Transmit diversity and combining scheme for spatial multiplexing over correlated channels

Space-time block codes (STBC) are combined with a spatial multiplexing (SM) technique to improve SM system performance in the presence of fading correlation. The data rate is compromised for diversity gain in the combined system. Using Alamouti's scheme at the transmitter, a general combining scheme is presented for a 2/spl times/2 multiple-input multiple-output (MIMO) system and extended, with modification, to MIMO systems with more antennas at both ends.