Research On Pmdadaptive Compensation Technology Based On Computational Intelligence

Polarization Mode Dispersion (PMD) is the main factor of limiting the further improve for the transmission rate and transmission distance of the optical fiber communication system. It has the important theoretical value and application value to take the PMD compensation technology study.This paper tries to solve the key problems in the PMD adaptive compensation using the computational intelligence method, such as improved Particle Swarm Optimization (PSO) and Support Vector Machines (SVM). Main research contents and innovation work are as follows:(1)Since the basic Particle Swarm Optimization (BPSO) is trapped in local optimum and has finite particle velocity, this paper put forward QPSO algorithm possesses the uantum behaviors combined with quantum theory. Compared with the genetic algorithm, BPSO algorithm and the improved PSO algorithm with gradient search factor,QPSO algorithm has fast convergence, and is not easy to be trapped in local optimum. On this basis, the paper takes out the new QDPSO algorithm to give the new idea for optimizing and solving the discrete problem, according to the deficiency of the QPSO algorithm on the discrete data treatment.(2)It plays the most important role of the adaptive algorithm in the PMD optical domain adaptive equalizing system. Equalization result of the optical domain adaptive equalizer has been influenced, because of the slow convergence speed and huge operation of the normal adaptive algorithm(such as LMS algorithm, RLS algorithm).On this basis, the PMD optical domain adaptive equalizing scheme based on QPSO adaptive algorithm has been first proposed,which compared with the normal adaptive algorithm, the better equalization result has been obtained and the poor equalization result problem which brings by the limitation of the properties for the equalizer adaptive algorithm has been solved.(3)Control algorithm is the core of the adaptive compensation unit in the PMD optical domain adaptive compensation system. Compensation effect of the optical domain adaptive compensator has been influenced, because of the slow convergence speed and be easily trapped in local optimum of the normal control algorithm (such as simplex algorithm, GA algorithm). On this basis, the PMD optical domain adaptive compensation scheme based on QPSO adaptive algorithm has been first proposed,which compared with the normal control algorithm, the better equalization result has been obtained and the poor compensation effect problem which brings by the limitation of the properties for the compensator control algorithm has been solved. (4) The PMD adaptive compensation scheme with the recognition function of signal modulation mode has been first put forwarded. The differ modulation signals has been transmitted in the future all optical network. The signal modulation mode recognition link which use the Support Vector Machines to accurately identify the different signal modulation mode has been added before the compensation of the optical signal with PMD. Then according to the identification result, the compensation has been made by using the compensation scheme which has the best compensation effect for the modulation mode, in order to get the further improvement of the compensation effect.(5) The signal modulation recognition scheme has been designed and realized in this paper,which based on the Support Vector Machines (SVM). The Amplitude modulation, Frequency modulation,and Phase modulation have been done to get the recognition accuracy of 94.4%, which can meet the actual demand very commendably.