Effect of Different Atmospheric Conditions on the Performance of the FSO System at 1550nm

Free Space Optics (FSO) communication is an efficient technology and has gained significant importance in the recent years because of its unique features such as license free spectrum, lager bandwidth, ease of deployment etc. This paper compares the performance of NRZ-OOK and RZ-OOK modulation techniques in the FSO system under different weather conditions such as clear weather, fog, haze, mild rain, medium rain at 1550 nm wavelength. The variation of the BER, Q-Factor and eye diagram has been analyzed in relation to the link length. It has also been analyzed that NRZ technique performs better than RZ and for each weather condition the BER increases as distance/link length increases. In simulation results, it has been analyzed that within the distance range of 100m to 1000m, for each weather condition a certain distance range is achieved above which system does not work efficiently and these distances are termed as threshold distances.