The Research Of DSP-based Optical Polarization Mode Dispersion Adaptive Compensation System

As the high-speed and long-distance development of optical fiber communication systems, fiber polarization mode dispersion (PMD) issues in single-mode optical stand out gradually. It has become one important limiting factor in high-speed and long-distance optical transmission. Polarization mode dispersion will cause pulse broadening and inter-symbol interference in digital transmission systems,seriously affecting the signal transmission quality. The studies to prevent the pulse broadening and inter-symbol interference by compensation the PMD in optical fiber communications came into being, and has begun to continuous development and in-depth.Based on863research projects,this paper attempt to research the data transmission characteristics in DSP-based optical polarization mode dispersion adaptive compensation system by applying the160Gbit/s optical transmission technology. The main tasks are as follows:(1) Learning polarization mode dispersion and polarization-state theory, researching the relationship between degree of polarization(DOP) and polarization mode dispersion, in order to find a way to compensate polarization mode dispersion through the DOP control.(2) Learn the characteristics and effects of FPGA, DSP, polarimeter, polarization controllers, chips in digital to analog converter circuit and amplifier circuit by consulting material.(3) Design the FPGA software part of the system based on the improved FPGA+DSP hardware development board. Learn and master the Quartus II application development platform and logical programming language VHDL; Design data transmission procedures and timing of logic by finding out the communication mode between FPGA, DSP, analog-digital conversion digital-analog circuit. Finally finish the compensation function by board debugging.(4) Design the software part on DSP development board.Learn how to use CCS software development platform. Analyze the working principle of DSP/BIOS and EMIF. Writing the main function and interrupt functions to complete the data read and write operations.(5) Test the data control, data transmission function and polarization mode dispersion compensation function by experimenting the adaptive compensation system.Observe the data transmission efficiency and effectiveness.Improve the system, summed up the deficiencies of the system, Propose new ideas and future directions for further research.