Secure Performance of an Untrusted AF Relay System with a Friendly Wireless Powered Jammer

Abstract EN

We propose a jam-then-harvest protocol for dual-hop cooperative networks with an untrusted relay, where an external friendly jammer helps keep information secret from the untrusted relay by transmitting a priori jamming signal for the destination.

In particular, the wireless powered jammer scavenges energy from the received forwarded signal and recovers its initial energy to perform jamming in next time slot.

We analytically derive an exact expression of the probability of nonzero secrecy rate (PNSR) for the proposed jam-then-harvest protocol.

For performance comparison, cooperative jamming with the constant power supply is provided as a lower bound benchmark.

Our results show that the proposed protocol not only can achieve the secure communication but also can harvest the enough energy without a loss of performance in the low jamming power region.