Relay Beamforming Strategies for Physical-Layer Security

TL;DR

This paper investigates relay beamforming strategies to enhance physical-layer security, proposing iterative algorithms for optimal design under power constraints and robust methods for imperfect channel information.

Contribution

It introduces novel iterative algorithms for optimal relay beamforming under power constraints and robust designs for imperfect CSI in physical-layer security.

Findings

Iterative algorithms effectively maximize secrecy rates.

Robust beamforming designs improve security with imperfect CSI.

The methods outperform existing approaches in simulated scenarios.

Abstract

In this paper, collaborative use of relays to form a beamforming system and provide physical-layer security is investigated. In particular, amplify-and-forward (AF) relay beamforming designs under total and individual relay power constraints are studied with the goal of maximizing the secrecy rates when perfect channel state information (CSI) is available. In the AF scheme, not having analytical solutions for the optimal beamforming design under both total and individual power constraints, an iterative algorithm is proposed to numerically obtain the optimal beamforming structure and maximize the secrecy rates. Robust beamforming designs in the presence of imperfect CSI are investigated for decode-and-forward (DF) based relay beamforming, and optimization frameworks are provided.