Improved Hybrid Precoding Scheme for mmWave Large-Scale MIMO Systems

Abstract

Due to the limited spectrum resources, communication utilizing millimeter wave (mmWave) has become a research hotspot, deemed to be an important technology of 5G, in which plenty of antennas can be deployed. However, in mmWave large-scale MIMO systems, it is not feasible to directly use full digital precoding, bringing high energy consumption and high complexity. To overcome this difficulty, hybrid precoding is proposed. In this paper, we put forward a relative weighted-based hybrid precoding scheme on the basis of an energy-efficient precoding architecture only using switches and inverters called SI-based architecture, aimed at adaptively updating the probability distribution of elements in an analog beamformer in the hybrid precoder by minimizing cross entropy. Hence, our proposed scheme can achieve higher achievable sum rate than the conventional method without relative weighted. At last, we provide some simulation results to validate the superiority of our proposed precoding scheme.