Dynamic Degradation in Chaos-Based Optical Fiber Communications: Performance Impact and Improvement Method

Chaos-based optical fiber communication technology offers strong protection for the security of modern optical information transmission. However, chaotic systems are susceptible to dynamic degradation in communication scenarios with finite-precision computation. This paper investigates the impact of dynamic degradation on the performance of secure optical fiber communication systems. To address this issue, we propose an encryption framework based on a cellular automaton based discrete chaotic system (CA-DCS). The CA-DCS employs an 8-state cellular automaton as the chaotic source, generating a highly random discrete sequence through finite-state chaotic evolution. Chaotic confusion and constellation masking are then applied to mask the physical layer data. We demonstrate encrypted data transmission at 32 GBaud over 400 km standard single-mode fiber. The results indicate that dynamic degradation undermines the physical layer security masking and exacerbates transmission impairments, resulting in a performance penalty of 5.3 dB. The proposed scheme maintains robust chaotic masking even under finite-precision computation and offers an expandable key space of 10240. This study highlights key performance-limiting factors in chaos-based optical fiber communication and suggests a promising direction for future research in secure chaotic communication technologies.