140 Modeling of FSO Link and Error Performance Analysis under Weak Turbulence

Signal transmitted in Free Space Optical communication (FSO) link is influenced by both the atmospheric turbulence and performance of the photo-detector, becomes much uncertain. According to both weak turbulence channel model and photoelectric detection channel model, two exact probability density functions(pdfs) of photoelectric count are proposed respectively in discrete and continuous forms. Based on these expressions, we derive the probability density functions of the output current, and establish a mathematic model of error performance for FSO link. The model characterizes factors about weak turbulence as well as detector, such as scintillation and background noise, etc. Simulations results are consistent with anticipate analysis, and the presented model can lead to an efficient performance evaluation.