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. This article considers 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 propose 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.

翻译：无蜂窝大规模MIMO系统通过将单个高性能接入点（AP）替换为多个连接到中央处理单元（CPU）的小型分布式AP，旨在扩展无线网络的覆盖范围。另一种被称为非授权随机接入（URA）范式的无线新方法，使得大量设备能在上行链路同时通信。本文考虑准静态瑞利衰落信道与可扩展无蜂窝系统的结合，其中分布式AP配备少量接收天线，为各装备单天线的设备提供服务。研究目标是通过评估可扩展无蜂窝系统的性能，将先前的URA结果推广至更现实的信道环境。为此，我们提出一种将URA范式适配至各种无蜂窝场景的编码方案。实验证据表明，使用无蜂窝架构可提升URA系统的性能，尤其是在考虑大规模衰减和衰落时。