Joint Clock Synchronization and Localization for 6G Integrated Communication and Sensing

Integrated communication and sensing (ICAS) is an enabling technique of 6G communications, which requires an accurate clock synchronization among transceivers. The accuracy of conventional time synchronization methods in 4G/5G communication networks is usually around 100 ns, which is sufficient for signal detection, but unsatisfied for ICAS-driven applications. In this paper, we aim to provide an accurate clock synchronization solution for ICAS, which is challenging due to the disturbance of random channel fading, multipath interference and uncertain UE location parameters. To address this challenge, we propose a joint framework of synchronization, position and channel estimation (SPACE) for 6G ICAS. A novel successive convex approximation-based SPACE algorithm is developed to simultaneously estimate UE clock shift, UE location and multipath channel states, and the effect of multipath interference and channel fading on clock synchronization will be alleviated via channel compensation. It is verified by simulations that our SPACE solution outperforms state-of-the-art localization and synchronization baselines due to our problem-specific joint framework development.