Scalable Cell-Free Massive MIMO Unsourced Random Access System

TL;DR

This paper explores the integration of cell-free massive MIMO systems with unsourced random access to enhance wireless communication coverage and performance in realistic fading channels.

Contribution

It introduces a scalable coding scheme that adapts URA to cell-free systems, demonstrating improved performance over traditional architectures.

Findings

Cell-free architecture enhances URA performance in fading channels.

The proposed coding scheme adapts URA to various cell-free scenarios.

Empirical results show improved coverage and reliability.

Abstract

Cell-Free Massive MIMO systems aim to expand the coverage area of wireless networks by replacing a single high-performance Access Point (AP) with multiple small, distributed APs connected to a Central Processing Unit (CPU) through a fronthaul. Another novel wireless approach, known as the unsourced random access (URA) paradigm, enables a large number of devices to communicate concurrently on the uplink. We consider a quasi-static Rayleigh fading channel paired to a scalable cell-free system, wherein a small number of receive antennas in the distributed APs serve devices equipped with a single antenna each. The goal of the study is to extend previous URA results to more realistic channels by examining the performance of a scalable cell-free system. To achieve this goal, we construct a coding scheme that adapts the URA paradigm to various cell-free scenarios. Empirical evidence suggests that using a cell-free architecture can improve the performance of a URA system, especially when taking into account large-scale attenuation and fading.