One-Sided Precoder Designs for Interference Alignment

The aim of this paper is to propose a fast convergence algorithm of precoder to achieve feasible interference alignment. By limiting the optimization only on the transmitters´ side, it relaxes the assumption of channel reciprocity which will alleviate the significant overhead induced by alternating between the forward and reverse communication links. A lower complexity and higher robustness modified steepest descent (SD) algorithm in the complex space is introduced first. Then we reform the optimization problem on the complex Stiefel manifold and derive a novel SD algorithm to achieve perfect interference alignment. Simulation results suggest that comparing with previous methods, the novel SD algorithm on Stiefel manifold has better convergence performance and higher system capacity.