On the Effect of Air Bubbles-Induced Scattering on Turbid Waters: An Experimental UOWC Channel Modeling Approach
Abstract
The influence of the oceanic medium on the underwater optical wireless communication (UOWC) highlights the need for an accurate mathematical channel characterization that models the properties of realistic oceanic environments, significantly optimizing the development of practical UOWC system designs. However, a need remains to provide a deeper insight into the behavior of air bubbles in turbid waters. This article presents an analysis and a statistical characterization of the received optical power fluctuations when considering different air bubble sizes and levels of particle-induced scattering. Experimental measurements were conducted in a water tank, manipulating water turbidity levels by dissolving a commercial antacid. Afterward, some evaluation metrics, such as the scintillation index, the average outage duration, and the coherence time, are calculated to provide an analytical framework of the air bubbles-induced fading in turbid environments. Additionally, the statistical behavior of small and large air bubbles are analytically described through the generalized Gamma distribution and a mixture of two generalized Gamma distributions, respectively, and validated with a coefficient of determination above 0.95 for all the considered turbid waters. Results demonstrate that water turbidity dramatically affects the stochastic behavior of the underwater channel in the presence of air bubbles, resulting in a significant reduction in light blockage due to the collection of scattered photons. As a result, the scintillation index and the average outage duration are noticeably reduced for more turbid water. © 2023 IEEE.
Pedro Salcedo-Serrano
Postdoctoral Researcher / External Collaborator
Postdoctoral researcher and external collaborator of WOCLab working on optical wireless communications, underwater optical links, channel modelling and performance analysis.
José María Garrido-Balsells
Professor of Telecommunications Engineering
Professor at the University of Málaga working on wireless optical communications, free-space optical links, underwater optical wireless communications, optical channel modelling and experimental communication systems.
Beatriz del Castillo-Vázquez
Associate Professor of Telecommunications Engineering
Associate Professor at the University of Málaga working on wireless optical communications, free-space optical links, underwater optical wireless communications, optical channel modelling and system-level performance analysis.
Antonio Puerta-Notario
Emeritus Professor / Senior Researcher
Emeritus Professor at the University of Málaga with a long-standing research activity in signal theory, optical wireless communications, visible light communications, free-space optical links and communication system modelling.
Antonio García-Zambrana
Professor of Telecommunications Engineering
Professor at the University of Málaga working on wireless optical communications, free-space optical links, underwater optical wireless communications, visible light communications, and FPGA/RFSoC-based real-time prototyping.