Performance of MIMO Beamforming Transmission Scheme in the Presence of Mutual Coupling

This paper reports investigations into mutual coupling effects on performance of a beamforming transmission scheme of a multiple-input multiple-output (MIMO) system operating under Rician channel conditions. It is shown that the presence of mutual coupling in a transmitting array antenna degrades the radiation pattern. However, it does not adversely affect the system capacity. If the correlated Rayleigh component (NLOS) dominates the channel, the mutual coupling leads to lower capacity. The presence of mutual coupling results in a higher capacity when the LOS component prevails. For some specific ranges of array inter-element spacing, mutual coupling can be seen as beneficial in terms of increasing the capacity when a signal beamforming strategy is applied.