Effects of Turbulence Induced Scattering on Underwater Optical Wireless Communications

This paper presents a comprehensive description of the relative effect of optical underwater turbulence in combination with absorption and scattering. Turbulence induced scattering is shown to cause and increase both spatial and temporal spreading at the receiver plane. It is also demonstrated that the relative impact of turbulence on a received signal is lower in a highly scattering channel. Received intensity distributions are presented confirming that fluctuations in received power from this method follow the commonly used Log-Normal fading model. The impact of turbulence induced scattering on maximum achievable data rate in the underwater channel is investigated.Comment: 9 pages, 10 figures and 3 table

Underwater Optical Wireless Communications Link for Short-Range Data Transmission: A Proof of Concept Study

Gemstone Team OPTICThe purpose of this thesis is to lay the groundwork for the development of a cost-effective Underwater Optical Wireless Communications system. Currently, one of the largest barriers to the expansion of underwater enterprise and research is a lack of high-speed wireless communication systems. Wireless communication underwater is essential for safety, improving aquatic technology, and many other marine ventures, yet it is still technologically limited. Current methods, such as acoustic communication, are often power inefficient, cumbersome, and expensive. The proposed system would enable scuba divers and researchers to bridge the technological gaps in available underwater data transmission systems. This paper proposes using visible light to wirelessly transmit data underwater. Visible light is an effective carrier wave underwater due to its large bandwidth and low absorption coefficient. Using light emitting diodes, silicon PIN photodetectors, waterproof enclosures, and consumer-grade microcontrollers, a model for the development of a wireless optical communications system is proposed. The system also adopts a modular design which allows each component to evolve as needed. The proposed system can transmit and receive audio and vitals signals underwater, illustrating the potential of a technology that could make diving and other underwater endeavors safer and more efficient. Furthermore, the proposed data link shows the potential for this technology to be used in other underwater applications that were previously limited by data speeds or mobility. Above all, this technology seeks to build upon existing knowledge of optical wireless communication and advance the field of underwater science and technology