Robust Hybrid Beamforming in Millimeter Wave Systems With Closed-Form Least-Square Solutions

Zhen Luo, Lei Zhao, Hongqing Liu, Yong Li

Abstract: Robust hybrid beamforming is developed for millimeter wave multiple-input multiple-output (MIMO) systems. The channel state information (CSI) with correlated estimation errors is used for averaging the mutual information formulation. It is proved that the robust hybrid beamforming scheme can be solved via an Euclidean distance minimization problem as the design with the perfect CSI assumption. An alternating method is proposed to solve the hybrid processors with closed-form least-square solutions in each iteration. Simulation results show that the proposed beamforming scheme prevails existing hybrid beamforming designs.