OTFS-FMCW waveform design for low complexity joint sensing and communication

Joint sensing and communication (JSAC) systems are becoming attractive technologies since they can map the radio environment while performing communication using the same frequency bands. This is achieved by radar signal processing of the received signal that is composed of a known waveform. However, varying the waveform used for JSAC will create a trade-off between throughput and computational complexity. In this paper, we propose a joint orthogonal time-frequency space (OTFS)-frequency modulated continuous wave (FMCW) waveform design to perform JSAC to achieve high data rates due to OTFS and low-complex simple radar receiver thanks to FMCW. This is done by exploiting the simultaneous locality property of the FMCW in both time-frequency and delay-Doppler domains to orthogonally superimpose OTFS and FMCW, and use them for communication and sensing, respectively. Then, we provide an analysis of the computational complexity of the proposed design. The conducted simulation results demonstrate that the proposed waveform design can achieve accurate low-complexity radar parameters estimation while preserving high data rates.