Research On Portable Wireless Data Transmission System Based On Visible Light

In recent years,with the rapidly development of semiconductor lighting technology,it has been widely applicated in many areas. White LED replace incandescent lamp, fluorescent lamp and the other traditional lighting sources gradually,which will become mainstream lighting tools in the future. Meanwhile,white LED also has the characteristics of fast response and wide spectrum range,which provides a condition for application in the field of communication. So,the visible light communication system based on white LED has the dual functions of lighting and communication and it has a wide range of applications in the indoor,outdoor and the other special scenes.Based on the visible light communication analysis of the principle, advantages and the research status both at home and abroad, this paper has carried out an in-depth study on LOS channel modeling, light source layout and hardware platform of visible light communication system. The main contents and results are as follows:Firstly, the LOS channel model of the visible light communication system is built, and the the optical power attenuation and the SNR(signal-to-noise ratio) and the BER(bit error rate) of the system in the visible light communication system are simulated and analyzed. Which provides a theoretical basis for the later physical construction and indoor light source layout.Secondly, in the traditional light source layout mode, this paper used the illumination compensation technology and designed the 5 arrays layout model and the annular layout model,which improved the uniformity of the illumination distribution under the receiving plane. At the same time,this paper proposes a optimization light source layout model which can consider illumination and communication. In this kind of 5 arrays layout model, the uniformity of illumination distribution reaches 88.98% and the error rate reaches 5.07x10-7.Thirdly, We designed the hardware communication platform based on white LED. In the case of serial debugging assistant and oscilloscope,the feasibility of hardware circuit in the visible light communication system is verified. Under the action of 0.5W single LED lamp beads, the results show that the communication distance within 0.3m range, the information transmission has stable and without distortion at the maximum serial port communication rate.Finally, in order to verify that the design of the visible light communication hardware platform has a certain practical value in the room, this paper combines the visible light communication hardware platform with the indoor environment monitoring. Under the action of 0.5W single LED lamp beads, the results show that the communication distance within 0.3m range, the host computer interface shows good and the system achieved effective monitoring of indoor environment and stable data transmission without distortion.