An apparatus for mapping data in a wireless communication system. The apparatus includes circuitry for generating a precoding matrix for multi-antenna transmission based on a precoding matrix indicator (PMI) feedback from at least one remote receiver where the PMI indicates a choice of precoding matrix derived from a matrix multiplication of two matrices from a first code book and a second codebook. The apparatus further includes circuitry for precoding one or more layers of a data stream with the precoding matrix and transmitting the precoded layers of data stream to the remove receiver.

A high angular resolution processing method for MIMO system applies a symmetric array antenna for receiving an input signal matrix. The input signal matrix is a transmission signal or reflex signal of at least one target object. The method includes following steps. Step S1: outputting a conversion matrix according to an amount of the symmetric array antenna; step S2: performing a real number conversion using the input signal matrix and a plurality of angle-related pursuit matrixes through the conversion matrix, obtaining a real number input signal matrix and real number pursuit matrixes; and step S3: inputting the real number input signal matrix and the real number pursuit matrixes to an orthogonal matching pursuit model. Obtaining an amount of the target object and an angle of a location corresponding to the target object.

Mechanisms for reduction of channel state information (CSI) feedback overhead are disclosed for full dimensional multiple input, multiple output (FD-MIMO) systems with large dimension antenna ports. In one aspect, rank-dependent CSI antenna port measurements are used in order to limit the number of antenna ports for high rank CSI reporting. Another aspect allows a user equipment (UE) to select subband feedback for aperiodic CSI porting on an uplink shared channel when the UE is to report subband quality and precoding indicators. Another aspect provides for on-demand CSI feedback that dynamically configures CSI feedback parameters. To reduce the signaling overhead, the multiple parameter sets may be pre-configured with different values for dynamic reporting parameters.

A method of a user equipment (UE) for a channel state information (CSI) feedback in a wireless communication system is provided. The method comprises receiving, from a base station (BS), CSI feedback configuration information including a number (K.sub.0) of coefficients for the CSI feedback, deriving, based on the CSI feedback configuration information, the CSI feedback including K.sub.1 coefficients that are a subset of a total of Q coefficients, wherein K.sub.1≤K.sub.0 and K.sub.0<Q, and transmitting, to the BS, the CSI feedback including the K.sub.1 coefficients over an uplink channel.

A method for operating a user equipment (UE) comprises receiving configuration information for a CSI report. The configuration information includes information to: configure a codebook and parameters for the codebook, the codebook comprising a precoding matrix indicator (PMI) indicating a set of components S to represent N.sub.3 precoding matrices, where N.sub.3≥1; and partition the PMI into two subsets, a first PMI subset indicating a first subset of components S1 from the set of components S, and a second PMI subset indicating a second subset of components S2 from the set of components S different from the first subset of components S1. The method further comprises determining the CSI report based on the configuration information, the CSI report including the second PMI subset indicating the second subset of components S2, and transmitting the determined CSI report over an uplink (UL) channel.

Methods, systems, and devices for wireless communications are described. A wireless device may apply phase precompensation to multiple user-multiple input multiple output (MU-MIMO) communications with different wireless devices. The wireless device may measure one or more axis offsets between antenna arrays of the wireless device and other antenna arrays of different wireless devices. The wireless device may perform MU-MIMO communications with the different wireless devices by applying phase precompensation according to the axis offset. For example, the wireless device may transmit or receive communications from multiple wireless devices using the phase precompensation.

A method and system to signal transmission layers or dedicated reference signal ports to be used in a multiple input multiple output system, the method including providing a downlink control signal containing information for transmission layers or dedicated reference signal ports utilized, the dedicated reference signal ports being associated with the transmission layers; and using the information to demodulate data on each transmission layer.

A signal generation method is used in a transmission device that transmits a plurality of transmission signals from a plurality of antennas at the same frequency and at the same time, in the case where larger power change is performed on a first transmission signal than on a second transmission signal during generation process of the first transmission signal and the second transmission signal, the first transmission signal and the second transmission signal are mapped before the power change such that a minimum Euclidian distance between possible signal points for the first signal is longer than a minimum Euclidian distance between possible signal points for the second signal.

A method for a channel state information (CSI) feedback comprises receiving CSI feedback configuration information for the CSI feedback including a spatial channel information indicator based on a linear combination (LC) codebook, wherein the spatial channel information comprises at least one of a downlink channel matrix, a covariance matrix of the downlink channel matrix, or at least one eigenvector of the covariance matrix of the downlink channel matrix; deriving the spatial channel information indicator using the LC codebook that indicates a weighted linear combination of a plurality of basis vectors or a plurality of basis matrices as a representation of at least one of a downlink channel matrix, a covariance matrix of the downlink channel matrix, or at least one eigenvector of the covariance matrix of the downlink channel matrix; and transmitting over an uplink channel, the CSI feedback including the spatial channel information indicator.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive downlink control information (DCI) that indicates a first transmission configuration indicator (TCI), a second TCI, and a precoding matrix. The first TCI may be associated with a first set of antenna indices of the precoding matrix and the second TCI may be associated with a second set of antenna indices of the precoding matrix. The UE may transmit an uplink transmission based at least in part on the DCI. Numerous other aspects are provided.