unit 420 is further configured to send configuration information of one or more of the following:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the first set of base vectors is defined by a protocol
  • the second set of basis vectors are defined by a protocol; or,
  • the first set of base vectors and the second set of base vectors are defined by a protocol
  • the Kronecker product of the first set of base vectors and the second set of base vectors is defined by a protocol.
  • the measured value includes R columns, and the nth column y n of the R columns satisfies:
  • ⁇ is a normalization coefficient
  • M is the number of base vectors
  • M base vectors are M columns in the Kronecker product of the first set of base vectors and the second set of base vectors, An i-th column vector among the M base vectors corresponding to the nth column
  • the dimension is N T ⁇ N SB ⁇ 1, for Linear superposition coefficient, for Amplitude factor, for The phase coefficient
  • N T is the number of transmitting antenna ports of the reference signal
  • N SB is the number of frequency domain units included in the frequency domain resource for transmitting the reference signal
  • R is the number of receiving antenna ports or channels of the reference signal
  • the rank of the matrix is determined, 1 ⁇ i ⁇ M, 1 ⁇ n ⁇ R, and i, n, M, and R are integers.
  • the CSI is used to indicate one or more of the following:
  • the CSI includes one or more of the following:
  • Indication information of M base vectors corresponding to the rth column of the R columns indication information of M amplitude coefficients corresponding to the M base vectors, or M corresponding to the M base vectors Indication information of the phase coefficient;
  • the indication information of the M base vectors corresponding to the rth column includes: a position of each of the M base vectors corresponding to the rth column in a pre-configured matrix,
  • the pre-configured matrix is the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the indication information of the M base vectors corresponding to the rth column includes: a position and a position of each of the M column vectors corresponding to the rth column in the first group base vector The position in the second set of base vectors.
  • the value of M is indicated by the network device or by a protocol.
  • the measured value includes R matrices, and the nth matrix Y n of the R matrices satisfies:
  • ⁇ is a normalization coefficient
  • M B is the number of first base vectors
  • M T is the number of second base vectors
  • M B first base vectors are M B columns in the first set of base vectors
  • M T second basis vectors are M T columns in the second set of base vectors, a b-th first base vector of the M B first base vectors corresponding to the n-th matrix
  • the dimension is N T ⁇ 1, a t- th second base vector of the M T second base vectors corresponding to the n-th matrix
  • the dimension is N SB ⁇ 1
  • Is a phase factor, 1 ⁇ b ⁇ M B, 1 ⁇ t ⁇ M T, b , t, M B, M T is an integer.
  • the CSI includes one or more of the following:
  • M B the column vectors of first indication information, the indication information T M second column vector of the column vector of first M B and M T the column vector corresponding to the second M B T ⁇ M information indicating a magnitude of the coefficients, or the number M B of the first column of M T vector and the second column vector corresponding to the instruction information M B T ⁇ M phase coefficients,
  • the first column indicates the number M B of the information vector includes a number M B of the first row first column vector of each vector position in said first set of column vectors
  • the second M T The indication information of the column vector includes the position of each of the M T second column vectors in the second set of column vectors.
  • the value of M B is indicated by the network device, or is defined by a protocol
  • the value of M T is indicated by the network device, or is defined by a protocol.
  • the measured value corresponds to one of a plurality of antenna port groups for transmitting a reference signal.
  • the communication device 400 can correspond to a terminal device in the communication method 200 in accordance with an embodiment of the present invention, which can include a module for performing the method performed by the terminal device of the communication method 200 of FIG.
  • the modules in the communication device 400 and the other operations and/or functions described above are respectively used to implement the corresponding processes of the communication method 200 in FIG. 2, and specifically, the receiving unit 410 is configured to perform steps 210 and 230 in the method 200, The sending unit 420 is configured to perform the step 220 in the method 200.
  • the specific process in which each module performs the foregoing steps is described in detail in the method 200. For brevity, details are not described herein again.
  • the communication device 400 can be a network device or a chip disposed in the network device.
  • the sending unit 420 is configured to send a reference signal, where the reference signal is used for channel measurement;
  • the receiving unit 410 is configured to receive channel state information CSI, where the CSI is used to indicate a set of measurement values, the set of measured values is used to determine a precoding matrix, or the set of measured values is the precoding matrix, and the measurement And the second set of base vectors a Kronecker product correlation of a basis vector, wherein the first base vector comprises an inverse discrete Fourier transform IDFT vector or a Kronecker product of two IDFT vectors, the second base vector comprising discrete Fu Fourier transform DFT vector;
  • the sending unit 420 is further configured to precode the signal according to the precoding matrix determined by the measured value, and send the precoded signal.
  • the sending unit 420 is further configured to send configuration information of one or more of the following:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the receiving unit 410 is further configured to receive configuration information of one or more of the following:
  • the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors are the first set of basis vectors, or the second set of basis vectors, or the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the first set of base vectors is defined by a protocol
  • the second set of basis vectors are defined by a protocol; or,
  • the first set of base vectors and the second set of base vectors are defined by a protocol
  • the Kronecker product of the first set of base vectors and the second set of base vectors is defined by a protocol.
  • the measured value includes R columns, and the nth column y n of the R columns satisfies:
  • ⁇ is a normalization coefficient
  • M is the number of base vectors
  • M base vectors are M columns in the Kronecker product of the first set of base vectors and the second set of base vectors, An i-th column vector among the M base vectors corresponding to the nth column
  • the dimension is N T ⁇ N SB ⁇ 1, for Linear superposition coefficient, for Amplitude factor, for The phase coefficient
  • N T is the number of transmitting antenna ports of the reference signal
  • N SB is the number of frequency domain units included in the frequency domain resource for transmitting the reference signal
  • R is the number of receiving antenna ports or channels of the reference signal
  • the rank of the matrix is determined, 1 ⁇ i ⁇ M, 1 ⁇ n ⁇ R, and i, n, M, and R are integers.
  • the CSI is used to indicate one or more of the following:
  • the CSI includes one or more of the following:
  • Indication information of M base vectors corresponding to the rth column of the R columns indication information of M amplitude coefficients corresponding to the M base vectors, or M corresponding to the M base vectors Indication information of the phase coefficient;
  • the indication information of the M base vectors corresponding to the rth column includes: a position of each of the M base vectors corresponding to the rth column in a pre-configured matrix,
  • the pre-configured matrix is the Kronecker product of the first set of base vectors and the second set of base vectors.
  • the indication information of the M base vectors corresponding to the rth column includes: a position and a position of each of the M column vectors corresponding to the rth column in the first group base vector The position in the second set of base vectors.
  • the value of M is indicated by the network device or by a protocol.
  • the measured value includes R matrices, and the nth matrix Y n of the R matrices satisfies:
  • ⁇ is a normalization coefficient
  • M B is the number of first base vectors
  • M T is the number of second base vectors
  • M B first base vectors are M B columns in the first set of base vectors
  • M T second basis vectors are M T columns in the second set of base vectors
  • the dimension is N T ⁇ 1
  • F t n is the tth second base vector of the M T second base vectors corresponding to the nth matrix
  • the dimension is N SB ⁇ 1
  • Is a phase factor
  • 1 ⁇ b ⁇ M B, 1 ⁇ t ⁇ M T, 1 ⁇ n ⁇ R , b, t, n, R, M B, M T are integers.
  • the CSI includes one or more of the following:
  • M B the column vectors of first indication information, the indication information T M second column vector of the column vector of first M B and M T the column vector corresponding to the second M B T ⁇ M information indicating a magnitude of the coefficients, or the number M B of the first column of M T vector and the second column vector corresponding to the instruction information M B T ⁇ M phase coefficients,
  • the first column indicates the number M B of the information vector includes a number M B of the first row first column vector of each vector position in said first set of column vectors
  • the second M T The indication information of the column vector includes the position of each of the M T second column vectors in the second set of column vectors.
  • the value of M B is indicated by the network device, or is defined by a protocol
  • the value of M T is indicated by the network device, or is defined by a protocol.
  • the measured value corresponds to one of a plurality of antenna port groups for transmitting a reference signal.
  • the communication device 400 can correspond to a network device in the communication method 200 in accordance with an embodiment of the present invention, which can include a module for performing the method performed by the network device of the communication method 200 of FIG.
  • the modules in the communication device 30 and the other operations and/or functions described above are respectively used to implement the corresponding processes of the communication method 200 in FIG. 2, and specifically, the sending unit 420 is configured to perform steps 210 and 230 in the method 200, The receiving unit 410 can be used to perform the step 220 in the method 200.
  • the specific process in which each unit performs the above-mentioned corresponding steps has been described in detail in the method 200. For brevity, no further details are provided herein.
  • FIG. 5 is a schematic structural diagram of a terminal device 600 according to an embodiment of the present application.
  • the terminal device 600 includes a processor 601 and a transceiver 602.
  • the terminal device 600 further includes a memory 603.
  • the processor 602, the transceiver 602 and the memory 603 communicate with each other through an internal connection path for transferring control and/or data signals
  • the memory 603 is for storing a computer program
  • the processor 601 is used for the memory 603.
  • the computer program is called and executed to control the transceiver 602 to send and receive signals.
  • the processor 601 and the memory 603 may be combined to form a processing device 604 for executing the program code stored in the memory 603 to implement the above functions.
  • the memory 603 may also be integrated in the processor 601 or independent of the processor 601.
  • the terminal device 600 may further include an antenna 610, configured to send uplink data or uplink control signaling output by the transceiver 602 by using a wireless signal.
  • the terminal device 600 may correspond to a terminal device in the communication method 200 according to an embodiment of the present application, and the terminal device 600 may include a module for performing a method performed by the terminal device of the communication method 200 of FIG. 2, and
  • the various modules in the terminal device 600 and the other operations and/or functions described above are respectively implemented to implement the corresponding flow of the communication method 200 of FIG.
  • the memory 603 is configured to store program code, so that when the processor 601 executes the program code, and controls the transceiver 602 to perform steps 210 to 230 in the method 200, each module performs a specific process of the corresponding step in the method. It has been described in detail in 200, and will not be repeated here for brevity.
  • the foregoing processor 601 can be used to perform the actions implemented by the terminal in the foregoing method embodiments, and the transceiver 602 can be used to perform the actions of the terminal to transmit or transmit to the network device in the foregoing method embodiments.
  • the transceiver 602 can be used to perform the actions of the terminal to transmit or transmit to the network device in the foregoing method embodiments.
  • the above processor 601 and memory 603 can be integrated into one processing device, and the processor 601 is configured to execute program code stored in the memory 603 to implement the above functions.
  • the memory 603 can also be integrated in the processor 601.
  • the terminal device 600 described above may also include a power source 605 for providing power to various devices or circuits in the terminal.
  • the terminal device 600 may further include one or more of an input unit 614, a display unit 616, an audio circuit 618, a camera 620, a sensor 622, and the like, the audio circuit.
  • an input unit 614 a display unit 616
  • an audio circuit 618 a camera 620
  • a sensor 622 a sensor
  • the audio circuit a speaker 6182, a microphone 6184, and the like can also be included.
  • FIG. 6 is a schematic structural diagram of a network device 700 according to an embodiment of the present application.
  • the network device 700 includes a processor 710 and a transceiver 720.
  • the network device 700 further includes a memory 730.
  • the processor 710, the transceiver 720, and the memory 730 communicate with each other through an internal connection path for transferring control and/or data signals.
  • the memory 730 is configured to store a computer program, and the processor 710 is configured to be called from the memory 730.
  • the computer program is run to control the transceiver 720 to send and receive signals.
  • the above processor 710 and memory 730 can synthesize a processing device, and the processor 710 is configured to execute the program code stored in the memory 730 to implement the above functions.
  • the memory 730 can also be integrated in the processor 710 or independent of the processor 710.
  • the network device may further include an antenna 740, configured to send downlink data or downlink control signaling output by the transceiver 720 by using a wireless signal.
  • the network device 700 can correspond to a network device in the communication method 200 in accordance with an embodiment of the present application, which can include a module for performing the method performed by the network device of the communication method 200 of FIG.
  • each module in the network device 700 and the other operations and/or functions described above are respectively implemented to implement the corresponding flow of the communication method 200 in FIG.
  • the memory 730 is configured to store the program code, so that when the program code is executed, the processor 710 controls the transceiver 720 to perform step 210 to step 230 in the method 200 through the antenna 740, and each module performs the specific steps of the foregoing steps.
  • the process has been described in detail in the method 200 and will not be described again for brevity.
  • processors in the embodiment of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), and dedicated integration.
  • DSPs digital signal processors
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • the general purpose processor may be a microprocessor or the processor or any conventional processor or the like.
  • the memory in the embodiments 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 may be a read-only memory (ROM), a programmable read only memory (ROMM), an erasable programmable read only memory (erasable PROM, EPROM), or an electrical Erase programmable EPROM (EEPROM) or flash memory.
  • the volatile memory can be a random access memory (RAM) that acts as an external cache.
  • RAM random access memory
  • RAM random access memory
  • SRAM static random access memory
  • DRAM dynamic random access memory
  • synchronous dynamic randomness synchronous dynamic randomness.
  • Synchronous DRAM SDRAM
  • DDR SDRAM double data rate synchronous DRAM
  • ESDRAM enhanced synchronous dynamic random access memory
  • SLDRAM synchronous connection dynamic random access memory Take memory
  • DR RAM direct memory bus random access memory
  • the application further provides a computer program product, comprising: computer program code, when the computer program code is run on a computer, causing the computer to execute the embodiment shown in FIG. 2 The method in .
  • the application further provides a computer readable medium storing program code, when the program code is run on a computer, causing the computer to execute the embodiment shown in FIG. 2 The method in .
  • the application further provides a system including the foregoing network device and one or more terminal devices.
  • the above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination.
  • the above-described embodiments may be implemented in whole or in part in the form of a computer program product.
  • the computer program product comprises one or more computer instructions or computer programs.
  • the processes or functions described in accordance with embodiments of the present application are generated in whole or in part.
  • the computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable device.
  • the computer instructions can be stored in a computer readable storage medium or transferred from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be from a website site, computer, server or data center Transfer to another website site, computer, server, or data center by wire (eg, infrared, wireless, microwave, etc.).
  • the computer readable storage medium can be any available media that can be accessed by a computer or a data storage device such as a server, data center, or the like that contains one or more sets of available media.
  • the usable medium can be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium.
  • the semiconductor medium can be a solid state hard drive.
  • the size of the sequence numbers of the foregoing processes does not mean the order of execution sequence, and the order of execution of each process should be determined by its function and internal logic, and should not be applied to the embodiment of the present application.
  • the implementation process constitutes any limitation.
  • the disclosed systems, devices, and methods may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.
  • 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, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.
  • each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product.
  • the technical solution of the present application which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including
  • the instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present application.
