Effect of Mutual Coupling on the Channel Capacity of MIMO Systems

The reciprocity theorem is applied to derive an exact expression that is used to remove the coupling effects embedded in the receiving voltages of an antenna array. The correlation coefficients of the multiple-input–multiple-output (MIMO) channel established with the antenna array is also modified to incorporate the direction-dependent coupling effects more accurately. The effects of mutual coupling on the channel capacity of MIMO systems in a line-of-sight (LOS), as well as a multipath environments, under different coupling assumptions, are simulated and compared.