The Research Of Visible Light Communication System Based On White LED

Visible light communication technology is an emerging wireless optical communication technology. The visible light communication technology has a good development with the invention and application of LED white light. White LED can not only provide indoor lighting, but also can be applied to wireless optical communication system network to meet the individual needs of the indoor. In the lighting, white LED has energy-saving, environmental protection and other features, that fluorescent, incandescent, and other traditional lighting sources will eventually be replaced by white LED, White LED lighting will become the next generation of solid. Meanwhile, the white LED also has a short response time, coupled with its high-speed modulation characteristics. White LED can be designed based on the indoor wireless communication system visible. Thus designed white LED-based visible light indoor wireless communication systems, Compared with traditional infrared and radio communication, White LED has advantages, for example:a high transmitting power, no electromagnetic interference and the of spectrum resources without the need to apply etc.In this paper, an indoor visible light communication system based on white LED is studied, white LED structure and principle, and when used as a communication source voltage characteristics, spectral characteristics of electro-optical conversion characteristics and physical characteristics special to do a more in-depth analysis. Made a theoretical study of radiation on the radiation mode, photons emitted radiation mechanism and mathematical model. And studied the communication channel communication system, the composition of the communication link are analyzed, given the level of brightness based on power source and the receiver layout. According to international standards, general office lighting requirements are the 3001x-15001x. Through analysis, this paper designed the layout of the light source, in line with international requirements for indoor lighting and communications. In the study of communication quality, Studied the communication quality on the code rate and receiver perspective, Finally, proposed a wireless communication system modulation based on OFDM and SC-FDMA in the uplink and downlink.In this paper, Based on the analysis of the white LED their own characteristics to the radiation used in a wireless communication system, and its radiation characteristics of the different links, proposed a white LED modulation using the SC-FDMA in uplink.