Effect of Channel Estimation Errors on the Performance of MIMO-OFDM Systems in Correlated Fading Channels

In this paper, we investigate the effect of inaccurate channel estimation on the bit error rate (BER) performance of the convolutionally coded MIMO-OFDM systems with multilevel quadrature amplitude modulation (M-QAM, M=16, 64) and different diversity orders, particularly in spatially correlated fading channels. It is shown that, in a highly correlated fading channel, the 16-QAM system employing increased diversity order is remarkably more sensitive to the channel estimation errors than the same system but with the 64-QAM. On the other hand, when the fading correlation of the channel is low, the 16-QAM system with antenna diversity appears to become more robust to the channel estimation errors than the 64-QAM system with the same antenna diversity in terms of the BER performance