Statistical studies of fading in underwater wireless optical channels in the presence of air bubble, temperature, and salinity random variations
Journal article, 2018

Optical signal propagation through underwater channels is affected by three main degrading phenomena, namely, absorption, scattering, and fading. In this paper, we experimentally study the statistical distribution of intensity fluctuations in underwater wireless optical channels with random temperature and salinity variations, as well as the presence of air bubbles. In particular, we define different scenarios to produce random fluctuations on the water refractive index across the propagation path and, then, examine the accuracy of various statistical distributions in terms of their goodness of fit to the experimental data. We also obtain the channel coherence time to address the average period of fading temporal variations. The scenarios under consideration cover a wide range of scintillation index from weak to strong turbulence. Moreover, the effects of beam-expander-and-collimator (BEC) at the transmitter side and aperture averaging lens (AAL) at the receiver side are experimentally investigated. We show that the use of a transmitter BEC and/or a receiver AAL suits single-lobe distributions, such that the generalized Gamma and exponentiated Weibull distributions can excellently match the histograms of the acquired data. Our experimental results further reveal that the channel coherence time is on the order of 10-3 s and larger which implies to the slow fading turbulent channels.

temperature-induced turbulence

coherence time

Underwater wireless optical communications

fading statistical distribution

air bubbles

goodness of fit

salinity variation

Author

Mohammad Vahid Jamali

University of Michigan

Ali Mirani

Chalmers, Microtechnology and Nanoscience (MC2), Photonics

Alireza Parsay

Sharif University of Technology

Bahman Abolhassani

Ohio State University

Pooya Nabavi

University of Central Florida

Ata Chizari

University of Twente

Pirazh Khorramshahi

University of Maryland

Sajjad Abdollahramezani

Georgia Institute of Technology

Jawad A. Salehi

Sharif University of Technology

IEEE Transactions on Communications

00906778 (ISSN) 15580857 (eISSN)

Vol. 66 10 4706-4723 8370053

Subject Categories

Telecommunications

Communication Systems

Signal Processing

DOI

10.1109/TCOMM.2018.2842212

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Latest update

6/30/2023