Low-Resolution DACs Aided Partially-Connected Hybrid Precoding Design for MU-MISO System

The utilization of hybrid beamforming (HBF) and low-resolution (LR) quantizers can greatly alleviate the pressure on energy consumption in millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) systems. However, partially-connected (PC) architectures that restrict the use of phase shifters can result in further deterioration of spectral efficiency (SE) with the configuration of LR quantizers. In this letter, we propose a two-stage hybrid precoding design for a downlink multi-user (MU) multiple-input single-output (MISO) system with LR digital-to-analog converters (DAC) to mitigate the impact of quantization distortion on SE. Simulation results show that the proposed algorithm has a significant performance improvement over conventional precoding algorithms and can be easily extended to the ideal quantization case.