Asymptotic performance of space-time block codes over correlated Rician MIMO channels

The effect of correlated fading on the performance of space-time block codes (STBCs) over multiple-input multiple-output (MIMO) Rician fading channels is studied. The asymptotic error probability formulas for orthogonal STBC and the asymptotic pair-wise error probability (PEP) for non-orthogonal STBC in correlated Rician MIMO channels with high average signal-to-noise ratios (ASNRs) are derived, in terms of the diversity and coding gains. We show that the phase vector Phi of the channel line-of-sight (LOS) components and the fading correlation pattern have a significant impact on the performance of STBC in correlated Rician fading channels. The asymptotic upper and lower bounds of the receiver performance as a function of vector Phi are derived. Our results show that with correlated fading the phase vector Phi affects the effective Rice K-factor at the STBC receiver output, and hence may result in a coding gain significantly higher than the independent fading case. Furthermore, when the channel covariance matrix is rank deficient and under some mild conditions, the receiver´s performance approaches that in a non-fading channel