Performance analysis of free space optical communication system in the presence of physical limitations

The fundamental aim of this study is to identify an appropriate connection between atmospheric attenuation and visibility in thick or dense fog. The atmospheric attenuation in optical waves, due to low atmospheric visibility conditions, causes a performance degradation of Free Space Optical (FSO) communication systems. Simulation is conducted to determine the relationship between visibility in fog and optical attenuation (dB/ km) at an optical wavelength of 1550 nm. In this study, the Bit Error Rate (BER) performance for FSO systems is investigated. The BER is evaluated in the presence of atmospheric attenuation, visibility and pointing errors. The performance of FSO communication system is tested using On-Off Keying (OOK) modulation scheme .Simulation results is demonstrated to confirm the analytical results. The results have drawn the conclusion that the BER increases in adverse weather and over greater distances. Moreover, the BER increases as the pointing error increases. Also, the FSO system suffers higher power penalty