Low-Complexity Hybrid Precoding With Dynamic Beam Assignment in mmWave OFDM Systems

摘要

We propose the two-stage multiuser hybrid zero-forcing (ZF) precoding schemes with dynamic beam assignment for mmWave orthogonal frequency division multiplexing systems. In the first stage, hierarchical beam search is developed to reduce complexity in radio-frequency (RF) domain, where variable beamwidth sector codeword is generated by beam broadening, and dominant sector directions are selected based on effective power metric. In the second stage, ZF precoding with dynamic beam assignment is employed in the digital domain, where two low-complexity dynamic beam assignment strategies based on effective channel after RF beamforming are proposed for high system throughput. Simulation results validate the effectiveness of our proposals.