Bit error rate performance of underwater optical wireless communication test bed simulating the seawater conditions

Underwater wireless communication (UWC) is one of the most challenging forms of communication due to the dynamic nature of oceans. At present acoustic communication is the most mature technology available for UWC. However, this technology has limitations in terms of bandwidth, data rates, latency, multipath propagation, etc., Radio frequency communication is also not feasible in the underwater environment due to the high conductivity of the sea water and high absorption of RF waves in fresh water. Underwater Wireless Optical Communication (UWOC) has lots of potential in water environment and has an advantage over acoustic and RF in terms of higher data rates, bandwidth, least latency, low power requirement, and small components. The blue-green visible range of the visible spectrum (410–550 nm) has the least attenuation underwater, i.e. low absorption and scattering. Although UWOC promises the said advantages but also has a lot of challenges. In this paper, we aim at evaluation a link performance of UWOC test bed (in a laboratory scale) with varying salinity and turbidity close to the sea water conditions in a water tank. The results indicate the trends of deterioration of BER with the increasing salinity and turbidity and the need of power requirement of laser for clear oceans to get higher ranges and requirement of the better receiver to get satisfactory ranges in coastal water.