Decorrelating two signals using three side-by-side antennas

The paper describes how an array of three side-by-side antenna elements can exploit the array topology to decorrelate two independent signals at the transmitter side. The idea is to map the signals onto an orthogonal set of angular functions (basis). This is done by feeding the central element with the first signal, while feeding the other two by anti-phased versions of the second signal. The mutual information of the proposed scheme is evaluated in different outdoor macro-cellular propagation scenarios.