Spectral-Efficient L/E-ACO-SCFDM-Based Dimmable Visible Light Communication System

Abstract

In this paper, we propose a dimmable visible light communication (VLC) system based on spectral-efficient layered/enhanced asymmetrically clipped optical single-carrier frequency-division multiplexing (L/E-ACO-SCFDM). L/E-ACO-SCFDM superimposes multi-layer ACO-SCFDMs occupying different subcarriers for enhancing the spectral efficiency of the system. Both the adjustable layer polarities and the low peak-to-average-power ratio property of ACO-SCFDM make it better suited to the linearity-limited VLC system. Meanwhile, L/E-ACO-SCFDM has the signal-to-noise ratio averaging advantage, which can effectively resist the high-frequency distortion caused by the bandwidth limitation of the VLC system. Based on the maximization of spectral efficiency of the system, the layer amplitudes, layer spectral efficiencies, and bias voltage are jointly optimized for providing the efficient communication under different illumination requirements. Benefiting from the numerous strengths, the proposed L/E-ACO-SCFDM-based dimming scheme can achieve at least 22.0% average spectral efficiency gain compared with several state-of-the-art OFDM-based dimming schemes within the same dimming range, which shows the great superiority for future practical applications of VLC.