In physical-layer security, secrecy capacity is an important performance metric. This work aims to determine the secrecy capacity for an indoor visible light communication system consisting of a transmitter, a legitimate receiver and an eavesdropping receiver. In such a system, both signal-independent noise and signal-dependent noise are considered. Under nonnegativity and average optical intensity constraints, lower and upper bounds on secrecy capacity are derived by the variational method, the dual expression of the secrecy capacity, and the concept of “the optimal input distribution that escapes to infinity”. By an asymptotic analysis at large optical intensity, there is a small gap between the asymptotic upper and lower bounds. Then, by adding a peak optical intensity constraint, we further analyze the exact and asymptotic secrecy-capacity bounds. For practical considerations, the effects of imperfect channel state information, multi-photodiode eavesdropper, and artificial noise on secrecy performance are also discussed. Finally, the derived secrecy-capacity bounds are verified by numerical results.
Bibliographical noteKAUST Repository Item: Exported on 2023-03-06
Acknowledgements: This work was supported in part by the Natural Science Foundation of Jiangsu Province under Grant BK20221328, in part by the open research fund of Chuan and Zang Smart Tourism Engineering Research Center of Colleges and Universities of Sichuan Province under Grant ZLGC2022A01, in part by the open research fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, China under Grant JZNY202115, in part by the Jiangsu Province Science and Technology Project under Grant BE2021031, and in part by the Jiangsu Province Information Innovation Laboratory Project.
ASJC Scopus subject areas
- Applied Mathematics
- Computer Science Applications
- Electrical and Electronic Engineering