Performance Analysis of Digital Beamforming mmWave MIMO with Low-Resolution DACs/ADCs

TL;DR

This paper evaluates the impact of low-resolution DACs/ADCs on the performance of digital beamforming mmWave MIMO systems, highlighting a trade-off between energy efficiency and spectral efficiency.

Contribution

It provides a detailed analysis of channel estimation performance and system trade-offs in fully digital mmWave MIMO with low-resolution quantizers.

Findings

4-bit quantization balances energy and data rate effectively

Low-resolution DACs/ADCs cause manageable distortion in system performance

Moderate quantization resolutions improve power efficiency without significant spectral loss

Abstract

Future wireless communications will rely on multiple-input multiple-output (MIMO) beamforming operating at millimeter wave (mmWave) frequency bands to deliver high data rates. To support flexible spatial processing and meet the demands of latency critical applications, it is essential to use fully digital mmWave MIMO beamforming, which relies on accurate channel estimation. However, ensuring power efficiency in fully digital mmWave MIMO systems requires the use of low-resolution digital-to-analog converters (DACs) and analog-to-digital converters (ADCs). The reduced resolution of these quantizers introduces distortion in both transmitted and received signals, ultimately degrading system performance. In this paper, we investigate the channel estimation performance of mmWave MIMO systems employing fully digital beamforming with low-resolution quantization, under practical system constraints. We evaluate the system performance in terms of spectral efficiency (SE) and energy efficiency (EE). Simulation results demonstrate that a moderate quantization resolutions of 4-bit per DAC/ADC offers a favorable trade-off between energy consumption and achievable data rate.