Based On Dsp Processing The Brillouin Dofs Data Processing System

This dissertation is focus on the design and realization of signal detection and processing subsystem of the Brillouin scattering distributed sensing system. We also gave the experimental results of the distributed fiber-optical sensor based on Brillouin scattering. This work is supported by the National High Technology Research and Development Program of China and Nature Science Fund of Zhejiang province China.Through analyzing the methods of distributed fiber-optical sensor, we proposed the Brillouin scattering distributed sensing system based on coherent detection as a finial scheme. A signal detection and processing subsystem based on Hilbert transform has also been proposed and realized based on the characteristics of Brillouin scattering signals. This signal detection and processing subsystem is composed of hardware circuits and software. A four-layer printed circuit board has been designed to realize hardware circuits. In hardware circuits, we used a high-speed AD converter, a FPGA(Field Programmable Gate Array), a high-speed SRAM and a USB protocol controller. We designed proper software for all the modules of FPGA and successfully realized high-speed sampling, digital signal processing based on Hilbert transform, digital accumulation, RAM control interface, data transmission and an interface to PC. The software is also designed to work with signal detection and processing subsystem and gather the temperature or stress information along the fiber. The principles and the ideas of the above-mentioned system, and the key points of the realization process of the blue print are discussed in detail. After testing and adjusting the system, we finally realized all the functions of signal detection and processing subsystem and experiments have been performed in real environment.