چكيده به لاتين
Given the importance of advancing communication technologies between divers, submarines, unmanned underwater vehicles, and ships, this thesis was designed to address this subject under the title of “Simulation of underwater laser communications.”
We briefly review optical communications in free space, provided its similarity to an underwater environment. We then introduce our simulations in this stochastic environment. We next theoretically analyze and simulate the effect of oceanic phenomena including absorption, scattering, and turbulence on various parameters of propagating laser beam in seawater. These parameters include intensity, beam width, spectral degree of coherency, and effective width of spectral degree of coherence. Additionally, Link quality factors such as BER and SNR are theoretically analyzed and simulated.
To build a realistic simulation, we have optimized our design for an optical sender/receiver model. Moreover, we have collected chlorophyll measurements and local water features from various reliable sources including NASA‘s database. In our theoretical simulations of a complete communication link; for signal attenuation along the link in seawater, we have utilized extended Huygens-Fresnel principle; and for modeling the effect of optical sender/receiver system, we have used the extension of Collins’ integral. We initially study the weakening phenomena due to the absorbance and scattering and then impose the effect of oceanic turbulence. Finally, we study and analyze the effect of Iranian seas’ parameters on optical underwater communication.
