Decomposed and Distributed Directional Modulation for Secure Wireless Communication

TL;DR

This paper introduces a novel AN-aided decomposed and distributed directional modulation scheme that enhances physical-layer security in wireless communication by exploiting spatial signatures for an additional range dimension of security.

Contribution

It proposes a new D3M scheme that uses decomposed and distributed signals with orthogonal branches, improving security beyond angle dependence and minimizing transmit power.

Findings

Enhanced security demonstrated through simulations

Achieved reliable transmission with minimal power

Superimposed artificial noise effectively masks confidential info

Abstract

Directional modulation and artificial noise (AN)-based methods have been widely employed to achieve physical-layer security (PLS). However, these approaches can only achieve angle-dependent secure transmission. This paper presents an AN-aided decomposed and distributed directional modulation (D3M) scheme for secure wireless communications, which takes advantage of the spatial signatures to achieve an extra range-dimension security apart from the angles. Leveraging decomposed and distributed structure, each of modulated signal is represented by mutually orthogonal in-phase and quadrature branches, which are transmitted by two distributed transmitters to enhance PLS. In particular, we first aim to minimize transmit message power by integrated design of the transmit beamformers, subject to prescribed received signal-to-noise ratio (SNR) for the legitimate user (LU) and no inter-branch interference. This guarantees reliable and accurate transmission for the LU with the minimum transmit message power. Considering the leakage power on the sidelobes, AN is superimposed on the messages to try to mask the confidential information transmission. Simulation results demonstrate the security enhancement of our proposed D3M system.