  • the foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

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Abstract

本申请提供了一种通信方法、通信装置和系统，能够减小终端设备测量的复杂度。该方法包括：接收参考信号，该参考信号用于信道测量；发送CSI，该CSI用于指示测量值，该测量值用于确定预编码矩阵，或，该测量值为预编码矩阵。其中，该测量值与第一组基矢量和第二组基矢量相关，或者，该测量值与第一组基矢量和第二组基矢量的克罗内克尔积相关，第一组基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT的克罗内克尔积，第二组基矢量包括离散傅里叶变换DFT矢量。

Description

通信方法、通信装置和系统 技术领域
本申请涉及无线通信领域，并且更具体地，涉及通信方法、通信装置和系统。
背景技术
在大规模多输入多输出(massive multiple-input multiple-output，Massive MIMO)技术中，可通过预编码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，有利于提高信号质量，实现空分复用，提高频谱利用率。
目前，已知一种确定预编码矩阵的方法，接收端设备根据接收到的参考信号来反馈信道状态信息(Channel State Information，CSI)，发送端设备可以根据接收端设备的两级反馈来确定预编码矩阵。在第一级反馈中，接收端设备可通过遍历第一级码本中多个正交波束矢量确定较优的一个或多个波束矢量，在第一级反馈中，各个子带上可以选择相同的一个或多个波束矢量，即，第一级反馈可以是宽带反馈；在第二级反馈中，接收端设备可以在各个子带上独立反馈幅度和相位，这可通过在各个子带上分别遍历第二级码本中的幅度和相位来确定，即，在不同的子带上选择的幅度和相位可能是不同的，故第二级反馈可以是子带反馈。
然而，随着Massive MIMO技术的发展，天线端口数目呈现增加的趋势。随着天线端口数的增加，上述确定预编码矩阵的方法复杂度也随之增大，这对接收端设备，尤其是下行传输中的终端设备，提出了挑战。
发明内容
本申请提供一种通信方法、通信装置和系统，能够减小接收端设备测量的复杂度。
第一方面，提供了一种通信方法，包括：
接收参考信号，所述参考信号用于信道测量；
发送信道状态信息CSI，所述CSI用于指示测量值集合，所述测量值集合用于确定预编码矩阵，或者，所述测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；
其中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关；其中，所述第一组基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT矢量的克罗内克尔积，所述第二基矢量包括离散傅里叶变换DFT矢量。
应理解，测量值集合可包括一个或多个测量值，每个测量值对应于一个天线端口组，故所述测量值集合所包含的测量值的个数可以为天线端口组数。
在本申请实施例中，所述测量值包括R个列，每个列的维度为(N T·N SB)×1；或者，所述测量值包括R个矩阵，每个矩阵的维度为N T×N SB；N T为一个天线端口组中的天线数， N SB为传输所述参考信号的频域单元数，R由接收所述参考信号的天线数或者信道矩阵的秩确定，p≥1，N T≥1，N SB≥1，R≥1，N T、N SB、R均为正整数。
在一种可能的实现方式中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关，可以通过测量值集合基于第一组基矢量和第二组基矢量对信道矩阵处理来实现，或者，也可以通过基于第一组基矢量和第二组基矢量对预编码矩阵处理来实现。这也就是相当于把信道矩阵或预编码矩阵做了数学变换后通过CSI发送给网络设备。因此，网络设备可以由根据接收到的CSI指示的测量值集合确定预编码矩阵。
基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
结合第一方面，在第一方面的某些实现方式中，所述方法还包括：
接收以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
即，网络设备可以为终端设备配置第一组基矢量、第二组基矢量或者两组基矢量的克罗内克尔积。
结合第一方面，在第一方面的某些实现方式中，所述方法还包括：
发送以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
即，终端设备向网络设备反馈第一组基矢量、第二组基矢量或者两组基矢量的克罗内克尔积。
第二方面，提供了一种通信方法，包括：
发送参考信号，所述参考信号用于信道测量；
接收信道状态信息CSI，所述CSI用于指示测量值集合，所述测量值集合用于确定预编码矩阵，或者，所述测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；其中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关；其中，所述第一组基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT矢量的克罗内克尔积，所述第二基矢量包括离散傅里叶变换DFT矢量；
根据由所述测量值确定的预编码矩阵对信号进行预编码，并发送预编码后的信号。
应理解，测量值集合可包括一个或多个测量值，每个测量值对应于一个天线端口组，故所述测量值集合所包含的测量值的个数可以为天线端口组数。
在本申请实施例中，所述测量值包括R个列，每个列的维度为(N T·N SB)×1；或者，所述测量值包括(N SB·R)个列，每个列的维度为N T×1；N T为一个天线端口组中的天线数，N SB为传输所述参考信号的频域单元数，R由接收所述参考信号的天线数或者信道矩阵的秩确定，p≥1，N T≥1，N SB≥1，R≥1，N T、N SB、R均为正整数。
在一种可能的实现方式中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关，可以通过基于第一组基矢量和第二组基矢量对信道矩阵处理来实现，或者，也可以通过基于第一组基矢量和第二组基矢量对预编码矩阵处理来实现。这也就是相当于把信道矩阵或预编码矩阵做了数学变换后通过CSI发送给网络设备。因此，网络设备可以由根据接收到的CSI指示的测量值确定预编码矩阵。
基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
结合第二方面，在第二方面的某些实现方式中，所述方法还包括：
发送以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
即，网络设备可以为终端设备配置第一组基矢量、第二组基矢量或者两组基矢量的克罗内克尔积。
结合第二方面，在第二方面的某些实现方式中，所述方法还包括：
接收以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
即，终端设备向网络设备反馈第一组基矢量、第二组基矢量或者两组基矢量的克罗内克尔积。
结合第一方面或第二方面，在某些可能的实现方式中，所述第一组基矢量由协议定义；或者，
所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量的克罗内克尔积由协议定义。
即，第一组基矢量、第二组基矢量或两组基矢量的克罗内克尔积也可以由协议定义。
应理解，本申请对于终端设备获取第一组基矢量、第二组基矢量或该两组基矢量的克罗内克尔积的具体方法不做限定，例如，可以由网络设备定义也可以预先定义，如协议定义，也可以由终端设备反馈等。
结合第一方面或第二方面，在某些可能的实现方式中，所述测量值包括R个列，所述R个列中的第n列y n满足：
Figure PCTCN2018076904-appb-000001
其中，α为归一化系数，M为基矢量的数量，M个基矢量为所述第一组基矢量和所述第二组基矢量的克罗内克尔积中的M个列，
Figure PCTCN2018076904-appb-000002
为所述M个基矢量中的第i个列矢量，且
Figure PCTCN2018076904-appb-000003
的维度为N T·N SB×1，
Figure PCTCN2018076904-appb-000004
为
Figure PCTCN2018076904-appb-000005
的线性叠加系数，
Figure PCTCN2018076904-appb-000006
为
Figure PCTCN2018076904-appb-000007
的幅度系数，
Figure PCTCN2018076904-appb-000008
为
Figure PCTCN2018076904-appb-000009
的相位系数，N T为所述参考信号的发送天线端口数，N SB为传输所述参考信号的频域资源所包括的频域单元数，R由所述参考信号的接收天线端口数或信道矩阵的秩确定，1≤i≤M，1≤R，i、M、R均为整数。
应理解，第n个列向量可以是R个列向量中的任意一个。作为一种理解，所述R个列向量中的任意第n个列向量均满足上述公式(条件)，即，
Figure PCTCN2018076904-appb-000010
由于一个测量值中每个列的维度是基于一个天线端口组而言的。每个列向量中的M个基矢量、与M个基矢量对应的M个幅度系数以及与M个基矢量对应的M个相位系数可通过CSI来指示。即，CSI可包括R组指示信息，每组指示信息指示以下一项或多项：M个基矢量、与M个基矢量对应的M个幅度系数或与M个基矢量对应的M个相位系数。
在本申请实施例中，与R个列对应的R组指示信息可以相互独立地反馈，也可以通过差分的方式反馈。例如，在M个基矢量、与M个基矢量对应的M个幅度系数以及与M个基矢量对应的M个相位系数这三项都由终端设备来反馈的情况下，对于R个列中的某一列可以通过M个基矢量、M个绝对幅度以及M个绝对相位来指示，剩余的(R-1)列可通过M个基矢量、M个相对幅度以及与M个相对相位来指示。本申请对此不做限定。
结合第一方面或第二方面，在某些可能的实现方式中，所述CSI包括以下一项或多项：
与所述R个列中的第r列对应的M个基矢量的指示信息，与所述M个基矢量对应的M个幅度系数的指示信息，或者与所述M个基矢量对应的M个相位系数的指示信息。
或者说，所述CSI用于指示以下一项或多项：
与所述R个列中的第r列对应的M个基矢量、与所述M个基矢量对应的M个幅度系数或者与所述M个基矢量对应的M个相位系数；
其中，r在[1，R]中遍历取值，且r为整数。
根据CSI中所指示的与所述R个列中的第r列对应的M个基矢量、与所述M个基矢量对应的M个幅度系数或者与所述M个基矢量对应的M个相位系数，带入
Figure PCTCN2018076904-appb-000011
可以得到该测量值中的第r个列向量。将该列向量转换为维度为N T×N SB的矩阵，便得到了与第r个接收天线或第r个层对应的预编码矩阵。
应理解，对于测量值中的R个列来说，均可以通过上述列举的一项或多项来构造一个列向量。通过在[1，R]中对r遍历取值，便可以得到一个维度为N T×(N SB·R)的预编码矩阵。
结合第一方面或第二方面，在某些可能的实现方式中，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个基矢量中每个基矢量在预先配置的矩阵中的位置，所述预先配置的矩阵为所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
即，与所述第r列对应的M个基矢量可以通过在第一组基矢量和第二组基矢量的克罗 内克尔积(也就是上述预先配置的矩阵)中的位置来指示，由该预先配置的矩阵确定出的M个列向量也就是用于构造上述测量值的M个基矢量
Figure PCTCN2018076904-appb-000012
结合第一方面或第二方面，在某些可能的实现方式中，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个列矢量中每个列矢量在第一组基矢量中的位置和在第二组基矢量中的位置。
即，与所述第r列对应的M个基矢量可以通过在第一组基矢量中的位置和在第二组基矢量中的位置指示，由第一组基矢量确定得到的一个列向量和由第二组基矢量确定得到的一个列向量通过克罗内克尔积可得到用于构造上述测量值的一个基矢量。
结合第一方面或第二方面，在某些可能的实现方式中，M的取值由网络设备指示，或者，由协议定义。
结合第一方面或第二方面，在某些可能的实现方式中，所述测量值包括R个矩阵，所述R个矩阵中的第n个矩阵Y n满足：
Figure PCTCN2018076904-appb-000013
其中，β为归一化系数，M B为第一基矢量的数量，M T为第二基矢量的数量，M B个第一基矢量为所述第一组基矢量中的M B个列，M T个第二基矢量为所述第二组基矢量中的M T个列，
Figure PCTCN2018076904-appb-000014
为与所述第n个矩阵对应的M B个第一基矢量中的第b个第一基矢量，且
Figure PCTCN2018076904-appb-000015
的维度为
Figure PCTCN2018076904-appb-000016
为与所述第n个矩阵对应的M T个第二基矢量中的第t个第二基矢量，且
Figure PCTCN2018076904-appb-000017
的维度为N SB×1，
Figure PCTCN2018076904-appb-000018
为线性叠加系数，
Figure PCTCN2018076904-appb-000019
为幅度系数，
Figure PCTCN2018076904-appb-000020
为相位系数。
应理解，上述第n个矩阵可以是R个矩阵中的任意一个。作为一种理解，所述R个矩阵中的任意第n个矩阵均满足上述公式(条件)，即，
Figure PCTCN2018076904-appb-000021
由于一个测量值是基于一个天线端口而言的，每个矩阵Y的维度可以为N T×N SB。每个矩阵中的M B个第一基矢量、M T个第二基矢量、M B·M T个幅度系数以及M B·M T个相位系数可通过CSI来指示。即，CSI可包括R组指示信息，每组指示信息指示以下一项或多项：M B个第一基矢量、M T个第二基矢量、M B·M T个幅度系数或M B·M T个相位系数。
在本申请实施例中，与R个矩阵对应的R组指示信息可以相互独立地反馈，也可以通过差分的方式反馈，本申请对此不做限定。
结合第一方面或第二方面，在某些可能的实现方式中，所述CSI包括以下一项或多项：
与所述R个矩阵中的第r个矩阵对应的M B个第一列矢量的指示信息，与所述第r个矩阵对应的所述M T个第二列矢量的指示信息，与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个幅度系数的指示信息，或者与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个相位系数的指示信息，
其中，所述M B个第一列矢量的指示信息包括所述M B个第一列矢量中每个第一列矢量在所述第一组列矢量中的位置，所述M T个第二列矢量的指示信息包括所述M T个第二列矢量中每个第二列矢量在所述第二组列矢量中的位置。
结合第一方面或第二方面，M B的取值由网络设备指示，或者，由协议定义；M T的取值由网络设备指示，或者，由协议定义。
第三方面，提供了一种终端设备，所述终端设备具有实现上述第一方面的方法设计中 的终端设备的功能。这些功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个与上述功能相对应的单元。
第四方面，提供了一种网络设备，所述网络设备具有实现上述第二方面的方法设计中的网络设备的功能。这些功能可以通过硬件实现，也可以通过硬件执行相应的软件实现。所述硬件或软件包括一个或多个与上述功能相对应的单元。
第五方面，提供了一种终端设备，包括收发器、处理器和存储器。该处理器用于控制收发器收发信号，该存储器用于存储计算机程序，该处理器用于从存储器中调用并运行该计算机程序，使得该终端设备执行上述第一方面或第一方面中任意一种可能的实现方式中的方法。
第六方面，提供了一种网络设备，包括收发器、处理器和存储器。该处理器用于控制收发器收发信号，该存储器用于存储计算机程序，该处理器用于从存储器中调用并运行该计算机程序，使得该网络设备执行上述第二方面或第二方面中任意一种可能的实现方式中的方法。
第七方面，提供了一种通信装置，该通信装置可以为上述方法设计中的终端设备，或者为设置在终端设备中的芯片。该通信装置包括：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或第一方面中的任意一种可能的实现方式中终端设备所执行的方法。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。
第八方面，提供了一种通信装置，该通信装置可以为上述方法设计中的网络设备，或者为设置在网络设备中的芯片。该通信装置包括：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或第二方面中的任意一种可能的实现方式中网络设备所执行的方法。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。
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：计算机程序代码，当所述计算机程序代码在计算机上运行时，使得计算机执行上述各方面中的方法。
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程序代码，当所述计算机程序代码在计算机上运行时，使得计算机执行上述各方面中的方法。
第十一方面，提供了一种芯片系统，该芯片系统包括处理器，用于支持终端设备实现上述方面中所涉及的功能，例如，生成，接收，发送，或处理上述方法中所涉及的数据和/或信息。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存终端设备必要的程序指令和数据。该芯片系统可以由芯片构成，也可以包括芯片和其他分立器件。
第十二方面，提供了一种芯片系统，该芯片系统包括处理器，用于支持网络设备实现上述方面中所涉及的功能，例如，生成，接收，发送，或处理上述方法中所涉及的数据和/或信息。在一种可能的设计中，所述芯片系统还包括存储器，所述存储器，用于保存终端设备必要的程序指令和数据。该芯片系统可以由芯片构成，也可以包括芯片和其他分立器件。
附图说明
图1是适用于本申请实施例的通信方法的通信系统的示意图；
图2是本申请实施例提供的通信方法的示意性流程图；
图3是多个天线端口配置于多个天线面板的示意图；
图4是本申请一实施例提供的通信装置的示意性框图；
图5是本申请实施例提供的终端设备的结构示意图；
图6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 of Mobile communication，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)系统或新一代无线接入技术(new radio access technology，NR)等。
图1是适用于本申请实施例的通信方法的通信系统的示意图。如图1所示，该通信系统100包括网络设备102，网络设备102可包括多个天线，例如，天线104、106、108、110、112和114。可选地，网络设备102所包括的多个天线可以被划分为多个天线组，每个天线组可以包括一个或多个天线，例如，一个天线组可包括天线104和106，另一个天线组可包括天线108和110，再一个天线组可包括天线112和114。
应理解，上文和图1仅为便于理解，示出了6个天线被划分为3个天线组的情形，然而这不应对本申请构成任何限定，网络设备102可以包括更多或更少的天线，网络设备102所包括的天线可以被划分为更多或更少的天线组，每个天线组可以包括更多或更少的天线。
另外，网络设备102可附加地包括发射机链和接收机链，本领域普通技术人员可以理解，它们均可包括与信号发送和接收相关的多个部件，例如处理器、调制器、复用器、解调器、解复用器或天线等。
