نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار،دانشگاه جامع امام حسین (ع)، تهران،ایران
2 استادیار،دانشگاه جامع امام حسین (ع)، تهران،ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Free-Space Optical (FSO) Communication has many advantages such as high bandwidth, high security and can also be a good alternative to radio communication systems. Atmospheric conditions, rain, snow, fog, environmental factors such as strong winds and the movement or vibration of the transmitter platform can cause the transmission light to break or spread, and as a result lead to deviations in the signal propagation path and pointing errors or misalignment errors between the transmitter and receiver. Different methods are used to reduce the effect of weather conditions on pointing errors in FSO. Atmospheric conditions, rain, snow, fog, environmental factors such as strong winds and the movement or vibration of the transmitter platform can cause the transmission light to break or spread, and as a result lead to deviations in the signal propagation path and pointing errors or misalignment errors between the transmitter and receiver. Different methods are used to reduce the effect of weather conditions on pointing errors in open space communications.
In this paper, a model to investigate the FSO attenuation and turbulence effects on its performance is presented and a closed-form expressions for calculating the Bit Error Rate (BER) has been proposed for the gamma-gamma atmospheric turbulence channel and pointing errors.
Because of the atmospheric turbulence effects, in practice, terrestrial FSO links are used for two fixed points over distances up to several kilometers. In this paper using combinational mitigation techniques has shown that an FSO system having 4 transmitters with total 600mW of optical power and a receiver with at least 25cm optical aperture can communicate data, in the week turbulence condition (weather conditions in arid and semi-arid), with a maximum range of 10 km and a BER of better than10-6.
کلیدواژهها [English]
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