A novel asymmetrically clipped optical orthogonal frequency division multiplexing system based on lifting wavelet transform for visible light communications

Abstract

SummaryIn multicarrier visible light communication (VLC) systems, orthogonal frequency division multiplexing (OFDM) has attracted a lot of attention due to its high data rate, simple equalization, and resistance to intersymbol interference (ISI). However, high peak‐to‐average‐power ratio (PAPR) and Light Emitting Diodes (LED) nonlinearity have important effects on the performance of indoor VLC‐OFDM systems. Asymmetrically clipped optical (ACO)‐OFDM is a technique that waste spectral efficiency to transmit a single pole frequency division multiplexed signal over a single pole channel. In this study, a new ACO‐OFDM method based on lifting wavelet transform (LWT)‐ACO‐OFDM is proposed to restore this spectral efficiency and increase the performance of the ACO‐OFDM system. The performance of the proposed method is verified by computer simulation studies over additive white Gaussian noise (AWGN) channel and multipath optical channel for analytical and simulated bit error rate (BER) performance criterion. From the obtained simulation results, it is seen that the proposed method provides approximately 16‐dB SNR gain against the classic VLC‐OFDM, roughly 12‐dB Signal to Noise Ratio (SNR) improvement versus the Direct Current (DC)‐biased optical (DCO)‐OFDM, and nearly 6‐dB SNR enhancement against ACO‐OFDM on the additive white Gaussian noise channel. It is observed from computer simulation results that similar SNR gains are obtained in multipath optical channels.