Minimizing ISI And Maximizing Bit Rate Capacity Using OFDM Introducing To WDM Based Optical Network System


Orthogonal frequency division multiplexing (OFDM) is an attractive modulation format that recently received a lot of attention in the fiber-optic communication. The main advantage of optical OFDM is that it can cope with virtually unlimited amount of intersymbol interference (ISI). In high-speed optical transmission systems, ISI is caused for instance by chromatic dispersion of the fiber optic cable and it is serious issue in long-haul systems whose bit rate is higher. High order dispersion such as a third-order and higher-order dispersion effects are not fully compensated using the traditional dispersion compensating devices such as Dispersion compensating fiber (DCF), Optical Filters etc. Thus the received signals at the receiver end would be distorted dramatically, even if only a small outside effect affects the transmission link.

Generally this work devotion to evaluating the performance of wavelength division multiplexing (WDM) in terms of capacity and ISI, investigating the effect of introducing OFDM on the performance of the WDM optical network, and comparing the performance of WDM and OFDM based WDM optical networks by using opt software simulator.

Key words: ISI; WDM; OFDM; DCF; BER and Data Bit Rate

D. K. SebhatuG.W.Wagaye, M. T.Girmay, S. K.Gebremaryam