Performance Enhancement for MMW-RoF System Based on Dynamic Probabilistic Shaping Obfuscation and Tricolor Scrambling

A physical layer performance-enhanced scheme for millimeter-wave (MMW) radio-over-fiber (RoF) system based on dynamic probabilistic shaping obfuscation, tricolor scrambling and grouping disturbed precoding is proposed in this paper. In this scheme, the dynamic probabilistic shaping obfuscation is firstly executed for QAM symbol, which complete the obfuscation of constellation and the adjustment of probability distribution, then the hash value from data is processed for the tricolor scrambling to realize the key-driven constellation-level diffusion of the plaintext in the ciphertext, finally, the peak-to-average power ratio (PAPR) of the signal is reduced by the grouping encrypted precoding. The processed hash key is embedded into the synchronization head to realize the key distribution. The encrypted signals are experimentally transmitted in 100 GHz MMW-RoF system with 50 km single-mode fiber and 5 m wireless channel. The results show that the proposed scheme is sensitive to plaintext changes at any position, while achieving PAPR reduction of ∼2.6 dB and receiver optical power gain of ∼2.6 dB. The analyses show that the proposed scheme enhances the security performance and error rate performance of system.