Secure Wireless Communication via Polarforming

TL;DR

This paper introduces polarforming with polarization-reconfigurable antennas to enhance security in wireless communication by jointly optimizing beamforming and polarization adjustments, significantly improving secrecy rates.

Contribution

It proposes a novel joint optimization algorithm for beamforming and polarforming in secure wireless systems with polarization-reconfigurable antennas.

Findings

Polarforming significantly outperforms fixed-polarization antennas in security performance.

Joint optimization of beamforming and polarforming maximizes secrecy rate.

Simulation results confirm the effectiveness of the proposed approach.

Abstract

Polarforming is a promising technique that enables dynamic adjustment of antenna polarization to mitigate depolarization effects commonly encountered during electromagnetic (EM) wave propagation. In this letter, we investigate the polarforming design for secure wireless communication systems, where the base station (BS) is equipped with polarization-reconfigurable antennas (PRAs) and can flexibly adjust the antenna polarization to transmit confidential information to a legitimate user in the presence of an eavesdropper. To maximize the achievable secrecy rate, we propose an efficient iterative algorithm to jointly optimize transmit beamforming and polarforming, where beamforming exploits spatial degrees of freedom (DoFs) to steer the transmit beam toward the user, while polarforming leverages polarization DoFs to align the polarization state of the EM wave received by the user with that of its antenna. Simulation results demonstrate that, compared to conventional fixed-polarization antenna (FPA) systems, polarforming can fully exploit the DoFs in antenna polarization optimization to significantly enhance the security performance of wireless communication systems.