LED Visible light communication system based on FPGA

On the basis of the physical characteristics research and analysis of white LED and the photodiode including current, amplitude-frequency characteristics and response time, the experimental system achieves the goal of visible light communication successfully with the 115200bps baud rate in distance of 9.6 meters. The experiment is based on the principle of intensity modulation and direct detection (IM / DD), using LOS link design with white LED lighting array 16 8, choosing Manchester code as modulation with a good synchronization and strong anti-noise capability to achieve indoor unidirectional downlink communication of lower error rates and long-distance transmission. The transmitter and receiver board have some advantages with a strong mobility, low cost and high sensitivity. Manchester encoding, decoding algorithm and serial communication interface are designed by Verilog HDL. Implemented on Alter FPGA development system DE2.