A robust interference alignment technique for the MIMO interference channel with uncertainties

Interference alignment (IA) is a transmission technique for exploiting all available degrees of freedom in the frequency- or time-selective interference channel with an arbitrary number of users, which can achieve linear capacity scaling. However, standard approach requires perfect channel state information (CSI) and is sensitive to inevitable channel imperfection, which motivates us to consider the robust design. In this work, a robust interference alignment approach is designed for multiple-input multiple-output (MIMO) interference channel to handle channel imperfections. Based on the norm-bounded error model, the proposed robust design minimizes the interference signals that spill out the interference subspace. The underlying problem is recast to semidefinite programming (SDP) form by using Schur complement theorem, and the optimum solutions are obtained iteratively. Simulation results reveal the robustness of the worst-case design against channel uncertainties.