Power Splitting-Based SWIPT With Dual-Hop DF Relaying in the Presence of a Direct Link

This letter investigates the outage performance of dual-hop decode and forward relay systems in the presence of a direct link between the source and the destination, where simultaneous wireless information and power transfer is exploited at the relay by using a static/dynamic power splitting (PS) scheme. An analytical expression for the outage probability is derived to determine the optimal static PS ratio. Moreover, we study the dynamic PS scheme and derive a closed-form expression for the optimal dynamic PS ratio to minimize the outage probability at a given target rate. Furthermore, an analytical expression for the outage probability with the optimal dynamic PS ratio is also presented. It is shown that a full diversity gain can be achieved in the investigated system with static/dynamic PS scheme, and that the dynamic PS scheme outperforms the static PS scheme.