Modeling and performance analysis of free space optical communication system

In this paper, an attempt has been made to investigate the impact of free space transfer function taking into effects of atmospheric turbulence, pointing errors and path loss factor on the performance of free space optical communication system. The performance of the proposed free space optical communication system is studied by developing a MATLAB simulator using simulink in which free space is used as a communication channel. Finally, we evaluated the Bit Error Rate (BER) performance of the proposed system varying with different system parameters such as distance, transmitter power, path loss factor, atmospheric turbulence and received signal power. The BER is highly degraded on severe atmospheric turbulence condition ever for a short distance of free space channel. The effect of path loss factor due to dense fog is also severe on the BER even though the turbulence effect and free space distance is short. The optimum transmitted input power and receiver antenna radius at which the BER is minimum, is strongly dependent on free space distance and atmospheric parameters.