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或可设置于该设备的芯片，该设备包括但不限于：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(例如，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还可以包括射频单元(radio unit，RU)。CU实现gNB的部分功能，DU实现gNB的部分功能，比如，CU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实现无线链路控制(radio link control，RLC)、媒体接入控制(media access control，MAC)和物理(physical，PHY)层的功能。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层信令或PHCP层信令，也可以认为是由DU发送的，或者，由DU+RU发送的。可以理解的是，网络设备可以为CU节点、或DU节点、或包括CU节点和DU节点的设备。此外，CU可以划分为接入网RAN中的网络设备，也可以将CU划分为核心网中的网络设备，本申请对此不做限定。
网络设备102可以与多个终端设备通信，例如，网络设备102可以与终端设备116和终端设备122通信。可以理解，网络设备102可以与类似于终端设备116或122的任意数目的终端设备通信。
应理解，该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)中的无线终端等等。本申请的实施例对应用场景不做限定。本申请中将前述终端设备及可设置于前述终端设备的芯片统称为终端设备。
如图1所示，终端设备116与天线112和114通信，其中天线112和114通过前向链路118向终端设备116发送信号，并通过反向链路120从终端设备116接收信号。此外，终端设备122与天线104和106通信，其中天线104和106通过前向链路124向终端设备122发送信号，并通过反向链路126从终端设备122接收信号。
例如，在频分双工FDD系统中，例如，前向链路118可利用与反向链路120所使用的不同频带，前向链路124可利用与反向链路126所使用的不同频带。
再例如，在时分双工TDD系统和全双工(full duplex)系统中，前向链路118和反向链路120可使用共同频带，前向链路124和反向链路126可使用共同频带。
被设计用于通信的每组天线和/或区域可称为网络设备102的扇区。例如，可将天线组设计为与网络设备102覆盖区域的扇区中的终端设备通信。在网络设备102通过前向链路118和124分别与终端设备116和122进行通信的过程中，网络设备102的发射天线可利用波束成形来改善前向链路118和124的信噪比。此外，与网络设备通过单个天线向它所有的终端设备发送信号的方式相比，在网络设备102利用波束成形向相关覆盖区域中随机分散的终端设备116和122发送信号时，相邻小区中的移动设备会受到较少的干扰。
在给定时间，网络设备102、终端设备116或终端设备122可以是无线通信发送装置和/或无线通信接收装置。当发送数据时，无线通信发送装置可对数据进行编码以用于传输。具体地，无线通信发送装置可获取要通过信道发送至无线通信接收装置的一定数目的数据比特，例如，无线通信发送装置可生成、从其它通信装置接收、或在存储器中保存等要通过信道发送至无线通信接收装置的一定数目的数据比特。这种数据比特可包含在数据的传输块或多个传输块中，传输块可被分段以产生多个码块。
此外，该通信系统100可以是公共陆地移动网络PLMN网络或者设备对设备(device to device，D2D)网络或者机器对机器(machine to machine，M2M)网络或者其他网络，图1仅为便于理解而示例的简化示意图，网络中还可以包括其他网络设备和更多或更少的终端设备，图1中未予以画出。
在该通信系统100中，网络设备102与终端设备116或122可采用MIMO技术进行无线通信。应理解，MIMO技术是指在发送端设备和接收端设备分别使用多个发射天线和接收天线，使信号通过发送端设备与接收端设备的多个天线传送和接收，从而改善通信质量。它能充分利用空间资源，通过多个天线实现多发多收，在不增加频谱资源和天线发射功率的情况下，可以成倍地提高系统信道容量。
MIMO可以分为单用户多输入多输出(single-user MIMO，SU-MIMO)和多用户多输入多输出(multi-user MIMO，MU-MIMO)。Massive MIMO基于多用户波束成形的原理，在发送端设备布置几百根天线，对几十个目标接收机调制各自的波束，通过空间信号隔离，在同一频率资源上同时传输几十条信号。因此，Massive MIMO技术能够充分利用大规模天线配置带来的空间自由度，提升频谱效率。
在采用MIMO技术通信的过程中，可通过预编码减小多用户之间的干扰以及同一用户的多个层(或者说，流)之间的干扰。其中，预编码可以是在已知信道状态的情况下，通过在发送端设备对待发射信号做预先的处理，即，借助与信道状态相匹配的预编码矩阵来对待发射信号进行处理，使得经过预编码的待发射信号与信道相适配，使得接收端设备消除信道间影响的复杂度降低。因此，通过对发射信号的预编码处理，接收信号质量(例如信号与干扰加噪声比(signal to interference plus noise ratio，SINR))得以提升。因此，通过预编码可以实现发送端设备与多个接收端设备在相同的时频资源上传输，也就是实现了MU-MIMO。应注意，有关预编码的相关描述仅用于举例，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，还可以通过其他方式进行预编码(例如在无法获知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)，具体内容本文不再赘述。
在一种可能的实现方式中，接收端设备可根据发送端设备发送的参考信号进行信道测量，以确定与信道状态相适配的预编码矩阵，并向发送端设备反馈。目前，已知一种确定预编码矩阵的方法，接收端设备根据接收到的参考信号来测量并反馈信道状态信息(channel state information，CSI)，发送端设备可以根据接收端设备的反馈来确定预编码矩阵。可选地，接收端设备的CSI反馈可以分为两级反馈，在第一级反馈中，接收端设备可通过遍历第一级码本中多个正交波束矢量确定较优的一个或多个波束矢量来反馈，即，在各个子带上可以选择相同的波束矢量，故第一级反馈可以为宽带反馈；在第二级反馈中，接收端设备可以在各个子带上独立反馈幅度和相位，这可通过在各个子带上分别遍历第二 级码本中的幅度和相位来确定，即，在不同的子带上选择的幅度和相位可能是不同的，故第二级反馈可以为子带反馈。网络设备可以根据第一级反馈和第二级反馈来确定预编码矩阵。
然而，这种测量和反馈的方式对于接收端设备来说，计算的复杂度较高。随着Massive MIMO技术的发展，天线端口数目呈现增加的趋势，信道测量的计算复杂度会进一步加大，对于接收端设备来说，尤其是下行传输中的接收端设备(例如，终端设备)，计算复杂度也会进一步增加，因此，可能会增加接收端设备的功率消耗，对接收端设备提出了挑战。
有鉴于此，本申请提供一种通信方法，以减小接收端设备信道测量的复杂度，从而减小接收端设备的功率消耗。
下面结合附图详细说明本申请实施例。
应理解，在下文示出的实施例中，第一、第二、第三等仅为便于区分不同的对象，而不应对本申请构成任何限定。例如，区分不同的基矢量、不同的矩阵、不同的指示信息等。
还应理解，在本申请中，“天线”和“天线端口”经常交替使用，但本领域的技术人员可以理解其含义。应当指出的是，在不强调其区别时，其所要表达的含义是一致的。。天线端口，可以理解为被接收端设备所识别的发射天线，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，每个天线端口可以与一个参考信号端口对应。
还应理解，在下文示出的实施例中，“预先获取”可包括由网络设备信令指示或者预先定义，例如，协议定义。其中，“预先定义”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。
还应理解，本申请实施例中涉及的“保存”，可以是指的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。
还应理解，本申请实施例中，名词“网络”和“系统”经常交替使用，但本领域的技术人员可以理解其含义。信息(information)，信号(signal)，消息(message)，信道(channel)有时可以混用，应当指出的是，在不强调其区别时，其所要表达的含义是一致的。“的(of)”，“相应的(corresponding，relevant)”和“对应的(corresponding)”有时可以混用，应当指出的是，在不强调其区别时，其所要表达的含义是一致的。
还应理解，本申请实施例中的“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。
还应理解，“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这三种情况。字符“/”一般表示前后关联对象是一种“或”的关系。“至少一个”是指一个或一个以上；“A和B中的至少一个”，类似于“A和/或B”，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B中的至少一个，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。
本申请的技术方案可以应用于无线通信系统中，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可以通过无线空口通信。例如，该通信系统中的网络设备可以对应于图1中所示的网络设备102，终端设备可以对应于图1中所示的终端设备116或122。
以下，不失一般性，以一个终端设备和一个网络设备的交互过程为例详细说明本申请提供的通信方法。其中，该终端设备可以为处于无线通信系统中与网络设备具有无线连接关系的任意终端设备。应理解，网络设备可以与处于该无线通信系统中的具有无线连接关系的多个终端设备基于相同的技术方案通信。本申请对于终端设备的数量或网络设备的数量并不做限定。
图2是从设备交互的角度示出的本申请一实施例提供的通信方法200的示意性流程图。如图2所示，该方法200可以包括步骤210至步骤230。
在步骤210中，网络设备发送参考信号。
相对应地，在步骤210中，终端设备接收参考信号。
具体地，网络设备发送的参考信号可用于进行下行信道测量。作为示例而非限定，该参考信号可以包括信道状态信息参考信号(channel state information-reference signal，CSI-RS)。应理解，CSI-RS作为用于下行信道测量的参考信号，仅为示例性说明，而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，例如，下行解调参考信号(demodulation reference signal，DMRS)，跟踪信号(tracking reference signal，TRS)，相位跟踪参考信号(phase tracking reference signal，PTRS)等。
在Massive MIMO中，网络设备可以配置多个天线端口。网络设备可通过所配置的多个天线端口发送参考信号，以便于终端设备进行下行信道测量和CSI反馈。
可选地，该多个天线端口可被划分为一个或多个天线端口组。在被划分为多个天线端口组的情况下，每个天线端口组中可包括一个或多个天线端口。在一种可能的设计中，该网络设备可配置一个或多个天线面板，每个天线面板可以配置有一个或多个天线端口组，每个天线端口组包括一个或多个天线端口。
为便于理解，图3示出了多个天线端口配置于多个天线面板的示意图。具体地，图3中示出了在2个天线面板配置多个天线端口的示意图。其中，每个天线面板配置了8个天线端口，图中的每个×代表不同极化方向的两个天线端口。故图3中示出的每个天线面板配置有4个天线端口。在天线面板#1上，天线端口0和天线端口1可以为同一极化方向的天线端口，例如，水平极化方向，可对应一个相同的波束矢量(或者称，预编码向量)，例如记作b 1；天线端口4和天线端口5可以为同一极化方向的天线端口，例如，垂直极化方向，可对应另一个相同的波束矢量，例如记作b 2。与之相似地，在天线面板#2上，天线端口2和天线端口3可对应波束矢量b 1，天线端口6和天线端口7可对应波束矢量b 2。其中，b 1和b 2可以是两个正交的离散的傅里叶逆变换(Inverse Discrete Fourier Transform，IDFT)矢量，或者也可以是表征空间电磁波特性的数学矢量，本申请实施例对此并未特别限定。
上文中为了便于理解，结合图3说明了在多个天线面板配置多个天线端口的情形，然而，本申请实施例并不限定天线与天线端口的对应关系，一个或多个物理天线可以被配置 为一个天线端口。其中，天线端口可以理解为被接收端设备所识别的发射天线，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，每个天线端口与一个参考信号对应。在本申请实施例中，每个天线端口可以与一个用于信道测量的参考信号端口对应，例如，在下行信道测量中，一个天线端口可以与一个用于下行信道测量的CSI-RS端口对应，此时天线端口也可称为CSI-RS端口；在上行信道测量中，一个天线端口也可以与一个用于上行信道测量的SRS端口对应，此时天线端口也可称为SRS端口。
应理解，图3仅为便于理解而给出的示意图，不应对本申请构成任何限定。例如，该天线面板也可以配置更多的天线端口，或者，该网络设备也可以配置更少或更多的天线面板，本申请实施例对此并未特别限定。
还应理解，基于天线面板对天线端口进行分组仅为一种可能的实现方式，或者说，一种可能的分组规则，而不应对本申请构成任何限定，本申请对于天线端口组的分组规则并不做限定。
在本申请实施例中，网络设备可以通过一个或多个天线端口组向终端设备发送参考信号。由于不同的天线端口组对应于不同的极化方向，因此网络设备可以基于不同的极化方向发送参考信号，从而可以获得完整的信道测量结果。
当网络设备基于多个天线端口向终端设备发送参考信号时，可以通过显式或隐式的方式指示天线端口的数量。
具体地，若采用显式的方式指示天线端口的数量，则可选地，该方法还包括：网络设备发送天线端口数的信息。相对应地，该方法还包括：终端设备接收天线端口数的信息。
可选地，该天线端口数的信息可携带在高层信令或者物理层信令中。作为示例而非限定，高层信令例如可以包括RRC消息或MAC CE。作为示例而非限定，物理层信令例如可以包括下行控制信息。
其中，下行控制信息例如可以为LTE协议或NR协议中的DCI(downlink control information)，或者，也可以为物理下行控制信道中传输的其他可用于承载下行控制信息的信令。
应理解，这里所说的物理下行控制信道可以是LTE协议或NR协议中定义的PDCCH(physical downlink control channel，物理下行控制信道)、增强物理下行控制信道(enhanced PDCCH，EPDCCH)，也可以是NR中的PDCCH，以及随着网络演变而定义的具有上述功能的其他下行信道。
若采用隐式的方式指示天线端口的数量，则该天线端口的数量可以是预先定义的，例如，协议定义。
应理解，上文中列举的获取天线端口数的具体方法仅为示例性说明，不应对本申请构成任何限定，本申请对于获取天线端口数的具体方法不做限定。
当网络设备基于多个天线端口组向终端设备发送参考信号时，可以通过显式或隐式的方式指示天线端口组的配置信息。
具体地，若网络设备采用显式的方式指示天线端口组的配置信息，则可选地，该方法还包括：网络设备发送天线端口组的配置信息，该天线端口组的配置信息可用于指示天线端口组的数量。
可选地，上述天线端口组的配置信息可携带在高层信令或者物理层信令中。
上文中对高层信令和物理层信令分别作了举例说明，为了简洁，这里不再赘述。
可选地，该天线端口组的配置信息还可用于指示每个天线端口组所包含的天线端口的端口号、极化方向等信息。
若采用隐式的方式指示天线端口组的配置信息，则该天线端口的数量可以是预先定义的，例如，协议定义。
可选地，网络设备和终端设备还可以根据预先定义好的分组规则，确定每个天线端口组中所包含的天线端口的端口号。例如，该预设的分组规则可以包括：可以将端口号为奇数的天线端口确定为一个天线端口组，将端口号为偶数的天线端口确定为另一个天线端口组；或者，可以按照天线端口号从小到大或从大到小的顺序，将2N T个天线端口中前N T个端口号对应的天线端口确定为一个天线端口组，将后N T个端口号对应的天线端口确定为另一个天线端口组。
可选地，天线端口组的配置信息可通过显式和隐式结合的方式来指示。
例如，网络设备通过信令指示天线端口组数，终端设备和网络设备基于预先定义好的分组规则，确定每个天线端口组中所包含的天线端口的端口号。
由此，终端设备便可以获知网络设备发送参考信号所使用的天线端口组的数量以及每个天线端口组所包含的天线端口的数量。应理解，上文列举的用于指示天线端口组的配置信息的方法仅为示例性说明，而不应对本申请构成任何限定，本申请对于获取天线端口组的配置信息的具体方法不做限定。
可选地，该方法还包括：
网络设备发送参考信号的时频资源的位置信息。
其中，参考信号的时频资源的位置信息例如可通过导频图样(pattern)来确定。
可选地，该方法还包括：
网络设备发送参考信号的周期和子帧偏移的配置信息
其中，该参考信号的周期和子帧偏移可用于确定参考信号的时域位置。
可选地，该方法还包括：
网络设备发送参考信号的起始资源块RB的位置信息和/或RB的数量信息。
其中，参考信号的起始RB的位置信息和/或RB的数量信息可用于确定该参考信号的频域位置和/或占用的频域资源的大小。作为示例而非限定，参考信号的起始RB的位置例如可以通过相对于终端设备的带宽部分(band width part，BWP)的偏移量来确定。
可选地，上文列举的参考信号的时频资源的位置信息、周期和子帧偏移的配置信息、起始RB的位置信息和/或RB的数量信息等均可称为参考信号的配置信息，可用于确定参考信号的时频资源。上述配置信息通过高层信令或物理层信令指示，也可通过高层信令和物理层信令相结合的方式来指示，可以通过相同的信令指示，也可以通过不同的信令指示，具体的指示方式可参考现有技术，为了简洁，这里省略对上述配置信息的指示方式的详细说明，本申请对于上述配置信息的指示方式不做限定。
在步骤220中，终端设备发送CSI。
相对应地，在步骤220中，网络设备接收CSI。
在本申请实施例中，该CSI可用于指示测量值集合。该测量值集合可包括一个或多个 测量值。每个测量值对应于用于发送参考信号的一个天线端口组。
在一种可能的实现方式中，该测量值与第一组基矢量和第二组基矢量相关，或者，该测量值与第一组基矢量和第二组基矢量的克罗内克尔积相关，可以通过基于第一组基矢量和第二组基矢量对信道矩阵处理来实现，或者，也可以通过基于第一组基矢量和第二组基矢量对预编码矩阵处理来实现。例如，终端设备可根据接收到的参考信号进行信道估计得到信道矩阵，并基于信道矩阵可进一步得到预编码矩阵，例如对信道矩阵进行奇异值分解(singular value decomposition，SVD)。假设信道矩阵为H，对信道矩阵进行SVD得到：
H＝U·S·V H。
其中，U、V H为酉矩阵，S为对角矩阵，其非零元素(即对角线上的元素)即为信道矩阵H的奇异值，这些奇异值通常可以按照由大到小的顺序排列。右酉矩阵V H的共轭转置V即为预编码矩阵。换句话说，预编码矩阵也就是根据信道矩阵H计算得到的预编码矩阵。
应理解，上述示例的通过SVD确定预编码矩阵的方法仅为一种可能的实现方式，而不应对本申请实施例构成任何限定。例如，网络设备还可以利用最小均方误差(minimum mean square error，MMSE)、迫零(zero-forcing，ZF)、最大比合并(maximal ratio combining，MRC)等接收机算法确定预编码矩阵。
需要说明的是，基于上文列举的确定预编码矩阵的方法所确定得到的预编码矩阵与信号处理过程中实际使用的预编码矩阵可能相同，也可能相接近。基于上文列举的方法所确定得到的预编码矩阵可理解为一种理想的预编码矩阵。
基于参考信号进行信道测量可得到信道矩阵，或进一步得到预编码矩阵，因此，该测量值可以与信道矩阵相关，或者，该测量值可以与预编码矩阵相关。终端设备通过CSI向网络设备指示测量值，以便于网络设备根据测量值确定预编码矩阵。网络设备可直接将该测量值作为预编码矩阵，也可以对测量值进行变换处理以得到预编码矩阵，后文中会结合具体的实施例详细说明由测量值确定预编码矩阵的具体过程。
