Hybrid-model for space-time block code over spatial correlated and time-selective fading channels

Most existing space-time block code (STBC) schemes have been developed based on the assumption that the channels are independently identically distributed (i.i.d.) and show quasi-static fading (QSF). However, realistic wireless channels are either spatially correlated fading (SCF), determined by various physical parameters, e.g., antenna spacing, antenna arrangement, angle spread, angle of arrival, etc., or time-selective fading (TSF), caused by Doppler shifts. We propose a hybrid-model (HM), which combines a first-order autoregression model (ARM), to model the flat TSF Rayleigh channel, with an exponential correlation model (ECM), to model the SCF channel. Based on the HM and the decoder proposed by T.A. Tran and A.B. Sesay (see IEEE Trans. Wireless Commun., vol.3, p.855-64, 2004), we derive the theoretical bit error probability (BEP) of the scheme. Finally, analytical and simulation results are presented to verify the validity of our HM and arrive at a useful conclusion: high SCF dominates the performance loss when the TSF is small, whereas large TSF contributes to the performance loss whatever degree SCF is.