Space-time eigenbeam coding in wideband correlated fading environments

To improve the performance of space-time coding in downlink wideband correlated fading environments, a novel transmission scheme combining eigenbeamforming and OFDM is proposed. Provided that the channel correlated statistics are available at the transmitter, the wideband correlated fading channels can be converted into an independent FIR channel with 2 transmitting antennas and N receiving antennas by eigenbeamforming and reducing the dimensions. Then OFDM is utilized to convert this FIR channel into a group of independently parallel subchannels to carry space-time codes. With the new structure, the performance of space-time coding over downlink wideband correlated fading channels has been greatly improved and the complexity of the system has greatly decreased. The validity of the proposed system is verified by simulations under different conditions and a comparison is made of the new structure with the structure available theoretically and computationally.