Adaptive Visible Light Positioning with MSE Inner Loop for Underwater Environment

The Internet of Underwater Things is a paradigm coming up beside well-known Internet of Things, but focusing on a specific environment that is the underwater scenario. Due to high attenuation and then limited performance, communication links in this harsh scenario are provided by dedicated wireless technologies such as optical wireless communication, acoustic communication. The high data rate achievable with underwater optical wireless makes it an enabling candidate technology for effective underwater communication systems. One of the most prominent topics related with underwater communication, is localisation, for all those underwater applications requiring high accuracy, such as marine ecology, seabed monitoring, etc. However, the high dynamic characteristics of the underwater environment can limit the localisation accuracy, thus resulting in high estimation errors. In this paper, we present an adaptive localisation algorithm that exploits optical wireless connectivity, in the visible range. It takes into account information about water turbidity and is able to dynamically correct the estimation error in case of variable water conditions. The effectiveness of the proposed approach has been compared to a previous technique, which does not exploit information about the environment and then results to be effective only if exists an apriori knowledge of the real water conditions.