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Applied Math Seminar
MIMO Capacity Through Correlated Channels in the Presence of Correlated
Interferers and Noise: A (not so) Large N Analysis |
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The use of multi-antenna arrays in both transmission and reception promises huge increases in the throughput of wireless communication systems. It is therefore important to analyze the capacities of such systems in realistic situations, which may include spatially correlated channels and correlated noise, as well as correlated interferers with known channel at the receiver. Here we present an approach that provides analytic expressions for the statistics, i.e. the moments of the distribution of the mutual information of multi-antenna systems with arbitrary correlations, interferers and noise. Although this method is valid formally for large antenna numbers, it produces extremely accurate results even for arrays with as few as two or three antennas. We also develop a method to analytically optimize over the input signal covariance when the channel covariance is available at the receiver, which enables us to calculate analytic closed-loop capacities with covariance feedback. In many cases of interest this closed-loop capacity is very close to the full closed loop capacity in which the transmitter has full channel knowledge. We apply this analytic approach to a number of important examples and we compare our results with simulations to establish the validity of this approach. This method provides a simple tool to analyze the statistics of throughput for arrays of any size. |