BER Performance of UWOC With APD Receiver in Wide Range Oceanic Turbulence

In this paper, the bit error rate (BER) performance of underwater wireless optical communication (UWOC) systems with on-off keying (OOK) modulation and an avalanche photodiode (APD) detector are analyzed in a wide range of oceanic turbulence environment, such as lognormal, Gamma, K, Weibull, and Exponentiated Weibull distributions. To achieving this goal, a new mathematical system model is established, which has not only considered the aggregated degrading phenomena, namely the absorption, scattering, and turbulence, but also been suitable for describing UWOC with APD receiver. Then the closed-form expressions of the BER performances of UWOC with APD for different turbulence distributions are derived in detail by subdividing the working situation into high and lower inter-symbol interference (ISI) scenarios. Theoretical analysis and computer simulations show that no matter what the ISI levels are, the derived closed-form expressions for system BER under various turbulences can approximate the accurate integral ones well. This is obviously helpful to the design and performance evaluation of UWOC systems.