Performance analysis of wavelength diversity wireless optical communication system in ocean turbulence

Due to seawater absorption, scattering attenuation and ocean turbulence effects, the optical signal at the receiving end of the underwater wireless optical communication (UWOC) system will flicker. The flickering signal will result in a decrease in the transmission performance of the UWOC system. Based on the Gamma-gamma distribution of the ocean turbulence channel model, according to the equivalent structural parameters represented by ocean turbulence parameters and anisotropy factors, the closed expressions of the outage probability (OP) and the average bit error rate (BER) of the wavelength diversity UWOC system were derived. With the increase of the anisotropy factor, the changes in the outage probability and the average bit error rate of UWOC system with different wavelength diversity orders were analyzed. The average bit error rate difference of the UWOC system between the optimal combining (OC) and the equal gain combining (EGC) used at the receiving end technology were compared, and the influence of different ocean turbulence parameters and transmission distances on the performance of the wavelength diversity UWOC system was simulated. The numerical results show that the ocean turbulence effect on the UWOC system gradually weakens with the increase of the anisotropy factor. The UWOC system with wavelength diversity technology has significantly improved the outage probability and the average bit error rate than the UWOC system without wavelength diversity technology.