Adaptive Adjustment Strategy for Optimal Reception Area Selection for Trans-Air-Sea Optical Communications

With the increasing demand for ocean communication, trans-air-sea wireless optical communication (WOC) has attracted growing attention. Due to spatial variations in signal attenuation, low-power regions are more susceptible to signal loss and channel instability, limiting system performance. To address this problem, an adaptive adjustment strategy for selecting the optimal reception area is proposed, which aims to maximize the received power. The strategy is based on the photon transmission model, and a local photon distribution based optimal reception area adjustment (LPD-ORAA) algorithm is designed by combining the properties of photon distribution. The LPD-ORAA consists of two parts, adaptive grid division and GE-based local optimization. By combining these two components, the optimal reception area can be effectively determined. Simulation results show that the average normalized received power (NRP) of the optimal reception area obtained by LPD-ORAA is 1.35 dB higher than that of the traditional alignment under various seawater conditions. Compared with the baseline algorithm, LPD-ORAA achieves higher NRP and lower channel impulse response. Finally, we verify the effectiveness of the LPD-ORAA algorithm in a pool environment. Experimental results show that the optimal reception area determined by LPD-ORAA is more suitable for trans-air-sea WOC than the traditional alignment.