Degradation on the performance of MIMO system under a correlated sub-channels condition

The multi-input multi-output communication architecture has recently emerged as a new paradigm for wireless communications in a rich multipath environment, and it has demonstrated spectral efficiencies far beyond those offered by conventional techniques. However, the correlation between individual sub-channels in a real-world wireless channel may result in a substantial degradation on the performance of the MIMO system. We investigate the MIMO link level performance with zero-forcing (ZF) and minimum mean-square error (MMSE) detections under the scenario that the individual sub-channels are correlated. We show that, for the exponential correlation channel model, an increase in channel correlation between the transmission paths results in a decrease in signal-to-noise ratio (SNR) at the receiver.