为了便于理解和说明，以一个天线端口组为例来说明测量值，该天线端口组可以为用于发送参考信号的多个天线端口组中的一个。该测量值可以包括R个列，每个列的维度为(N T·N SB)×1；或者，该测量值包括R个矩阵，每个矩阵的维度为N T×N SB。
其中，N T为一个天线端口组中的天线数，N SB为传输所述参考信号的频域单元数，R由接收所述参考信号的天线数或者信道矩阵的秩确定，p≥1，N T≥1，N SB≥1，R≥1，N T、N SB、R均为正整数。
可选地，该测量值可以与第一组基矢量和第二组基矢量相关，或者，该测量值可以与第一组基矢量和第二组基矢量的克罗内克尔(Kronecker)积相关。
例如，终端设备至少可基于第一组基矢量和第二组基矢量对信道矩阵进行处理，或者，也可基于第一组基矢量和第二组基矢量对预编码矩阵进行处理，或者说，第一组基矢量和第二组基矢量可用于对信道矩阵或预编码矩阵进行变换处理。
其中，第一组基矢量可以包括多个列矢量，该多个列矢量中的每个列矢量可以为IDFT矢量，或者，也可以为两个IDFT矢量的克罗内克尔积；第二组基矢量可以包括多个离散的傅里叶变换(Discrete Fourier Transform，DFT)矢量。
可选地，该第一组基矢量可以包括多个列矢量，该多个列矢量中的每个列矢量可以是以下任意一项：
a)一个IDFT矢量，例如，该组基矢量包括的第m(0≤m≤N-1)个基矢量可以为N(N≥1，且N为正整数)维IDFT矢量，该IDFT矢量的数学表达式比如可以为：
Figure PCTCN2018076904-appb-000022
或者
b)一个IDFT矢量与一个标量数值的乘积；或者
c)一个IDFT矢量与一个DFT矢量的乘积，其中，DFT矢量的数学表达式比如可以为：
Figure PCTCN2018076904-appb-000023
或者
d)一个IDFT矢量与一个离散余弦变换DCT(Discrete Cosine Transform，DCT)矢量的乘积，该DCT矢量中第m个N维基矢量的第一个元素
Figure PCTCN2018076904-appb-000024
的数学表达式比如可以是：
Figure PCTCN2018076904-appb-000025
剩余N-1个元素
Figure PCTCN2018076904-appb-000026
的数学表达式比如可以是：
Figure PCTCN2018076904-appb-000027
或者
e)一个IDFT矢量与一个离散余弦逆变换IDCT(Inverse Discrete Cosine Transform，IDCT)矢量的乘积，该IDCT矢量中的第一个N维基矢量比如可以为
Figure PCTCN2018076904-appb-000028
第m个N维基矢量比如可以为
Figure PCTCN2018076904-appb-000029
或者
f)两个IDFT矢量的Kronecker乘积；或者
g)两个DFT基的Kronecker乘积；或者
h)两个DCT基的Kronecker乘积；或者
i)两个IDCT基的Kronecker乘积。
其中，Kronecker乘积是两个矩阵的直积，即一个矩阵中的所有元素分别乘以另一矩阵组成的分块矩阵，例如，k×l维的矩阵A和p×q维的矩阵B的Kronecker乘积得到kp×lq维的矩阵
Figure PCTCN2018076904-appb-000030
在本申请实施例中，终端设备可以预先获取第一组基矢量和第二组基矢量。
其中，该第一组基矢量和第二组基矢量分别可以是预先定义的，例如协议定义，或者，也可以是由网络设备配置给终端设备的，或者，还可以是由终端设备向网络设备反馈的。 本申请对此不做限定。若该第一组基矢量和第二组基矢量是由网络设备配置给终端设备的，则第一组基矢量和第二组基矢量可以通过同一个信令来指示，也可以通过不同的信令来指示，本申请对此不做限定。
若第一组基矢量和第二组基矢量是预先定义的，则网络设备和终端设备可预先保存多组可用作第一组基矢量的列矢量的集合(为便于区分和说明，例如记作第一集合)和多组可用作第二组基矢量的列矢量的集合(为便于区分和说明，例如记作第二集合)。其中，第一集合中可包括多组基矢量与多个索引的一一对应关系，该多组基矢量中的每组基矢量都可以是维度为N T×N 1的矩阵。每组基矢量中的各列矢量之间可以是不完全正交的，也就是非正交基矢量，也可以是完全正交的，也就是正交基矢量。可选地，正交基矢量可以是完备正交基矢量，也可以是非完备正交基矢量，其中，完备正交基矢量满足：对于任意相同维度的矢量均可用该正交基矢量进行线性组合表征。第二集合中可包括多组基矢量与多个索引的一一对应关系，该多组基矢量中的每组基矢量都可以是维度为N SB×N 2的矩阵。
若第一组基矢量和第二组基矢量是由网络设备配置的，则可选地，该方法还包括：
网络设备发送第一组基矢量的指示信息；以及
网络设备发送第二组基矢量的指示信息。
在第一集合中，多组基矢量可以与多个索引一一对应；在第二集合中，多组基矢量也可以与多个索引一一对应。网络设备可将第一组基矢量的索引和第二组基矢量的索引分别通过信令发送给终端设备。
或者，可选地，该方法还包括：
网络设备发送第一组基矢量和第二组基矢量的指示信息。
第一集合中的一组基矢量和第二集合中的一组基矢量的组合可对应一个索引。因此网络设备可以通过联合编码的方式，通过一个索引指示第一组基矢量和第二组基矢量。
或者，网络设备可通过位图向终端设备指示第一组基矢量和第二组基矢量，位图中的每个比特位可对应一组基矢量。例如，当位图中的比特位置“0”时，表示所对应的一组基矢量不是第一组基矢量或第二组基矢量；当位图中的比特位置“1”时，表示所对应的一组基矢量为第一组基矢量或第二组基矢量。
应理解，网络设备向终端设备指示第一组基矢量和第二组基矢量的具体方法可以通过现有技术中的方法来实现，为了简洁，这里不再赘述。还应理解，上文所列仅为几种可能的实现方式，而不应对本申请构成任何限定。
可选地，网络设备在向终端设备指示第一组基矢量和第二组基矢量之前，可以预先确定第一组基矢量和第二组基矢量。
在一种可能的实现方式中，基于终端设备发送的SRS或DMRS确定第一组基矢量。例如，根据SRS或DMRS估计互易的上行信道，并对其进行特征分解得到特征矩阵，通过从预先保存的多组基矢量构成的集合中寻找与特征矩阵距离最小的基，得到第一组基矢量；或者，通过对该多组基矢量构成的集合进行遍历，基于容量最大化准则、信干噪比(SINR)最大化准则或其他准则来确定第一组基矢量。应理解，以上列举的用于确定第一组基矢量的具体方法仅为示例性说明，上述基于距离最小值、最大化准则等确定第一组基矢量的具体过程可以与现有技术相似，为了简洁，这里不再赘述。
若该第一组基矢量和第二组基矢量是由终端设备向网络设备反馈的，则该终端设备可通过CSI来指示第一组基矢量和第二组基矢量。
在一种可能的设计中，网络设备和终端设备可预先保存有多组可用作第一组基矢量的列矢量的集合(即，第一集合)和多组可用作第二组基矢量的列矢量的集合(为即，第二集合)。上文中已经对第一集合的多组基矢量和第二集合中的多组基矢量做了详细说明，为了简洁，这里不再赘述。
终端设备可遍历第一集合中的多组基矢量和第二集合中的多组基矢量的方法确定待反馈的第一组基矢量和第二组基矢量。后文中会结合方式四对终端设备确定第一组基矢量和第二组基矢量的方法做详细说明。
应理解，上述列举的终端设备获取第一组基矢量和第二组基矢量的具体方法仅为示例性说明，而不应对本申请构成任何限定。例如，可以将网络设备配置和终端设备反馈的方法结合使用，来确定第一组基矢量和第二组基矢量。比如，网络设备配置第一组基矢量，终端设备在预先定义的第二集合中遍历各组基矢量来选择第二组基矢量，并反馈给网络设备。
在本申请实施例中，终端设备也可以预先获取第一组基矢量和第二组基矢量的克罗内克尔积。第一可以组基矢量和第二组基矢量的克罗内克尔积可以是预先定义的，例如协议定义，或者，也可以是由网络设备配置给终端设备的。本申请对此不做限定。
通过协议定义或者网络设备配置第一组基矢量和第二组基矢量的克罗内克尔积的具体方法与通过协议定义或网络设备配置第一组基矢量和第二组基矢量的具体方法相似，为了简洁，这里不再赘述。
基于上文中对第一组基矢量和第二组基矢量的定义，本领域的技术人员可以理解，对信道矩阵或理想预编码矩阵的变换处理可至少包括：对信道矩阵或理想预编码矩阵进行IDFT和DFT。
在本申请实施例中，终端设备可基于天线端口数为N T的一组天线端口对N SB个频域单元进行测量和反馈，则该第一组基矢量可包括N 1个维度为N T×1的列向量，该第二组基矢量可包括N 2个维度为N SB×1的列向量。因此，该第一组基矢量可以通过一个维度为N T×N 1的矩阵表征，该第二组基矢量可以通过一个维度为N SB×N 2的矩阵表征。其中，0<N 1≤N T，0<N 2≤N SB，N 1、N 2均为整数，且N 1、N 2的取值可以相同或不同，本申请对此不做限定。频域单元例如可以包括：子带或者物理资源块(physical resource block，PRB)，或者还可以为现有或未来协议中定义的用于表示频域资源的其他单位，本申请对此不做限定。频域单元的个数N SB可以由系统预定义或者由网络设备通过信令配置，本申请对此不做限定。
对于Massive MIMO中的一个天线阵列来说，天线数目较多，在空间上可以形成很多波束，这些波束在空间的指向性可能是不同的，甚至有可能在任意方向都可以形成一个波束。其中，第一IDFT可理解为将天线上的信道矩阵或理想预编码矩阵投影到波束域，随着天线数目变多，波束变窄，空间信道相关性变高，到达终端设备的信号质量较好的波束数量较少，对应到波束域中的信道矩阵或理想预编码矩阵也就变得稀疏，从而可以仅仅对能够到达终端设备且信号质量较好的一个或几个波束做进一步测量。相同的波束在不同的频域单元(例如，子带或PRB)上由于频选、衰落等因素，在不同的子带上反馈的幅度和 /或相位有可能不同。DFT变换可理解为波束域-频域到波束域-时域的投影，由此可将频域上的信道矩阵或理想预编码矩阵转换到时域上，从而可以将频域上独立反馈的与多个(例如，N SB)频域单元一一对应的多个幅度和/或相位转换成时域上的多个(例如，记作M)点的幅度和/或相位。在通常情况下，N SB是大于M的。该M个点可以是经过上述变换处理之后得到的功率较大的波束。其中，M的值可以是预先定义的，例如，协议定义，或者，也可以是网络设备指示的，或者，还可以是终端设备反馈的，本申请对此不做限定。
为了反馈信道矩阵或预编码矩阵，终端设备可以基于第一组基矢量和第二组基矢量向网络设备指示测量值。
为便于理解，这里以预编码矩阵作为变换处理的对象为例来说明。假设第一组基矢量记作G 1，第二组基矢量记作G 2，预编码矩阵记作V，则基于第一组基矢量和第二组基矢量对该预编码矩阵进行变换处理而得到的一种可能的形式可以是：
Figure PCTCN2018076904-appb-000031
为便于区分，可将
Figure PCTCN2018076904-appb-000032
记作V'。为了反馈该预编码矩阵V，进而可进一步对变换处理后得到的V'进行变换处理，得到的测量值的一种可能的形式可以是：G 1V'G 2 T，将
Figure PCTCN2018076904-appb-000033
代入G 1V'G 2 T，进一步变形可得到
Figure PCTCN2018076904-appb-000034
也就是V。
终端设备所反馈的CSI可以是该测量值的量化值。应理解，上文所说明的变换处理过程仅为便于理解而示出，实际的变换过程可能并不限于上述列举的步骤。终端设备基于信道矩阵或预编码矩阵确定测量值，以及测量值的具体量化方式在后文中会结合具体的实施例详细说明，这里暂且省略对该具体过程的详细描述。
可选地，该方法200还包括：步骤230，网络设备基于由CSI所指示的测量值确定的预编码矩阵对待发送的信号进行预编码，并发送预编码后的信号。
网络设备在接收到CSI之后，可以根据该CSI所指示的测量值确定预编码矩阵，从而能够基于确定得到的预编码矩阵对待发送的信号进行预编码，并发送预编码后的信号。
与之对应地，在步骤230中，终端设备接收预编码后的信号。
具体地，终端设备在步骤220中发送的CSI可用于确定信道矩阵或预编码矩阵。在一种可能的实现方式中，网络设备可根据确定得到的信道矩阵或预编码矩阵，进一步确定用于对待发送的信号进行预编码的预编码矩阵，该预编码矩阵即天线域-频域的预编码矩阵。在另一种可能的实现方式中，网络设备也可根据第一组基矢量和第二组基矢量对测量值进一步做变换处理，以确定波束域-时延域的预编码矩阵，再对待发送的信号进行预编码。本申请对于网络设备对待发送的信号的具体处理方式不做限定。
需要说明的是，终端设备所反馈的CSI是基于预先定义的码本以及多次变换处理而确定的，因此网络设备根据CSI所确定的信道矩阵(或预编码矩阵)与终端设备基于参考信号所确定的信道矩阵(或预编码矩阵)可能是相同的，也可能是相接近的。网络设备由此而确定得到的预编码矩阵可以较好地与当前的信道状态相适配，也就能够获得较好的接收性能。
因此，基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时， 通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
下面将结合具体的实施例详细说明终端设备基于第一组基矢量和第二组基矢量得到测量值并反馈CSI的过程以及网络设备根据CSI确定预编码矩阵的过程。
在本申请实施例中，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵进行变换处理，或者，也可以基于第一组基矢量和第二组基矢量对理想预编码矩阵进行变换处理，对不同的矩阵处理得到的测量值可能不同，下文中会分别以信道矩阵和理想预编码矩阵为例详细说明基于第一组基矢量和第二组基矢量得到测量值的过程。
需要说明的是，网络设备可通过多个发送天线(即，天线端口)发送参考信号，该多个天线端口可以归属于同一个天线端口组，或者，该多个天线端口也可以归属于不同的天线端口组。终端设备可通过多个接收天线(即，天线端口)接收参考信号。对于终端设备的任意一个频率单元来说，信道矩阵的维度可以为：发送天线数×接收天线数。
为便于说明和理解，下文中以一个终端设备的一个接收天线基于一个发送天线组中的天线端口发送的参考信号进行测量和反馈的过程为例详细说明本申请实施例，其中，该网络设备的一个发送天线组可配置有N T(N T≥1，且N T为正整数)个天线端口，终端设备可配置有N R(N R≥1，且N R为正整数)个接收天线。应理解，该网络设备可配置有多个天线端口组，每个天线端口组均可包含N T个天线端口。本申请对于网络设备所配置的发送天线数和接收天线数均不作限定。
另外，该终端设备可以对系统配置的N SB个频率单元进行信道测量和反馈。
其中，N SB可以根据第二组基矢量的矩阵维度确定，例如，该第二组基矢量所包含的行数可以为N SB。或者，N SB可以根据以下至少一个参数确定：系统带宽、CSI-RS带宽、BWP带宽或反馈带宽。例如，根据预定义的N SB和载波带宽、CSI-RS带宽、BWP带宽、载波频点或CSI反馈带宽中的任意一个之间的对应关系，以及配置的载波带宽、CSI-RS带宽、BWP带宽、载波频点或CSI反馈带宽中任意一个确定N SB。
基于上述参数，对于N SB个频率单元中的第n sb(1≤n sb≤N SB)个频率单元来说，信道矩阵(为便于区分，例如记作H sb)的维度可以为N T×N R。对于终端设备的每一个接收天线来说，在空间域-频率域的信道矩阵(为便于区分，例如记作H r)的维度可以为N T×N SB。其中，该信道矩阵中的第n sb列是第n sb个频率单元上所有天线端口到接收天线的信道相应系数，可对应于信道矩阵H sb中第H r行的转置。
终端设备可以对每个接收天线所对应的信道矩阵进行SVD可得到与每个接收天线对应的预编码矩阵。因此，对于终端设备的第r(1≤r≤N R)个接收天线来说，或者说，对于秩为A(1≤A≤min{N T，N R}，且R为整数)的信道矩阵而言，对于第r(1≤r≤A)个层(layer)而言，预编码矩阵(为便于区分，例如记作V r)的维度也可以为N T×N SB。
需要说明的是，通常情况下，配置于网络设备的发送天线数N T可能大于或等于配置于终端设备的接收天线数N R，也就是，1≤A≤N R，下文中，在未作出特别说明的情况下，为方便说明，假设A＝N R。但应理解，这不应对本申请构成任何影响，在A也可以为小于N R的正整数。并且，秩的值可以由终端设备所反馈的RI确定。
也就是说，测量值可以包括N R个列，每个列的维度可以是(N T·N SB)×1；或者，测量 值可以包括N R个矩阵，每个矩阵的维度可以是N T×N SB。
假设第一组基矢量为G 1，第二组基矢量为G 2，第一组基矢量的维度例如可以为N T×N 1，第二组基矢量的维度例如可以为N SB×N 2。
下面分别以信道矩阵和预编码矩阵作为终端设备变换处理的对象，详细说明终端设备反馈CSI的过程以及网络设备根据CSI确定预编码矩阵的过程。
1、以预编码矩阵为变换处理的对象：
基于第一组基矢量和第二组基矢量对预编码矩阵V r进行变换处理而得到的一种可能的形式是
Figure PCTCN2018076904-appb-000035
为便于区分，可将
Figure PCTCN2018076904-appb-000036
由上述各矩阵的维度以及变换可知，V P,T的维度可以为N 1×N 2。为了反馈该预编码矩阵V r，可进一步对V r进行变换处理，得到测量值y r。该测量值y r可理解为对应于第r个接收天线的测量值，或者，对应于第r个层的测量值。
在本申请实施例中，该测量值y r的一种可能的形式可以是：G 1V PTG 2 T。将
Figure PCTCN2018076904-appb-000037
可进一步变形可得到
Figure PCTCN2018076904-appb-000038
也就是V r。可以理解，该V r的维度可以为N T×N SB。
换句话说，终端设备可以通过CSI将预编码矩阵V r反馈给网络设备。
本领域的技术人员可以理解，经过上述变换处理得到的测量值可以与第一组基矢量和第二组基矢量相关，或者，该测量值可以与第一组基矢量和第二组基矢量的克罗内克尔积相关。
在本申请实施例中，终端设备对预编码矩阵的变换处理的方式以及网络设备根据CSI确定预编码矩阵可至少包括以下四种中的任意一种。下面分别对这四种方式做详细说明。
A、方式一
方式一可包括步骤i)至步骤viii)，其中步骤i)至步骤v)可以为终端设备执行的操作，步骤vi)至步骤vii)可以为网络设备执行的操作。
步骤i)、
终端设备可以基于第一组基矢量对理想预编码矩阵按列进行IDFT，得到维度为N 1×N SB的矩阵。
例如，终端设备可以将维度为N T×N SB的预编码矩阵V r左乘维度为N T×N 1的第一组基矢量G 1的共轭转置
Figure PCTCN2018076904-appb-000039
比如得到
Figure PCTCN2018076904-appb-000040
则V P的维度可以为N 1×N SB。
步骤ii)、
终端设备可以基于第二组基矢量对IDFT处理的结果按行进行DFT，得到维度为N 1×N 2的矩阵。
例如，可以将维度为N SB×N 2的第二组基矢量G 2的共轭转置的转置右乘维度为N 1×N SB的矩阵V P，比如得到V P,T，V P,T＝V P(G 2 *) T，也就是，
Figure PCTCN2018076904-appb-000041
则V P,T的维度可以为N 1×N 2。
步骤iii)、
终端设备可以根据经IDFT得到的矩阵确定M个波束。
例如，基于预先获取的M值，对IDFT处理得到的矩阵V P,T中的各元素的功率按照由大到小的顺序排序，找出功率值较大的M个元素，而将其余元素置零。其中，功率可以与幅值的平方成正比，因此可以从经IDFT得到的矩阵所包含的N T×N SB个元素中确定M 个幅值的绝对值较大的元素。在该V P,T的N 1×N 2个元素中，M个功率较大的元素中的任意一个元素的功率大于剩余的N 1×N 2-M个元素中的任意一个元素的功率。终端设备可将剩余的(N 1×N 2-M)个元素置零，得到处理后的矩阵(为便于区分和说明，例如记作第一矩阵V P,T')，该第一矩阵的维度仍然可以为N 1×N 2。
步骤iv)、
终端设备可以将第一矩阵转换为维度为(N 1·N 2)×1的列向量。
