Real-Time Water-to-Air Communication System Under Dynamic Water Surface and Strong Background Radiation

This work explores water-to-air optical wireless communication (W2A-OWC) transmission schemes and realizes a prototype of real-time W2A-OWC system based on field programmable gate array. This prototype comprises underwater nodes, aerial nodes, and transmitter-receiver hardware circuits. The real-time system employs multiple-input multiple-output technique and the low density parity check (LDPC) code of 5G-new radio for dynamic W2A-OWC. Additionally, the impact of background radiation is mitigated through spatial optical filtering. To validate the practical feasibility of the system, experiments are conducted in both indoor water tank and outdoor deep pool under strong background radiation. The frame error rate of the real-time system is tested under different LDPC code rates and transmitter-receiver configurations. The experimental results verify the feasibility of the realized W2A-OWC system.