An extended space-time transmit diversity scheme for frequency selective fading channels

This paper presents a transmit diversity scheme for frequency selective fading channels. The proposed scheme uses a space-time block code (ST-BC) with three transmit antennas combined with orthogonal frequency division multiplexing (OFDM). This scheme provides a diversity order as the maximal-ratio receiver combining (MRRC) scheme. It achieves diversity of 3n for n receive antennas and has code rate of 3/4. A maximum-likelihood detector with linear processing is used which results in low computational complexity. Simulation results are provided to show the comparison between the proposed scheme and MRRC.