Space-time-frequency block coded OFDM with subcarrier grouping and constellation precoding

This paper proposes novel space-time-frequency (STF) block coding for multi-antenna OFDM transmissions over frequency-selective Rayleigh fading channels. Incorporating subcarrier grouping and choosing appropriate system parameters, we first convert our system into a set of group STF (GSTF) systems. This enables simplification of STF block coding within each GSTF system. We derive design criteria for STF block coding, and exploit existing ST coding techniques to construct STF block codes. The resulting codes are shown capable of achieving both maximum diversity and coding gains, while affording low-complexity decoding. The performance merits of our design is confirmed by corroborating simulations, and compared with existing alternatives.