The Impact of Vertical Salinity Gradient on Non-Line-of-Sight Underwater Optical Wireless Communication

The non-line-of-sight (NLOS) underwater communication can offer a viable route in signal propagation and coverage, thus mitigating the pointing, acquisition, tracking difficulties line-of-sight optical communication. However, implementing NLOS link is non-trivial. While technique relies on light scattering, i.e., channel turbulence facilitate communication, associated path-loss (PL) be significant. Signal fading degrade robustness, which arises due to ocean water temperature salinity fluctuation gradients. To evaluate robustness of natural waters, we systematically measure metrics, such as bit error ratio, PL, signal-to-noise ratio (SNR), bodies uniform nonuniform vertical ranging from 30–40‰ (part-per-thousand). We found that salinity-induced establish with PL reduction 2.35 dB/m SNR increase by 32.5 $\%$ for dynamic water. Furthermore, strong correlation was obtained between strength fluctuations received SNR. Finally, Gaussian distribution statistical scintillation behavior. These results demonstrated benefit using regime wireless sensor networks aiding designers engineers.