利用FPGA(field-programmable gate array,现场可编程门阵列)为主控芯片, 实现了5 Mbit/s的2-PPM(pulse position modulation,脉冲位置调制)调制可见光图像传输系统。整个系统分为发射端与接收端两大模块, 全部由FPGA实现。将处理好的图片信号由上位机通过串口发送到FPGA中, 经过调制转换为2-PPM信号, 并设计了信号传输数据帧格式, 然后调制到红光LED(light emitting diode)上并发送出来; 在接收端, 根据数据帧格式完成了数据信号的同步和解调, 并将解调后恢复的图像在液晶屏上显示出来。实验证明该系统可以实现可见光图像信号的传输。

A 5 Mbit/s 2-pulse position modulation(PPM) modulated visible light image transmission system was realized, using field-programmable gate array (FPGA) as the main control chip. The whole system was divided into two modules: transmitter and receiver, all of which were implemented by FPGA.Firstly, the processed picture signal was sent to the FPGA through the serial port by the host computer, and modulated into 2-PPM signal, the signal transmission data frame format was designed, then modulated onto the red light emitting diode (LED) and sent out. Secondly,at the receiving end, the synchronization and demodulation of the data signal were completed according to the data frame format, and the image recovered after demodulation was displayed on the liquid crystal screen. Experiments show that the system can realize the transmission of visible light image signals.