Optimum and Suboptimum Receivers for Space-Time Coded Systems in Correlated Fading

We consider a space-time coded system in a correlated Rayleigh flat fading environment. The channel state information (CSI) is obtained from the known pilot code matrix prior to data reception. We consider three receiver structures: (1) a suboptimum one in which the imperfect CSI is used in place of perfect CSI in a perfect CSI optimum receiver, (2) the optimum receiver I in which the imperfect CSI is used in the maximum likelihood sense (3) the optimum receiver II that jointly processes the received data codes and the pilot codes. The system performance in the cases of all three receivers is analyzed in terms of the pairwise error probability.