Research on the Key Technologies of Transmitter for LED Lighting Communication System

This paper mainly studies the LED illumination of visible light communication system, the key technology on launch. Through the analysis of the basic characteristics of white LED, it respectively designed for analog and digital modulation communication system to the launch of the LED driver circuit. At the same time it solved the following the design requirements:(1) By outputting the stability of the light power as large as possible broaden the coverage system; (2) Making use of the Matlab simulated indoor lighting, receiving the simulation diagram of power and light intensity. Through changing parameters for many times get the best lighting layout. Use OFDM coding technology to reduce the code rate, increased the signal pulse cycle, weakening the multiparty propagation caused by the influence of the ISI, also add protection interval between OFDM signal, further weakening the effect of ISI. At all, the Microcontrollers are used for data transmission test. According to the characteristics of Microcontrollers' serial output data, it set up the launch driver circuit, achieved the desired goal and completed the data transmission very well.