Study Of Indoor Visible Light Communication Based On White LED

Due to the significant advantages of high brightness, low power consumption, low cost, white led are more and more popular in the lighting market. Visible light communication Based on white LED, which has a lower cost while achieving two functions of lighting and communication, with a wealth of spectrum resources, no electromagnetic interference, green, better confidentiality, more suitable for kinds of occasions. Because of these advantages, visible light communication technology has been widespread concerned and supported by many research institutions and countries of the world since it was proposed.This paper focuses on the study of indoor visible light communication system based on white LED, completes the following work:(1) The advantages of visible light communication compared to traditional wireless optical communication, and the development of visible light communication in domestic and international is described.(2) The emitting mechanism of the LED, the type of white LED and production process are introduced. The voltage characteristics, spectral characteristics and modulation characteristics are analyzed. A bandwidth test platform of LED is designed to test the white LED modulation bandwidth.(3) Indoor visible light communication channels is studied, the communication link and the impulse response of the channel are analyzed with reference to indoor infrared communication. A method to get the best LED lights layout which satisfied lighting and communications is proposed, and a simulation to verify the feasibility of the method is conducted by MATLAB.(4)A set-point indoor visible light communication system is designed using optical intensity modulation- direct detection of transmit- receive mode, OOK modulation scheme. The working principle of the transmitter and the receiver in detail by three different signals of characters, audio, video is expounded, and the design of serial communication circuit, amplifier circuit, driver circuit, photoelectric detection circuit module is completed.(5) Performance of the system is tested. Test results show that, the communication system can transmit characters, audio, video signal well in a certain range. The transmission rate of the system is 9600 bps and communication distance is 0.6m, with a certain resistance to ambient light noise.