OTFS ISAC SDR Implementation and Experiment Testing fo UAV Micro-Doppler Analysis

This paper proposes a software-defined radio (SDR) experimental system based on Orthogonal Time Frequency Space Integrated Sensing and Communication (OTFS ISAC) to analyze micro-Doppler (MD) features of unmanned aerial vehicles (UAVs) in urban environments. OTFS modulation maps information symbols onto a two-dimensional delay-Doppler (DD) grid, effectively mitigating intercarrier interference (ICI) and Doppler shifts in high-mobility scenarios. This inherent coupling between the delay-Doppler domain and radar parameters enables the ISAC paradigm. However, traditional OTFS ISAC systems struggle to identify UAVs in urban low-altitude settings due to their subtle micro-movements and complex electromagnetic environments, limiting the reliability of low-altitude security systems. We developed an SDR-based OTFS ISAC UAV sensing system tailored for urban scenarios to address these challenges. The MD effect induced by UAV rotor rotation is analyzed through range filtering and joint time-frequency (TF) domain analysis to achieve UAV feature extraction. Real-world experiments demonstrate the effectiveness of the proposed OTFS ISAC system in UAV MD analysis.