Affiliation:
1. Air Force Engineering University
Abstract
In this paper, we investigate the energy
efficiency optimization for a parallel relay-assisted underwater
wireless optical communication (UWOC) system with simultaneous
lightwave information and power transfer (SLIPT) over an aggregate
channel. In this system, relay nodes are equipped with energy
harvesting devices, getting energy from the direct current component
of the received signal transmitted by the source node. These nodes
utilize the harvested energy to transmit the signal to the destination
node with the decoding and forwarding strategy. The harvested energy
for each relay node is derived by the Gauss–Laguerre quadrature
formula and the outage probability is deduced by the Meijer-G
function. Then, the system’s energy efficiency can be calculated and
an energy efficiency maximization problem is built up with respect to
the bias current. We propose a three-level-iteration algorithm to
solve this problem. In the first level, the Dinkelbach method is used
to represent energy efficiency in a parametric subtractive form. In
the second level, we use the penalty function method to convert the
object function and constraint. In the third level, the objective
function is transformed into a quadratic function by using a
successive convex approximate method, thereby solving for the bias
current. The effects of system parameters on energy efficiency are
also analyzed. Theoretical results and Monte Carlo simulations suggest
that employing the solved bias current can significantly improve the
system’s energy efficiency.
Funder
Natural Science Basic Research Program of Shaanxi Province
Fundamental Research Funds for the Central Universities
National Natural Science Foundation of China
Subject
Atomic and Molecular Physics, and Optics,Engineering (miscellaneous),Electrical and Electronic Engineering