Low-Complexity ZF Detection for Double Space-Frequency Transmit Diversity Based OFDM System in Frequency Selective Fading Channel

In this paper, we propose an efficient low complexity MIMO detection method for double space-frequency transmit diversity (D-SFTD) based coded OFDM system. The proposed MIMO detector involves three-step filtering process to efficiently de-correlate spatially-multiplexed and space-frequency-coded signals without direct matrix inversion process. As the proposed MIMO detector takes advantage of frequency selectivity, not a favorable channel condition for SFBC system, performance degradation caused by low correlation between two consecutive subcarriers is compensated by assigning weighting factor per subcarrier. From computer simulation results, our scheme in D-SFTD outperforms previously proposed suboptimal MIMO detection methods such as iterative interference cancellation based V-BLAST.