Energy Efficiency Maximization for Intercluster Transmission in Wireless Sensor Networks Deploying Discrete Power Splitters

In energy-constrained clustered wireless sensor networks (WSNs), communication between cluster heads often utilizes cooperative simultaneous wireless information and power transfer (SWIPT) techniques to enhance data transmission energy efficiency. This paper focuses on maximizing the cooperative transmission energy efficiency between two cluster heads equipped with low-cost and low-complexity discrete power splitters. In such cases, discrete power splitting ratios lead to a non-convex optimization issue for resource allocation. We propose an algorithm based on a variable-dimension expansion method to effectively find the optimal power transmission and harvesting energy allocation policies. Numerical experiment findings confirm the proposed DSNRA algorithm's convergence and superiority under the impact of power splitting resolutions and maximum transmit power.