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

TL;DR

This paper analyzes the performance of MMSE MIMO receivers with correlated channels in the large antenna limit, providing asymptotic mutual information distribution and validating results with simulations.

Contribution

It extends previous work to correlated channels using the replica method, deriving the asymptotic mutual information mean and variance for large MIMO systems.

Findings

Mutual information converges to a Gaussian distribution as the number of antennas grows.

Results match well with simulations even at moderate antenna counts.

Provides a theoretical framework for correlated MIMO channel analysis.

Abstract

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 the replica method, we generalize our results obtained in arXiv:0810.0883 to Kronecker-product correlated channels and calculate the asymptotic mean and variance of the mutual information of a MIMO system of parallel MMSE subchannels. The replica method allows us to use the ties between the optimal receiver mutual information and the MMSE SIR of Gaussian inputs to calculate the joint moments of the SIRs of the MMSE subchannels. Using the methodology discussed in arXiv:0810.0883 it can be shown that the mutual information converges in distribution to a Gaussian random variable. Our results agree very well with simulations even with a moderate number of antennas.