基于遗传算法的偏振模色散补偿系统的设计与实现软件工程专业论文.docx

哈尔滨工业大学工程硕士学位论文 哈尔滨工业大学工程硕士学位论文 II II Abstract Due to the imperfectness of the optical fiber, outside stress, environment, bi-reflectivity and etc. , polarization mode dispersion(PMD) has become the main obstacle that limits the upgrading of bit rates and span of relay distance. Fsed b y urthermore, the statistic property of PMD caused by external conditions and other reasons makes the PMD compensation extremely difficult. Thus how to compensate for PMD has become the key problem in the optical fiber communication system both at home and abroad This thesis mainly studies PMD compensation methods. With the design of fully utilizing the advantage of genetic algorithm, the compensate for polarization mode dispersion system solved the problem of find the best one form multiple solutions. genetic algorithm easily been trapped into local optima. Using Reasonable threshold to ensure the solution can satisfy the system requirements. Using the FPGA parallel deal with data, the response time for the compensator is at the level of millisecond. The compensate for PMD system uses wavelate analyser measuring light, calculates degree of polarization as a feedback signal for PMD compensation system. Though changing the control voltage of polarization controller, make the degree of polarization of system best. This dissertation firstly explains the background and source of the research, the development status of the similar systems in the world, and then clarifies the goals of the system. From control algorithm, system interaction, and maintenance, the system requirements are analyzed; key technology, algorithm, system environments are explained. The dissertation introduces the processing of compensator and designs the system architecture and key components; for improving the response time of the compensator this dissertation introduces use FPGA in the PMD compenstion system. After the system designs are accomplished, detailed implementation of the system and key processes, after th