Joint Estimation of Clock Skew and Offset of Listening Nodes in Wireless Sensor Networks Based on Correlation Detection

Clock synchronization is a critical technology in wireless sensor networks, which provides a foundation for various operations between network nodes. The accuracy of synchronization and network energy consumption are essential factors that synchronization protocols must consider. The accuracy of clock synchronization can be improved through information exchange between nodes. However, frequent information exchange will increase the communication overhead of the network as the number of nodes increases. Therefore, researchers have proposed implicit synchronization, a low-energy synchronization mechanism. In implicit synchronization, nodes only need to listen to the information transmission between the reference node and the active node to synchronize their clocks to the reference node, thereby reducing energy consumption. However, in current implicit synchronization scenarios, the timestamp is mainly used for synchronization, which reduces clock synchronization accuracy due to the random delay of timestamps. To address this issue, the paper proposes a joint estimation algorithm for clock skew and offset that combines correlation detection and implicit synchronization. The algorithm ensures high clock synchronization accuracy while reducing energy consumption as the entire process is completed at the physical layer. The simulation results show that the proposed algorithm is superior to the traditional algorithm regarding clock synchronization accuracy in the implicit synchronization scenario.