A comparison between mathematical tools for analyzing FSO systems over Gamma-Gamma atmospheric channel

Atmospheric turbulence induce-fading is one of the major link impairments that degrade the performance of Free Space Optical (FSO) communication systems. In this paper, the authors present the performance difference between the Meijer-G function and infinite Power Series expansion as mathematical tools for analyzing the performance of FSO system over Gamma-Gamma atmospheric turbulence. The Probability Distribution Function (PDF) for the Gamma-Gamma channel is obtained in terms of Meijer-G function and infinite power series expansion. Thus, the Average Bit Error Rate (ABER) and outage probability close-form expressions of a Subcarrier Intensity Modulation (SIM) that employed Bipolar Phase-Shift Keying (BPSK) are then derived using the statistical channel PDF. Under the same atmospheric conditions, the results show that both analyses offer the same performance but power series expansion analysis yield the best computational running time than the Meijer-G analysis. It is also deduced that Meijer-G close-form expression does not reveal insight into the system design compare to the power series approach but offers a traceable close-form result for the two performance metrics as compared to the Power Series Expansion.