终端设备可以将维度为N 1×N 2的第一矩阵转换为维度为(N 1·N 2)×1的列向量。例如，可以将维度为N 1×N 2的第一矩阵中的第二列至第N 2列元素依次拼接在第一列元素下方，得到维度为(N 1·N 2)×1的列向量。该列向量中的第一个元素至N 1个元素可对应于矩阵的第一列，该列向量中的第N 1+1个元素至第2N 1个元素可对应于矩阵的第二列，以此类推。为便于区分和说明，例如将该列向量记作u，该列向量u可包含N 1×N 2个复数元素，其中有M个非零元素。
该M个非零元素的位置可用于指示M个波束的位置。具体地，该M个非零元素在列向量u中的N 1×N 2行中的位置可对应于该M个波束在预先定义的维度为(N T·N SB)×(N 1·N 2)的矩阵的N 1×N 2列中的位置，该N 1×N 2列中的M个列矢量即为M个波束的波束矢量。其中，该预先定义的维度为(N T·N SB)×(N 1·N 2)的矩阵可以是第一组基矢量G 1和第二组基矢量G 2的克罗内克尔积
Figure PCTCN2018076904-appb-000042
对于终端设备来说，该M个波束所发射的信号具有较好的信号接收质量，也就是被选择的较优的M个波束。
其中，M的取值可以是预先定义，例如，协议定义，也可以是由网络设备指示，本申请对此不做限定。
如果该M的值由网络设备指示，则可选地，该方法还包括：终端设备接收M的指示信息。相应地，网络设备发送M的指示信息。
可选地，M的指示信息可携带在高层信令中，也可以携带在物理层信令中。作为示例而非限定，高层信令例如包括RRC消息或MAC CE等。作为示例而非限定，物理层信令例如包括DCI。
步骤v)、
终端设备发送CSI，该CSI可用于指示测量值。
当终端设备基于N R个接收天线或N R个层进行测量和反馈时，终端设备可以向网络设备发送N R组指示信息。对于有一个天线端口组而言，可选地，该CSI可以包括N R组指示信息，每组指示信息可以包括以下一项或多项：
a)M个波束的指示信息；
b)与该M个波束对应的幅度系数的指示信息；
c)与该M个波束对应的相位系数的指示信息。
在某些情况下，网络设备可以将上述a)至c)三项中的任意一项或两项预先定义好，而仅需要反馈剩余的两项或一项。例如，网络设备预先定义了M个波束，则终端设备可以仅反馈与该M个波束对应的幅度系数的指示信息和与该M个波束对应的相位系数的指示信息；又例如，网络设备预先定义了M个波束和M个波束的幅度系数，则终端设备可仅反馈该M个波束的相位系数。为了简洁，这里不再一一列举。
需要说明的是，在本申请实施例中，与N R个列对应的N R组指示信息可以相互独立地 反馈，也可以通过差分的方式反馈。例如，在M个基矢量、与M个基矢量对应的M个幅度系数以及与M个基矢量对应的M个相位系数这三项都由终端设备来反馈的情况下，对于N R个列中的某一列可以通过M个基矢量、M个绝对幅度以及M个绝对相位来指示，剩余的(N R-1)列可通过M个基矢量、M个相对幅度以及与M个相对相位来指示。本申请对此不做限定。
下面将分别详细说明终端设备指示上述a)至c)三项的具体方式。
a)M个波束的指示信息：
该M个波束的指示信息可以为上述M个功率较大的元素在维度为(N 1·N 2)×1的列向量u中的位置信息。在一种可能的设计中，可以通过联合编码的方式来指示该M个功率较大的元素的位置，故可能需要
Figure PCTCN2018076904-appb-000043
个比特的开销。在另一种可能的设计中，可通过位图的方式来指示每个功率较大的元素的位置，每个比特对应第一矩阵中的一个元素，故可能需要N 1×N 2个比特的开销。
应理解，上述列举的指示该M个波束的具体方法仅为几种可能的是实现方式，而不应对本申请构成任何限定。本申请并不排除采用其他方式来指示该M个波束在维度为N 1×N 2的第一矩阵中的位置。
本领域的技术人员可以理解，该M个波束可对应M个波束矢量，或者说，M个基矢量。因此，在一种可能的实现方式中，该M个波束在上述维度为(N 1·N 2)×1的列向量u中的位置也就是该M个基矢量在第一组基矢量G 1和第二组基矢量G 2的Kronecker积
Figure PCTCN2018076904-appb-000044
中的位置。该
Figure PCTCN2018076904-appb-000045
的维度可以为(N T·N SB)×(N 1·N 2)。也就是说，上述M个波束在维度为(N 1·N 2)×1的列向量u的N 1·N 2个行中的位置，即可对应于M个基矢量在W中的N 1·N 2个列中的位置。上述M个基矢量可以是从
Figure PCTCN2018076904-appb-000046
中的N 1·N 2个列中确定的M个列,每个列都包含N T·N SB个元素。
因此，上述M个波束的指示信息可以包括该M个基矢量在预先配置的矩阵中的位置，该预先配置的矩阵，该矩阵即由
Figure PCTCN2018076904-appb-000047
得到的矩阵。
在另一种可能的实现方式中，该M个波束所对应的M个基矢量中，每个基矢量可以满足：
Figure PCTCN2018076904-appb-000048
其中，v i可以是M个基矢量中的第i个基矢量，1≤i≤M且i为正整数，g i,1可以是维度为N T×1的列向量，可理解为第i个基矢量的第一分量，可从第一组基矢量G 1中确定，g i,2可以是维度为N SB×1的列向量，可理解为第i个基矢量的第二分量，可从第二组基矢量G 2中确定。则每个基矢量满足
Figure PCTCN2018076904-appb-000049
则每个基矢量可包括N T·N SB个元素。
因此，上述M个波束的指示信息可以包括该M个基矢量中的每个基矢量的第一分量在第一组基矢量中的位置和每个基矢量的第二分量在第二组基矢量中的位置。
b)与M个波束对应的幅度系数的指示信息：
与M个波束对应的M个幅度系数可对应于上述第一矩阵中的M个功率较大的复数元素的模。终端设备可以将该M个复数元素的模的量化值发送给网络设备。
在一种可能的设计中，网络设备和终端设备可预先保存有多个幅度系数与多个索引的对应关系，该多个幅度系数与多个索引的对应关系例如可以称为幅度码本。终端设备可将幅度码本中与M个复数元素的实部最接近的M个幅度系数的索引发送给网络设备，以便 网络设备基于M个索引确定M个幅度系数。
在另一种可能的设计中，网络设备和终端设备可预先保存多个幅度系数与多个索引的对应关系以及多个幅度差分值与多个索引的对应关系，该多个幅度系数与多个索引的对应关系例如可以称为第一幅度码本，该多个幅度差分值与多个索引的对应关系例如可以称为第二幅度码本。终端设备可以采用差分的方式来反馈，以减小反馈开销。例如，可将M个复数元素中最大幅度的绝对值指示给网络设备，比如将第一幅度码本中与该最大幅度最接近的幅度系数的索引发送给网络设备，将剩余的(M-1)个复数元素的幅度相对于上述最大幅度的差分值指示给网络设备，比如将与剩余的(M-1)个复数元素的幅度相对于上述最大幅度的差分值最接近的(M-1)个差分值的索引发送给网络设备。其中，用于指示最大幅度的比特开销可以大于用于指示剩余的(M-1)个相对幅度的比特开销，比如，最大幅度的比特开销为b个比特，每一个相对幅度的比特开销为c个比特，b＞c，网络设备根据接收到的CSI中各字段的比特数的不同，可以确定各字段中承载的索引所对应的码本。
基于上文列举的用于指示与M个波束对应的幅度系数的方法，可以分别通过a个比特均匀量化每个复数元素的幅度，也可以通过b个比特量化最大幅度，通过(M-1)c个比特量化相对幅度，本申请对此不做限定。
c)与M个波束对应的相位系数的指示信息：
与M个波束对应的M个相位系数可由上述第一矩阵中的M个功率较大的复数元素的实部和虚部确定。终端设备可以根据该M个复数元素的实部和虚部确定所对应的M个相位系数，并将相位系数的量化值发送给网络设备。
在一种可能的设计中，网络设备和终端设备可预先保存多个相位系数与多个索引的对应关系，该多个相位系数与多个索引的对应关系例如可以称为相位码本。终端设备可将相位码本中与M个复数元素的所对应的M个相位系数最接近的M个相位系数的索引发送给网络设备，以便网络设备基于M个索引确定M个相位系数。
在另一种可能的设计中，网络设备可预先保存多个相位系数与多个索引的对应关系以及多个相位差分值与多个索引的对应关系，该多个相位系数与多个索引的对应关系例如可以称为第一相位码本，该多个相位差分值与多个索引的对应关系例如可以称为第二相位码本。终端设备可以采用差分的方式来反馈，以减小反馈开销。例如，可以将M个复数元素中的第一个复数元素的相位系数指示给网络设备，比如将第一相位码本中与第一个复数元素的相位系数最接近的相位系数的索引发送给网络设备，将剩余的(M-1)个复数元素的相位系数相对于第一个复数元素的相位系数的差分值指示给网络设备，比如将与剩余的(M-1)个复数元素的相位系数相对于第一个复数元素的相位系数的差分值最接近的(M-1)个差分值的索引发送给网络设备。其中，用于指示第一个复数元素的相位系数的比特开销可以大于用于指示剩余的(M-1)个差分值的比特开销，比如，第一个复数元素的相位系数的比特开销为j个比特，每一个差分值的比特开销为k个比特，j＞k，网络设备根据接收到的CSI中各字段的比特数的不同，可以确定各字段中承载的索引所对应的码本。
基于上文列举的用于指示与M个波束对应的相位系数的方法，可以分别通过l个比特均匀量化每个复数元素的相位，也可以通过j个比特量化第一个复数元素的相位，通过 (M-1)k个比特量化相对幅度，本申请对此不做限定。
基于上文中在b)和c)中列举的指示方法，可将幅度系数均匀量化和相位系数均匀量化的方式结合使用，或者，也可将幅度系数非均匀量化和相位系数均匀量化的方式结合使用，或者，也可将幅度系数非均匀量化和相位系数均匀量化的方式结合使用，或者，还可以将幅度相位非均匀量化和相位系数非均匀量化的方式结合使用，本申请对此不做限定。
应理解，以上列举的多种用于指示M个波束以及与M个波束对应的幅度系数和与M个波束对应的相位系数的具体方法以及量化的比特开销仅为示例性说明，而不应对本申请构成任何限定。
还应理解，上文中的a)、b)和c)中的一项或多项分别可以单独反馈；当需要反馈a)、b)和c)中的多项时，任意两项或三项可以通过联合编码的方式来指示，本申请对此不做限定。
在本申请实施例中，该CSI中的N R组指示信息可用于指示N R个列向量，该N R个列可构成一个测量值Z。该测量值Z可以包括N R个列向量，该N R个列向量可理解为测量值Z的N R个分量。可以理解的是，该N R个分量也可以理解为一个测量值，即，对应一个接收天线或对应一个层的测量值。下文中，测量值Z和测量值y n交替出现，本领域的技术人员可以理解，这两者的维度是不同的，测量值y n可以是测量值Z中的第n个列向量。
其中，该N R个列中的第n(1≤n≤N R，n为整数)列可表示为y n，y n满足：
Figure PCTCN2018076904-appb-000050
其中，α为归一化系数，M为基矢量的数量，M个基矢量为第一组基矢量G 1和第二组基矢量G 2的克罗内克尔积中的M个列，
Figure PCTCN2018076904-appb-000051
为所述M个基矢量中的第i个列矢量，且
Figure PCTCN2018076904-appb-000052
的维度为N T·N SB×1，
Figure PCTCN2018076904-appb-000053
为
Figure PCTCN2018076904-appb-000054
的线性叠加系数，
Figure PCTCN2018076904-appb-000055
为
Figure PCTCN2018076904-appb-000056
的幅度系数，
Figure PCTCN2018076904-appb-000057
为
Figure PCTCN2018076904-appb-000058
的相位系数。N T为发送参考信号的天线端口数，N SB为传输参考信号的频域资源所包括的频域单元数，1≤i≤M，i、M均为整数。
需要说明的是，该N R个列中的每个列都可满足上述
Figure PCTCN2018076904-appb-000059
的结构，或者说，具有相同的维度。但对于每个列向量来说，用于构造列向量的M个基矢量、M个幅度系数或M个相位系数中的一项或多项由可能不同，因此，该N R个列中的任意两列可能是不同的，也可能是相同的。本申请对此不做限定。
可选地，该测量值y n可等价于
Figure PCTCN2018076904-appb-000060
则该测量值y n可以是维度为(N T·N SB)×1的列向量。
测量值y r可以理解为对应于第r个接收天线或第r个层的测量值，即，n＝r。由于上述维度为(N 1·N 2)×1的列向量u由第一矩阵V P,T'转换而来，而第一矩阵V P,T'是在对V P,T处理之后得到的矩阵，因此，上述测量值y r可认为是基于V P,T转换而来。将该维度为(N T·N SB)×1的测量值y r进一步转换为维度为N T×N SB的矩阵，该矩阵是一个逼近预编码矩阵V r的矩阵。
可选地，该测量值y n可以等价于G 1V P,T'G 2 T转换而成的列向量。由于G 1V P,T'G 2 T为维度为N 1×N 2的矩阵，则转换得到的列向量的维度为(N 1·N 2)×1。
测量值y r可以理解为对应于第r个接收天线或第r个层的测量值，即，n＝r。由于上 述第一矩阵V P,T'是在对V P,T处理之后得到的矩阵，因此，上述测量值y r可认为是基于V P,T转换而来。将该维度为(N T·N SB)×1的测量值y r进一步转换为维度为N T×N SB的矩阵，该矩阵是一个逼近预编码矩阵V r的矩阵。
因此，上述测量值Z的维度可以为(N T·N SB)×N R。
应理解，上文描述的与测量值等价的两种可能的形式仅为示例性说明，并且为了便于理解，上文中示出了具体的变换过程，但这并不代表终端设备执行了上述操作，终端设备可直接向网络设备反馈CSI来指示上述测量值，以便于网络设备确定预编码矩阵。
由于上述变换处理是从一个接收天线或一个层的角度来描述的，对于终端设备的多个接收天线或多个层来说，其变换处理的过程是相似的。因此，对于终端设备的多个接收天线或多个层来说，多个接收天线或多个层所对应的测量值可构成测量值Z。在[1，N]中对n遍历取值，便可得到该测量值Z。
应理解，上述实施例中，为便于说明，假设该信道矩阵的秩等于接收天线数。但这仅为示例性说明，不应对本申请构成任何限定，本申请对于秩的取值并不限定，例如，秩也可以为小于接收天线数的整数值。
步骤vi)、
网络设备可根据接收到的CSI确定测量值。
网络设备可以根据接收到的CSI中的每组指示信息，得到与一个接收天线或一个层对应的测量值，该测量值的维度可以为(N T·N SB)×1。具体地，网络设备可以根据预先定义的矩阵(即，
Figure PCTCN2018076904-appb-000061
)中多个列向量与多个索引的对应关系确定M个波束矢量，或者，根据预先定义的第一组基矢量中多个列向量与多个索引的对应关系以及第二组基矢量中多个列向量与多个索引的对应关系确定M个波束矢量。网络设备还可根据预先保存的多个量化值与多个幅度系数的对应关系，和/或，多个量化值与多个相位系数的对应关系，确定与M个波束对应的M个幅度系数，和/或，与M个波束对应的M个相位系数。由此可以根据CSI中的一组指示信息得到测量值y r。
网络设备可进一步将该测量值y r转换为维度为N T×N SB的矩阵。比如，网络设备可将测量值y r的第(N T·N SB-N T+1)行至第(N T·N SB)行作为第二矩阵的第N SB列，将测量值y r的第(N T·N SB-2N T+1)行至第(N T·N SB-N T)行作为第二矩阵的第N SB列，以此类推。为便于区分和说明，可将由该测量值y r恢复得到的维度为N T×N SB的矩阵记作第三矩阵V P,T”'。
可以理解，该第三矩阵V P,T”'与步骤iii)中的第一矩阵V P,T'相同或相接近，也就是与终端设备基于参考信号测量得到的预编码矩阵V r相同或相接近。因此，该第三矩阵V P,T”'也就是网络设备根据CSI确定的与一个接收天线或一个层对应的预编码矩阵。
进一步地，网络设备可通过在[1，N R]中对n遍历取值，可以得到测量值Z'。该测量值Z'的维度可以为(N T·N SB)×N R。通过对测量值Z'中的每个列执行上述操作，可得到N R个维度为N T×N SB的矩阵。在保持行数不变的前提下，将该N R个N T×N SB的矩阵依次拼接可得到一个维度为N T×(N R·N SB)的矩阵。该维度为N T×(N R·N SB)的矩阵即可以理解为与一个天线端口组对应的预编码矩阵。
可以理解，网络设备根据CSI计算得到的测量值Z'与终端设备对预编码矩阵V r进行上述变换处理后得到的测量值Z可能相同或相接近。也就是说，网络设备基于CSI确定的 预编码矩阵与基于参考信号确定的预编码矩阵可能相同或相接近。
步骤vii)、
可选地，网络设备也可进一步由测量值转换得到的N R个维度为N T×N SB的矩阵进行IDFT和DFT的逆变换。
例如，网络设备对由测量值Z'中的第r列转换得到的第三矩阵V PT”'进行IDFT和DFT的逆变换，得到
Figure PCTCN2018076904-appb-000062
根据测量值Z'中的每个列转换得到的N R个维度为N T×N SB的矩阵进行IDFT和DFT的逆变换可得到N R个维度为N T×N SB的矩阵，在保持行数不变的前提下，将该N R个N T×N SB的矩阵依次拼接可得到一个维度为N T×(N R·N SB)的矩阵。该维度为N T×(N R·N SB)的矩阵即可以理解为与一个天线端口组对应的预编码矩阵。
进一步地，若考虑多个天线端口组，例如天线端口组数为p，则终端设备和网络设备可以分别对每个天线端口组执行上述操作，得到p个维度为N T×(N R·N SB)的矩阵。然后在保持列数不变的前提下，将得到的维度为N T×(N R·N SB)的矩阵依次拼接得到一个维度为(p·N T)×(N R·N SB)的矩阵，该(p·N T)×(N R·N SB)的矩阵即为与p个天线端口组对应的预编码矩阵。
应理解，若终端设备基于多个天线端口组进行信道测量和反馈，则该终端设备可以基于相同的指示方式向网络设备反馈与多个天线端口组对应的多组指示信息。例如，可以基于不同的天线端口组，按照上文中所列举的方式指示M个波束、与M个波束对应的M个幅度系数以及与M个波束对应的M个相位系数，或者，也可以基于其中的一个天线端口组(例如记作天线端口组#1)，按照上文中所列举的方式指示与天线端口组#1对应的M个波束、与该M个波束对应的M个幅度系数和与该M个波束对应的M个相位系数，基于剩下的一个或多个天线端口组(例如记作天线端口组#2)，反馈与天线端口组#2对应的M个波束、与该M个波束对应的M个幅度系数与天线端口组#1的M个幅度系数的差分值以及与该M个波束对应的M个相位系数与天线端口组#1中的M个相位系数的差分值。因此，基于多个天线端口组所反馈的CSI可以包括与该多个天线端口组对应的N R组指示信息，与该多个天线端口组对应的N R组指示信息可用于指示多个测量值构成的测量值集合。
还应理解，终端设备可以基于多个天线端口组，针对每个天线端口组所对应的M个波束、与M个波束对应的M个幅度系数以及与M个波束对应的M个相位系数中的一项或多项作反馈，本申请对此不做限定。
基于上述方法，终端设备可通过FFT和IFFT的快速运算获得待反馈的测量值，通过CSI将测量值的量化值发送给网络设备，网络设备可以根据CSI，通过FFT和IFFT的逆运算确定得到预编码矩阵。相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
B、方式二
方式二可包括步骤i)至步骤vx)，其中步骤i)至步骤v)可以为终端设备执行的操 作，步骤vi)至步骤vx)可以为网络设备执行的操作。
步骤i)、
终端设备可以基于第一组基矢量对预编码矩阵进行IDFT，得到维度为N 1×N SB的矩阵。
步骤ii)、
终端设备可以基于第二组基矢量对IDFT处理的结果进行DFT，得到维度为N 1×N 2的矩阵。
经过步骤i)和步骤ii)可得到矩阵
Figure PCTCN2018076904-appb-000063
为便于区分和说明，将该维度为N 1×N 2的矩阵V P,T记作第四矩阵。
应理解，方式二中的步骤i)和步骤ii)的具体过程和方式一的步骤i)和步骤ii)的具体过程相同，为了简洁，这里不再赘述。
步骤iii)、
终端设备将DFT得到的矩阵转换为列向量。
例如，可以将经过IDFT得到的维度为N 1×N 2的矩阵V P,T中的第二列至第N SB列元素依次拼接在第一列元素下方，得到维度为N 1·N 2×1的列向量。为便于区分和说明，将该维度为的列向量记作x。该列向量中的第一个元素至N 1个元素可对应于矩阵的第一列，该列向量中的第N 1+1个元素至第2N 1个元素可对应于矩阵的第二列，以此类推。
步骤iv)、
终端设备可以对该维度为N 1·N 2×1的列向量进行压缩变换，得到维度为M×1的列向量。
