Currently

white LED is widely used in lighting.Simultaneously

it has also achieved success in the area of Visible Light Communication（VLC）technology.In this paper

a short distance transmission system is designed by using white LED as the signal transmission medium.Pulse Width Modulation（PWM）is applied to modulate the audio signal and the ambient temperature signal.At the receiver side

current feedback circuit and the voltage amplification circuit are utilized to enhance the dynamic range of the PWM wave peak value.Then we use STM32 to demodulate the optical pulses.We also use Time-Division Multiplexing（TDM）technology to realize the real-time short-distance transmission of audio signals and digital signals from 300 to 3400Hz.The results show that the waveform has no obvious distortion on the oscilloscope after the transmission.