Performance Improvement of Turbid Underwater Wireless Optical Communication Link Using Ratiometric Signal Processing

This article introduces a technique of improving the link performance of the underwater wireless optical communication (UWOC) system in terms of signal-to-noise ratio (SNR) by incorporating a novel ratiometric signal processing (RSP) scheme at the receiver node. In addition, the temporal fluctuations in the attenuation coefficient information (ACI) of the UWOC channel in the nonuniform turbulent regime are analyzed, and the corresponding distribution function is analytically derived. The consistency of the obtained statistical distribution of the ACI parameter is analyzed by simulating the experimental data in a UWOC prototype link within a laboratory-controlled turbulent regime. The experimental outcomes indicate a relative improvement in the SNR by 1.70 to 3.23 dB in the nonuniform turbulent conditions upon incorporating the proposed RSP technique at the receiver node. It is also observed that the mean square error and an average difference of the received images that are processed by incorporating the RSP technique are lower as compared to that of the images without processing at the receiver node in the UWOC prototype link. The approach of implementing the proposed RSP technique is observed to improve the performance of the UWOC link.