Transmission Strategy for MIMO Correlated Rayleigh Fading Channels with Mutual Coupling

The influence of mutual coupling among multi- antenna systems is usually not negligible due to limited antenna spacing available in practice. A thorough understanding of such influence, however, is still unavailable in the literature, although it is important to the design of a transmit strategy. In this paper, by formulating the equivalent channel matrix by S-parameters that characterize mutual coupling, we obtain an explicit expression for the channel capacity. The maximization of the channel capacity leads to the optimal precoding strategy for the transmitter. Numerical examples are presented to illustrate the method.