Enhanced linear precoding in coordinated multicell broadcast systems

Communication quality in interference-limited cellular networks depends heavily on the coordination among base stations (BSs) for mitigating the interference. In this paper we present a novel linear precoding technique based on phase alignment in coordinated networks to provide spectrally efficient communications in cellular downlink systems employing M-ary phase-shift keying (M-PSK) modulation. We consider a wireless interference network consisting of K BS where each BS transmitting d independent data streams which can be shared among mobile units. We also assume zero-forcing coordination among all BSs. To evaluate the performance of the proposed network configuration, we compare it with interference alignment (IA). Simulation results show that for the fixed number of degrees of freedom per cell, the proposed scheme achieves much better sum rate as well as symbol error rate performance than zero-forcing IA (ZFIA) while requiring much less number of transmit and receive antennas.