Photonics-Assisted Millimeter-Wave Integrated Sensing and Communication Based on OTFS

In the future 6G networks, the integrated sensing and communication (ISAC) technologies in the millimeter-wave (mmWave) band will foster innovation across multiple emerging fields, bringing substantial improvements to society. To address the limitations of ISAC systems based on conventional electronic methods in the mmWave band, the photonics-assisted scheme has been developed, offering advantages such as wide operating bandwidth and immunity to electromagnetic interference. However, in increasing non-line-of-sight (NLOS) propagation scenarios, the prevalent multipath effects significantly degrade the performance of photonics-assisted mmWave ISAC systems. In this paper, we propose a novel photonics-assisted mmWave ISAC system employing the orthogonal time frequency space (OTFS) modulation. The system employs OTFS modulation to map data to the delay-Doppler (DD) domain, enhancing the communication performance in NLOS scenarios. Experimental results demonstrate a 15.71 Gbit/s net data rate and 3 cm range resolution over 1 m wireless link. Furthermore, the proposed OTFS-based ISAC system demonstrates promising potential for NLOS scenarios by improving communication performance while maintaining high sensing resolution.