Photonics Terahertz Dual-Band Anti-Jamming Integrated Sensing and Communication System Empowered by Permutation Frequency Hopping

Integrated sensing and communication (ISAC) has emerged as a favorable candidate to support the forthcoming 6G applications. However, conventional ISAC systems, constrained to operate within predetermined frequency ranges, remain highly susceptible to narrowband, fixed-frequency jamming, which poses significant challenges in hostile electromagnetic environments. In this paper, a dual-band anti-jamming ISAC system operating in the D-band is proposed using permutation frequency hopping (PFH). Compared with traditional single-band frequency hopping spread spectrum systems, the dual-band PFH system exploits frequency diversity, maintaining sensing and communication even when one sub-band is jammed. Besides, it possesses superiorities of non-repeating adjacent frequencies and zero maximum out-of-phase Hamming autocorrelation, thereby enhancing anti-jamming robustness and reducing the probability of signal interception by hostile receivers. By leveraging the opposite-phase characteristic of linear frequency modulation-orthogonal frequency division multiplexing signal, the low-cost self-coherent communication receiver is realized. The dual-band PFH system reduces the functional interruption probability under various broadband noise jamming of 32.22%, 61.72% and 83.27%, respectively. In the sensing receiver, the identification of five interference types is realized by dual-band signatures. Finally, the coherent fusion processing enables a large equivalent bandwidth resolution and thus an enhanced spectral efficiency. In experiments, a dual-band signal centered at 132 GHz is generated. A data rate of ∼470 Mbit/s and an equivalent range resolution of 1.94 cm are achieved. By processing simulated echoes, the two-dimensional imaging resolution of ∼1.875 cm × ∼1.99 cm is obtained. The proposed scheme offers a promising solution for anti-jamming ISAC system in complex electromagnetic environments.