A Survey on Multiple-Antenna Techniques for Physical Layer Security

TLDR

Physical layer security exploits channel characteristics such as fading, noise, and interference to enhance wireless security, complementing high‑layer encryption. This survey reviews multiple‑antenna techniques for physical layer security, focusing on transmit beamforming, and outlines future research directions and challenges. Multiple‑antenna techniques improve legitimate reception and degrade eavesdropper quality by exploiting spatial degrees of freedom, and the survey investigates these methods across point‑to‑point, dual‑hop relaying, multi‑user, and heterogeneous networks.

Abstract

As a complement to high-layer encryption techniques, physical layer security has been widely recognized as a promising way to enhance wireless security by exploiting the characteristics of wireless channels, including fading, noise, and interference. In order to enhance the received signal power at legitimate receivers and impair the received signal quality at eavesdroppers simultaneously, multiple-antenna techniques have been proposed for physical layer security to improve secrecy performance via exploiting spatial degrees of freedom. This paper provides a comprehensive survey on various multiple-antenna techniques in physical layer security, with an emphasis on transmit beamforming designs for multiple-antenna nodes. Specifically, we provide a detailed investigation on multiple-antenna techniques for guaranteeing secure communications in point-to-point systems, dual-hop relaying systems, multiuser systems, and heterogeneous networks. Finally, future research directions and challenges are identified.