Energy‐efficient UOWC‐RF systems with SLIPT

Abstract

This letter investigates a two‐hop underwater optical wireless communication‐radio frequency setup consisting of an autonomous underwater vehicle (AUV), a communication buoy, and an onshore data center (ODC). The information transmission between AUV and ODC occurs in two phases. In the first phase, the AUV communicates to the buoy over the optical wireless link. The buoy harvests the energy by using simultaneous lightwave information and power transfer and also decodes the information. In the subsequent phase, the buoy transmits the decoded information to the ODC over an RF link by utilizing the harvested energy at the first phase. A joint optimization problem is proposed to minimize the total optical energy consumption at the AUV by optimally selecting the DC‐bias and the time allocated to the first and second phases subject to the minimum required end‐to‐end rate. Due to the non‐convexity of the original problem, an alternative approach is used to make it convex. For certain system parameters, our results show a significant energy savings of J at the required rate of 2 bits per channel use.