Coordinated-security based on probabilistic shaping and encryption in MMW-RoF system.

A coordinated-security probabilistic shaping (PS) physical layer encryption scheme is proposed for a W-band millimeter-wave radio-over-fiber (MMW-RoF) system. This scheme mainly includes substituting encryption, coordinated encrypted PS, and unequal length grouping scrambling, which can realize the coordination between PS and chaotic encryption. The key space of the proposed scheme is 10, which can effectively prevent against brute force cracking and chosen-plaintext attacks. The encrypted orthogonal frequency division multiplexing (OFDM) signal is successfully transmitted over 50-km standard single-mode fiber (SSMF) and a 5-m wireless channel. The results show that the proposed scheme achieves 0.8-dB received optical power gain at a bit error rate (BER) of 10 compared with a traditional OFDM signal. The superiority of the proposed scheme in security performance and BER performance has been verified.