Distributed cooperative precoder selection for interference alignment

This paper presents a distributed, low-feedback, linear-precoding technique to completely cancel interference in the presence of colored Gaussian noise. The selection of the precoder is based only on locally available channel-state information (CSI) at the receiver. We consider the downlink of a cellular broadband wireless system where base stations and user equipment are assumed to have at least two antennas each, and users are scheduled based on fractional frequency reuse. We present a distributed algorithm that helps the interfering base station (BS) to simultaneously beamform to its own user while still minimizing the interference on the unintended user. Simulation results show that the proposed scheme considerably improves the performance of the cell-edge users while causing only a mild degradation in the performance of the in-cell users, thereby leading to an increase in the overall system throughput. © 2006 IEEE.