Analysing the Effect of Scintillation on Free Space Optics Using Different Scintillation Models

Abstract

Free space optics has gained a lot of popularity within a few spans of years. Although the concept of communication using modulated optical signals is not new, it did not come in existence practically due to the popular traditional wireless RF communication technology. Free space optics has the capability to provide greater bandwidth and higher data rates. Apart from the advantages of free space optics communication technology, it faces several serious complications majorly arising from the geographical location where it is installed, weather and also on the physical properties of atmosphere like index of refraction. Scintillation, also known as atmospheric scintillation is a problem that occurs due to the turbulence in atmosphere which causes hindrance for the propagating optical signal. Study of scintillation models could be used as an effective tool to reduce its effect on the free space communication. In this paper we present an analytical study on a terrestrial FSO model over Gamma-Gamma and Log-Normal channel model. The study includes analysis of effects of coding techniques mainly RZ/NRZ and index of refraction structure on the performance of the FSO link considered which suffers from atmospheric scintillation.