Digital equalization techniques for dispersion compensation in ultra-long haul 100 Gb/S direct detection optical OFDM system

In this article, we demonstrate the use of Symbol-Spaced, Fractionally-Spaced Decision Feedback Equalizers(SS-DFE, FS-DFE) using Least Mean Square(LMS) algorithm and Maximum Likelihood Sequence Estimator for the compensation of accumulated Chromatic Dispersion and Polarization Mode Dispersion over a maximum distance of 5000 km in a 100 Gbps Direct Detecction Orthogonal Frequency Division Multiplexing(DD-OFDM) system. BER is 10e −4 at 8.5 dBm for MLSE and 10e-3 at 7dBm for SS-TDE DFE equalization, 10e-3 at 7dBm for FS-TDE DFE equalization and 10e-1 at 4dBm without equalization for a distance of 5000km.