Enhancement of the performance of DWDM free space optics (FSO) communications systems under different weather conditions

Abstract

Frees Space Optical (FSO) communication is one of the communication systems types that uses a free space to transmit information carried by light. It is previously known that the single input single output (SISO) technique is susceptible to atmospheric attenuation because of the effect of weather conditions. The proposed system is a combination of dense wavelength division multiplexing (DWDM) and multiple input multiple output (MIMO) techniques with Fork components. The main Fork component is configured in the Optisystem simulator to connect to another Fork components to increase the power of transmitted signals and ensure the arrival of the transmitted signals to the receiver of the FSO system. The key idea in the proposed system is to mitigate the attenuation that will be happened to the transmitted optical signal which propagated through free space due to different weather conditions. The study is done based on using the Optisystem simulation toolbox that is used to emulate different weather attenuation conditions in two types of FSO systems. The first is the traditional DWDMSISO and the second is a proposed system named Hybrid DWDM-MIMO. A comparison between the proposed system and the traditional system is made in terms of the quality factor under different weather attenuation. The proposed system shows promising results in the performance and the quality of the received signal. The transmission path length of the proposed system under dense fog attenuation of 260 dB/km is enhanced to (30.43%) in comparison with traditional DWDM-SISO, also transmission path length of the proposed system under heavy rain attenuation of 9.29 dB/km is enhanced to (55.55%) in comparison with traditional DWDMSISO. The transmission path length of the proposed system under heavy dry snow of attenuation of 131.835 dB/km is enhanced to (26.19%) in comparison with traditional DWDM-SISO.