Combination of interference alignment and beamforming in cellular networks

In this paper, a new technique is proposed to improve the throughput performance of relay backhaul links in cellular networks for the case of imperfect channel knowledge,which could be implemented with small changes to existing TD-LTE standards. The technique is based on interference alignment (IA) and beamforming (BF). Considering the effect of power gain and inter-cell interference, transmit and receive matrices are jointly designed to increase the SINR at receivers. As the collaboration between Base-Stations (BSs) is not allowed in order to simplifying the implementation, two distributed algorithms, ‘Maximize SINR’ and “Minimize Interference”, are provided in iterative manner. Simulation results show that the combination of IA and BF achieves considerable performance gain. Thereinto, the algorithm of ‘Maximize SINR’ behave excellent both in high and low SNR region, and the throughput performance of ‘Minimize Interference’ outperform traditional BF in the high SNR region.