Compensation Nonlinear Damages For Co-OFDM Communication System

In recent years, the coherent optical orthogonal frequency division multiplexing（CO-OFDM）communication system due to high spectral efficiency and a strongrobustness for chromatic dispersion and polarization mode dispersion has become a hotspot. However, due to it is sensitive of the nonlinear effect which greatly limiting itstransmission performance. The research results show that backward propagation (BP)algorithm can well compensate the nonlinear damage has been regard as a promisingmethod. Because of its high computational complexity makes it more difficult to achieve.In view of this, according the relationship between the nonlinear damage and the opticalpower propose a selecting an appropriate threshold power point to reduce the highcomputational complexity of BP compensation algorithm. The main contents are asfollows:(1) First, elaborate the CO-OFDM system’s principles and the main technologies. UseVPI simulation software to build CO-OFDM system model. Based on the simulationplatform analyze the nonlinear damage’s influence for CO-OFDM system’s performance.(2) Second, based on deduce the NLSE get the nonlinear phase compensation factor.Select appropriate experimental conditions to improve BP compensation algorithm and toreduce its high computational complexity.(3) At last, compare the compensation performance of the traditional and the improvedBP algorithm. Through comparison know that the improved BP compensation algorithmnot only reduces the computational complexity but also slightly improve the compensationperformance of the system than the original BP compensation algorithm.