Sensing-Aided Secure Multicast in Rotatable Antenna-Enabled ISAC Systems
Abstract
Acquiring the channel state information (CSI) of passive eavesdroppers remains a fundamental challenge in physical layer security. The sensing capability of integrated sensing and communication (ISAC) systems enables estimation of a potential eavesdropper's angle of departure (AoD) before secure transmission. Accordingly, a sensing-aided secure multicast scheme is proposed using a rotatable antenna (RA) architecture that combines array-level and element-level rotations with analog beamforming. The scheme comprises eavesdropper sensing and secure communication stages. In the sensing stage, the maximum likelihood estimator (MLE) and corresponding Cramer--Rao bound (CRB) are derived for eavesdropper AoD estimation. The two rotation levels are then optimized through cyclic coordinate search to minimize the worst-case CRB. The resulting AoD estimate and CRB determine the center and width of the angular uncertainty region, respectively. In the communication stage, the constant-modulus analog beamformer and RA configuration are jointly optimized to maximize the worst-case secrecy rate over this region. After angular discretization and smooth approximation, the resulting problem is solved using a product-space joint optimization framework. Numerical simulation results validate the convergence and effectiveness of the proposed algorithms. It is demonstrated that i) the proposed RA-enabled sensing design effectively improves the eavesdropper AoD estimation accuracy; ii) a high and nearly constant secrecy rate is maintained over the uncertainty region; and iii) the joint optimization of the two rotation levels yields lower CRBs and higher secrecy rates than schemes employing either a fixed-position array or a single rotation level.
Related
- Antenna Orientation Optimization for Rotatable Antenna-Enabled ISAC Systems
- Rotatable Antenna-Enabled Space-Air-Ground Integrated Networks: Opportunities and Challenges
- Pinching-Antenna-Enabled ISAC: A Unified Architecture for Flexible Communication and Sensing
- Joint Antenna Geometry and Transmit Covariance Design for Near-Field Multicast ISAC with Pinching Antenna Arrays
- Secrecy Sum-Rate Maximization for RSMA-Enabled Pinching-Antenna Systems
BibTeX
@misc{wang2026sensingaided,
title = {{Sensing-Aided Secure Multicast in Rotatable Antenna-Enabled ISAC Systems}},
author = {Zequan Wang and Liang Yin and Chongjun Ouyang and Hao Xu and Yunan Sun and Yitong Liu and Hongwen Yang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.08718},
eprint = {2605.08718},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.08718},
}
RIS
TY - UNPB
TI - Sensing-Aided Secure Multicast in Rotatable Antenna-Enabled ISAC Systems
AU - Zequan Wang
AU - Liang Yin
AU - Chongjun Ouyang
AU - Hao Xu
AU - Yunan Sun
AU - Yitong Liu
AU - Hongwen Yang
PY - 2026
DA - 2026/09/13
PB - arXiv
DO - 10.48550/arxiv.2605.08718
UR - https://arxiv.org/abs/2605.08718
AB - Acquiring the channel state information (CSI) of passive eavesdroppers remains a fundamental challenge in physical layer security. The sensing capability of integrated sensing and communication (ISAC) systems enables estimation of a potential eavesdropper's angle of departure (AoD) before secure transmission. Accordingly, a sensing-aided secure multicast scheme is proposed using a rotatable antenna (RA) architecture that combines array-level and element-level rotations with analog beamforming. The scheme comprises eavesdropper sensing and secure communication stages. In the sensing stage, the maximum likelihood estimator (MLE) and corresponding Cramer--Rao bound (CRB) are derived for eavesdropper AoD estimation. The two rotation levels are then optimized through cyclic coordinate search to minimize the worst-case CRB. The resulting AoD estimate and CRB determine the center and width of the angular uncertainty region, respectively. In the communication stage, the constant-modulus analog beamformer and RA configuration are jointly optimized to maximize the worst-case secrecy rate over this region. After angular discretization and smooth approximation, the resulting problem is solved using a product-space joint optimization framework. Numerical simulation results validate the convergence and effectiveness of the proposed algorithms. It is demonstrated that i) the proposed RA-enabled sensing design effectively improves the eavesdropper AoD estimation accuracy; ii) a high and nearly constant secrecy rate is maintained over the uncertainty region; and iii) the joint optimization of the two rotation levels yields lower CRBs and higher secrecy rates than schemes employing either a fixed-position array or a single rotation level.
ER -