Continuous phase modulation with chaotic interleaving for visible light communication systems based on orthogonal frequency division multiplexing

Visible light communication (VLC) is one of the most promising technologies which offers high data rates and flexible cost-effective networking solutions for indoor applications. In VLC systems, the optical orthogonal frequency division multiplexing (OFDM) is considered as an efficient technique to avoid VLC channel selectivity. However, OFDM suffers from the high peak-to-average-power-ratio (PAPR) problem, which degrades the VLC system performance. In this article, we consider the use of a chaotic-interleaver-based continuous-phase-modulation (CI-CPM) scheme together with frequency domain equalization (FDE) at the receiver end of the VLC system. A direct current bias is added to the signal to provide real-valued non-negative signals for intensity modulation. The proposed scheme outperforms the conventional ones in terms of PAPR. Additionally, it takes the advantages of CPM power efficiency and frequency diversity. Furthermore, three types of FDE techniques are considered and compared including the zero-forcing (ZF) equalizer, the minimum mean square error equalizer and the regularized ZF equalizer.