Target Detection for OTFS-Aided Cell-Free MIMO ISAC System

This paper focuses on enhancing target detection performance for a multi-user integrated sensing and communication (ISAC) system using cell-free multiple-input multiple-output (MIMO) technology and orthogonal time frequency space (OTFS) waveform in high-speed vehicular environments. The former helps integrate sensing and communication technologies, whereas the latter enables delay-Doppler processing in which a doubly dispersive channel appears with almost constant and flat frequencies. We propose a sensing-centric (SC) approach for target detection using communication signals with/without sensing signals. Power allocation is optimized to maximize the sensing signal-to-noise ratio (SNR) of the proposed SC scheme while ensuring a required quality-of-service (QoS) for the communication user equipment (UEs), and adhering to each access point's (AP's) power budget. Numerical results show that the proposed SC scheme vastly outperforms a communication-centric method that minimizes the total power consumed at the APs subject to the same constraints.