Secure two-way communication via a wireless powered untrusted relay and friendly jammer
This work addresses secure communication in wireless networks with untrusted relays, offering incremental improvements in secrecy rates for applications like IoT or military systems.
The paper tackles secure two-way communication via a wireless powered untrusted relay and friendly jammer, deriving a closed-form lower bound for the ergodic secrecy sum rate and showing that the proposed network with friendly jamming outperforms traditional one-way and two-way without jamming policies in secrecy performance.
In this paper, we propose a self-dependent two-way secure communication where two sources exchange confidential messages via a wireless powered untrusted amplify-and-forward (AF) relay and friendly jammer (FJ). By adopting the time switching (TS) architecture at the relay, the data transmission is accomplished in three phases: Phase I) Energy harvesting by the untrusted relay and the FJ through non-information transmissions from the sources, Phase II) Information transmission by the sources and jamming transmissions from the FJ to reduce information leakage to the untrusted relay; and Phase III) Forwarding the scaled version of the received signal from the untrusted relay to the sources. For the proposed system, we derive a new closed-form lower bound expression for the ergodic secrecy sum rate (ESSR). Numerical examples are provided to demonstrate the impacts of different system parameters such as energy harvesting time, transmit signal-to-noise ratio (SNR) and the relay/FJ location on the secrecy performance. The numerical results illustrate that the proposed network with friendly jamming (WFJ) outperforms traditional one-way communication and the two-way without friendly jamming (WoFJ) policy.