Novel transmission schemes, enabled by recent advances in the fields of metamaterial (MTM), leaky-wave antenna (LWA) and directional modulation (DM), are proposed for enhancing the physical layer (PHY) security. MTM-LWAs, which offer compact, integrated, and cost-effective alternatives to the classic phased-array architectures, are particularly of interest for emerging wireless communication systems including Internet-of-Things. The proposed secure schemes are devised to accomplish the functionalities of directional modulation (DM) transmitters for orthogonal frequency-division multiplexing (OFDM) and non-contiguous OFDM transmissions, while enjoying the implementation benefits of MTM-LWAs. Specifically, transmitter architectures based on the idea of time-modulated MTM-LWA have been put forth as a promising solution for PHY security for the first time. The PHY security for the proposed schemes are investigated from the point of view of both passive and active attacks where an adversary aims to decode secret information and feed spurious data to the legitimate receiver, respectively. Numerical simulations reveal that even when the adversary employs sophisticated state-of-the-art deep learning based attacks, the proposed transmission schemes are resistant to these attacks and reliably guarantee system security.

提出了由超材料 (MTM)、漏波天线 (LWA) 和定向调制 (DM) 领域的最新进展实现的新型传输方案，以增强物理层 (PHY) 的安全性。MTM-LWA 为经典的相控阵架构提供了紧凑、集成且具有成本效益的替代方案，对于包括物联网在内的新兴无线通信系统特别感兴趣。所提出的安全方案旨在完成正交频分复用 (OFDM) 和非连续 OFDM 传输的定向调制 (DM) 发射机的功能，同时享受 MTM-LWA 的实施优势。具体来说，基于时间调制 MTM-LWA 思想的发射机架构首次被提出作为 PHY 安全性的有前途的解决方案。从被动攻击和主动攻击的角度研究了所提出方案的 PHY 安全性，其中攻击者旨在分别解码秘密信息并将虚假数据馈送到合法接收器。数值模拟表明，即使对手采用先进的基于深度学习的复杂攻击，所提出的传输方案也能抵抗这些攻击并可靠地保证系统安全。