Influence of Mutual Coupling on the Transmission Strategy Design for MIMO Correlated Rayleigh Fading Channels

The influence of mutual coupling among Multiple Input Multiple Output antenna (MIMO) systems is usually not negligible due to limited antenna spacing available in practice. A thorough understanding of such influence, however, is not available in the literature, although it is important to the design of a transmission strategy. In this paper, by formulating the equivalent channel matrix in terms of S-parameters that characterize mutual coupling, the authors obtain an explicit expression for the channel capacity. The maximization of the channel capacity so obtained leads to the optimal pre-coding strategy for the transmitter.