Tradeoff Between BER and Secrecy Capacity for CDMA-Based Underwater OWC Systems

This study explores the performance and security of a vertical underwater optical wireless communication (UOWC) systems in the presence of propagation loss, beam spreading and aiming loss, and oceanic turbulence. In addition, we examine optical code-division multiple-access (CDMA), a technology that facilitates the transmission of data between various sources (such as underwater sensors, submarines, autonomous underwater vehicles (AUV), divers, etc.) and destinations (such as ships, buoys, underwater telescopes, etc.) asynchronously and simultaneously. We provide an analytical technique for accurately predicting both the bit error rate (BER) and security capacity. Furthermore, several types of code families including new modified prime code, modified quadratic congruence code, Hadamard code, and prime code are applied and compared. Finally, the tradeoff between BER and secrecy capacity offers a valuable understanding of the feasibility in implementing the UOWC system using CDMA.