Advanced LED Driving Approach for Visible Light Communication Systems

Researches from the point of view of communication have proved that visible light is a kind of effective information-transferring media, which shares that same infrastructure, the light-emitting diode (LED) with illumination while guarantees a high data rate. However, there is one thing that needs to be compromised: the power efficiency of the LED driver, owing to the fact that the high frequency modulated AC signals used for communication has to be injected into the LED through a linear power amplifier. Advanced LED drivers are therefore essential and this paper reviews and compares the state-of-the-art driver circuits from the view-point of power electronics. Two main methodologies including using advanced circuits, and providing an adaptive power supply (pre-regulator) for the linear power amplifier are discussed. Based on the existing pre-regulator, a novel switched-capacitor pre-regulator that can generate multilevel voltages for the linear power amplifier is proposed and initially simulated. Results show that with the pre-regulator, the efficiency of the LED driver is significantly increased from 60% to 80% at a wide range of output power.