A beamformee device includes a channel estimator, first and second beamforming matrix providers and a dimension reduction unit. The channel estimator receives a NDP through a channel, and obtains channel information of the channel based on the NDP. The first beamforming matrix provider provides wideband beamforming matrices based on the channel information. The dimension reduction unit generates equivalent channel information based on the wideband beamforming matrices. The second beamforming matrix provider provides beamforming matrices based on the equivalent channel information. The wideband beamforming matrices and the subcarrier beamforming matrices are fed back to the beamformer device. Any one or any combination of the plurality of wideband beamforming matrices and the plurality of subcarrier beamforming matrices are selected from codebooks.

Embodiments of this disclosure provide techniques for receiving reference signals by a user equipment (UE) from a base station in a downlink channel, as well as transmitting a linear combination index from the UE to the base station. In particular, the linear combination index identifies a combination of beams selected from a set of beams in accordance with the RS.

Embodiments of this disclosure provide techniques for receiving reference signals by a user equipment (UE) from a base station in a downlink channel, as well as transmitting a linear combination index from the UE to the base station. In particular, the linear combination index identifies a combination of beams selected from a set of beams in accordance with the RS.

A mobile station connected to a multi-carrier cellular communication system having a plurality of sub-carriers. The sub-carriers are classified into K frequency sub-bands, channel state information (CSI) of the frequency sub-bands is represented by matrices W.sup.i (i=0 . . . K−1), where K is an integer greater than 1. The mobile station determines a first sub-index k.sub.1 for the K matrices W.sup.1 (i =0...K -1), and a second sub-index k2 for each one of the K matrices W.sup.i (i=0 . . . K−1). The first sub-index k.sub.1 is common for all frequency sub-bands, and the second sub-index k.sub.2 is specific for the indexed matrix that corresponds to one frequency sub-band. The mobile station reports to a base station of the multi-carrier cellular communication system the first sub-index k.sub.1 and at least one second sub-index k.sub.2.

A method for simultaneous design of a hybrid transceiver in an OFDM-based wideband multi-antenna system is provided. The method comprises: designing transmission/reception analog beamforming commonly used for each subcarrier by using product information of subcarrier channel information; and designing baseband beamforming for an effective channel of each subcarrier.

A method for implementing co-polarized feedback for frequency domain compression is disclosed. The method includes feeding back compressed channel state information, wherein at least one layer is restricted to be transmitted on one polarization and the feedback for the at least one layer only involves the channel state information on the one polarization.

A receiving device for use in a wireless OFDM communication system comprises two or more receive antennas for receiving OFDM signals received over a channel from a transmission device having two or more transmit antennas and applying transmit beamforming, and circuitry configured to perform channel estimation to estimate the channel, generate transmit beamforming information based on the channel estimation, said transmit beamforming information comprising beamforming information per subcarrier or time domain tap, determine a reduced set of transmit beamforming information from said transmit beamforming information, wherein said reduced set comprises beamforming information for a reduced set of subcarriers in the frequency domain or for a reduced set of taps in the time domain, wherein the subcarriers of said reduced set or the taps of said reduced set are determined based on an error criterion, and feed back the reduced set of transmit beamforming information to the transmission device.

A method and apparatus for channel state information feedback and a storage medium are provided according to the present disclosure. The method includes: performing by a terminal channel measurement according to a reference signal; selecting M subbands from K subbands of a CSI reporting band, and reporting to a base station the M subbands' Relative Power Indicator (RPI) and Phase Indicator (PI) of a weighted coefficient associated with a precoding codebook index, where M and K are integers greater than or equal to 1, M<K; each subband is a set of R resource blocks RB, where R is an integer greater than or equal to 1.

A repeater generates repetition signals by repeating an uplink signal over a plurality of subframes. If the plurality of subframes do not include a transmission candidate subframe of a sounding reference signal used to measure uplink reception quality, a controller sets a first transmission format to all the plurality of subframes, and if the plurality of subframes include the transmission candidate subframe, the controller sets a second transmission format to all the plurality of subframes. A transmitter transmits the repetition signals using the set transmission format.

Provided are a method and device for reporting channel state information (CSI), a method and device for processing channel state information, and a storage medium. The method for reporting channel state information includes: dividing M subbands to be reported into two sets; determining a relative value between CSI of each subband in a second set and CSI of a reference subband corresponding to the each subband in the second set; and reporting CSI of each subband in a first set and the relative value of the each subband in the second set to a base station.