Abstract: From several years Free Space Optical (FSO) Communication system has become more and more interesting and also which can be used as an exchange or alternative to radio frequency (RF) communication system. In this paper the effect of atmospheric turbulence mainly called pointing error on Free Space Optical communication system is investigated. The end to end capacity of dual hop Free Space Optical communication system assuming that the channel state information is only known at the receiver part. The performance of the considered system is mainly affected by misalignment fading, atmospheric turbulence induced fading, pointing errors. Numerically evaluated and computer simulation results are further provided to demonstrate the comparison of Free Space Optical communication system with and without pointing errors in dual amplify and forward relayed system over turbulence channel.

Keywords: Amplify and Forward, Atmospheric turbulence, Dual-hop system, Free Space Optics, Pointing errors