Performance Improvement of Dimmable VLC System with Variable Pulse Amplitude and Position Modulation Control Scheme

Dimming support is one of the main challenges for visible light communication (VLC). In this paper, we propose a multilevel combined modulation scheme to provide both information transmission and dimming control functions. This dimming control scheme is done by the combination of M-2-PAPM (pulse amplitude position modulation) with pulse width modulation, and is called variable pulse amplitude and position modulation (VPAPM). To investigate its performance, we compare it with other modulation schemes for dimmable VLC system in terms of power and bandwidth efficiencies. In addition, we establish a system model to analyze its BER performance. The results show that the proposed scheme has higher bandwidth efficiency than other schemes, and also can provide good power efficiency, which make it an alternative modulation scheme for VLC.