Dispersion compensation through digital filtering in an optical OOK modulation system

In this work an optimal linear filter in the sense that minimizes the mean square error between its output and a desired signal is presented. The objective is to mitigate the chromatic dispersion of an optical communications system with an intensity modulation scheme such as on-off keying (OOK), where direct detection for demodulation reduces the receiver complexity. The proposed equalizer operates in the electrical domain of the system, after the photodetector. The mathematical model is presented and the expressions to calculate the filter coefficients are derived. Finally, as a measure of its performance, the probability of bit error of the system is evaluated through numerical simulations.