This work considers the problem of integrated sensing and communications (ISAC) with a massive number of unsourced and uncoordinated users. In the proposed model, known as the unsourced ISAC system (UNISAC), all active communication and sensing users simultaneously share a short frame to transmit their signals, without requiring scheduling with the base station (BS). Hence, the signal received from each user is affected by significant interference from numerous interfering users, making it challenging to extract the transmitted signals. UNISAC aims to decode the transmitted message sequences from communication users while simultaneously detecting active sensing users and estimating their angles of arrival, regardless of the identity of the senders. In this paper, we derive an approximate achievable result for UNISAC and demonstrate its superiority over conventional approaches such as ALOHA, time-division multiple access, treating interference as noise, and multiple signal classification. Through numerical simulations, we validate the effectiveness of UNISAC's sensing and communication capabilities for a large number of users.

翻译：本文研究了面向海量无源、非协调用户的集成感知与通信问题。在所提出的无源ISAC系统（UNISAC）模型中，所有活跃的通信与感知用户无需与基站进行调度协调，即可同时共享一个短帧来传输信号。因此，来自每个用户的接收信号会受到大量干扰用户的显著影响，使得提取传输信号具有挑战性。UNISAC的目标在于，无论发送者身份如何，均能从通信用户中解码传输的信息序列，同时检测活跃的感知用户并估计其到达角。本文推导了UNISAC的近似可达结果，并证明了其相对于传统方法（如ALOHA、时分多址、将干扰视为噪声以及多重信号分类）的优越性。通过数值仿真，我们验证了UNISAC在面向大量用户时的感知与通信能力有效性。