Real-time underwater visible light mobile communication with conditional feedback threshold under random receiver orientations

The capability for real-time mobile communication is crucial for underwater visible light communication applications. In practical real-time underwater visible light mobile communication (UVLMC) systems, movement orientation significantly impacts communication performance. However, there is limited research on this aspect. We propose a real-time UVLMC system based on the conditional feedback threshold (CFT) to enhance performance under random receiver orientations. In experiments, we achieved real-time UVLMC over a distance of 60 meters with a data rate of 2 Mb/s under random receiver orientations in a tap water channel. The system can operate under a mean polar angle and azimuth angle as large as 40° and 120°, respectively, at a moving speed of 0.15 m/s with a dynamic range of 7 meters. This represents a 4.8-fold improvement in dynamic range compared to the system without the CFT mechanism.