Evaluating 60 GHz Band Underwater Optical Wireless Communication Performance Based on Low-Density Parity Check Coding Under Diverse Water Conditions and Noise Levels

Underwater optical wireless communication (UOWC) is a recent advancement in optical wireless communication (OWC) that offers a higher capacity and bandwidth for underwater applications than traditional acoustic systems. However, UOWC links are vulnerable to the complex influences of aquatic environmental conditions involving concentrations of contaminant factors and sources of noise that degrade their performance, thus complicating their design and practical implementation. To compensate for the deterioration caused by these issues, techniques such as low-density parity-check (LDPC) coding have been proposed to enhance error correction and system performance. Therefore, in this study, we evaluate the performance of LDPC-coded line-of-sight UOWC channels under different aquatic environmental impacts, noise factors, and optical property parameters. The signal-to-noise ratio (SNR), bit error rate (BER), and Q-factor were among the most important metrics studied via simulations using OptiSystem v.21 and MATLAB. The results show that for a 6G-UOWC system operating at 60 GHz and 10 Gbps, the maximum transmission distances are 25 m in pure water and 1.96 m in harbor water at a depth of 7 m. Solar noise reduces these distances, whereas LDPC coding significantly improves performance by extending the maximum distance to 29 m in clear water. Moreover, a comparative analysis of different field-of-view (FOV) settings revealed that a lower FOV reduces the impact of solar noise across depths. In addition, the maximum achievable data rate with LDPC coding reached 18 Gbps, with distances varying from 21 m under optimal conditions to 1.65 m under less favorable conditions.