A Relay Selection Based Bidirectional Full-Duplex Communication Scheme

Full-duplex (FD) is an emerging technology to alleviate the spectrum crunch. Self-interference is the major issue needs to be solved to realize FD devices, especially for the bidirectional FD model wherein two FD featured devices communicate with each other directly. Beamforming is an effective technology to reduce the self-interference by optimally allocating transmission power. However, the beamforming based self-interference cancellation schemes are not applicable in bidirectional FD model when FD featured transceivers are far away from each other, since large transmission power is needed to guarantee the signal to be received successfully. To enable the beamforming based self-interference cancellation mechanism for bidirectional FD communications with large distance, we propose a relay selection based self-interference cancellation mechanism. By introducing relays, two links in bidirectional FD communications are separated, which enables successful self-interference cancellation with existing beamforming based mechanisms. Simulation provides the guidance of optimal relay deployment. It also shows our proposed relay selection enabled self-interference cancellation mechanism outperforms the existing bidirectional FD communication schemes.