Ambiguity Analysis of Multi-User OTFS-LFM Waveform for ISAC

Orthogonal Time Frequency and Space (OTFS) is a promising Integrated Sensing and Communication (ISAC) Waveform which has potential applications in 6G applications such as autonomous vehicles, UAV-assisted networks, etc. In this paper, we analyse the performance of OTFS-Linear Frequency Modulated (OTFS-LFM) waveform. We address the gap in literature where the sensing performance of OTFS is studied only as a single-user waveform. We show that the parameter estimation performance of the OTFS-LFM as a Multi-User waveform is critically dependent on the Multi-User configuration of the waveform. The study thus provides strategies for multi-user symbol placement in OTFS-LFM for improved parameter estimation.