Secrecy Outage Analysis in Energy Harvesting Relay Networks with a Friendly Jammer

Physical layer security is a suitable replacement or complement to the traditional cryptography method for securing a wireless network. Physical layer security exploits the random characteristics of a wireless channel. Deploying multiple relays and a jammer can secure the system performance, however, extra power is required. RF energy harvesting is a promising solution to a wireless network's energy scarcity problem. RF energy is widely available in the environment due to billions of devices broadcasting it. Therefore, a secure, green system model is proposed with a source, destination, energy harvested relaying nodes, energy harvested jammer, power beacon and an eavesdropper. The theoretical analysis and simulations are provided to evaluate the system performance. The results show that when the number of relays increases, the secrecy outage probability of the considered system decreases. In addition, the system with a jammer outperforms that without a jammer, especially in high SNR scenarios. Finally, the energy harvesting time fraction is an important parameter and needs to be designed carefully in a system.