Self-Interference Aided Channel Estimation in Two-Way Relaying Systems

In this paper, we propose a novel channel estimation scheme for the broadcast phase of the newly invented two- way relaying technique. Instead of using pilot sequences, we exploit the self-interference, which contains the data known at the receivers, to get a first estimate of the channel. Then a decision- directed iterative estimation process is started to improve the accuracy of the channel estimates. We consider a block fading channel model. The simulation results show that the proposed scheme has similar performance as pilot-aided channel estimation schemes in our simulation environment. Since pilot sequences are no longer needed in our proposed scheme, higher spectrum efficiency is achieved without performance loss.