The study of wavelet de-noising in multi-span nonlinear intensity-modulated fiber communication systems

In this work, wavelet de-noising with several different types of wavelets such as db4, coif4 and dmey wavelets was applied at the end of the multi-span intensity-modulated fiber communication systems. The results of numerical simulations carried out in different fiber links demonstrated that the wavelet de-noising method could remove the random amplitude fluctuation and pulse breaking induced by the interaction of ASE noise and fiber dispersion and nonlinearity. The normalized energy deviation (NED) of the signal without and with de-noising in dispersion compensation fiber link were plotted to show the effectiveness of the wavelet de-noising in the fiber-optic communication systems and wavelet de-noising with demy wavelet can achieve better result than with other type wavelet.