Analytical Mutual Information Distribution and Delay-Limited Capacity for Spatially Correlated Multiple-Antenna Systems

In this paper, we derive the probability density function of the mutual information between transmitted and received complex signals of spatially correlated multiple-input multiple-output (MIMO) communication systems. Using this density we study the most important information-theoretic measures, the so-called delay-limited capacity, outage capacity, ergodic capacity and capacity variance of spatially correlated MIMO channels. Numerical results show how the channel correlation degrades the information-theoretic measures of MIMO communication systems. We also show that the density of mutual information of correlated/uncorrelated MIMO systems can be approximated by a Gaussian density with derived mean and variance, even for a finite number of inputs and outputs