Consistency clock synchronization relative frequency offset estimation method based on weighted median

Abstract

The invention relates to a consistency clock synchronization relative frequency offset estimation method based on a weighted median, and belongs to the technical field of wireless sensor networks. Themethod is oriented to a wireless sensor network scene in which communication time delay is exponentially and randomly distributed; a relative clock relation between nodes is considered, a Laplace variable model is obtained through timestamp data processing, then a weighted median method is adopted to estimate relative frequency offset, logic clock parameters of the nodes are compensated in combination with an average consistency method, and finally the effect that logic clocks of the nodes in a network are kept synchronous is achieved. The invention provides two relative frequency offset estimation methods, namely an interval-based weighted median estimation method and a threshold-based weighted median estimation method. The time stamp interval is estimated by searching an optimization value of the time stamp interval, and the method is suitable for scenes with high requirements on relative frequency offset estimation precision; the latter reduces the storage requirement of the estimation method by setting a threshold value, and is suitable for a node storage resource limited scene.

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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