Physical-Layer Security for Frequency Diverse Array Based Directional Modulation in Fluctuating Two-Ray Fading Channels

TL;DR

This paper introduces a low-memory FDA-DM scheme with analytical performance analysis in fluctuating two-ray fading channels, enhancing physical-layer security for 5G systems.

Contribution

It proposes a symmetrical multi-carrier FDA model in three dimensions and a single-point AN aided scheme that reduces memory use while analyzing its PLS performance in FTR channels.

Findings

Reduced memory consumption compared to traditional methods

Closed-form bounds for secrecy rate and outage probability

Validated analytical expressions through simulations

Abstract

The frequency diverse array (FDA) based directional modulation (DM) technology plays an important role in the implementation of the physical-layer security (PLS) transmission of 5G and beyond communication system. In order to meet the tremendous increase in mobile data traffic, a new design consuming less memory for the FDA-DM-based PLS transmission is urgently demanded. In this paper, an analytical symmetrical multi-carrier FDA model is proposed in three dimensions, namely, range, azimuth angle, and elevation angle, which differs from the conventional analytical approach with only range and azimuth angle considered. Then, a single-point (SP) artificial noise (AN) aided FDA-DM scheme is proposed, which reduces memory consumption of FDA-DM systems significantly compared with the conventional zero-forcing (ZF) and singular value decomposition (SVD) approaches. Moreover, the PLS performance of the proposed low-memory-consumption FDA-DM scheme is analyzed in fluctuating two-ray (FTR) fading channels for the first time, including bit error rate (BER), secrecy rate (SR), and secrecy outage probability (SOP). More importantly, the closed-form expressions for the lower bound of the average SR and the upper bound of the SOP are derived, respectively. The effectiveness of the analytical expressions is verified by numerical simulations. This work opens a way to lower the memory requirements for the DM-based PLS transmission of 5G and beyond communication system.