The enhancement of system performance in quasi-orthogonal space-time-frequency codes

In this paper, we describe how full-diversity quasi-orthogonal space-time-frequency block codes (QOSTFBCs) suffer from low coding advantage. Then, we propose a method for improving the coding advantage of this code family, and we subsequently modify their performances. Simulation results determine that our proposed method is very effective, and in some cases, it could enhance the performance of the MIMO-OFDM space-time-frequency coded system which works based on QOSTFBCs as much as 6 dB.