Performance Analysis of Underwater Optical Communication System in Turbulent Link

Underwater wireless optical communication (UWOC) systems have been identified as a suitable replacement technology with high data rates over relatively medium transmission ranges for underwater communication. In the research, we propose new hybrid modulation format carrying letters system. This combines pulse position (PPM) digital interval (DPIM) to increase transporting speed. The proposed UWOC system is experimentally investigated in laboratory clean and turbulent water channel. message was electrically modulated transmitter PPM-DPIM then applied laser diode. diode emitted light at wavelength of 650 nm power 60 mW. At receiver, photodiode, its amplifier circuits, sends received signal microprocessor restore origin message. results showed that signal-to-noise ratio (SNR) decreased elongating distance. addition, attenuation raised increasing bubbles source also situated distances 25 cm, 50 75 cm from waters. locating bubble decreases system's performance. best were obtained when away transmitter. Finally, formats (PPM-DPIM) can speed letter transmission, reduce bit error rate (BER), minimize effect scattering channels.