A New Transmit Beamforming Scheme for Bidirectional Relaying

In this paper, we study the bidirectional/two-way relaying while considering dual antennas at the relay. With detect-and-forward relaying, we propose a transmit beamforming scheme using equal gain transmission (EGT) principle in the bidirectional relaying. Analytical outage probability and symbol error probability for the proposed scheme are presented and a close match with the numerical results is observed. Through numerical results, we show that EGT based transmit beamforming performs slightly worse than the optimum transmit beamforming scheme, while EGT is simpler to implement and requires partial channel state information (CSI). We also show that EGT based transmit beamforming outperforms existing transmission schemes in the presence of CSI error .