Performance Analysis of Multi-Wavelength Underwater Optical Channels in the Presence of Absorption, Scattering, and Optical Turbulence

This paper investigates the performance of Gaussian-beam underwater wireless optical communication (UWOC) links in the weak-turbulence regime by explicitly incorporating wavelength-dependent absorption and scattering effects alongside optical turbulence. These channel impairments collectively introduce attenuation, fading, and temporal irradiance fluctuations that degrade link reliability. An intensity-modulated direct-detection system employing on–off keying (OOK) is considered, where wavelength diversity is realized through multi-wavelength transmission to enhance robustness against underwater channel impairments. System performance is evaluated using key statistical and temporal fading metrics, including the probability of fade, fade rate, mean fade duration, and mean time between fades. Numerical results demonstrate that absorption and scattering significantly modify channel behavior compared to turbulence-only models, while multi-wavelength transmission provides substantial improvements in fading mitigation and overall link stability.