A method of channel state information (CSI) report can include receiving a CSI report configuration at a user equipment (UE) from a base station, the CSI report configuration being associated with a set of CSI reference signal (CSI-RS) resources corresponding to multiple transmission reception points (TRPs), performing a channel measurement based on the CSI-RSs resources corresponding to the multiple TRPs, determining a precoder matrix indicator (PMI) based on measurement results of the channel measurement, the PMI corresponding to a precoder matrix, denoted W, of a Type II CSI codebook, the precoder matrix having a spatial domain (SD) basis vector matrix, denoted W.sub.1, SD basis selection of the SD basis vector matrix being TRP-specific, and transmitting a CSI report to the base station, the CSI report including the PMI.

The frequency domain basis may be fed back in a CSI report from a user equipment (UE), with extra overhead and computation cost. In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE configured to receive, from a base station, CSI reference signals (CSI-RS). The apparatus may be further configured to receive, from the base station, a configuration including a frequency domain basis restriction indicating a frequency domain basis subset, where the frequency domain basis subset is selected from a frequency domain basis set. The apparatus may be configured to prepare, upon receiving the frequency domain basis restriction, a CSI report based on the CSI-RS and the frequency domain basis subset. The apparatus may be further configured to transmit the CSI report to the base station.

The disclosure provides a method of providing implicit channel state information (CSI) feedback from a user equipment (UE). The method includes determining a precoding matrix indicator (PMI) selection decision metric, selecting one of a sub-band (SB) linear combination coefficient (LCC) selection method, a wideband (WB) LCC selection method, or a sub-band group (SBG) LCC selection method, based on the determined PMI selection decision metric, determining, using the selected LCC selection method, PMI indices based on sub-bands configured by a base station, and transmitting the determined PMI indices to the base station.

A method and apparatus for feeding back a type II port selection codebook, a method and apparatus for determining a type II port selection codebook, and a computer-readable storage medium are provided. The method for feeding back the type II port selection codebook includes: acquiring a to-be-measured reference signal, and determining the type II port selection codebook based on a measurement result of the to-be-measured reference signal; generating feedback parameters based on the type II port selection codebook, wherein the feedback parameters include a strongest coefficient index, amplitudes of all coefficients, and phases of at least a portion of coefficients in a weighting coefficient matrix in the type II port selection codebook; and transmitting the feedback parameters.

Systems, methods, apparatuses, and computer program products for reducing overhead associated with channel state information through the use of network signaled user equipment specific adjustments that can be applied by the user equipment before measurement of reference signals are provided. For example, a method can include receiving a configuration from a network and receiving reference signals from the network. The method can also include adjusting the received reference signals based on the configuration prioir to performing measurements on the adjusted received reference signals. The user equipment can provide a report based on the measurements to the network.

Embodiments of this application disclose an information feedback method and a related apparatus. A terminal device sends first information to a network apparatus, where the first information includes a total quantity of nonzero coefficients at all spatial layers of the terminal device, and the nonzero coefficients are used to constitute a weighting coefficient matrix in a codebook. The first information further includes first indication information, and the first indication information indicates whether second information sent by the terminal device to the network apparatus carries indication information of a location of a nonzero coefficient. In this way, a coding bit rate of the indication information sent by the terminal device to the network apparatus is reduced while correct data transmission is ensured.

The disclosure provides methods of providing implicit channel state information (CSI) feedback from a user equipment (UE). A method performed by a first device includes determining a feedback parameter selection decision metric; selecting a particular method from a plurality of methods, based on the feedback parameter selection decision metric; determining, based at least in part on the particular method, and based on a configuration of an associated second device, one or more values associated with precoding; and transmitting the one or more values to the second device.

A method for operating a user equipment (UE) comprises receiving configuration information about a channel state information (CSI) report, the configuration information including codebook parameters (M, ?, ?), wherein: M is a number of frequency domain basis vectors, ? is a number ?1, and ? is a number ?1; identifying values of M, ?, and ?; determining a value of K.sub.1 based on ?, where K.sub.1 is a number of selected CSI reference signal (CSI-RS) ports from a total of P CSI-RS ports; determining a maximum number of non-zero coefficients based on ?; determining the CSI report based on the values of M, K.sub.1, and the maximum number of non-zero coefficients; and transmitting the CSI report.

A channel state information transmission method, applied to a first communication node, is provided. The method includes: receiving configuration information of a second communication node; receiving a channel state information reference signal sent by the second communication node, according to the configuration information; and reporting channel state information according to the configuration information, wherein the channel state information is determined according to the channel state information reference signal; wherein the configuration information includes configuration information of the channel state information.

Certain aspects of the present disclosure provide techniques for channel state information (CSI) reporting with time domain (TD) compression. A method that may be performed by a user equipment (UE) includes receiving one or more CSI-RS from a base station (BS). The UE measures the one or more CSI-RS. The UE determining a mapping order for placing CSI feedback in one or more CSI reports and sends the one or more CSI reports to the BS based on the measurements, the one or more CSI reports providing TD compressed CSI feedback including at least linear combination coefficients associated with TD bases used for the TD compression.