Performance Investigation of Different Modulation Schemes in RoF Systems under the Influence of Self Phase Modulation

Abstract

Abstract The Radio over Fiber (RoF) system has emerged out a promising solution to the last mile connectivity along with higher data rates making it the preference for future communication networks. But fiber nonlinearities induce crosstalk and degrade the performance of the system. This paper presents a simulative investigation & comparison of Mach Zehender Modulator (MZM) and Optical Phase Modulator (OPM) including the effects of Self Phase Modulation. A single channel RoF system has been designed using MZM and OPM respectively. The model is analyzed for different ranges of dispersion and input channel power. It is observed that as the dispersion modulus increases the SPM induced pulse broadening also increases. The pulse broadening also increases with increase in the channel input power. Further it is revealed that MZM offers 0.3 dB more channel output power compared to OPM when dispersion is increased from 2 to 10 ps/nm/km. With the increase in channel input power from 10 to 17.5 dBm, OPM suppress SPM effects better than MZM and provides 2 dB more channel output power.