Over-sampling codebook-based hybrid minimum sum-mean-square-error precoding for millimeter-wave 3D-MIMO

Hybrid precoding design is challenging for millimeter-wave massive MIMO. Most prior hybrid precoding schemes are designed to maximize the sum spectral efficiency, while seldom investigating the bit-error-rate (BER). Therefore, this letter designs an over-sampling codebook (OSC)-based hybrid minimum sum-mean-square-error (min-SMSE) precoding to optimize the BER. Specifically, given the effective baseband channel consisting of the real channel and analog precoding, we first design the digital precoder/combiner based on min-SMSE criterion to optimize the BER. To further reduce the SMSE between the transmit and receive signals, we propose an OSC-based joint analog precoder/combiner design. Simulation results show that the proposed scheme can achieve the better performance than its conventional counterparts.