Highly robust underwater wireless optical communication system with optical background rejection and adaptive algorithm under strong artificial illumination

The concurrent operation of underwater wireless optical communication (UWOC) and artificial illumination represents a crucial functional requirement for underwater platforms. Nevertheless, intense background illumination significantly interferes with the performance of optical communication, leading to a reduction in the signal-to-noise ratio (SNR), an increase in bit-error rates (BER), and ultimately resulting in communication failure. We demonstrate a highly robust UWOC system that achieves an over 30 dB system-level equivalent tolerance to background illumination, including over 20 dB optical rejection and over 10 dB electrical-domain equivalent suppression. This system is enabled by a synergistic optical-electrical architecture comprising spectral avoidance, 5-ns gated sampling centered on the line-of-sight peak, and a real-time FPGA-implemented sliding-window adaptive decision threshold (ADTSW) algorithm. Under 300 W continuous illumination, we successfully achieved a 33 m underwater optical communication link with 20 Mbps in pool water and uninterrupted high-definition video streaming transmission between mobile platforms, in the South China Sea at the 17 m communication link with 3.125 Mbps. The proposed UWOC system offers a reliable solution for underwater data links in strong illumination environments.