Physical Layer Security Jamming: Theoretical Limits and Practical Designs in Wireless Networks

Physical layer security has been recently recognized
as a promising new design paradigm to provide security in
wireless networks. In addition to the existing conventional cryp-
tographic methods, physical layer security exploits the dynamics
of fading channels to enhance secured wireless links. In this
approach, jamming plays a key role by generating noise signals
to confuse the potential eavesdroppers, and significantly improves
quality and reliability of secure communications between legitimate terminals. This article presents theoretical limits and practical designs of jamming approaches for physical layer security. In particular, the theoretical limits explore the achievable secrecy rates of user cooperation based jamming whilst the
centralized, and game theoretic based precoding techniques are reviewed for practical implementations. In addition, the emerging wireless energy harvesting techniques are exploited to harvest the required energy to transmit jamming signals. Future directions of these approaches, and the associated research challenges are also briefly outlined.