Performance of closed-loop transmit antenna diversity system with channel estimation errors and fading correlation

The effect of channel estimation errors and fading channel correlation on closed-loop transmit diversity (CTD) systems is investigated in frequency flat Rayleigh fading channels. A bit error rate expression for the CTD system is analytically derived as a function of the channel correlation coefficient, feedback delay, and fading index. Numerical results show that the performance degradation caused by the estimation errors is more severe than that caused by the fading correlation. It is interpreted that the performance of the CTD system is more sensitive to the beamforming error rather than to the fading correlation.