Cancellation-Based Friendly Jamming for Physical Layer Security

Security has become an increasingly important issue in wireless communications for the IoT (Internet of Things) environments, to which physical layer approaches can contribute by differentiating desired transceiver and wiretap channels for security of confidential data. In this paper, we propose an optimal power allocation strategy for practical physical-layer security, based on friendly jamming with cancellation for anti-eavesdropping. In particular, secrecy outage probability is evaluated in scenarios involving a pair of transmitter-receiver and a passive eavesdropper near the receiver. We derive the optimal power allocation strategy and the required cancellation capability to enhance secrecy performance. Numerical results verify the tradeoff between jamming power ratio and cancellation capability. Furthermore, our proposed scheme can achieve the improved secrecy rate regardless of availability of eavesdropper channel information.