The Research Of Indoor Visible Light Communication Using White LED

White light emitting diodes are playing an important role in our daily life, owing to their small seize, low price, no electromagnetic radiation, no pollution and so on. Meanwhile, it is a highly sensitive device. So adopting the white light emitting diodes as the light source of the indoor visible light communication is a feasible and unusual idea attracting the attention of more and more researchers.Firstly, we put forward the view of using white LED for indoor visible light communication called indoor visible light communication using white LED. We also compare it with infrared communication and radio communication. Then we analyze the applications and the current research trend of indoor visible light communication using white LED. Finally, we get the research situation by scanning the relative papers in detail.By researching the emitting principles and working characteristics, we decide to employ light intensity modulation and direct detection principle to design indoor visible light communication system based on white LEDs. The indoor visible light communication based on white LEDs includes transmitter and receiver. We finish the design of baseband OFDM modulation on FPGA and the DAC converts the modulated signals to analog signals. The transmitter modulates the analog signal into the light of white LED to finish the electro-optical conversion. The receiver is designed to realize the conversion of optical signal to electronic signal, including photoelectric detection circuit, preamplifier circuit, lowpass filter and A/D circuit. The photoelectric detection circuit converts the optical signal to electronic signal. The low-pass filter filters the noise of voltage signal. In a word, the indoor visible light communication based on white LED is to achieve the process of electro-optical conversion and photoelectric conversion.At last, all modules of transmitter and receiver are tested and integrated into a signal board. We also tested the communication system, drawing the conclusion that it is feasible to use the white LED as the light source of visible light communication.