Electronic Dispersion Compensation In High Speed Optical Transmission System

Optical communication is a must-need for its large bandwidth and excellent signal quality in the core communication network. Higher standards such as larger amount of information, longer communication distance and more reliability in the core network are need for broadband communications. However, there is a major factor, dispersion, limiting transmission distance and affecting the quality of communication as transmission rate increased. Dispersion is usually inhibited in two ways: one is dispersion compensation using optical fiber or fiber Bragg grating, the other is EDC (Electronic dispersion compensation). In recent years, with the development of electronic chips technology, EDC, which has been used in 10Gbit/s optical transmission system, attracts more and more interest due to its flexibility and self-adaptive ability. So the study of EDC is of much academic and practical significance.In this thesis, the development of dispersion compensation in optical domain and current researches status of EDC is illustrated. Dispersion compensation in both optical and electrical domains has been compared. Also, the development of new modulation technique is introduced.Principle of equalizer and adaptive algorithm related has been analyzed. After study about performance of 10Gbit/s NRZ optical system, we find out that the more the tap equalizer used, the better performance could be got, while significant improvement couldn't be attained when the number of tap equalizer is bigger than a certain value.Simulation of intensity modulation and phase modulation is accomplished based on the analysis of modulation principle. Spectrum and back-to-back eye diagram are analyzed according to simulation results. EOP is used for the evaluation of system performance and dispersion tolerance of different modulation.Finally, we built several different models for different modulation with FFE and DFE. According to simulation results given by these models, the right equalizers for different models had been chosen. The performance of the above equalizers in intensity and phase modulation had been compared and analyzed theoretically.