LAUSR

Multiband integrated sensing and communication (ISAC) systems towards multiple functions and multiple users will play an important pole in future 6G wireless networks. Here, we propose and experimentally demonstrate a multiband ISAC system using optical frequency upconversion and coherent receiving techniques for millimeter-wave (MMW) high-capacity wireless communication and high-resolution sensing functions. The MMW multiband ISAC signals are simultaneously generated by a single photonic MMW frequency upconverter consisting of an optical frequency comb, a wavelength selective switch, an I/Q Mach-Zehnder modulator, and a high-speed photodetector. A multi-channel coherent photonic MMW de-chirper with phase compensation is utilized for coherent multiband radar signal processing, which facilitates the coherence-processing-free multiband data fusion and thus leading to an ultra-high resolution radar detection. Meanwhile, the communication receiving and demodulation towards multiband/multiuser scenarios are achieved by coherent receiving technology. In experiments, a photonic MMW ISAC system delivering Ka-band and V-band wireless signals is implemented, achieving a communication data rate of 16 Gbit/s and a two-dimension radar imaging of 3.75-cm range resolution, respectively. More importantly, after the multiband data fusion, an 8.6-mm ultra-high resolution is successfully achieved for radar ranging and imaging.