Simulation of Chromatic Dispersion Effects in a Metropolitan ITU-T G. 652.D Optical Fiber Link at 10 Gbps, 100 Gbps and 200 Gbps with NRZ and RZ Modulation Format

Abstract

For decades, telecommunication networks have been evolving with the use of optical fiber as transmission medium. Data is transmitted through optical fiber in the form of light. Light pulses, while propagating in the optical fiber, undergo effects of different nature due to certain phenomena. Among these phenomena, Chromatic Dispersion (CD) is a phenomenon that results from the dependence of the optical fiber core’s refractive index with the wavelength. Thus, the components of the light pulse propagate with different speeds in the optical fiber. This results in a broadening of the light pulses, thus causing signal degradation. CD limits the performance of optical fiber telecommunication systems, especially when transmission rates are increased. It is therefore important to study it in order to find mechanisms to reduce its negative impact on signals. From a simulation, we study and analyze, in this work, the effect of CD in an ITU-T G.652.D optical fiber link of a metropolitan network to be deployed in Lomé, the capital city of Togo. The NRZ and RZ modulation formats are considered using bit rates of 10 Gbps, 100 Gbps and 200 Gbps and the study is operated at a wavelength of 1550 nm with a power of 10 dBm (10 mW). We use eye diagram, Min BER and Q-Factor to carry out the performance analysis of the transmission link with the different links. The distortion of the signal is a function of the distance. RZ format is good for short distance and NRZ is good for long distance. At 100 Gbps, the signal is much more distorted than 10 Gbps.