Shifting The Paradigm Of Duplex Filter Designs With Spatial Duplexing

The paper describes a duplexing technique for mobile handsets. The idea is to reuse the local transmit and receive antennas as a spatial duplexer. This is done by properly weighting the transmit antennas such that the transmit signal is projected in the null space of the self interference channel matrix. Simulation and measurement results are provided.