Two-dimensional power allocation scheme for NOMA-based underwater visible light communication systems.

In this work, a two-dimensional power allocation scheme combining fractional transmit power allocation (FTPA) and the sine cosine algorithm (SCA) is proposed for non-orthogonal multiple access (NOMA)-based underwater visible light communication (UVLC) systems. Considering the proposed power allocation scheme, a downlink NOMA-based UVLC system using blue-light-emitting diodes in the deep-sea environment is set up to evaluate the influence of the FTPA coefficient and SCA on system communication performance. The simulation results demonstrate that the two-dimensional power allocation scheme can effectively reduce the impact of user pairing on system performance and improve the system transmission rate compared with the conventional power allocation scheme.