High-rate space-time block coding schemes

A rate-6/4 full-diversity orthogonal space-time block code (STBC) is constructed for QPSK and 2 transmit antennas by applying constellation scaling and rotation to the set of quaternions used in Alamouti code. Also given is a rate-9/8 full-diversity quasi-orthogonal space-time block code (QOSTBC) for 4 transmit antennas. Lastly, a rate-10/8 code is presented for 4 transmit antennas. Simulation results indicate that these high-rate codes achieve better throughputs in the high signal-to-noise ratio region.