Moreover, the information pulse duration, T 0, values are varying from 2 ps to 6 ps and the operational wavelength, λ, is taken to be 470 nm, which is a typical value for the UOWC systems. For the numerical results presented below, typical values of water temperature and salinity, i.e., S a = 35 ‰, Te = 0 ☌, have been chosen, while the underwater depth is fixed at 100 m and the corresponding pressure is estimated through the expression P ≅ 0.104 d, as mentioned above. Moreover, the fade probability of the system can be estimated from (21). Through the above procedure, a novel joint PDF was derived (19) in order to describe the irradiance fluctuations at the receiver, due to their simultaneous effect. In this work, the joint influence of time jitter, log-normal turbulence and chromatic dispersion in an UOWC system was studied, which uses longitudinal Gaussian chirped pulses as information carrier. Then, using the derived mathematical expression for the PDF, the performance of the link is estimated by means of its probability of fade and the relative numerical results are presented, using typical values for the UOWC links. The joint influence of all the above effect is estimated and the corresponding probability distribution function (PDF) is extracted. Additionally, as far as the time jitter effect is concerned, it has been assumed here that the probability of detecting a pulse earlier is equal to detecting it later, and the normal distribution has been chosen in order to investigate its influence. Thus, the log-normal distribution model has been used for the representation of the fluid turbulence effect, while the influence of the group velocity dispersion (GVD) is studied for both signs of a pulse’s chirp. It is assumed that the communication system uses longitudinal chirped Gaussian pulses as information carriers and that the fluid turbulence is weak. In this work-for the first time and to the best of our knowledge-the simultaneous influence of turbulence, time jitter and chromatic dispersion is investigated for an UOWC link. Furthermore, due to their capability for ultrafast data transmission, the time jitter effect also affects their characteristics. Additionally, the turbulence of the fluid, water purity and dispersion significantly affect the performance and the operation of the wireless communication link. Thus, the water strongly attenuates the information signal and consequently their effective link length is of some tens of meters. However, the performance of these systems is dominated by the characteristics of the medium, where the pulses are propagating. Many recent theoretical and experimental works have been done in order to estimate the effectiveness of the transmitter/receivers, link, modulation formats, etc. More specifically, the UOWC links, due to their very large bandwidth, can achieve very high data rates and real time communications inside the water, with low energy consumption and very high security standards. Underwater optical wireless communication (UOWC) systems have attracted significant research and commercial interest in recent years due to their very significant advantages that they offer.
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