Self-Interference Cancellation in Asynchronous Channel-Unaware Two-Way Relay Networks

Abstract In this paper, we consider asynchronous channel-unaware two-way relay networks in which, two single-antenna sources exchange information through a multiple-antenna amplify and forward relay. These networks confront two challenges; the asynchronization of the received signals and existence of self-interference signals. To overcome these challenges, we propose a combination of a self-interference cancellation signalling scheme with an asynchronous detection scheme. This combination completely cancels the self-interference and the effect of asynchronization. To analyze the performance of the proposed scheme, we obtain an upper bound the pair wise error probability. This bound shows that, at high signal to noise ratios, the proposed scheme achieves non-zero diversity in contrast to its counterparts which are suffering from error floor and zero diversity. Moreover, it is shown that the coding gain increases with the number of relay antennas. This analytical results are confirmed by the numerical simulation results. Furthermore, power allocation between two sources and the relay is investigated numerically.