Design of a Wide-angle Li-Fi Receiver For Underwater Vehicle Communication

An underwater wireless optical communication system is presented. It serves as a moderate-distance and bidirectional wireless communication interface between underwater vehicles and a light sphere in a short distance communication applications, such as an underwater sensor node. The system has two parts, one is a fixed communications node (a light sphere), the other is an underwater vehicle node, both are using light emitting diodes and PIN diodes as receiver, The fixed communications node performs a wide range, send-and-receive bidirectional communication with a moving underwater vehicle node. The fixed node adopts a spherical design with multiple receivers installed with an equal-divide circular platform, convex lens enhance power received on the receivers. The TDMA multiplexing technology and cyclic redundancy check are used to reduce the packet error. The design was verified using underwater vehicle experiment in a large water tank. It is shown that the system can perform 19Kbps for bidirectional communication.