Robust Beamforming for Enhancing Security in Multibeam Satellite Systems

TL;DR

This paper introduces a robust beamforming approach to improve physical layer security in multibeam satellite systems, effectively countering eavesdroppers with only approximate location knowledge.

Contribution

It develops a novel joint ADMM-Dinkelbach beamforming method to maximize secrecy rate under power and QoS constraints with unknown eavesdropper regions.

Findings

The proposed algorithm enhances security against eavesdroppers.

Simulation results show improved secrecy rates.

Method effectively handles non-convex optimization problems.

Abstract

This paper proposes a robust beamforming (BF) scheme to enhance physical layer security (PLS) of the downlink of a multibeam satellite system in the presence of either uncoordinated or coordinated eavesdroppers (Eves). Specifically, with knowing only the approximate locations of the Eves, we aim at maximizing the worst-case achievable secrecy rate (ASR) of the legitimate user (LU), subject to the constraints of per-antenna transmit power and quality of service (QoS) requirement of the LU. Since the optimization problem is non-convex, we first adopt the discretization method to deal with the unknown regions of the Eves and then exploit the log-sum-exp function to approximate the objective function. Afterwards, a BF method joint alternating direction method of multipliers (ADMM) with Dinkelbach iteration is presented to solve this non-convex problem. Finally, simulation results verify that our robust BF algorithm can effectively improve the security of multibeam satellite systems.