Evaluating the Impact of Low-resolution DACs on a Downlink Massive MIMO System Performance

Abstract

This project investigates the impact of low-resolution digital-to-analog converters (DACs) on the performance of downlink massive multiple-input multiple-output (MIMO) systems, emphasizing the trade-offs between power efficiency and system performance, with a specific focus on a Downlink Multi-User MultipleInput Single-Output (MU-MISO) configuration. DACs are critical components in modern wireless systems, such as millimeter-wave systems, and are significant contributors to power consumption. Reducing the resolution of DACs provides a sustainable approach to lowering power consumption and costs. However, this introduces quantization noise, which degrades system performance metrics such as bit error rate (BER), spectral efficiency (SE), and throughput. A MATLABbased system-level simulator was developed to model the behavior of massive MU-MISO systems under varying DAC resolution bits. Numerical results demonstrate that 1-bit DAC systems exhibit significantly higher BER due to quantization error. This error limits the system’s performance, especially in higherorder modulation schemes. However, advanced techniques like quantization and precoding schemes effectively mitigate these effects, ensuring improved performance for MU-MISO systems under low-resolution DAC constraints.