BER variation of an optical wireless communication system in underwater turbulent medium with any temperature and salinity concentration

Abstract

The effect of natural turbulence on an underwater wireless optical communication (UWOC) link using the on-off-key (OOK) modulation scheme and a coherent plane wave is analyzed in terms of the signal-to-noise ratio (SNR) and the bit-error-rate (BER). The optical turbulence is considered to be isotropic and homogeneous, which is typically the case along the horizontal paths in relatively shallow channels, under a variety of conditions for the average temperature (< T > in [0 degrees C, 30 degrees C]) and average salinity concentration (< S > in [0ppt, 40ppt] ) of water that cover most of the naturally available Earth's basins. It is found that apart from the strength of turbulence, the BER is in direct relation with < T > and < S >, and can vary through several orders of magnitude with the change in these quantities within their natural ranges. In addition, the effects of the source wavelength, the temperature-salinity gradient ratio, the temperature dissipation rate, the energy dissipation rate and the probability density function model of the fluctuating irradiance on the UWOC system are examined in detail.