The equalization-enhanced phase noise was introduced when fully using electronic dispersion compensation in high-speed optical coherent communication system. Using electronic dispersion compensation to compensate the residual chromatic dispersion was proposed, to realize the transmission at 100 Gbit/s per specified channel and beyond on the existing 10 Gbit/s fiber-optic transmission line were realized. By using VPI, the 112 Gbit/s optical coherent system performance with finite impulse response filter and overlap frequency domain equalization filter were compared, which is used to compensate the residual chromatic dispersion.Simulation results indicate that in the same tap length, FIR has more effective residual chromatic dispersion compensation ability than overlap frequency domain equalization.Also, the finite impulse response filter has more stable equalization performance and lower computation complexity, and it is suitable for the hybrid chromatic dispersion compensation.