Linear and Non-Linear Equalizer for Chromatic Dispersion Compensation in Coherent Optical Receiver

Optical fibers are now widely used in communication systems, mainly because they offer much faster data transmission rates. But by increasing transmission rates over longer distances, the data is affected by nonlinear inter-symbol interference caused by dispersion phenomena. Efficient and low-cost dispersion compensation is necessary to achieve useful transmission distances in optical communication systems at higher bit rates. Adaptive equalizers can be used to compensate the effects caused by nonlinear inter symbol inference, i.e., restoring the original signal as transmitted. This paper evaluates the performance of single layer feed forward equalizer using least mean square algorithm and multilayer perceptron equalizer based on artificial neural networks using back error propagation algorithm for chromatic dispersion compensation at bit rate of 12.5 Gb/s. This paper compares these two adaptation techniques in coherent receiver based on analogue electronic dispersion equalizers by simulation and experiment.