例如，基于预先获取的压缩变换矩阵ψ对N 1·N 2×1的列向量x进行压缩变换。比如通过列向量x左乘压缩变换矩阵ψ，得到ψx。该压缩变换矩阵的维度例如可以为M×(N 1·N 2)，将上述维度为(N 1·N 2)×1的列向量x左乘该压缩变换矩阵ψ可得到维度为M×1的列向量。经过压缩得到的维度可以为M×1的列向量可理解为终端设备基于参考信号测量得到的测量值y r。
其中，上述压缩变换矩阵可以预先定义，例如，协议定义，也可以由网络设备指示，本申请对此不做限定。
步骤v)、
终端设备可以向网络设备发送CSI，该CSI用于指示测量值。
基于上述变换处理后，终端设备可以将维度为M×1的测量值y r中的M个复数元素的实部和虚部的量化值分别反馈给网络设备，以便于网络设备根据接收到的CSI确定测量值。
例如，对每个复数元素使用预定义的比特数进行量化，比如使用20个比特量化一个复数元素，实部使用10个比特，虚部使用10个比特。10比特中的前面6个比特可用于量化整数部分，后面4个比特可用于量化小数部分。
因此，终端设备发送给网络设备的CSI中可携带M个复数元素的量化值。终端设备可将该M个复数元素的量化值单独编码并反馈给网络设备，也可以将M个复数元素的量化值联合编码并反馈给网络设备，本申请对此不做限定。
需要说明的是，终端设备和网络设备预先保存有多个量化值与多个数值的对应关系， 终端设备可基于该对应关系量化每个复数元素，网络设备也可基于该对应关系根据量化值确定每个复数元素。
由于上述变换处理是从一个接收天线或一个层的角度来描述的，对于终端设备的多个接收天线或多个层来说，其变换处理的过程是相似的。因此，对于终端设备的多个接收天线或多个层来说，测量值可以记作Z，Z可以包括多个列，在上文中已经说明，接收天线数或秩的取值均可以为N R，则该测量值Z中的每个列向量对应一个测量值y n(1≤n≤N R，且n为正整数)。该测量值Z所包括的列数即该测量值Z所包括的测量值分量的个数。即，n在[1，N R]中遍历取值，且n为正整数。
因此，上述测量值Z的维度可以为M×N R。
步骤vi)、
网络设备可以根据CSI确定测量值。
网络设备可以根据预先保存的多个量化值与多个数值的对应关系，根据CSI中的量化值，确定M个复数元素，由此得到维度为M×1的列向量，也就是测量值y r'。可以理解，该网络设备根据CSI确定得到的测量值y r'与终端设备基于预编码矩阵变换处理得到的测量值y r可以相同或相接近。
步骤vii)、
网络设备可以基于压缩变换矩阵将测量值恢复为维度为(N 1·N 2)×1的列向量。
网络设备可以通过压缩变换的逆变换，将维度为M×1的列向量转换为维度为(N 1·N 2)×1的列向量。为便于区分和说明，将经过压缩变换的逆变换得到的维度为(N 1·N 2)×1的列向量记作x'。可以理解，网络设备经对测量值y r'进行压缩变换的逆变换得到的列向量x'与终端设备根据预编码矩阵V r转换得到的列向量x可以相同或相接近。
步骤viii)、
网络设备可以进一步将该维度为M×1的列向量转换为维度为N 1×N 2的矩阵。
网络设备可以进一步将该维度为M×1的列向量x'转换成维度为N 1×N 2的矩阵V P,T'。为便于区分和说明，将该维度为N 1×N 2的矩阵V P,T'记作第五矩阵。可以理解，该第五矩阵V P,T'是根据终端设备反馈的CSI所确定的测量值y r'转换得到，因此该第五矩阵V P,T'与终端设备根据预编码矩阵V r转换得到的第四矩阵V P,T是相同或者相接近的。
应理解，网络设备将维度为M×1的列向量x'转换成维度为N 1×N 2的第五矩阵的具体过程与方式一的步骤vii)中将列向量转换为第三矩阵的具体过程相似，为了简洁，这里不再赘述。
步骤vx)
网络设备可以根据第五矩阵确定预编码矩阵。
网络设备可基于第一组基矢量和第二组基矢量，对第五矩阵V P,T'进行IDFT和DFT可得到预编码矩阵V r'，即，V r'＝G 1V P,T'(G 2) T。上文中已经说明，第五矩阵V P,T'与第四矩阵V P,T是相同或者相接近，因此，V r'也就可以近似的等于G 1V P,T(G 2) T，将
Figure PCTCN2018076904-appb-000064
代入便可得到V r'近似等于
Figure PCTCN2018076904-appb-000065
简化后可得到V r'近似等于V r。因此，该网络设备根据第五矩阵确定得到的预编码矩阵V r'与终端设备基于参考信号确定的预编码矩阵V r是相同或相接近的。
进一步地，网络设备可以通过在在[1，N R]中对n遍历取值，可以得到测量值Z'。该 测量值Z'的维度可以为M×N R。通过对测量值Z'中的每个列执行上述操作，可得到N R个维度为N T×N SB的预编码矩阵。
再进一步地，若考虑多个天线端口组，例如天线端口组数为p，则终端设备和网络设备可以分别对每个天线端口组执行上述操作，然后在保持列数不变的前提下，将得到的维度为N T×(N R·N SB)的矩阵依次拼接得到一个维度为(p·N T)×(N R·N SB)的矩阵。
基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
C、方式三
方式三可包括步骤i)至步骤vi)，其中，步骤i)至步骤v)可以为终端设备执行的操作，步骤vi)可以为网络设备执行的操作。
步骤i)、
终端设备可基于第一组基矢量对预编码矩阵进行IDFT，得到维度为N 1×N SB的矩阵。
例如，终端设备可将预编码矩阵V r左乘第一组基矢量G 1的共轭转置得到维度为N 1×N SB的矩阵
Figure PCTCN2018076904-appb-000066
应理解，方式三中的步骤i)的具体过程和方式一的步骤i)的具体过程相同，为了简洁，这里不再赘述。
步骤ii)、
终端设备可根据经IDFT得到的矩阵确定M B个波束矢量。
具体地，终端设备可以基于预先获取的M B(1≤M B≤N 1，且M B为正整数)，从IDFT处理得到的维度为N 1×N SB的矩阵中确定功率较大的M B个行。比如对IDFT处理得到的矩阵中的各行元素的功率求和后按照由大到小的顺序排列，找出功率值较大的M B个行，保留该M B个行中的元素不变，而将其余行的元素置零。上述处理后得到的矩阵的维度仍为N 1×N SB。为方便区分和说明，将经过上述处理的矩阵记作第六矩阵U P。该第六矩阵中的非零元素所在的M B个行的位置可用于指示在波束域-频域上功率较大的M B个波束的波束矢量。即，该M B个行在第六矩阵中的位置可对应于M B个波束矢量在维度为N T×N 1的第一组基矢量G 1的N 1个列中的位置。
应理解，从维度为N 1×N SB的矩阵中确定功率较大的M B个行的具体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，本申请对于确定功率较大的M B个行的具体方式不做限定。
其中，M B的值可以预先定义，例如，协议定义，也可以由网络设备指示，本申请对此不做限定。
如果M B的值由网络设备指示，则可选地，该方法还包括：终端设备接收M B的指示信息。相应地，网络设备发送M B的指示信息。
可选地，M B的指示信息可携带在高层信令中，也可以携带在物理层信令中。作为示例而非限定，高层信令例如包括RRC消息或MAC CE等。作为示例而非限定，物理层信令例如包括DCI。
步骤iii)、
终端设备可对第六矩阵进行DFT，得到维度为N 1×N 2的矩阵。
例如，终端设备可将第六矩阵U P右乘第二组基矢量G 2的共轭转置的转置，得到维度为N 1×N 2的矩阵
Figure PCTCN2018076904-appb-000067
应理解，方式三中的步骤iii)的具体过程和方式一中的步骤ii)的具体过程相似，只是矩阵的维度不同，为了简洁，这里不再赘述。
步骤iv)、
终端设备可对DFT得到的矩阵确定M T个波束矢量。
具体地，终端设备可以基于预先获取的M T(1≤M T≤N 2，且M T为正整数)，对DFT处理得到的维度为N 1×N 2的矩阵中的各列元素的功率求和后按照由大到小的顺序排序，找出功率值较大的M T个列，保留该M T个列中的元素不变，而将其余列的元素置零。上述处理后得到的矩阵的维度仍为N 1×N 2。为方便区分和说明，将经过上述处理的矩阵记作第七矩阵U P,T'。该第七矩阵中非零元素所在的M T个列的位置可用于指示在波束域-时域上功率较大的M T个波束的波束矢量。即，该M T个列在第七矩阵中的位置可对应于M T个波束矢量在维度为N SB×N 2的第二组基矢量G 2中的N 2个列中的位置。
应理解，从维度为N 1×N 2的矩阵中确定功率较大的M T个列的具体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，本申请对于确定功率较大的M T个列的具体方式不做限定。
其中，M T的值可以预先定义，例如，协议定义，也可以由网络设备指示，本申请对此不做限定。
如果M T的值由网络设备指示，则可选地，该方法还包括：网络设备发送M T的指示信息。相应地，终端设备接收M T的指示信息。
可选地，M T的指示信息可携带在高层信令中，也可以携带在物理层信令中。作为示例而非限定，高层信令例如包括RRC消息或MAC CE等。作为示例而非限定，物理层信令例如包括DCI。
可选地，M B的指示信息和M T的指示信息可以携带在同一个信令中，或者携带在不同的信令中，本申请对此不做限定。
步骤v)、
终端设备发送CSI，该CSI可用于指示测量值。
当终端设备基于N R个接收天线或N R个层进行测量和反馈时，终端设备可以向网络设备发送N R组指示信息。可选地，CSI可以包括N R组指示信息，每组指示信息包括以下一项或多项：
d)M B个第一基矢量的指示信息；
e)M T个第二基矢量的指示信息；
f)与该M B个第一基矢量和M T个第二基矢量对应的M个幅度系数的指示信息；
g)与该M B个第一基矢量和M T个第二基矢量对应的M个相位系数的指示信息。
在某些情况下，网络设备和终端设备可以将上述d)至g)四项中的任意一项或多项预先定义好，而仅需要终端设备反馈剩余的一项或多项。例如，网络设备可预先定义M个波束，也就是预先定义上述M B个第一基矢量和M T个第二基矢量，则终端设备可以仅反馈与该M个波束对应的幅度系数的指示信息和与该M个波束对应的相位系数的指示信息；又例如，网络设备可预先定义M个波束和M个波束的幅度系数，则终端设备可仅反馈该M个波束的相位系数。为了简洁，这里不再一一列举。
下面将分别详细说明终端设备指示上述d)至g)四项的具体方式。
d)M B个第一基矢量的指示信息：
该M B个第一基矢量的指示信息可以为上述M B个行在维度为N 1×N SB的第六矩阵中的位置信息。该M B个行在维度为N 1×N SB的第六矩阵中的位置也就对应于M B个波束矢量在第一组基矢量的N 1个列中的位置。
在一种可能的设计中，可以通过联合编码的方式来指示该M B个行的位置，故可能需要
Figure PCTCN2018076904-appb-000068
个比特的开销。在另一种可能的设计中，可通过位图的方式指示N 1个行向量中功率较大的M B个行向量，位图中的每个比特为可对应于N 1个行向量中的一个，因此需要N 1个比特的开销。
应理解，上述列举的指示该M B个第一基矢量的具体方法仅为几种可能的实现方式，而不应对本申请构成任何限定。本申请并不排除采用其他方式来指示该M B个第一基矢量在维度为N 1×N SB的第六矩阵中的位置。
e)M T个第二基矢量的指示信息：
该M T个第二基矢量的指示信息可以为上述M T个列向量在维度为N 1×N 2的第七矩阵中的位置信息。该M T个列向量在维度为N 1×N 2的第七矩阵中的位置也就对应于M T个波束矢量在第二组基矢量的N 2个列中的位置。
在一种可能的设计中，可以通过联合编码的方式来指示该M T个列向量的位置，故可能需要
Figure PCTCN2018076904-appb-000069
个比特的开销。在另一种可能的设计中，可通过位图的方式指示N 2个列向量中功率较大的M T个列向量，位图中的每个比特为可对应于N 2个列向量中的一个，因此需要N 2个比特的开销。
应理解，上述列举的指示该M T个第二基矢量的具体方法仅为几种可能的是实现方式，而不应对本申请构成任何限定。本申请并不排除采用其他方式来指示该M T个第二基矢量在维度为N 1×N 2的第七矩阵中的位置。
通过上述对M B个第一基矢量的指示和对M T个第二基矢量的指示，可以确定得到M B个第一基矢量和M T个第二基矢量，M B个第一基矢量和M T个第二基矢量的克罗内克尔积即为M个波束的波束矢量。
f)与M个波束矢量对应的M个幅度系数：
与M个波束矢量对应的M个幅度系数可对应于第七矩阵中的M B×M T个非零元素的幅值。在一种可能的实现方式中，可将第七矩阵中的M B×M T个非零元素抽取出来构成维度为M B×M T个非零元素的矩阵，各非零元素之间的相对位置不变。则各元素在维度为M B×M T中的行数和列数分别可对应于P b,t中的下角标b和t。
g)与M B个第一基矢量对应的相位系数和与M T个第二基矢量对应的相位系数的指示 信息：
与M个波束矢量对应的M个相位系数可由第七矩阵中的M B×M T个非零元素的实部和虚部确定。在一种可能的实现方式中，可将第七矩阵中的M B×M T个非零元素抽取出来构成维度为M B×M T个非零元素的矩阵，各非零元素之间的相对位置不变。则各元素在维度为M B×M T中的行数和列数分别可对应于C b,t中的下角标b和t。
应理解，上文中的d)、e)、f)和g)中的一项或多项分别可以单独反馈；当需要反馈d)、e)、f)和g)中的多项时，任意两项或更多项可以通过联合编码的方式来指示，本申请对此不做限定。
上文中从一个接收天线或一个层的角度来描述了CSI中一组指示信息，对于终端设备的多个接收天线或多个层来说，通过CSI中的多组指示信息指示测量值的方式是相似的。
该测量值Z中包括N R个列向量，与N R组指示信息一一对应。该测量值Z所包括的列数N R也就是该测量值Z所指示的测量值的个数。即，n可以在[1，N R]中遍历取值，且n为正整数。
在方式三中，测量值至少可通过下文所列举的形式一和形式二两种形式来表示，下面分别结合形式一和形式二详细说明基于CSI确定测量值的具体过程。
形式一、
测量值Z可包括N R个测量值，测量值Z中的每个列向量对应一个测量值，该N R个列中的第n列可表示为y n，y n满足：
Figure PCTCN2018076904-appb-000070
其中，α为归一化系数，M为基矢量的数量，M个基矢量为第一组基矢量G 1和第二组基矢量G 2的克罗内克尔积中的M个列，
Figure PCTCN2018076904-appb-000071
为与所述第n列对应的M个基矢量中的第i个列矢量，且
Figure PCTCN2018076904-appb-000072
的维度为N T·N SB×1，
Figure PCTCN2018076904-appb-000073
为
Figure PCTCN2018076904-appb-000074
的线性叠加系数，
Figure PCTCN2018076904-appb-000075
为 的幅度系数，
Figure PCTCN2018076904-appb-000077
为
Figure PCTCN2018076904-appb-000078
的相位系数。
在形式一中，M满足M＝M B·M T，因此，终端设备只要预先获取M、M B和M T中的任意两个的取值，便可以确定出另一个值。换句话说，协议可以定义M、M B和M T中至少两个的取值，或者，网络设备可以仅发送M、M B和M T中至少两个的指示信息。
可选地，该测量值可等价于
Figure PCTCN2018076904-appb-000079
其中，u为由维度为N 1×N 2的第七矩阵转换得到的维度为(N 1·N 2)×1的列向量。具体地，若将第七矩阵中的第二列至第N 2个列依次拼接在第一列元素下方，可以得到维度为(N 1·N 2)×1的列向量u。该列向量u中的第一个元素至N 1个元素可对应于矩阵的第一列，该列向量中的第N 1+1个元素至第2N 1个元素可对应于矩阵的第二列，以此类推。
若将维度为(N 1·N 2)×1的列向量u左乘第一组基矢量G 1和第二组基矢量G 2的克罗内克尔积
Figure PCTCN2018076904-appb-000080
即，
Figure PCTCN2018076904-appb-000081
由此得到维度为(N T·N SB)×1的列向量。该维度为(N T·N SB)×1的列向量可以理解为对应于第r个接收天线或第r个层的测量值y r。
可选地，该测量值可等价于G 1U P,T'G 2 T转换得到的列向量。
若以第一组基矢量和第二组基矢量对维度为N 1×N 2的第七矩阵U P,T'进行IDFT和DFT，比如得到的矩阵U P,T”，U P,T”＝G 1U P,T'G 2 T，则U P,T”的维度为N T×N SB。由于U P,T” 由U P,T'转换而来，而U P,T'是对U P,T进行了处理之后得到的矩阵，U P,T是基于预编码矩阵V r进行IDFT和DFT得到的，因此，该矩阵U P,T”可理解为是一个逼近预编码矩阵V r的矩阵。
若进一步将该维度N T×N SB为的矩阵转换为维度为(N T·N SB)×1的列向量。将维度为N T×N SB的矩阵U P,T”转换为维度为(N T·N SB)×1的列向量的具体方法可参考方式一中的步骤iv)，为了简洁，这里不再赘述。该维度为(N T·N SB)×1的列向量也就是对应于第r个接收天线的测量值y r，或者说，对应于第r个层的测量值y r。换句话说，终端设备将一个逼近预编码矩阵的矩阵通过列向量的方式向网络设备反馈。
应理解，上文描述的与测量值等价的两种可能的形式仅为示例性说明，并且为了便于理解，上文中示出了具体的变换过程，但这并不代表终端设备执行了上述操作，终端设备可直接向网络设备反馈CSI来指示上述测量值，以便于网络设备确定预编码矩阵。
上文中从一个接收天线或一个层的角度来描述了CSI中一组指示信息，对于终端设备的多个接收天线或多个层来说，通过CSI中的多组指示信息指示测量值的方式是相似的。
该测量值Z中包括N R个列向量，与N R组指示信息一一对应。该测量值Z所包括的列数N R也就是该测量值Z所指示的测量值的个数。即，n可以在[1，N R]中遍历取值，且n为正整数。
因此，该测量值Z的维度为(N T·N SB)×N R。
形式二、
在形式二中，该CSI中的N R组指示信息可以用于指示N R个维度为N T×N SB的矩阵Y。该N R个矩阵可以构成一个测量值Z。该测量值N R个矩阵，该N R个矩阵可理解为测量值Z的N R个分量。可以理解的是，该N R个分量也可以理解为一个测量值，即，对应一个接收天线或对应一个层的测量值。下文中，测量值Z和测量值Y n交替出现，本领域的技术人员可以理解，这两者的维度是不同的，测量值Y n可以是测量值Z中的第n个列向量。
事实上，该测量值Z可以是由N R个维度为N T×N SB的矩阵在行数不变的前提下拼接而成，拼接得到的测量值Z的维度可以为N T×(N R·N SB)。
其中，R个矩阵中的第n个矩阵Y n满足：
Figure PCTCN2018076904-appb-000082
其中，β为归一化系数，M B为第一基矢量的数量，M T为第二基矢量的数量，M B个第一基矢量为所述第一组基矢量中的M B个列，M T个第二基矢量为所述第二组基矢量中的M T个列，
Figure PCTCN2018076904-appb-000083
为与所述第n个矩阵对应的M B个第一基矢量中的第b个第一基矢量，且
Figure PCTCN2018076904-appb-000084
的维度为N T×1，
Figure PCTCN2018076904-appb-000085
为与所述第n个矩阵对应的M T个第二基矢量中的第t个第二基矢量，且
Figure PCTCN2018076904-appb-000086
的维度为
Figure PCTCN2018076904-appb-000087
为线性叠加系数，
Figure PCTCN2018076904-appb-000088
为幅度系数，
Figure PCTCN2018076904-appb-000089
为相位系数，1≤b≤M B，1≤t≤M T，b、t、M B、M T均为正整数。
在形式二中，M B、M T满足M B·M T＝M，因此，终端设备只要预先获取M、M B和M T中的任意两个的取值，便可以确定出另一个值。换句话说，协议可以定义M、M B和M T中至少两个的取值，或者，网络设备可以仅发送M、M B和M T中至少两个的指示信息。
可选地，该测量值可等价于G 1U P,T'G 2 T。
