In accordance with an example embodiment of the present invention, a method comprising: selecting, by a user equipment, a subset of linear combination coefficients from a linearized two-dimensional matrix having columns of frequency domain components and rows of spatial beams components for channel state information determination, wherein the number of linear combination coefficients in the subset is less than all of the linear combination coefficients; determining indication comprising information associated with column indices of the selected subset of linear combination coefficients from the linearized two-dimensional matrix, wherein the indication excludes the index of the column with lowest index of the linearized two-dimensional matrix; determining compressed channel state information comprising locations in the linearized two-dimensional matrix of the subset of linear combination coefficients and corresponding values of the linear combination coefficients at those locations; and reporting, from the user equipment toward the base station, the compressed channel state information.

The present invention relates to a method for a first terminal to report channel state information (CSI) in a wireless communication system, the method comprising the steps of: receiving, from a base station, an allocation of a group CSI report setting associated with a terminal group including the first terminal; broadcasting the group CSI report setting to the terminal group; and reporting group CSI to the base station, wherein the terminal group consists of the first terminal and at least one second terminal, and the group CSI report setting defines, as the group CSI, the CSI of the first terminal corresponding to a part of the CSI about each of a plurality of terminals constituting the terminal group.

Provided is a feedback method and apparatus in a multiple-input multiple-output (MIMO) communication system. A terminal may determine a preferred pre-coding matrix for a neighboring terminal, based on a reference rank determined by a base station and a preferred pre-coding matrix of the terminal. The terminal may calculate a channel quality indicator (CQI) based on the preferred precoding matrix for the neighboring terminal, and may feed the CQI back to the base station.

A method for a channel state information (CSI) feedback. The method 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.

The present invention relates to precoding and feedback channel information in wireless communication system. A method includes receiving a first Precoding Matrix Index (PMI) and a second PMI from a terminal; mapping one or two codewords into layers; precoding symbols mapped into the layers using a first precoding matrix derived from the first PMI and a second precoding matrix derived from the second PMI; and transmitting the precoded symbols to the terminal, wherein the reception of the first PMI is less frequent than the reception of the second PMI.

Aspects of the present invention provide apparatuses and methods for adaptive channel state feedback (CSF) estimation techniques. Downlink transmissions can be received at a mobile device. The downlink transmissions can be received after the mobile device has entered a power saving mode of operation. The downlink transmission received can be a discontinuous downlink subframe and can include one or more pilot symbols. A channel variation factor of the transmission channel can be determined based on the received downlink transmission. Based on the amount of variation of the transmission channel, either an earlier-received or a later-received pilot symbol can be used for CSF estimation. Further, either higher or lower weighted filter coefficients can be selected for use in CSF estimation based on the amount of variation of the transmission channel.

An electronic device at a base station end includes a processing circuit, the processing circuit being configured to: configure, in response to request signalling from a user equipment, an aperiodic beam-forming reference signal relevant to a first beam group for the user equipment, wherein the first beam group is determined by a base station according to channel state information periodically fed back by the user equipment; generate downlink control information, so as to indicate that the user equipment feeds back beam selection information according to the aperiodic beam-forming reference signal; determine, according to the beam selection information, one or a plurality of candidate beams and one or a plurality of corresponding second pre-coding codebooks; and determine an effective pre-coding codebook based on the one or multiple second pre-coding codebooks.

A base station includes a transceiver, and a processor configured to allocate at least one CSI-RS antenna port to a user equipment (UE), precode the at least one CSI-RS antenna port with a first precoding matrix, cause the transceiver to transmit the at least one CSI-RS antenna port precoded with the first precoding matrix through a channel to the UE, cause the transceiver to signal a number of the at least one antenna port to the UE, cause the transceiver to receive an index for a second precoding matrix from the UE, wherein the second precoding matrix is determined by the UE according to the at least one CSI-RS antenna port precoded with the first precoding matrix as received through the channel by the UE and the signaled number of the at least one antenna port, and precode transmission data with the first precoding matrix and the second precoding matrix.

A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, (precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed.

Disclosed are a signal method for a CoMP operation in a wireless communication system and a device therefor. Particularly, the signaling method for a CoMP operation between base stations in a wireless communication system comprises a step of transmitting, by a first base station, first CoMP information to a second base station, wherein: the first CoMP information includes CoMP hypothesis set information which is a collection of CoMP hypothesis information for one or more cells, benefit metric information associated with the CoMP hypothesis set, start system frame number (SFN) information, and start subframe number information; the CoMP hypothesis is hypothetical physical resource block (PRB) specific resource allocation information for one cell; the start SFN information indicates a start wireless frame number of the first CoMP information; and the start subframe number information can indicate a start subframe number of the first CoMP information.