Relative Frequency Offset Estimation Method for Consistent Clock Synchronization Based on Weighted Median

Abstract

The invention relates to a method for estimating a relative frequency offset of consistent clock synchronization based on a weighted median, and belongs to the technical field of wireless sensor networks. The present invention is oriented to wireless sensor network scenarios where the communication delay is exponentially randomly distributed, considers the relative clock relationship between nodes, obtains the Laplace variable model through time stamp data processing, and then uses the weighted median method to estimate the relative frequency offset, and Combined with the average consistency method to compensate the logical clock parameters of the nodes, the effect of keeping the logical clocks of the nodes in the network synchronous is finally achieved. The present invention proposes two relative frequency offset estimation methods: a weighted median estimation method based on an interval and a weighted median estimation method based on a threshold. The former is estimated by finding the optimal value of the time stamp interval, which is suitable for scenarios that require high relative frequency offset estimation accuracy; the latter reduces the storage requirements of the estimation method by setting a threshold value, and is suitable for scenarios where node storage resources are limited .

Description

technical field [0001] The invention belongs to the technical field of wireless sensor networks, and relates to a method for estimating relative frequency offset of consistent clock synchronization based on weighted median. Background technique [0002] Clock synchronization is an important supporting technology for wireless sensor networks. Many applications, such as deterministic scheduling, data fusion, and energy management, need to run on the basis of synchronous node clocks in the network. In recent years, considering the distributed nature of wireless sensor networks, consensus-based clock synchronization protocols have gained widespread attention due to their good robustness and scalability. [0003] The consensus clock synchronization protocol proposed earlier can achieve the synchronization effect while ignoring the influence of communication delay. However, in the actual data communication process of wireless sensor networks, communication delay can be divided in...

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Problems solved by technology

[0005] In view of this, the object of the present invention is to provide a method for estimating the relative frequency offset of consistent clock synchronization based on weighted median, which aims at the problem that the consistent clock synchronization mechanism under communication delay does not fully utilize the delay information. The clock data processing optimization method and the Laplace distribution model consider the different requirements of high precision or low storage, use the weighted median method to estimate the relative frequency offset, and use the average consistency method to compensate the logic clock parameters, so as to adapt to different scenarios and improve The effect of network clock synchronization accuracy

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