High-security colour shift keying modulation scheme with chaos-based constellation rotation for VLC system

With the aid of broad-band visible light and colour shift keying(CSK), visible light communication (VLC) can construct high speed broadcast network in public scenarios. However, due to the broadcast property of light beam, the malicious eavesdroppers located in the same light beam as the legitimate receivers may capture the information. In order to improve the security of VLC systems, in this paper, we propose to apply a chaos-based constellation rotation (CCR) method to CSK modulation scheme. Specifically, the information is modulated at a rotated constellation, while the rotation rule of constellation is determined by the non-repeating chaotic sequences. Since chaotic sequences are non periodic and sensitive to the initial value, the rotation pattern changes dynamically and the eavesdroppers can not retrieve the information in real time in high speed VLC systems. Moreover, the theoretical information leakage analysis is performed for the CCR based CSK (CCR-CSK) modulation scheme. Simulations are performed and the results demonstrate that CCR-CSK scheme achieves the same bit error rate (BER) as original CSK scheme does, while providing much lower information leakage and higher security information transmission for the users.