An Intermittent Cooperative Jamming Strategy for Securing Energy-Constrained Networks

Abstract

Friendly jamming is an unconventional approach to secure wireless communications. Specifically, a friendly jammer transmits jamming signals to an eavesdropper while a legitimate transmitter is sending data. The jamming signals only interfere with the eavesdropper, and thus, prevent data from being disclosed to unintended parties. Mainstream jamming schemes adopt a continuous jamming strategy (CJS), where the jammer is required to constantly transmit jamming signals in the entire duration of the legitimate transmission. In certain scenarios, however, the CJS may lead to excessive jamming, and cause a waste of energy and the degradation of jamming efficiency. To address the drawbacks of the CJS, we propose the concept of an intermittent jamming strategy (IJS), where a jammer alternates between jamming and non-jamming modes during the legitimate transmission. In this paper, we study the feasibility of the IJS for physical layer security. We first introduce a new metric to jointly measure security requirements and energy costs. Next, we formulate and solve an optimization problem with respect to the jamming duration proportion and the jamming power. Finally, we verify the feasibility of the IJS through extensive simulation experiments under different modulation methods.