High speed visible light communication system using QAM-DMT modulation based on digital zero-padding and differential receiver

摘要

We have proposed a novel hybrid software and hardware equalization scheme based on digital zero-padding pre-equalization and differential reception. We have experimental demonstrated a red LED based visible light communication system over 1-meter free space transmission with the measured BER below 7% FEC threshold. The signal is QAM-DMT modulated and the modulation level is varying from 32QAM to 128QAM. By applying the proposed hybrid scheme the measured maximum bit rate can be improved from 2.32Gb/s to 2.59Gb/s. And the highest modulation order is enhanced from 64QAM to 128QAM. Our experimental results clearly validate the feasibility of the scheme in future high-speed visible light communication system.