Secure information broadcasting analysis in an indoor VLC system with imperfect CSI

Abstract

In this paper, the physical layer security of an indoor visible light communication system, that consists of two transmission light-emitting diodes to broadcast the information towards the legitimate user, is investigated. Further, a secure LED selection scheme is proposed to select an LED that can perform secure information broadcasting, in the presence of an active and/or passive eavesdropper. The probability of secure information broadcasting is obtained in terms of the positive secrecy rate which is defined under the constraints of known or unknown imperfect channel state information of both legitimate and eavesdropping links. The channel state information (CSI) knowledge of each transmitting link is estimated with the use of a minimum mean square error technique. The performance metrics of the system are defined in terms of the average secrecy capacity and secrecy outage probability parameters. Further, the performance of the system is compared with the conventional stand-alone VLC system by varying various physical parameters. Further, analytical results are corroborated with the computer simulation results.