Diversity Analysis for Space-Time-Frequency (STF) Coded MIMO System with a General Correlation Model

Previous works on space-time-frequency (STF) codes have focused on frequency-selective but independent fading channels for MIMO-OFDM systems. However, insufficient antenna space, mobile scenarios, and multipath in practice cause correlation in the spatial, temporal, and frequency domains. This paper studies the effect of STF coding on the performance of MIMO-OFDM systems with general spatial, temporal, and frequency/path correlated channels. Specifically, we first derive an upper bound on the maximum achievable diversity and then prove achievability by giving an STF code design example. Finally, we show that our general diversity result recovers those in the existing literature for special correlation structures.