The Impact of Absorption and Scattering on Underwater Optical Wireless Communication (UOWC) Channel in The South China Sea: A Simulation Study

Underwater Optical Wireless Communication (UOWC) is a promising technology for short-range communication in marine environments, offering significant advantages in terms of high data transfer rates and low latency. However, its performance is highly dependent on environmental factors such as absorption, scattering, and turbulence of light in seawater. This study investigates the effects of absorption and scattering on UOWC systems in the South China Sea (SCS), a region with unique marine conditions and limited research on UOWC, by estimating the attenuation coefficient, simulating the UOWC channel models, and analysing system performance in terms of path loss, impulse response, and frequency response. A key contribution of this work is the estimation of the attenuation coefficient for SCS, which is essential for accurately modelling UOWC channels in this region. Based on theoretical calculations and empirical data, the attenuation coefficient is estimated to be 0.8748 m-¹, indicating moderate optical signal loss compared to other water types. Then, using Monte Carlo numerical simulations, this estimated coefficient is incorporated to analyse path loss, impulse response, and frequency response by varying the water depth. The obtained results show that both absorption and scattering considerably increase path loss and delay spread compared to the coastal water type, with laser and LED beams experiencing delays of up to 2.92 × 10-¹¹ and 1.13 × 10-9 seconds, respectively. Additionally, frequency-dependent attenuation leads to signal distortion. These findings offer practical implications for optimising UOWC systems in the South China Sea. The study highlights the need for further research to address regional variations in optical properties and improve system design for more reliable communication.