Exact capacity and symbol error probability analysis of STBC in spatially correlated MIMO Nakagami fading channels

In this paper, we exploit the single-input single-output equivalency of orthogonal space-time block coding (STBC) in order to analyze its performance over nonselective Nakagami-m fading channels, in the presence of spatial correlation. More specifically, we derive the exact average symbol error probability (SEP) of coherent M-PSK and M-QAM, when such modulation schemes are used along with STBC over correlated Nakagami-m fading channels. Besides, for integer values of the Nakagami parameter m, closed-form expressions for the derived SEP formulae are provided. Moreover, in the latter case, we also derive exact closed-form expressions for the ergodic Shannon capacity of STBC, when used in the presence of spatially correlated Nakagami-m fading channels. Numerical results are provided to assess the robustness of STBC to spatial correlation, by analyzing the effects of specific correlation parameters on the achievable symbol error probability