Abstract:

In the process of 5G evolution, the physical layer security of visible light communication (VLC) is gradually earning attention and discussion. However, the current research paradigm is limited to the discussion of visible light communication secure link based on conventional Lambertian LED sources, and there is no quantitative comparative study on the link security characteristics of commercial non-Lambertian sources, especially the benchmark security capacity under non-Lambertian link configurations. In view of the above problems, this paper extends the existent VLC security link modeling scheme, and quantifies the benchmark characteristics of typical non-Lambertian VLC security links within typical indoor environment. The numerical results show that compared with the conventional Lambert beam, the typical non Lambert beams could compress the spatial dynamic range of the benchmark security capacity from 0~10.78 bps/Hz to 0~6.40 bps/Hz, and the relevant mean value is dramatically reduced from the original 5.25 bps/Hz to 2.78 bps/Hz. Therefore, in the design and optimization of the VLC links, the influence of diverse source beams on the secrecy capacity characteristics should be considered, which could be viewed as a potential optimization dimension.

Key words: physical layer security, visible light communication, security capacity, optical beams, non-Lambertian beams