Performance Evaluation of a Wavelength Division Multiplexed (WDM) Free Space Optical Communication Link under Diverse Weather Conditions using Different Modulation Formats

In this paper, simulative analysis of 10Gbps DWDM system link with FSO channel using different modulation format under different weather condition has been performed. A 16×10 DWDM system has been analyzed with 1nm channel spacing and the effect of variation in input power and transmission distance is observed in terms of Q-factor values of received channels. From the study of variation in input power in the scenario of different weather condition (clear, haze, rain and fog) the best modulation format has been identified. It has been observed that DBNRZ modulation format is best result than other modulation formats. Similarly in the case of while varying link distance under different weather conditions, the best modulation format has been recognized. It has been observed that CSNRZ modulation format is better result than the other modulation formats. The BER performance of all received signals is also discussed.