Abstract: A basis feedback method and an apparatus are provided to implement an effective solution of feeding back a weighting coefficient matrix in a non-DFT basis. In this application, when a spatial domain eigenbasis and a frequency domain eigenbasis (or a space-frequency eigenbasis) are reported, the spatial domain eigenbasis and the frequency domain eigenbasis are decomposed based on a spatial domain basis and a frequency domain basis (or the space-frequency eigenbasis is decomposed based on a space-frequency basis); the spatial domain eigenbasis and the frequency domain eigenbasis (or the space-frequency eigenbasis) are respectively indicated by reporting weighting coefficients obtained through decomposition; and a reporting priority of the weighting coefficient is associated with a sequence number of a spatial domain basis, a sequence number of a frequency domain basis, a sequence number of a spatial domain eigenbasis, and a sequence number of a frequency domain eigenbasis.

Abstract: This application provides a communication method and a communication apparatus. The communication method includes: A terminal device reports a full-channel measurement result to a network device through two-stage feedback. The terminal device feeds back, at a first stage, at least one space-frequency basis group in which all antenna ports of the terminal device have a non-zero coefficient in a matrix corresponding to a space domain basis set and a frequency domain basis set, and specifically feeds back, at a second stage, a location at which each of all the antenna ports has a non-zero coefficient in the at least one space-frequency basis group. In embodiments of this application, resource overheads for full-channel feedback can be reduced in the two-stage feedback method.

Abstract: A channel state information (CSI) determining method and apparatus are provided, and relate to the wireless communication field. In the method, a network device sends at least two reference signals including a first reference signal and a second reference signal, and receives first information. The first information indicates that a part or all of information in CSI corresponding to the second reference signal is determined based on the first reference signal. A sending periodicity of the first reference signal is less than a sending periodicity of the second reference signal. According to the foregoing, the network device can be enabled to efficiently obtain the CSI.

Abstract: A method for determining channel state information and a communication apparatus. The method includes: sending first indication information, where the first indication information indicates a position for sending a downlink reference signal; receiving channel statistics information, where the channel statistics information is determined based on the downlink reference signal; sending second indication information, where the second indication information indicates a position for sending an uplink reference signal; and receiving the uplink reference signal, and determining channel state information based on the uplink reference signal and the channel statistics information. According to the method, a terminal device sends the uplink reference signal based on an indication of a network device, and therefore a large quantity of time-frequency resources may not be occupied. Therefore, the terminal device is not required to have high calculation complexity.

Abstract: This application provides a capability reporting method and an apparatus, to improve effectiveness of CSI report reporting, and may be applied to a communication system. The method includes: A terminal device generates first information. The first information includes at least one piece of capability information of the terminal device, and the capability information indicates a quantity of time domain units supported by the terminal device for a precoding matrix indicator (PMI). The terminal device sends the first information to a network device.

Abstract: Embodiments of this application provides a method and an apparatus for channel measurement. A network device sends first information, where the first information indicates K sending moments for sending an NZP CSI-RS and a sending gap m between adjacent sending moments in the K sending moments. After receiving the first information, a terminal device may determine a time domain location of a target CSI reference resource, and receive a measurement signal before the target CSI reference resource (time domain location). The terminal device reports, based on the measurement signal, CSI to the network device at a time domain location of CSI report, and the network device receives the reported CSI. According to the method in embodiments of this application, channel measurement and determining of channel information can be effectively completed, to ensure communication performance of the terminal device.

Abstract: This application provides a channel state information obtaining method and a related apparatus. The method includes: obtaining first information and second information, where the first information indicates a quantity NT of time units, and the second information indicates a Doppler basis corresponding to a channel of each of M antenna ports; receiving, in each of the NT time units, M reference signals from a second device, where the M reference signals occupy a same time-frequency resource, the M reference signals are determined based on a pilot signal and a phase shift of each of the M antenna ports, and NT and M are integers greater than 1; and determining, based on the M reference signals and the second information, channel state information corresponding to each of the M antenna ports.

Abstract: This application discloses a communication method and a communication apparatus. In the method, A communication apparatus determines first information, where the first information indicates a precoding matrix, and the first information includes a plurality of coefficients Cl,i,f,d, where l is a transport layer sequence number, i is a channel state information reference signal (CSI-RS) port sequence number or a spatial domain basis sequence number, f is a frequency domain basis sequence number, d is a Doppler domain basis sequence number, the coefficient Cl,i,f,d corresponds to a priority indication Pri(l, i, f, d), and the coefficients Cl,i,f,d in the first information are arranged based on Pri(l, i, f, d). The communication apparatus sends the first information to a network device.

Abstract: This application provides example channel state information determining methods and example related apparatuses. One example method includes sending, by a first communication apparatus, a first reference signal to a second communication apparatus. The access network device receives first measurement information from the second communication apparatus, where the first measurement information is measurement information determined based on the first reference signal. The access network device receives a second reference signal from the second communication apparatus, and determines channel state information based on the first measurement information and the second reference signal.