Real-time air-to-water mobile visible light communication using a trend differential detection method

In air-to-water (A2W) visible light communication (VLC) systems, supporting real-time mobile communication of the receiver is crucial. However, there have been few reports on A2W VLC systems with real-time mobility capability. In this Letter, we propose a trend differential detection (TDD) method for A2W real-time mobile VLC, which effectively extends the polar angle dynamic range of the traditional symbol differential detection (SDD) method. In the experiments, we achieved A2W real-time mobile communication at 2.0 Mb/s with a polar angle dynamic range of up to 32° under tap water conditions, representing a 1.6-fold improvement compared to the traditional SDD method. In addition, we also demonstrate A2W real-time mobile communication when the average wave height is 8 cm, and the polar angle dynamic range is 20°, showing that the receiver can move at a speed of 1.0 m/s while maintaining a bit error rate (BER) below the forward error correction (FEC) threshold at the same time.