Analysis of Oversampling in Uplink Massive MIMO-OFDM with Low-Resolution ADCs

TL;DR

This paper investigates how oversampling can enhance the sum rate in uplink massive MIMO-OFDM systems with low-resolution ADCs, showing that oversampling mitigates quantization distortion and can match unquantized performance at high SNR and OSR.

Contribution

It provides a closed-form expression for the achievable sum rate considering oversampling, ADC resolution, and SNR, revealing their joint impact on system performance.

Findings

Oversampling improves sum rate by reducing quantization distortion.

High SNR and OSR enable low-resolution systems to match unquantized performance.

Numerical results validate the analytical expressions and insights.

Abstract

Low-resolution analog-to-digital converters (ADCs) have emerged as an efficient solution for massive multiple-input multiple-output (MIMO) systems to reap high data rates with reasonable power consumption and hardware complexity. In this paper, we analyze the performance of oversampling in uplink massive MIMO orthogonal frequency-division multiplexing (MIMO-OFDM) systems with low-resolution ADCs. Considering both the temporal and spatial correlation of the quantization distortion, we derive an approximate closed-form expression of an achievable sum rate, which reveals how the oversampling ratio (OSR), the ADC resolution, and the signal-to-noise ratio (SNR) jointly affect the system performance. In particular, we demonstrate that oversampling can effectively improve the sum rate by mitigating the impact of the quantization distortion, especially at high SNR and with very low ADC resolution. Furthermore, we show that the considered low-resolution massive MIMO-OFDM system can achieve the same performance as the unquantized one when both the SNR and the OSR are sufficiently high. Numerical simulations confirm our analysis.