Performance of MMSE MIMO Receivers: A Large N Analysis for Correlated Channels

Linear receivers are considered as an attractive low- complexity alternative to optimal processing for multi-antenna MIMO communications. In this paper we characterize the performance of MMSE MIMO receivers in the limit of large antenna numbers in the presence of channel correlations. Using a different approach, we generalize our results obtained in [1] to correlated channels showing that the mutual information converges in distribution to a Gaussian random variable whose mean and variance can be characterized analytically. Our results agree very well with simulations even with a moderate number of antennas. We conclude by observing that for a fixed target rate and operating SNR, using a larger number of antennas and with a simple linear MMSE receiver may be a convenient design choice compared to limiting the number of antennas and insisting on more complicated non-linear receivers.