Research On Indoor Visible Light Communication System Based On White LED

Visible light communication is a novel wireless optical communication technology and rose with development of white LED fabrication techniques.White LED devices are used not only for illuminating rooms but also for an optical wireless communication system which is suitable for indoor private networks. In this thesis, a receiving and transmitting link for indoor visible light communication system based on white LED lights is proposed.In the thesis, based studies have been done on voltage to current character , radiation spectrum and modulation property of white LED when they are used as optical transmitters. Then the configuration and systematic design techniques are concentrated concerning white LED lighting source communication as well as high speed modulation techniques, visible light transceiver circuit. An optimal design of lightings layout on the visible light communication system is discussed.The results of computer simulation show that this optimal design is feasible for the visible light communication system. The system employing line-of-sight link and intensity modulation with direct detection, high modulation using white LED is done and a receiver is designed to receive and demodulate the optically transmitted information , receiving and transmitting experiment for indoor visible light communication based on white LED have been done and experimental results are shown .In the past, primarily OOK has been used for digital data modulation of such devices,OOK imposes limitations on the achievable data rates. Because of the inherent robustness of OFDM against multipath effects, OFDM is considered in combination with higher order modulation schemes in the thesis.