A Low Communication Overhead Privacy Preserving Collaboration Localization Method for Asynchronous Networks

Integrated Sensing and Communication (ISAC) entails the seamless integration of sensing capabilities with communication networks. A crucial aspect of ISAC technology involves estimating target positions utilizing wireless communication signal. However, the presence of asynchronous clocks poses significant challenges to precise localization. Furthermore, traditional networks operating in broadcast mode are susceptible to eavesdropping by malicious nodes, posing a severe risk of privacy leakage. To address these issues, this paper introduces a privacy-preserving asynchronous network localization method. Firstly, we establish a zero-sum noise-based broadcast model, in which, each node collaboratively generates the noise to protect the timestamps broadcast by all nodes, thereby ensuring the security of target location information. Secondly, timestamps broadcasted by two rounds of nodes are employed to estimate and compensate for the relative clock skew between the target node and each anchor node. This compensation enables high-precision location estimation of the target node. Finally, the Cramer-Rao Lower Bound (CRLB) is derived to assess the accuracy of relative clock skew estimation and the performance of the corrected TOA estimation. The evaluations demonstrate that the proposed method not only prevents the leakage of location information but also maintains positioning accuracy with low communication overhead. Specifically, it achieves an 8.7% improvement in localization accuracy over existing synchronization scheme, while simultaneously reducing communication overhead by more than 60% compared to traditional privacy-preserving approaches. These advantages substantially enhance both the security and operational efficiency of ISAC networks.