An Energy Efficient Li-Fi Transmitter with Single Inductor Multiple Output LED Driver

Abstract

High-Efficiency Light-Fidelity (Li-Fi) transmitter for simultaneous illumination and Visible Light Communications (VLC) using LED lighting is presented in this work. The proposed transmitter is based on Single Inductor Multiple Output (SIMO) buck converter with two independently controllable outputs or channels, namely lighting channel and communications channel for enabling flicker free illumination without affecting high-speed modulation of LEDs. By this approach, power converter switching frequency is decoupled from modulation frequency of LEDs, thereby optimizing SIMO converter switching frequency for efficiency and the VLC modulator frequency for high speed data transfers. GaN devices are used to realize VLC modulator for high speed modulation to further enhance the efficiency. Light output with high Color Rendering Index (CRI) is achieved by controlling white LEDs as primary illumination source at lighting channel and red color LEDs at communication channel. Simulations and experimental results to validate the proposed transmitter are presented.