Transmit Beamforming for Quasi-Orthogonal Space-Time Coded System in Rayleigh Fading Environments

In this paper, a beamforming scheme combined with quasi-orthogonal space-time block codes (QOSTBC) is proposed. At the transmitter, quasi-orthogonal space-time block coding signals is transmitted by using four independent transmit beams. As the receiver, a pairwise decoding algorithm is employed. A flat Rayleigh fading channel model is used in the simulations to compare performance of the proposed scheme with the traditional quasi-orthogonal space-time block codes approach where four independent transmit antennas are used.