瑞利后向散射信号硬件解调电路设计

Design of Demodulating Circuit for Rayleigh Backscatter Signal

光时域反射仪(OTDR)在光纤系统的测试中具有十分重要的作用,如何提高其分辨率和动态范围已经成为研究的一个难点[1-3].为了使设计的解调系统达到对测量精度和动态范围的要求,采用Xilinx xc3s400和USB单片机为主要的核心器件,分别完成对A/D的采样、通信等功能,A/D采用12位150 Mbps高速采样芯片完成对被测量的量化;通信方面以USB通信方式,以实现采集数据与PC机之间的数据传输.数据传输率达到30 M以上.在PC机开发可视化图形界面完成数据的处理和结果的显示.

Optical time domain reflectometer plays a very important role in the test of optical fiber system,how to improve its resolution and dynamic range has become a difficulty.In order to make the designed demodulation system to achieve the requirements for measuring accuracy and dynamic range,the Xilinx xc3s400 and USB singlechip were adopted as the main core device,the functions such as A/D sampling and communications were completed respectively,A/D takes 12 150 Mbps fast-sampling chips to accomplish the quantization of the measurement.Communications are realized in USB communication mode,in order to realize data collection and data transfer between PC.A data transfer rate reached over 30M.In developing visual graphic interface PC complete data processing and results.