Transmit Power Minimization for a Multi-Hop SWIPT Decode-and-Forward Sensor Network

A study of a multi-hop decode-and-forward (DF) simultaneous wireless information and power transfer (SWIPT) sensor network system is presented in this work. In the studied system model, a source communicates with a destination through the aid of multi-hop relays which harvest energy from their received signals. We apply power splitting (PS) based SWIPT relaying protocols for the relays harvesting energy. Focused on DF relaying protocol, we aim to minimize the transmit power at the source under a set end-to-end throughput constraint by optimizing PS ratios at the relays. Based on convex optimization techniques, the globally optimal PS ratio solution is obtained as a closed-form solution. Numerical results demonstrate the efficacy of the proposed optimal design over the conventional fixed PS ratio scheme.