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 describes a channel information feedback method and a communication apparatus. The method includes a terminal device that receives configuration information sent by a network device, where the configuration information is used to configure a feedback mode of channel information. The terminal device may feed back current channel information to the network device when the feedback mode configured by using the configuration information is a first mode. The terminal device may alternatively feeds back predicted channel information to the network device when the feedback mode configured by using the configuration information is a second mode. System performance is therefore improved by the method described in this application because channel information feedback requirements in different scenarios can be met.

Abstract: A channel state information reporting method and a related apparatus is described. The method includes: receiving a first channel state information reference signal CSI-RS; sending, to a network device, first channel state information CSI obtained based on a measurement result of the first CSI-RS. The first CSI includes indication information of a first vector set for the network device to determine a target precoding matrix. The method further includes receiving a second CSI-RS; and sending, to the network device, second CSI obtained based on a measurement result of the second CSI-RS and a second vector set.

Abstract: In accordance with an embodiment, a method includes obtaining Mv frequency domain components, where the Mv frequency domain components are a subset of N candidate frequency domain components, and Mv is a positive integer; and sending first indication information, where the first indication information indicates the Mv frequency domain components, the first indication information occupies ? log 2 ? ( N - 1 M v - 1 ) ? bits, and N is a positive integer greater than Mv.

Abstract: This application provides a resource configuration method. The method includes: A terminal device receives a channel state information CSI reporting configuration from a network device, where the CSI reporting configuration includes N fields, the N fields are in one-to-one correspondence with N CSI resource configurations, a first field in the N fields indicates a first carrier associated with a first CSI resource configuration that is in the N CSI resource configurations and that corresponds to the first field, the N CSI resource configurations are associated with N carriers, and N is a positive integer greater than 1; the terminal device obtains CSI based on the CSI reporting configuration; and the terminal device sends the CSI to the network device.

Abstract: This application provides a channel measurement method and a communication apparatus, to improve accuracy of a channel measurement result, and may be applied to a communication system. The method includes: A terminal device receives first information indicating a channel state information reference signal CSI-RS resource occupied by a CSI-RS, receives the CSI-RS on the CSI-RS resource, and sends channel state information CSI.

Abstract: This application provides a channel information obtaining method and a related device. In the method, first indication information may be received, where the first indication information indicates one of a plurality of parameter configuration combinations of a reference signal, and the plurality of parameter configuration combinations are associated with a same codebook. A terminal device may feed back channel state information based on the indicated parameter configuration combination.

Abstract: A pilot mapping method and an apparatus are provided, to implement pilot mapping corresponding to ports whose quantity is greater than 32. The method includes: determining time-frequency resource positions of CDM groups that correspond to each group of ports in X groups of ports and that are associated with Y positions, where each group of ports is distributed in a different resource block RB, X is determined based on a total quantity P of ports, a quantity of CDM groups is determined based on P and a type of the CDM group, X>1, Y?1, P>32, and X, Y, and P are integers; and sending first indication information, where the first indication information indicates the time-frequency resource positions of the CDM groups that correspond to each group of ports in the X groups of ports and that are associated with the Y positions.

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: In accordance with an embodiment, a method includes transmitting first indication information to a terminal device, where the first indication information indicates a first parameter combination including at least two of the following: a first value of Mv, a first value of ?, and a first value of ?. The first parameter combination is for determining that a first coefficient matrix to be indicated by the terminal device includes a maximum of K0 non-zero elements, and K0 is determined based on the first values of Mv, ?, and ?. The terminal device sends a second information indication to the network device, where the second indication information indicates K2 non-zero elements in the first coefficient matrix, and K2 is less than or equal to K0.

Abstract: In accordance with an embodiment, a method includes receiving first indication information from a network device, where the first indication information indicates a first parameter combination including at least two of the following: a first value of Mv, a first value of ?, and a first value of ?. The first parameter combination is configured to be used to determine a a maximum of K0 non-zero elements for a first coefficient matrix, and K0 is determined based on the first values of Mv, ?, and ?; sending a second information indication to the network device, where the second indication information indicates K2 non-zero elements in the first coefficient matrix, and K2 is less than or equal to K0.

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: Embodiments of this application provide an update method and a communications apparatus. The method includes: generating space domain vector update information, where the space domain vector update information is for updating a first group of space domain vectors to obtain a second group of space domain vectors, the space domain vector update information includes a plurality of groups of space domain vector coefficients, and each group of space domain vector coefficients is for performing weighted combination on the first group of space domain vectors, to obtain one space domain vector in the second group of space domain vectors; and sending the space domain vector update information.

Abstract: A channel state information feedback method includes: a terminal receives first indication information from a network device, and the terminal sends channel state information to the network device. The first indication information is used to indicate a type of a right multiplication matrix in a first codebook, and the first codebook satisfies a formula (I). W is the first codebook, W1 is a port selection matrix, (II) is a linear superposition coefficient matrix, Wf is the right multiplication matrix, and (III) is a conjugate transpose of Wf, and is used by the terminal to determine the channel state information based on the first codebook. According to the method, when there are a plurality of codebooks, the codebook used by the terminal to obtain the CSI can be clearly indicated.

Abstract: A method for indicating channel state information CSI measurement and a communication apparatus. A network device indicates, to a terminal device by using first indication information, one or more frequency domain units in a downlink reference signal resource that are used by the terminal device to obtain CSI. The terminal device determines, based on the first indication information, which frequency domain units in the downlink reference signal resource are used to obtain the CSI, and perform measurement in the frequency domain unit to obtain the CSI. The network device flexibly configures CSI measurement based on a system status, to control obtaining of the CSI. This helps the terminal device obtain the CSI more pertinently based on the indication in different cases.

Abstract: This application describes a channel information feedback method and a communication apparatus. The method includes a terminal device that receives configuration information sent by a network device, where the configuration information is used to configure a feedback mode of channel information. The terminal device may feed back current channel information to the network device when the feedback mode configured by using the configuration information is a first mode. The terminal device may alternatively feeds back predicted channel information to the network device when the feedback mode configured by using the configuration information is a second mode. System performance is therefore improved by the method described in this application because channel information feedback requirements in different scenarios can be met.

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.

Abstract: This application relates to the field of communication technologies, and provides an information transmission method and an apparatus. In this method, a radio access network device sends, to a terminal device, first indication information indicating first information and second information and second indication information indicating a first quantity of DFT vectors, the first information indicates a first quantity of to-be-selected ports, and the second information indicates a first compression factor. The radio access network device further sends a reference signal to the terminal device. The terminal device sends downlink channel state information to the radio access network device based on the first indication information, the second indication information, and the reference signal. The compression factor is a compression factor of a complex coefficient matrix. There is a correspondence between the compression factor and a quantity of transport layers.

Abstract: A channel state information feedback method includes: a terminal receives first indication information from a network device, and the terminal sends channel state information to the network device. The first indication information is used to indicate a type of a right multiplication matrix in a first codebook, and the first codebook satisfies a formula (I). W is the first codebook, W1 is a port selection matrix, (II) is a linear superposition coefficient matrix, Wf is the right multiplication matrix, and (III) is a conjugate transpose of Wf, and is used by the terminal to determine the channel state information based on the first codebook. According to the method, when there are a plurality of codebooks, the codebook used by the terminal to obtain the CSI can be clearly indicated.