若基于第一组基矢量和第二组基矢量对维度为N 1×N 2的第七矩阵U P,T'进行IDFT和 DFT，比如得到U P,T”，U P,T”＝G 1U P,T'G 2 T，则U P,T”的维度为N T×N SB。由于U P,T”由U P,T'转换而来，而U P,T'是对U P,T进行了处理之后得到的矩阵，U P,T是基于预编码矩阵V r进行IDFT和DFT得到的，因此，该矩阵U P,T”可理解为是一个逼近预编码矩阵V r的矩阵。该矩阵U P,T”也就可以理解为对应于一个发送天线端口组且对应于N r个接收天线或N r个层的测量值Y n。
应理解，上文描述的与测量值等价的可能的形式仅为示例性说明，并且为了便于理解，上文中示出了具体的变换过程，但这并不代表终端设备执行了上述操作，终端设备可直接向网络设备反馈CSI来指示上述测量值，以便于网络设备确定预编码矩阵。
进一步地，若考虑多个发送天线端口组，例如天线端口组数为p，则终端设备可以分别对每个天线端口组所对应的理想预编码矩阵执行上述步骤i)至步骤v)的操作，分别得到与p个天线端口组对应的p个测量值Z。或者，终端设备可以从p个天线端口组中选择一个天线端口组，对该天线端口组所对应的预编码矩阵执行上述步骤i)和步骤ii)的操作，得到功率较大的M B个行，将该M B个个行中的元素，剩余的(N 1-M B)个行中的元素置零。并将剩余的(p-1)个天线端口组的每个天线端口组中与该M B个行位置相同的M B个行中的元素保留下来，其余行的元素置零。由此可以得到p个维度为N 1×N SB的矩阵，然后通过执行步骤iii)至步骤v)的操作，可得到与p个天线端口组对应的p个测量值Z。
因此，基于多个天线端口组所反馈的CSI可以包括与该多个天线端口组对应的N R组指示信息，与该多个天线端口组对应的N R组指示信息可用于指示多个测量值构成的测量值集合。该测量值集合可以通过一个或多个测量值拼接构成的矩阵来表征，该矩阵的行数可以与各测量值的行数相同，列数可以为各测量值的列数之和。
应理解，上文列举的对多个天线端口组所对应的预编码矩阵的处理方式仅为几种可能的实现方式，而不应对本申请构成任何限定。
步骤vi)、
网络设备可根据接收到的CSI确定测量值。
具体地，网络设备可根据接收到的CSI，基于形式一或形式二确定测量值。
若网络设备基于形式一确定测量值，则网络设备可以根据接收到的CSI中的每组指示信息，得到与一个接收天线或一个层对应的测量值y n'，该测量值y n'的维度可以为(N T·N SB)×1。网络设备根据CSI确定的测量值y n'与终端设备基于预编码矩阵处理后得到的测量值y n可能相同或相接近。网络设备根据CSI确定测量值y n'的具体过程在方式一的步骤vii)中已经做了详细说明，为了简洁，这里不再赘述。网络设备可进一步将该测量值y n'转换为维度为N T×N SB的矩阵。网络设备将维度为(N T·N SB)×1的测量值转换为维度为N T×N SB的矩阵的具体过程在方式一的步骤vii)中已经做了详细说明，为了简洁，这里不再赘述。由该测量值y n'转换得到的维度为N T×N SB的矩阵与终端设备基于参考信号得到的预编码矩阵V r相同或相接近。因此，由该测量值y n'转换得到的维度为N T×N SB的矩阵也就是网络设备根据CSI确定的与一个接收天线或一个层对应的预编码矩阵。
若网络设备基于形式二确定测量值，则网络设备可以根据接收到的CSI中的每组指示信息，得到与一个接收天线或一个层对应的测量值Y n'，该测量值的维度可以为N T×N SB。网络生根据CSI确定的测量值Y n'与终端设备基于预编码矩阵处理后得到的测量值Y n可能相同或相接近。由于该测量值Y n'是根据终端设备基于矩阵U P,T”作出的反馈而确定，而矩 阵U P,T”逼近预编码矩阵V r，因此，该测量值与终端设备基于参考信号得到的预编码矩阵V r相同或相接近。也就是说，该测量值也就是网络设备根据CSI确定的与一个接收天线或一个层对应的预编码矩阵。
进一步地，网络设备可通过在[1，N R]中对n遍历取值，可以得到测量值Z'。该测量值Z'的维度可以为(N T·N SB)×N R。通过对测量值Z'中的每个列执行上述操作，可得到N R个维度为N T×N SB的矩阵。在保持行数不变的前提下，将该N R个N T×N SB的矩阵依次拼接可得到一个维度为N T×(N R·N SB)的矩阵。该维度为N T×(N R·N SB)的矩阵即可以理解为与一个天线端口组对应的预编码矩阵。
进一步地，若考虑多个天线端口组，例如天线端口组数为p，则终端设备和网络设备可以分别对每个天线端口组执行上述操作，得到p个维度为N T×(N R·N SB)的矩阵。然后在保持列数不变的前提下，将得到的p个维度为N T×(N R·N SB)的矩阵依次拼接得到一个维度为(p·N T)×(N R·N SB)的矩阵，该(p·N T)×(N R·N SB)的矩阵即为与p个天线端口组对应的预编码矩阵。
基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
D、方式四
上文中列举的方式一至方式三中，终端设备可预先获知第一组基矢量和第二组基矢量，进而根据第一组基矢量和第二组基矢量确定M个波束矢量。然而，这不应对本申请构成任何限定，终端设备也可以不预先获知第一组基矢量和第二组基矢量，基于预先保存的多组基矢量的集合(即，第一集合)和多组基矢量的集合(即，第二集合)。
第一集合可包括K 1(K 1≥1，且K 1为正整数)组基矢量，例如，记作G 1，a，1≤a≤K 1，第一集合中的每组基矢量可以为IDFT矢量，或者两个IDFT矢量的克罗内克尔积。可选地，第一集合中的每组基矢量均包括多个列矢量，该多个列矢量中的每个列矢量可以是步骤220中列举的a)至i)中的任意一项。为了简洁，这里不再赘述。
第二集合可包括K 2(K 2≥1，且K 2为正整数)组基矢量，例如，记作G 2，c，1≤c≤K 2，第二集合中的每组基矢量可以为DFT矢量。
在本申请实施例中，第一集合中的各组基矢量的维度均可以为N T×N 1，第二集合中的各组基矢量的维度均可以为N SB×N 2。
方式四可包括步骤1)至步骤4)，其中，步骤1)至步骤3)可以为终端设备执行的操作，步骤4)可以为网络设备执行的操作。并且，步骤3)和步骤4)可参照上文方式一至方式三中任意一种方式来实现。
步骤1)、
终端设备可遍历第一集合中的各组基矢量和第二集合中的各组基矢量，向网络设备反 馈被选择的第一组基矢量和第二组基矢量。
具体地，终端设备可以依次在[1，K 1]对a遍历取值，在[1，K 2]对c遍历取值，对a、c的每一个取值，基于第一集合中的一组基矢量G 1，a和第二集合中的一组基矢量G 2，c对预编码矩阵V进行IDFT和DFT处理，例如，
Figure PCTCN2018076904-appb-000090
得到一个维度为N 1×N 2的矩阵。
通过在[1，K 1]对a遍历取值，在[1，K 2]对c遍历取值，终端设备可以得到K 1×K 2个维度为N 1×N 2的矩阵。
应理解，终端设备对预编码矩阵进行IDFT和DFT处理的具体过程与方式一中的步骤i)和步骤ii)中的具体过程相似，为了简洁，这里不再赘述。
步骤2)、
终端设备从上述K 1×K 2个维度为N 1×N 2的矩阵中确定功率值最大的矩阵。
一种可能的实现方式是，终端设备将K 1×K 2个矩阵中每个矩阵所包含的N 1×N 2个元素的功率求和，可得到与K 1×K 2个矩阵对应的K 1×K 2个功率和，从该K 1×K 2个功率和中确定功率和的最大值，该功率和的最大值所对应的矩阵在第一集合中所使用的一组基矢量可确定为第一组基矢量，在第二集合中所使用的一组基矢量可确定为第二组基矢量。
终端设备可分别将第一组基矢量在第一集合中的索引和第二组基矢量在第二集合中的索引反馈给网络设备。
其中，终端设备反馈的第一组基矢量的维度可以为N T×M B，终端设备反馈的第二组基矢量的维度可以为N SB×M T。
步骤3)、
终端设备可以根据预编码矩阵以及由步骤1)和步骤2)确定的第一组基矢量和第二组基矢量对预编码，确定与M个波束对应的M个幅度系数和与M个波束对应的M个相位系数，并发送CSI。
由于M个波束已经在上述步骤1)和步骤2)中确定，终端设备可进一步确定与M个波束对应的M个幅度系数和与M个波束对应的M个相位系数并发送CSI的具体过程可通过上文中方式一至方式三中的任意一种方式来实现。具体地，终端设备可通过执行方式一中的步骤i)至步骤v)，或者，方式二中的步骤i)至步骤v)，或者，方式三中的步骤i)至步骤v)来确定并发送CSI。为了简洁，这里不再赘述。
步骤4)、
网络设备可以根据接收到的CSI确定预编码矩阵。
网络设备根据接收到的CSI确定预编码矩阵的具体过程可通过上文中方式一至方式三中的任意一种方式来实现。具体地，网络设备可通过执行方式一中的步骤vi)至步骤vii)，或者，方式二中的步骤vi)至步骤vx)，或者，方式三中的步骤vi)来确定测量值。为了简洁，这里不再赘述。
基于上述三种方式，终端设备可以通过CSI向网络设备指示测量值集合，网络设备可以根据CSI确定测量值集合，也就能够确定预编码矩阵。
基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待 反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性。换句话说，在保证了数据传输可靠性的前提下，大大降低了信道测量的复杂度，减小了功率消耗，因此有利于提高整个通信系统的性能。
需要说明的是，上文中的方式四仅为便于理解，示出了终端设备反馈第一组基矢量和第二组基矢量的具体过程，但这不应对本申请构成任何限定。终端设备可以仅第一组基矢量和第二组基矢量中的一组，另一组由网络设备指示或者预先定义。其中，由终端设备反馈的一组基矢量(例如为第一组基矢量)可以是从第一集合中遍历后确定出的第一组基矢量，该第一组基矢量可以包括M B个被选择的、维度为N T×1的列向量，该第二组基矢量可以为预先定义或网络设备指示，可包括N 2个维度为N SB×1的列向量，终端设备可以进一步从该第二组基矢量中选择并反馈M T个列向量。
应理解，通过SVD分解得到预编码矩阵的方法并不仅限于上文描述，终端设备也可以对每个频率单元所对应的信道矩阵进行SVD分解得到预编码矩阵，由此得到的预编码矩阵的维度可以是N T×N R。对该预编码矩阵的变换处理过程和CSI反馈过程与上文中描述的具体过程相似，为了简洁，这里不再赘述。
2、以信道矩阵为变换处理的对象：
以信道矩阵为变换处理的对象的具体实现过程与以预编码矩阵为变换处理的对象的具体实现过程大体相似，其区别在于根据信道矩阵做SVD的操作可以由网络设备来执行，即，终端设备可以直接以信道矩阵为变换处理的对象，通过上文中列举的方式一至方式四中的任意一种方式反馈CSI，网络设备可以通过与终端设备相对应的方式根据CSI得到测量值，并进一步根据测量值确定信道矩阵。网络设备可进一步对转换得到的信道矩阵进行SVD得到预编码矩阵。
终端设备和网络设备基于上文列举的方式一至方式四中的任意一种方式进行的操作的具体过程在上文中已经做了详细说明，为了简洁，这里不再赘述。
应理解，上文列举的通过对信道矩阵进行SVD得到预编码矩阵的方法仅为示例性说明，而不应对本申请构成任何限定。根据信道矩阵确定预编码矩阵的方法可以通过现有技术中的方法来实现，本申请对此不做限定。
因此，基于上述技术方案，终端设备可以基于第一组基矢量和第二组基矢量对信道矩阵或预编码矩阵进行处理，并将处理后的结果通过CSI反馈给网络设备，网络设备可以基于CSI确定测量值，进而确定预编码矩阵。由于终端设备可通过FFT和IFFT的快速运算获得待反馈的CSI，相比于现有技术中终端设备遍历码本中的各个码字确定预编码矩阵的过程而言，可以大大减小终端设备的计算复杂度，有利于减小终端设备的功率消耗。同时，通过反馈CSI便于网络设备确定合适的预编码矩阵来对待发送信号进行预编码，提高了数据传输的可靠性，有利于提高整个通信系统的性能。
应理解，上文中仅为便于理解，列举了测量值与第一组基矢量和第二组基矢量相关或者与第一组基矢量和第二组基矢量的克罗内克尔积相关的几种可能的实现方式，但这仅为示意性说明，不应对本申请构成任何限定，本申请并不排除采用其他的方法实现的可能。
还应理解，上文中仅为便于理解，以网络设备与终端设备间的下行信道测量和反馈的 过程为例详细说明本申请实施例，但这不应对本申请构成任何限定，本申请实施例所提供的方法同样适用于上行信道测量和反馈，在上行信道测量过程中，终端设备可以发送用于上行信道测量的参考信号，例如，SRS。应理解，SRS作为用于上行信道测量的参考信号，仅为示例性说明，而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，例如，上行DMRS等。上行信道测量和反馈的具体实现方法和过程与下行信道测量和反馈的具体实现方法和过程相似。为了简洁，这里省略对该具体过程的详细说明。
以上，结合图2和图3详细说明了本申请实施例提供的通信方法。以下，结合图4至图6详细说明本申请实施例提供的通信装置。
图4是本申请实施例提供的一种通信装置400的示意性框图。该通信装置400可适用于图1所示出的通信系统中。如图3所示，该通信装置400包括：接收单元410和发送单元420。
在一种可能的设计中，该通信装置400可以为终端设备或者配置于终端设备中的芯片。
其中，接收单元410可用于接收参考信号，该参考信号用于信道测量。
该发送单元420可用于发送信道状态信息CSI，该CSI用于指示测量值集合，该测量值集合用于确定预编码矩阵，或者，测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；其中，该测量值与第一组基矢量和第二组基矢量相关，或者，该测量值与第一组基矢量和第二组基矢量的克罗内克尔积相关。其中，第一组基矢量包括DFT矢量或两个DFT矢量的克罗内克尔积，第二组基矢量包括IDFT矢量。
可选地，该接收单元410还用于接收以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
可选地，该发送单元420还用于发送以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
可选地，所述第一组基矢量由协议定义；或者，
所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量的克罗内克尔积由协议定义。
可选地，所述测量值包括R个列，所述R个列中的第n列y n满足：
Figure PCTCN2018076904-appb-000091
其中，α为归一化系数，M为基矢量的数量，M个基矢量为所述第一组基矢量和所述第二组基矢量的克罗内克尔积中的M个列，
Figure PCTCN2018076904-appb-000092
为与所述第n列对应的M个基矢量中的第i个列矢量，且
Figure PCTCN2018076904-appb-000093
的维度为N T·N SB×1，
Figure PCTCN2018076904-appb-000094
为
Figure PCTCN2018076904-appb-000095
的线性叠加系数，
Figure PCTCN2018076904-appb-000096
为
Figure PCTCN2018076904-appb-000097
的幅度系数，
Figure PCTCN2018076904-appb-000098
为
Figure PCTCN2018076904-appb-000099
的相位系数，N T为所述参考信号的发送天线端口数，N SB为传输所述参考信号的频域资源所包括的频域单元数，R由所述参考信号的接收天线端口数或信道矩阵的秩确定，1≤i≤M，1≤n≤R，i、n、M、R均为整数。
可选地，所述CSI用于指示以下一项或多项：
与所述R个列中的第r列对应的M个基矢量、与所述M个基矢量对应的M个幅度系数或者与所述M个基矢量对应的M个相位系数；
其中，r在[1，R]中遍历取值，且r为整数。
可选地，所述CSI包括以下一项或多项：
与所述R个列中的第r列对应的M个基矢量的指示信息，与所述M个基矢量对应的M个幅度系数的指示信息，或者与所述M个基矢量对应的M个相位系数的指示信息；
其中，r在[1，R]中遍历取值，且r为整数。
可选地，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个基矢量中每个基矢量在预先配置的矩阵中的位置，所述预先配置的矩阵为所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
可选地，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个列矢量中每个列矢量在第一组基矢量中的位置和在第二组基矢量中的位置。
可选地，M的取值由网络设备指示，或者，由协议定义。
可选地，所述测量值包括R个矩阵，所述R个矩阵中的第n个矩阵Y n满足：
Figure PCTCN2018076904-appb-000100
其中，β为归一化系数，M B为第一基矢量的数量，M T为第二基矢量的数量，M B个第一基矢量为所述第一组基矢量中的M B个列，M T个第二基矢量为所述第二组基矢量中的M T个列，
Figure PCTCN2018076904-appb-000101
为与所述第n个矩阵对应的M B个第一基矢量中的第b个第一基矢量，且
Figure PCTCN2018076904-appb-000102
的维度为N T×1，
Figure PCTCN2018076904-appb-000103
为与所述第n个矩阵对应的M T个第二基矢量中的第t个第二基矢量，且
Figure PCTCN2018076904-appb-000104
的维度为N SB×1，
Figure PCTCN2018076904-appb-000105
为线性叠加系数，
Figure PCTCN2018076904-appb-000106
为幅度系数，
Figure PCTCN2018076904-appb-000107
为相位系数，1≤b≤M B，1≤t≤M T，b、t、M B、M T为整数。
可选地，所述CSI包括以下一项或多项：
所述M B个第一列矢量的指示信息，所述M T个第二列矢量的指示信息，与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个幅度系数的指示信息，或者与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个相位系数的指示信息，
其中，所述M B个第一列矢量的指示信息包括所述M B个第一列矢量中每个第一列矢量在所述第一组列矢量中的位置，所述M T个第二列矢量的指示信息包括所述M T个第二列矢量中每个第二列矢量在所述第二组列矢量中的位置。
可选地，M B的取值由网络设备指示，或者，由协议定义；M T的取值由网络设备指示，或者，由协议定义。
可选地，所述测量值对应于用于发送参考信号的多个天线端口组中的一个天线端口组。
应理解，通信装置400可以对应于根据本发明实施例的通信方法200中的终端设备，该通信装置400可以包括用于执行图2中通信方法200的终端设备执行的方法的模块。并且，该通信装置400中的各模块和上述其他操作和/或功能分别为了实现图2中通信方法200的相应流程，具体地，接收单元410用于执行方法200中的步骤210和步骤230，发送单元420用于执行方法200中的步骤220，各模块执行上述相应步骤的具体过程在方法200中已经详细说明，为了简洁，在此不再赘述。
在另一种可能的设计中，该通信装置400可以为网络设备或者配置于网络设备中的芯片。
其中，发送单元420可用于发送参考信号，所述参考信号用于信道测量；
接收单元410可用于接收信道状态信息CSI，所述CSI用于指示测量值集合，所述测量值集合用于确定预编码矩阵，或者，所述测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；其中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关，其中，所述第一基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT矢量的克罗内克尔积，所述第二基矢量包括离散傅里叶变换DFT矢量；
发送单元420还可用于根据由所述测量值确定的预编码矩阵对信号进行预编码，并发送预编码后的信号。
可选地，该发送单元420还用于发送以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
可选地，该接收单元410还用于接收以下一项或多项的配置信息：
