Secrecy-Capacity Bounds for Visible Light Communications With Signal-Dependent Noise

In physical-layer security, secrecy capacity is an important performance metric. This work aims to determine the for indoor visible light communication system consisting of a transmitter, legitimate receiver and eavesdropping receiver. such system, both signal-independent noise signal-dependent are considered. Under nonnegativity average optical intensity constraints, lower upper bounds on derived by variational method, dual expression capacity, concept “the optimal input distribution that escapes infinity”. By asymptotic analysis at large intensity, there small gap between bounds. Then, adding peak constraint, we further analyze exact secrecy-capacity For practical considerations, effects imperfect channel state information, multi-photodiode eavesdropper, artificial also discussed. Finally, verified numerical results.