This paper addresses the problem of scalability for a cell-free massive MIMO (CF-mMIMO) system performing Integrated Sensing and Communications (ISAC). Specifically, the case in which a large number of access points (APs) are deployed to perform simultaneous communication with mobile users and surveillance of the surrounding environment in the same time-frequency slot is considered, and a target-centric approach on top of the user-centric approach used for communication services is introduced. Consideration of other practical aspects such as the fronthaul load and scanning protocol issues are also treated in the paper. The proposed scalable ISAC-enabled system has lower levels of system complexity, permits to manage the case in which multiple targets are to be tracked/sensed, and achieves performance levels superior or in some cases close to those of the non-scalable solutions.

翻译：本文研究了面向集成感知与通信（ISAC）的无蜂窝大规模MIMO（CF-mMIMO）系统的可扩展性问题。具体而言，考虑了大量接入点（AP）在同一时频资源上同时与移动用户进行通信并监测周围环境的场景，并在用于通信服务的用户中心方法之上引入了目标中心方法。本文还探讨了前传负载和扫描协议等其他实际因素。所提出的可扩展ISAC系统具有较低的系统复杂度，能够处理需要跟踪/感知多个目标的情况，其性能水平优于或在某些情况下接近不可扩展方案。