BER of Underwater Wireless Optical Communication Systems with SIMO Detection over Strong Oceanic Turbulence

A spherical wave propagates through the strong underwater turbulence media is modeled as gamma-gamma random variable in the underwater wireless optical communication (UWOC) systems. To mitigate turbulence-induced fading, spatial diversity over UWOC links is proposed. Furthermore, the exact bit error rate (BER) expressions for both single-input single-output (SISO) and single-input multiple-output (SIMO) UWOC systems with optimal combining based on on-off keying (OOK) modulation are analytically derived. Then the system performance is simulated with various variations of the underwater turbulence, i.e. the rate of dissipation of kinetic energy per unit mass of fluid, the ratio of temperature to salinity contributions to the refractive index spectrum, and the UWOC system link length. The results show that the analytical expressions for describing the system performance are valid and spatial diversity can considerably improve the system performance. © 2019 Walter de Gruyter GmbH, Berlin/Boston.