MIMO Capacity in Correlated Interference-Limited Channels

This paper analyzes the capacity of MIMO channels in the presence of both antenna correlation and co-channel interference. We investigate the optimization of the input covariance, characterize the optimality of beamforming, and study the behavior of the input covariance in the low and high-power regimes. For the special case of separable correlations, we also derive analytical expressions for the key statistical properties of the spectral efficiency achievable with an arbitrary input covariance. Altogether, our analysis enables assessing the joint impact of correlation and interference on the capacity of multiantenna architectures in a cellular system.