Relay assisted interference management in co-channel interference systems

Interference alignment (IA) is known to achieve the maximum degrees of freedom at high SNR in interference channels, however, the reliability of IA is little discussed in literature. We consider a scenario consisting of multiple antenna transmit-receive pairs and a MIMO relay helping managing the interference. The interference management is performed in two subsequent transmission phases. Firstly, all the sources transmit data to the receivers and the relay. Secondly, both the sources and relay retransmit the data to the receivers. By leveraging the signal processing at the relay and adapting the combining filters, two suboptimal solutions for interference management are obtained. The reliability and sum-rate comparisons between the proposed schemes and the conventional ones are investigated by simulations. The results show that our proposed schemes can not only achieve a higher sum rate, but also enjoy better bit error rate (BER) at moderate and high SNRs.