Investigation on effects of system parameters on transmission depth in underwater wireless optical communication

Performance of underwater wireless optical communication (UWOC) with different vertical water channel conditions is experimentally analyzed. Experiment has been carried out by varying temperature and salinity of the vertical water channel. Underwater vertical channel is modeled by obtaining the best fit with the experimental data in terms of received optical power as a function of transmission depth and attenuation. This mathematical model is used to simulate UWOC system in Optisystem software to analyze the performance of UWOC in terms of Q factor and BER. Analysis has been carried out to obtain maximum reachable transmission depth at different data rates for fixed input power and maximum achievable data rate at different input power for fixed transmission depth. Maximum reachable transmission depth is also analyzed for different modulation index of the amplitude modulator. These analyses are carried out for optimal performance parameters such as Q factor (≥ 6) and BER (≤ 10–9). Apart from Q factor and BER, performance of the UWOC channel is analyzed through eye diagrams obtained at the receiver of the UWOC system in terms of eye height which reflects the quality of signal. This analysis will be helpful for power budgeting, data rate restriction with transmission depth in different water channel conditions to establish vertical UWOC link.