Performance Analysis of Cell-Free mmWave Massive MIMO with Low-Resolution DAC Quantization

Abstract

This paper focuses on the downlink of a cell-free massive multiple-input multiple-output (MIMO) system in which each of the access nodes (ANs) is equipped with low-resolution digital-to-analog converters (DACs). In particular, the system is assumed to operate over mmWave frequency with practical considerations such as pilot contamination and hybrid precoding scheme. By mimicking the effect of few-bit DACs with the additive quantization noise model (AQNM), a tight approximate rate expression is derived and analyzed with some simulation results, which provide deep understanding of the impacts from the few-bit quantization as well as channel estimation error on the performance of cell-free mmWave massive MIMO.