An OTFS-Based Synthetic Aperture Radar Imaging System for Joint Communication and Remote Sensing

Orthogonal time-frequency space (OTFS) modulation has demonstrated its robustness against high Doppler shift and is suitable for wireless communications under high mobility. We develop a joint communication and synthetic aperture radar (SAR) remote sensing system based on OTFS modulation for unmanned aerial vehicle (UAV) applications. A SAR imaging flow is proposed, including intra-pulse Doppler compensation and pilot-based channel estimation as range processing for an OTFS receiver operating in stripmap mode. The normalized fractional delay and Doppler shift are considered in the SAR channel model according to the practical conditions. The peak sidelobe ratio (PSLR) and impulse response width (IRW) of the imaging results are evaluated and compared to the conventional linear frequency modulation (LFM)-based SAR system. We show that the proposed processing flow can achieve good performance of SAR imaging without positioning deviation and supports applications of joint communication and remote sensing.