Cooperative Beamforming for Covert Communications in MIMO Ad Hoc Networks: Analysis and Optimization
作者：李钦龙 时间：2026年10月01日 13:40 点击数：
语言：English
发表刊物：IEEE Transactions on Communications
发表日期：2026年8月18日
摘要：
Ad hoc networks, due to their open and self-organizing nature, are particularly vulnerable to security threats. To address this challenge, covert communication has emerged as a promising technique for enhancing communication security by concealing the existence of transmissions from wardens. This paper systematically investigates cooperative beamforming for covert communication in MIMO ad hoc networks. Subsequently, the performance of the proposed scheme is analyzed, and an asynchronous scenario is further investigated to solve the beamformer optimization and relay selection problem in practical ad hoc networks. Specifically, multiple multi-antenna nodes in the ad hoc network cooperate to assist covert communication between a transmitter and a receiver when their direct link is long-distance or weak. The cooperative beamforming scheme is analyzed and compared with the multi-path transmission scheme, which is a benchmark cooperative scheme in ad hoc networks. The proposed scheme is shown to outperform the latter in terms of covert rate and detection error probability. Under the asynchronous scenario, a mixed-integer non-convex optimization problem is formulated to maximize the end-to-end covert rate subject to the covertness constraint. A graph based joint covert beamformer optimization and cooperative relay selection algorithm is proposed to solve the problem. Simulation results indicate that the cooperative beamforming scheme achieves a covert rate gain of more than 200% over the multi-path transmission scheme under identical covertness constraints. Furthermore, the proposed algorithm remains within 17% of the exhaustive-search upper bound over the evaluated parameter range and consistently outperforms all non-exhaustive benchmark algorithms in terms of end-to-end covert rate, while maintaining robustness against channel estimation errors and synchronization offsets.
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