Joint power splitting and secure beamforming design in the wireless-powered untrusted relay networks

In this work, we maximize the secrecy rate of the wireless-powered untrusted amplify-and-forward relay networks by jointly designing power splitting (PS) ratio and relay beamforming with the proposed global optimal algorithm (GOA) and local optimal algorithm (LOA). To guarantee secure communication, the destination-based artificial noise is sent to degrade the reception of the untrusted relay, and it also becomes a new source of energy powering relay to forward the information with power splitting (PS) technique. Simulation result shows that LOA can achieve satisfactory secrecy rate performance compared with that of GOA, but with less computation time. It also manifests that both proposed algorithms outperform the benchmark method.