Robust Hybrid Transceiver Designs for Millimeter Wave AF Cooperative Systems

In this paper, robust transceiver designs are proposed for millimeter wave multiple-input multiple-output cooperative systems with the amplify-and-forward cooperative strategy. Hybrid structures are adopted to jointly design the processors at the source, the relay, and the destination, respectively. Contrariwise to most existing works that develop codebook-based solutions with perfect channel state information (CSI) assumptions, the proposed designs present codebook- free solutions based on the so-called Alternating Direction Method of Multipliers approach and imperfect CSI with Gaussian-distributed errors. Numerical results show that the proposed designs provide substantial improved spectral efficiencies compared with the existing designs.