Bit Error Rate Performance of MISO-UWOC Systems with Equal Gain Combining in a Composite Oceanic Fading Environment

In this paper, the generalized Gamma distribution (GGD) is selected to characterize oceanic turbulence. A composite fading channel model is proposed, which comprehensively takes into account the GGD oceanic turbulence, zero boresight pointing errors, and the Elamassie underwater path loss. Closed-form expressions of the probability density function (PDF) and the cumulative distribution function (CDF) of the composite channel fading are derived first by using the Meijer-G function. Furthermore, the formulas of the average bit error rate (BER) of the on-off keying (OOK) modulated multiple-input and single-output (MISO)-underwater wireless optical communication (UWOC) systems with equal gain combining (EGC) are derived by adopting the higher transcendental multivariate Fox-H function. Finally, the Monte Carlo simulations are presented to validate the accuracy of the theoretical derivations above, and the influence of the key parameters of the systems on average BER is also investigated. The results show that in the composite fading environment, the error performance of the MISO-UWOC systems with EGC is significantly better than that of the traditional single-input single-output (SISO)-UWOC systems without any diversity.