Two Zero Forcing Beamfomers for the Full Duplex Two Way Relay Channel

We propose two closed form zero-forcing beamformers (ZFBF) for the full-duplex (FD) two way relay network, which efficiently suppress the self-interferences at the involved nodes so that the two way relaying can be implemented in a single time phase. We assume a large portion of the self-interferences are suppressed by analog circuit parts and the proposed digital domain beamforming remove the remaining interference. By repetitive applications of projection onto the orthogonal space combined with the geometric geodesic beamforming, the two schemes allow us to characterize the rate pair curves of the FD two way relay network by simply varying the angles forming the geodesic beamforming vectors. Two optimization approaches can be applied to find the angle parameters and the better ZFBF design.