Apparatus and method for transmitting/receiving data in a closed-loop multi-antenna system

A receiver in a closed-loop multi-antenna system, comprising:

• a channel estimator to receive a plurality of data streams from a plurality of respective transmit antennas of a transmitter and to generate a channel matrix through channel estimation of the received data streams;
• a reception beamforming matrix generator to generate a reception beamforming matrix from the channel matrix including only components of data streams transmitted from at least two transmit antennas allocated to the receiver from the plurality of the transmit antennas;
• and
• a Channel Quality Information (CQI) generator to calculate CQIs of channels that carry the data streams transmitted from the at least two transmit antenna allocated to the receiver using the channel matrix, the reception beamforming matrix, and a total Signal-to-Noise Ratio (SNR) obtained through the channel estimation, and to transmit the CQIs to the transmitter.

A method of transmitting data from a transmitter in a closed-loop multi-antenna system, comprising:

• allocating at least two transmit antennas from a plurality of transmit antennas to a receiver;
• transmitting data streams to the receiver through the at least two transmit antennas;
• receiving Channel Quality Information (CQIs) of channels that have carried the data streams transmitted from the at least two transmit antennas from the receiver;
• and
• allocating a transmit antenna to the receiver according to the CQIs.

A transmitter in a closed-loop multi-antenna system, comprising:

• a plurality of transmit antennas;
• a user selector to allocate at least two transmit antennas from the plurality of transmit antennas to a receiver;
• an encoder/modulator to encode and modulate data streams to be transmitted to the receiver and to output the coded and modulated data streams to the at least two transmit antennas;
• and
• a controller to receive, from the receiver, Channel Quality Information (CQIs) of channels that have carried the data streams transmitted from the at least two transmit antennas and to control the user selector and the encoder and modulator according to the CQIs.