Antenna Efficiency in Massive MIMO Detection

TL;DR

This paper introduces the concept of antenna efficiency to evaluate how quickly detection error probability decreases in massive MIMO systems as the number of antennas grows, providing analytical insights for ML and ZF detectors.

Contribution

It proposes a new performance metric called antenna efficiency and derives closed-form expressions for ML and ZF detectors in large-scale MIMO systems.

Findings

Antenna efficiency quantifies error probability decay rate with increasing antennas.

Closed-form expressions for ML and ZF detectors' antenna efficiency.

Numerical results validate the analytical model against realistic systems.

Abstract

In this paper, we consider the multi-user detection problem in a multiple-input multiple-output (MIMO) system, where the number of receive antennas at the base station (BS) grows infinitely large. We propose a new performance metric, called antenna efficiency, to characterize how fast the vector error probability (VEP) decreases as the number of receive antennas increases in the large system limit. We analyze the optimal maximum-likelihood (ML) detector and the simple zero-forcing (ZF) detector and prove that their antenna efficiency admits a simple closed form, which quantifies the impacts of the user-to-antenna ratio, the signal-to-noise ratio (SNR), and the constellation set on the VEP. Numerical results show that our analysis can well describe the empirical detection error performance in a realistic massive MIMO system.