所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
可选地，所述第一组基矢量由协议定义；或者，
所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量由协议定义；或者，
所述第一组基矢量和所述第二组基矢量的克罗内克尔积由协议定义。
可选地，所述测量值包括R个列，所述R个列中的第n列y n满足：
Figure PCTCN2018076904-appb-000108
其中，α为归一化系数，M为基矢量的数量，M个基矢量为所述第一组基矢量和所述第二组基矢量的克罗内克尔积中的M个列，
Figure PCTCN2018076904-appb-000109
为与所述第n列对应的M个基矢量中的第i个列矢量，且
Figure PCTCN2018076904-appb-000110
的维度为N T·N SB×1，
Figure PCTCN2018076904-appb-000111
为
Figure PCTCN2018076904-appb-000112
的线性叠加系数，
Figure PCTCN2018076904-appb-000113
为
Figure PCTCN2018076904-appb-000114
的幅度系数，
Figure PCTCN2018076904-appb-000115
为
Figure PCTCN2018076904-appb-000116
的相位系数，N T为所述参考信号的发送天线端口数，N SB为传输所述参考信号的频域资源所包括的频域单元数，R由所述参考信号的接收天线端口数或信道矩阵的秩确定，1≤i≤M，1≤n≤R，i、n、M、R均为整数。
可选地，所述CSI用于指示以下一项或多项：
与所述R个列中的第r列对应的M个基矢量、与所述M个基矢量对应的M个幅度系数或者与所述M个基矢量对应的M个相位系数；
其中，r在[1，R]中遍历取值，且r为整数。
可选地，所述CSI包括以下一项或多项：
与所述R个列中的第r列对应的M个基矢量的指示信息，与所述M个基矢量对应的M个幅度系数的指示信息，或者与所述M个基矢量对应的M个相位系数的指示信息；
其中，r在[1，R]中遍历取值，且r为整数。
可选地，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个基矢量中每个基矢量在预先配置的矩阵中的位置，所述预先配置的矩阵为所述第一组 基矢量和所述第二组基矢量的克罗内克尔积。
可选地，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个列矢量中每个列矢量在第一组基矢量中的位置和在第二组基矢量中的位置。
可选地，M的取值由网络设备指示，或者，由协议定义。
可选地，所述测量值包括R个矩阵，所述R个矩阵中的第n个矩阵Y n满足：
Figure PCTCN2018076904-appb-000117
其中，β为归一化系数，M B为第一基矢量的数量，M T为第二基矢量的数量，M B个第一基矢量为所述第一组基矢量中的M B个列，M T个第二基矢量为所述第二组基矢量中的M T个列，
Figure PCTCN2018076904-appb-000118
为与所述第n个矩阵对应的M B个第一基矢量中的第b个第一基矢量，且
Figure PCTCN2018076904-appb-000119
的维度为N T×1，F t n为与所述第n个矩阵对应的M T个第二基矢量中的第t个第二基矢量，且
Figure PCTCN2018076904-appb-000120
的维度为N SB×1，
Figure PCTCN2018076904-appb-000121
为线性叠加系数，
Figure PCTCN2018076904-appb-000122
为幅度系数，
Figure PCTCN2018076904-appb-000123
为相位系数，1≤b≤M B，1≤t≤M T，1≤n≤R，b、t、n、R、M B、M T均为整数。
可选地，所述CSI包括以下一项或多项：
所述M B个第一列矢量的指示信息，所述M T个第二列矢量的指示信息，与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个幅度系数的指示信息，或者与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个相位系数的指示信息，
其中，所述M B个第一列矢量的指示信息包括所述M B个第一列矢量中每个第一列矢量在所述第一组列矢量中的位置，所述M T个第二列矢量的指示信息包括所述M T个第二列矢量中每个第二列矢量在所述第二组列矢量中的位置。
可选地，M B的取值由网络设备指示，或者，由协议定义；M T的取值由网络设备指示，或者，由协议定义。
可选地，所述测量值对应于用于发送参考信号的多个天线端口组中的一个天线端口组。
应理解，通信装置400可以对应于根据本发明实施例的通信方法200中的网络设备，该通信装置400可以包括用于执行图2中通信方法200的网络设备执行的方法的模块。并且，该通信装置30中的各模块和上述其他操作和/或功能分别为了实现图2中通信方法200的相应流程，具体地，发送单元420可用于执行方法200中的步骤210和步骤230，接收单元410可用于执行方法200中的步骤220，各单元执行上述相应步骤的具体过程在方法200中已经详细说明，为了简洁，在此不再赘述。
图5是本申请实施例提供的终端设备600的结构示意图。如图5所示，该终端设备600包括：处理器601和收发器602，可选地，该终端设备600还包括存储器603。其中，其中，处理器602、收发器602和存储器603之间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603用于存储计算机程序，该处理器601用于从该存储器603中调用并运行该计算机程序，以控制该收发器602收发信号。
上述处理器601和存储器603可以合成一个处理装置604，处理器601用于执行存储器603中存储的程序代码来实现上述功能。具体实现时，该存储器603也可以集成在处理器601中，或者独立于处理器601。上述终端设备600还可以包括天线610，用于将收发器602输出的上行数据或上行控制信令通过无线信号发送出去。
具体地，终端设备600可以对应于根据本申请实施例的通信方法200中的终端设备，该终端设备600可以包括用于执行图2中通信方法200的终端设备执行的方法的模块，并且，该终端设备600中的各模块和上述其他操作和/或功能分别为了实现图2中通信方法200的相应流程。具体地，该存储器603用于存储程序代码，使得处理器601在执行该程序代码时，并控制收发器602执行方法200中的步骤210至步骤230，各模块执行上述相应步骤的具体过程在方法200中已经详细说明，为了简洁，在此不再赘述。
上述处理器601可以用于执行前面方法实施例中描述的由终端内部实现的动作，而收发器602可以用于执行前面方法实施例中描述的终端向网络设备传输或者发送的动作。具体请见前面方法实施例中的描述，此处不再赘述。
上述处理器601和存储器603可以集成为一个处理装置，处理器601用于执行存储器603中存储的程序代码来实现上述功能。具体实现时，该存储器603也可以集成在处理器601中。
上述终端设备600还可以包括电源605，用于给终端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600还可以包括输入单元614，显示单元616，音频电路618，摄像头620和传感器622等中的一个或多个，所述音频电路还可以包括扬声器6182，麦克风6184等。
图6是本申请实施例提供的网络设备700的结构示意图。如图6所示，该网络设备700包括处理器710和收发器720。可选地，该网络设备700还包括存储器730。其中，处理器710、收发器720和存储器730之间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730用于存储计算机程序，该处理器710用于从该存储器730中调用并运行该计算机程序，以控制该收发器720收发信号。
上述处理器710和存储器730可以合成一个处理装置，处理器710用于执行存储器730中存储的程序代码来实现上述功能。具体实现时，该存储器730也可以集成在处理器710中，或者独立于处理器710。
上述网络设备还可以包括天线740，用于将收发器720输出的下行数据或下行控制信令通过无线信号发送出去。
具体地，该网络设备700可对应于根据本申请实施例的通信方法200中的网络设备，该网络设备700可以包括用于执行图2中通信方法200的网络设备执行的方法的模块。并且，该网络设备700中的各模块和上述其他操作和/或功能分别为了实现图2中通信方法200的相应流程。具体地，该存储器730用于存储程序代码，使得处理器710在执行该程序代码时，控制该收发器720通过天线740执行方法200中的步骤210至步骤230，各模块执行上述相应步骤的具体过程在方法200中已经详细说明，为了简洁，在此不再赘述。应理解，在本申请实施例中的处理器可以是中央处理单元(Central Processing Unit，CPU)，该处理器还可以是其他通用处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application specific integrated circuit，ASIC)、现成可编程门阵列(field programmable gate array，FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。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。
还应理解，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，许多形式的随机存取存储器(random access memory，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(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)。
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2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，该计算机可读解释存储有程序代码，当该程序代码在计算机上运行时，使得该计算机执行图2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，其包括前述的网络设备和一个或多个终端设备。
上述实施例，可以全部或部分地通过软件、硬件、固件或其他任意组合来实现。当使用软件实现时，上述实施例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或计算机程序。在计算机上加载或执行所述计算机指令或计算机程序时，全部或部分地产生按照本申请实施例所述的流程或功能。所述计算机可以为通用计算机、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合的服务器、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，DVD)、或者半导体介质。半导体介质可以是固态硬盘。
应理解，本文中术语“和/或”，仅仅是一种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这三种情况。另外，本文中字符“/”，通常为“和/或”的简略形式。
应理解，在本申请的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。
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示例的单元及算法步骤，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。
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 (19)

  1. 一种通信方法，其特征在于，包括：
    接收参考信号，所述参考信号用于信道测量；
    发送信道状态信息CSI，所述CSI用于指示测量值集合，所述测量值集合用于确定预编码矩阵，或者，所述测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；
    其中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关，所述第一组基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT矢量的克罗内克尔积，所述第二基矢量包括离散傅里叶变换DFT矢量。
  2. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    接收以下一项或多项的配置信息：
    所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
  3. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    发送以下一项或多项的配置信息：
    所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
  4. 一种通信方法，其特征在于，包括：
    发送参考信号，所述参考信号用于信道测量；
    接收信道状态信息CSI，所述CSI用于指示测量值集合，所述测量值集合用于确定预编码矩阵，或者，所述测量值集合为所述预编码矩阵，所述测量值集合包括一个或多个测量值；其中，所述测量值与第一组基矢量和第二组基矢量相关，或者，所述测量值与所述第一组基矢量和所述第二组基矢量的克罗内克尔积相关，其中，所述第一基矢量包括离散傅里叶逆变换IDFT矢量或两个IDFT矢量的克罗内克尔积，所述第二基矢量包括离散傅里叶变换DFT矢量；
    根据由所述测量值确定的预编码矩阵对信号进行预编码，并发送预编码后的信号。
  5. 根据权利要求4所述的方法，其特征在于，所述方法还包括：
    发送以下一项或多项的配置信息：
    所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
  6. 根据权利要求4所述的方法，其特征在于，所述方法还包括：
    接收以下一项或多项的配置信息：
    所述第一组基矢量，或，所述第二组基矢量，或，所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
  7. 根据权利要求1或4所述的方法，其特征在于，所述第一组基矢量由协议定义；或者，
    所述第二组基矢量由协议定义；或者，
    所述第一组基矢量和所述第二组基矢量由协议定义；或者，
    所述第一组基矢量和所述第二组基矢量的克罗内克尔积由协议定义。
  8. 根据权利要求1至7中任一项所述的方法，其特征在于，所述测量值包括R个列，所述R个列中的第n列y n满足：
    Figure PCTCN2018076904-appb-100001
    其中，α为归一化系数，M为基矢量的数量，M个基矢量为所述第一组基矢量和所述第二组基矢量的克罗内克尔积中的M个列，
    Figure PCTCN2018076904-appb-100002
    为与所述第n列对应的M个基矢量中的第i个列矢量，且
    Figure PCTCN2018076904-appb-100003
    的维度为N T·N SB×1，
    Figure PCTCN2018076904-appb-100004
    为
    Figure PCTCN2018076904-appb-100005
    的幅度系数，
    Figure PCTCN2018076904-appb-100006
    为
    Figure PCTCN2018076904-appb-100007
    的相位系数，N T为所述参考信号的发送天线端口数，N SB为传输所述参考信号的频域资源所包括的频域单元数，R由所述参考信号的接收天线端口数或信道矩阵的秩确定，1≤i≤M，1≤n≤R，i、n、M、R均为整数。
  9. 根据权利要求8所述的方法，其特征在于，所述CSI用于指示以下一项或多项：
    与所述R个列中的第r列对应的M个基矢量、与所述M个基矢量对应的M个幅度系数或者与所述M个基矢量对应的M个相位系数；
    其中，r在[1，R]中遍历取值，且r为整数。
  10. 根据权利要求8或9所述的方法，其特征在于，所述CSI包括以下一项或多项：
    与所述R个列中的第r列对应的M个基矢量的指示信息，与所述M个基矢量对应的M个幅度系数的指示信息，或者与所述M个基矢量对应的M个相位系数的指示信息；
    其中，r在[1，R]中遍历取值，且r为整数。
  11. 根据权利要求10所述的方法，其特征在于，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个基矢量中每个基矢量在预先配置的矩阵中的位置，所述预先配置的矩阵为所述第一组基矢量和所述第二组基矢量的克罗内克尔积。
  12. 根据权利要求10所述的方法，其特征在于，与所述第r列对应的M个基矢量的指示信息包括：与所述第r列对应的所述M个列矢量中每个列矢量在第一组基矢量中的位置和在第二组基矢量中的位置。
  13. 根据权利要求8至12中任一项所述的方法，其特征在于，M的取值由网络设备指示，或者，由协议定义。
  14. 根据权利要求1至7中任一项所述的方法，其特征在于，所述测量值包括R个矩阵，所述R个矩阵中的第n个矩阵Y n满足：
    Figure PCTCN2018076904-appb-100008
    其中，β为归一化系数，M B为第一基矢量的数量，M T为第二基矢量的数量，M B个第一基矢量为所述第一组基矢量中的M B个列，M T个第二基矢量为所述第二组基矢量中的M T个列，
    Figure PCTCN2018076904-appb-100009
    为与所述第n个矩阵对应的M B个第一基矢量中的第b个第一基矢量，且
    Figure PCTCN2018076904-appb-100010
    的维度为N T×1，
    Figure PCTCN2018076904-appb-100011
    为与所述第n个矩阵对应的M T个第二基矢量中的第t个第二基矢量，且
    Figure PCTCN2018076904-appb-100012
    的维度为N SB×1，
    Figure PCTCN2018076904-appb-100013
    为幅度系数，
    Figure PCTCN2018076904-appb-100014
    为相位系数，1≤b≤M B，1≤t≤M T，1≤n≤R，b、t、n、R、M B、M T为整数。
  15. 根据权利要求14所述的方法，其特征在于，所述CSI包括以下一项或多项：
    所述M B个第一列矢量的指示信息，所述M T个第二列矢量的指示信息，与所述M B个 第一列矢量和所述M T个第二列矢量对应的M B·M T个幅度系数的指示信息，或者与所述M B个第一列矢量和所述M T个第二列矢量对应的M B·M T个相位系数的指示信息，
    其中，所述M B个第一列矢量的指示信息包括所述M B个第一列矢量中每个第一列矢量在所述第一组列矢量中的位置，所述M T个第二列矢量的指示信息包括所述M T个第二列矢量中每个第二列矢量在所述第二组列矢量中的位置。
  16. 根据权利要求14或15所述的方法，其特征在于，M B的取值由网络设备指示，或者，由协议定义；M T的取值由网络设备指示，或者，由协议定义。
  17. 根据权利要求1至16中任一项所述的方法，其特征在于，所述测量值对应于用于发送参考信号的多个天线端口组中的一个天线端口组。
  18. 一种通信装置，其特征在于，包括：
    处理器，用于从存储器调用并运行指令，以实现如权利要求1至17中任一项所述的方法。
  19. 根据权利要求18所述的装置，其特征在于，还包括：
    所述存储器。
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