Dual UAV Cluster-Assisted Maritime Physical Layer Secure Communications via Collaborative Beamforming

TL;DR

This work tackles secure, long-range maritime communications by deploying a CB-based dual-UAV cluster system, where one cluster forms a maritime UAV-enabled virtual antenna array (MUVAA) relay and another forms a MUVAA jammer to protect against eavesdropping. It jointly optimizes three objectives—maximize the legitimate SINR $f_1=γ_{Bob}$, minimize the eavesdropper SINR $f_2=γ_{Willie}$, and minimize total flight energy $f_3$—via a secure and energy-efficient maritime communication multi-objective optimization problem (SEMCMOP). To address NP-hard, large-scale complexity, the paper introduces IMOMA, an improved multi-objective mayfly algorithm with chaotic initialization and hybrid update strategies, achieving better Pareto fronts and energy efficiency than several baselines and state-of-the-art swarm methods. Simulation results demonstrate that CB-based dual-UAV configurations yield superior secure transmission performance and energy efficiency compared with non-CB, single-CB, and multi-hop approaches, with the IMOMA algorithm delivering notable improvements in security (e.g., up to 43.2% in the security-related objective) and convergence properties. The findings have practical significance for deploying energy-conscious, secure maritime links using UAV clusters and point to avenues for future work involving dynamic vessel positions, adaptive DRL policies, and high-altitude platforms to enhance system resilience and coverage.

Abstract

Unmanned aerial vehicles (UAVs) can be utilized as relay platforms to assist maritime wireless communications. However, complex channels and multipath effects at sea can adversely affect the quality of UAV transmitted signals. Collaborative beamforming (CB) can enhance the signal strength and range to assist the UAV relay for remote maritime communications. However, due to the open nature of UAV channels, security issue requires special consideration. This paper proposes a dual UAV cluster-assisted system via CB to achieve physical layer security in maritime wireless communications. Specifically, one UAV cluster forms a maritime UAV-enabled virtual antenna array (MUVAA) relay to forward data signals to the remote legitimate vessel, and the other UAV cluster forms an MUVAA jammer to send jamming signals to the remote eavesdropper. In this system, we formulate a secure and energy-efficient maritime communication multi-objective optimization problem (SEMCMOP) to maximize the signal-to-interference-plus-noise ratio (SINR) of the legitimate vessel, minimize the SINR of the eavesdropping vessel and minimize the total flight energy consumption of UAVs. Since the SEMCMOP is an NP-hard and large-scale optimization problem, we propose an improved swarm intelligence optimization algorithm with chaotic solution initialization and hybrid solution update strategies to solve the problem. Simulation results indicate that the proposed algorithm outperforms other comparison algorithms, and it can achieve more efficient signal transmission by using the CB-based method.

Figures (10)

• Figure 1: A CB-based dual UAV cluster-assisted maritime secure communication system.
• Figure 2: Evolutionary outline based on the MOMA.
• Figure 3: Gain distributions optimized by the IMOMA in larger scale network.
• Figure 4: Movement paths optimized by the IMOMA in larger scale network.
• Figure 5: The values of SINR of Bob and Willie obtained by the approaches of CB-based, non-CB, and single CB.