A Mixed-ADC Receiver Architecture for Massive MIMO Systems

TL;DR

This paper proposes a mixed-ADC receiver architecture for massive MIMO systems that combines one-bit and high-resolution ADCs, analyzing its data rates and demonstrating near-capacity performance with fewer high-resolution ADCs.

Contribution

It introduces a novel mixed-ADC architecture for massive MIMO, providing analytical tools to optimize ADC assignment and evaluate achievable data rates.

Findings

The mixed-ADC system achieves near-channel capacity with fewer high-resolution ADCs.

Analytical expressions for GMI are derived for SIMO channels.

ADC assignment schemes are proposed based on asymptotic analysis.

Abstract

Motivated by the demand for energy-efficient communication solutions in the next generation cellular network, a mixed-ADC receiver architecture for massive multiple input multiple output (MIMO) systems is proposed, which differs from previous works in that herein one-bit analog-to-digital converters (ADCs) partially replace the conventionally assumed high-resolution ADCs. The information-theoretic tool of generalized mutual information (GMI) is exploited to analyze the achievable data rates of the proposed system architecture and an array of analytical results of engineering interest are obtained. For deterministic single input multiple output (SIMO) channels, a closed-form expression of the GMI is derived, based on which the linear combiner is optimized. Then, the asymptotic behaviors of the GMI in both low and high SNR regimes are explored, and the analytical results suggest a plausible ADC assignment scheme. Finally, the analytical framework is applied to the multi-user access scenario, and the corresponding numerical results demonstrate that the mixed system architecture with a relatively small number of high-resolution ADCs is able to achieve a large fraction of the channel capacity without output quantization.