Optimization of Cognitive Two-Way Networks With Energy Harvesting Relays

This letter investigates the performance of an analog network coding based underlay cognitive two-way energy harvesting relay network. The amplify-and-forward relay harvests energy using the power-splitting relaying (PSR) protocol. Using approximate expressions for the terminal outages, throughput, and ergodic sum-rate, we derive insights into performance. Specifically, we derive closed-form expressions for the throughput maximizing interference temperature apportioning parameter (ITAP) and the PSR parameter, and show that they can be optimized separately. We also derive a closed-form expression for the ergodic sum-rate maximizing PSR parameter, and show that an ITAP of half maximizes ergodic sum-rate. Simulations demonstrate the accuracy of the derived expressions.