Estimation of Minimum Required Number of Coefficients of Digital Filter for Chromatic Dispersion Compensation in Optical Fiber

The 5G technology requires the application of optical fiber in the access network. The chromatic dispersion in fiber causes distortion of transmitted signal. The dispersion can be compensated by digital optical filters. The physical size of the filters depends on the number of coefficients. It is proved that the minimum number of coefficients is limited by the physical characteristics of optical fiber and has a quadratic dependence on frequency band. An analytical equation for estimating the number of coefficients is proposed. And the method for decreasing the total number of coefficients is considered.