🤖 AI Summary
The broadcast nature of wireless communications poses severe challenges to physical-layer security. Artificial noise (AN) exploits spatial degrees of freedom in multi-antenna channels to generate directional interference, significantly degrading eavesdropper channel capacity without compromising legitimate user performance—thereby enhancing secrecy rate. This paper provides a systematic survey of AN’s evolution, channel-aware modeling methodologies, and application paradigms in large-scale MIMO and beamforming systems. We establish a unified research framework encompassing design principles, fundamental performance limits, and integration with emerging technologies. Innovatively, we categorize prevailing AN schemes by their applicability conditions and inherent limitations, and explicitly identify three critical open challenges: low-overhead AN design, dynamic channel adaptation, and cross-layer coordination. The work delivers a structured technical roadmap and forward-looking guidance for advancing physical-layer secure communications.
📝 Abstract
Due to the broadcast nature of wireless communications, physical-layer security has attracted increasing concerns from both academia and industry. Artificial noise (AN), as one of the promising physical-layer security techniques, is capable of utilizing the spatial degree-of-freedom of channels to effectively enhance the security of wireless communications. In contrast to other physicallayer security techniques, the key distinguishing feature of AN is to generate specific interfering signals according to channel characteristics, increasing the secrecy capacity by reducing the wiretap channel capacity without affecting the legitimate channel capacity. Hence, this paper provides the latest survey of AN, including its evolution, modeling, backgrounds, applications, and future trends. Initially, we introduce the development, fundamentals, and backgrounds of AN. Subsequently, we highlight a comprehensive survey of the current state of research on various AN-empowered scenarios and AN-combined technologies. Finally, we discuss some technical challenges to tackle for AN-aided wireless security in the future.