An efficient PCCM masking scheme for PAPR reduction and encryption in OFDM-VLC system

Abstract

Wide usage of Orthogonal frequency division multiplexing (OFDM) in visible light communication (VLC) systems aids in sharing immense multimedia files. But, an increase in the peak-to-average power ratio (PAPR) becomes a setback for OFDM. This paper focuses on PAPR reduction and encrypted image transmission in OFDM-based VLC systems using masking approach. The proposed technique generates a mask with the random sequence from a Pi-based coupled chaotic map (PCCM). The ciphering of the transmitted image data involves twofold administration of the PCCM mask. First, the image data is confused using Arnold’s Cat Map (ACM), and then the PCCM mask is applied. For the second time, the PCCM masks are applied on the equal-sized blocks of the subdivided image data at the Quadrature Amplitude Modulation (QAM) mapper stage, hence secures the transmission path. The proposed masking scheme frustrates statistical, brute-force and differential attacks and has a large key space of about \(10^{340}\). The PCCM based masking scheme is able to reduce PAPR from 13.5 dB to 6 dB, with 56% reduction percentile when compared to the normal OFDM system, and the same is validated by Complementary cumulative distribution function (CCDF). The decryption quality of the PCCM mask based encryption approach is proven better with high correlation coefficient and output signal-to-noise ratio (SNR) values. This scheme also maintains the condition of the image shared with a Bit error rate (BER) improvement of \(\thicksim \)1.2 to 1.5 dB compared to the normal OFDM system. This proposed technique is evaluated by simulation experiments.