On Detection Issues in the SC-based Uplink of a MU-MIMO System with a Large Number of BS Antennas

TL;DR

This paper investigates detection issues in large-scale MU-MIMO uplink systems using SC/FDE, proposing semi-analytical performance evaluation methods and demonstrating that a large number of BS antennas can achieve near-optimal performance with low-complexity detection techniques.

Contribution

It introduces semi-analytical methods for performance evaluation and shows that massive MIMO effects enable near-optimal detection with reduced complexity.

Findings

Large number of BS antennas approximates SIMO MFB performance

Low-complexity iterative detection performs well in massive MIMO

Semi-analytical methods match Monte Carlo simulations accurately

Abstract

This paper deals with SC/FDE within a MU-MIMO system where a large number of BS antennas is adopted. In this context, either linear or reduced-complexity iterative DF detection techniques are considered. Regarding performance evaluation by simulation, appropriate semi-analytical methods are proposed. This paper includes a detailed evaluation of BER performances for uncoded 4-Quadrature Amplitude Modulation (4-QAM) schemes and a MU-MIMO channel with uncorrelated Rayleigh fading. The accuracy of performance results obtained through the semi-analytical simulation methods is assessed by means of parallel conventional Monte Carlo simulations, under the assumptions of perfect power control and perfect channel estimation. The performance results are discussed in detail, with the help of selected performance bounds. We emphasize that a moderately large number of BS antennas is enough to closely approximate the SIMO MFB performance, especially when using the suggested low-complexity iterative DF technique, which does not require matrix inversion operations. We also emphasize the achievable "massive MIMO" effects, even for strongly reduced-complexity linear detection techniques, provided that the number of BS antennas is much higher than the number of antennas which are jointly employed in the terminals of the multiple autonomous users.