Capacity Study of Non-Coherent MIMO Channels

This paper considers the capacity of non-coherent multiple-input multiple-output (MIMO) fading channels with memory. A general decomposition for the MIMO mutual information is found first, then asymptotic lower and upper bounds are derived based on the decomposition. It is found that the upper and the lower bound will converge and a MIMO fading number is derived when the number of receive antennas approaches to infinity. It is shown that inputs with independent Euclidean norm and phase-amplitude-ratio vector can achieve this fading number when the number of receive antennas is large. The derived MIMO fading number reduces to the fading number of single-input multiple-output (SIMO) systems. A MIMO non-asymptotic lower bound also is presented