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Performance analysis of FSO communications under LOS blockage
Optics Express
|October 19, 2017
Summary
We analyzed free-space optical (FSO) link performance under atmospheric turbulence and line-of-sight (LOS) blockage. The study introduces a new model for outage probability, showing blockage impact depends on turbulence intensity and blockage probability.
Area of Science:
- Optical communications
- Atmospheric physics
Background:
- Free-space optical (FSO) links are susceptible to performance degradation from atmospheric turbulence and temporary line-of-sight (LOS) blockages.
- The ℳ distribution is a robust model for atmospheric turbulence-induced fading, encompassing the Gamma-Gamma distribution.
Purpose of the Study:
- To analyze FSO link performance considering both atmospheric turbulence and LOS blockage.
- To derive novel analytical expressions for the ℳ distribution's statistical properties under LOS blockage.
- To develop a closed-form expression for outage probability (OP) under LOS blockage.
Main Methods:
- Modeling atmospheric turbulence using the ℳ distribution, which separates optical energy into coherent and incoherent components.
- Deriving new analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), and moment generating function (MGF) of the ℳ distribution under LOS blockage.
- Utilizing asymptotic analysis to simplify the outage probability expression in the high signal-to-noise ratio (SNR) regime.
Main Results:
- Novel analytical expressions for the PDF, CDF, and MGF of the ℳ distribution under LOS blockage were derived.
- A new closed-form expression for the outage probability (OP) under LOS blockage was obtained.
- Asymptotic analysis yielded expressions for diversity order and diversity gain in the high-SNR regime.
Conclusions:
- The derived expressions provide a comprehensive analysis of FSO link performance under combined turbulence and LOS blockage.
- The outage probability is significantly influenced by the interplay between atmospheric turbulence intensity and the probability of LOS blockage.
- The findings are crucial for designing robust FSO communication systems resilient to environmental disturbances.
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