# A Two-Ray Multipath Model for Frequency Diverse Array-Based Directional Modulation in MISOME Wiretap Channels

## TL;DR

This paper introduces a novel two-ray multipath model for FDA-based directional modulation in MISOME wiretap channels, jointly designing excitation and artificial noise to enhance physical layer security without affecting the intended receiver.

## Contribution

It presents the first two-ray multipath FDA-based directional modulation model with joint design of excitation and artificial noise for secure communications.

## Key findings

- Secrecy rate analysis confirms improved security performance.
- Numerical simulations demonstrate effective PLS transmission in multipath environments.
- The model maintains desired signal integrity while disrupting eavesdroppers.

## Abstract

A two-ray multipath model for frequency diverse array (FDA)-based directional modulation (DM) is proposed in multi-input single-output multi-eavesdropper (MISOME) wiretap channels for the first time. The excitation factors of the FDA and the weighting coefficients of the inserted artificial noise (AN) are jointly designed in a way which imposes no impact on the desired receiver while simultaneously distorting the received signals of eavesdroppers. Secrecy rate is analyzed for the proposed two-ray multipath FDA-based DM model. Numerical simulations verify the capability of physical layer secure (PLS) transmissions of the proposed FDA-DM model in two-ray multipath MISOME wiretap channels.