Soft-Output Detector for Uplink MU-MIMO Systems with One-Bit ADCs

Abstract

We consider an uplink multiuser multiple-input multiple-output (MU-MIMO) system with one-bit analog-to-digital converters (ADCs). In this system, numerous symbol detectors, such as maximum-likelihood, zero-forcing, and supervised-learning-based detectors, have been proposed by using one-bit quantized channel outputs. The limitation of these hard-decision detectors cannot generate soft outputs from one-bit quantized channel observations, which considerably degrades the performance of a following channel code. To address this problem, in this letter, we present a novel soft-output detector, in which a soft-metric is computed in (binary) Hamming space using weighted Hamming distances. Simulation results demonstrate that the proposed detector can significantly outperform the other detectors for a coded MU-MIMO system with one-bit ADCs.