On the Performance of Physical Layer Security for Continuous-Aperture Array (CAPA) Systems

Fuente: arXiv
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Auteurs principaux: Zhao, Boqun, Ouyang, Chongjun, Zhang, Xingqi, Liu, Yuanwei
Format: Preprint
Publié: 2024
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author Zhao, Boqun
Ouyang, Chongjun
Zhang, Xingqi
Liu, Yuanwei
author_facet Zhao, Boqun
Ouyang, Chongjun
Zhang, Xingqi
Liu, Yuanwei
contents A continuous-aperture array (CAPA)-based secure transmission framework is proposed to enhance physical layer security. Continuous current distributions, or beamformers, are designed to maximize the secrecy transmission rate under a power constraint and to minimize the required transmission power for achieving a specific target secrecy rate. On this basis, the fundamental secrecy performance limits achieved by CAPAs are analyzed by deriving closed-form expressions for the maximum secrecy rate (MSR) and minimum required power (MRP), along with the corresponding optimal current distributions. To provide further insights, asymptotic analyses are performed for the MSR and MRP, which reveals that i) for the MSR, the optimal current distribution simplifies to maximal ratio transmission (MRT) beamforming in the low-SNR regime and to zero-forcing (ZF) beamforming in the high-SNR regime; ii) for the MRP, the optimal current distribution simplifies to ZF beamforming in the high-SNR regime. The derived results are specialized to the typical array structures, e.g., planar CAPAs and planar spatially discrete arrays (SPDAs). The rate and power scaling laws are further analyzed by assuming an infinitely large CAPA. Numerical results demonstrate that: i) the proposed secure continuous beamforming design outperforms MRT and ZF beamforming in terms of both achievable secrecy rate and power efficiency; ii) CAPAs achieve superior secrecy performance compared to conventional SPDAs.
format Preprint
id arxiv_https___arxiv_org_abs_2412_13748
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On the Performance of Physical Layer Security for Continuous-Aperture Array (CAPA) Systems
Zhao, Boqun
Ouyang, Chongjun
Zhang, Xingqi
Liu, Yuanwei
Information Theory
Signal Processing
A continuous-aperture array (CAPA)-based secure transmission framework is proposed to enhance physical layer security. Continuous current distributions, or beamformers, are designed to maximize the secrecy transmission rate under a power constraint and to minimize the required transmission power for achieving a specific target secrecy rate. On this basis, the fundamental secrecy performance limits achieved by CAPAs are analyzed by deriving closed-form expressions for the maximum secrecy rate (MSR) and minimum required power (MRP), along with the corresponding optimal current distributions. To provide further insights, asymptotic analyses are performed for the MSR and MRP, which reveals that i) for the MSR, the optimal current distribution simplifies to maximal ratio transmission (MRT) beamforming in the low-SNR regime and to zero-forcing (ZF) beamforming in the high-SNR regime; ii) for the MRP, the optimal current distribution simplifies to ZF beamforming in the high-SNR regime. The derived results are specialized to the typical array structures, e.g., planar CAPAs and planar spatially discrete arrays (SPDAs). The rate and power scaling laws are further analyzed by assuming an infinitely large CAPA. Numerical results demonstrate that: i) the proposed secure continuous beamforming design outperforms MRT and ZF beamforming in terms of both achievable secrecy rate and power efficiency; ii) CAPAs achieve superior secrecy performance compared to conventional SPDAs.
title On the Performance of Physical Layer Security for Continuous-Aperture Array (CAPA) Systems
topic Information Theory
Signal Processing
url https://arxiv.org/abs/2412.13748