Mutual Coupling Cancelation for Compact Transmit Antenna Arrays

In this paper, for multiple-input multiple-output (MIMO) systems, we propose to design transmitters installed compact antenna arrays in consideration of the effect of mutual coupling. For this purpose, the transmitter-side coupling matrix consisting of antenna, mutual and load impedances is derived, similar to the receiver-side coupling matrix in literature, but different to the transmitter-side coupling matrix given and used in literature. We show that the transmitter-side coupling matrix derived in this paper is reasonable. With the given system model, the effect of mutual coupling is analyzed and a simple method to eliminate the transmitter-side mutual coupling effect is proposed, which can be employed in MIMO systems with or without channel state information at transmitters. Simulation results demonstrate that employing the method of canceling transmitter-side mutual coupling in MIMO systems installed compact transmit antenna arrays improves system performance significantly.