FP-based Hybrid Precoding with Dynamic Subarrays and Low-resolution PSs

Abstract

Hybrid precoding architectures with large-scale antenna arrays have emerged as an important technique in millimeter wave (mmWave) communication systems. Fully-connected architecture is often employed to achieve satisfactory performance close to fully-digital schemes. To reduce power consumption, partially-connected scheme with fixed-subarrays has been proposed, in which the analog precoder are usually realized by infinite-resolution phase shifters (PSs). In an effort to further improve energy efficiency, we introduce a novel hybrid precoding architecture with dynamic subarrays and hardware-efficient low-resolution PSs for mmWave multiuser multiple-input single-output (MU-MISO) systems. By dynamically mapping each RF chain to a non-overlap subarray via a switch network and corresponding PSs, multiple-antenna/multiuser diversities can be exploited to mitigate the performance loss caused by low-resolution PSs. Based on the theory of fractional programming (FP), we proposed an iterative hybrid precoder design algorithm with affordable computational complexity. Simulation results demonstrate the advantages of the proposed hybrid precoding architecture with dynamic subarrays and low-resolution PSs.