In-Band Full-Duplex Integrated Sensing and Communication Using OTFS Waveforms

It is envisioned that integrated sensing and communication (ISAC) is a promising technique to enable many emerging applications in future 6G networks. To provide reliable services in high-mobility scenarios, we develop a novel framework for the orthogonal time frequency space (OTFS)-based ISAC scheme. In-band full-duplex (IBFD) mode is considered for communication to enhance spectral efficiency. We give the channel representation in different domains and reveal the limitations and disadvantages of existing ISAC frameworks and propose a novel radar sensing method. We prove that the conventional MUSIC algorithm can be employed for angle estimation in OTFS systems and propose a delay-time domain-based range and velocity estimator. Then, we study the communication design based on the estimated radar sensing parameters, including the self-interference cancellation schemes with OTFS waveforms, which are lacking in the literature, to enable IBFD communication. The effectiveness of the proposed framework is verified through simulations. Numerical results demonstrate that the proposed ISAC waveform and associated estimation algorithm can provide both reliable communications and accurate radar sensing with reduced latency, improved spectral efficiency, etc.