Average consistency time synchronization method based on event triggering

Abstract

The invention relates to an average consistency time synchronization method based on event triggering, and belongs to the technical field of wireless networks. The method comprises the following steps of: aiming at the condition that communication time delay and clock time frequency offset exist in a wireless network, setting an updating period and an initial relative frequency offset estimation value and a logic clock compensation value of each node in the network, and updating a logic frequency offset estimation value step by step according to the period; judging whether the node meets a broadcast triggering condition or not according to the difference between the latest updated logic frequency offset value and the last broadcast logic frequency offset value; if the trigger condition is met, the node broadcasts relevant parameters of the hardware clock and the logic clock at the moment to other neighbor nodes; and relative frequency offset estimation is carried out by using a sequence least square method, and global consistency of a network clock is realized by using a proportional-integral estimator. According to the method, the influence of transmission time delay and clock time frequency offset in a wireless network is considered, compromise is achieved between communication overhead and synchronization precision, and high synchronization precision is achieved with appropriate communication overhead.

Description

technical field [0001] The invention belongs to the technical field of wireless networks, and relates to an event-triggered average consistency time synchronization method. Background technique [0002] Time synchronization is a key technology in wireless networks, which provides a common global time scale for each independent node in this distributed system. This technology meets the basic needs of many applications in wireless networks, such as data fusion, object tracking and cooperative transmission. The clock of each node in the network is maintained by a crystal oscillator. However, in the actual environment, factors such as temperature and pressure will affect the clock crystal oscillator of the node. At the same time, the crystal oscillator itself also has differences in manufacturing process and aging problems, resulting in crystal oscillator offset. The resulting clock frequency errors accumulate, so that the clocks of each node in the network cannot be synchroniz...

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Problems solved by technology

[0006] In view of this, the purpose of the present invention is to provide an event-triggered average consistency time synchronization method, while considering the influence of communication delay and clock time-varying frequency deviation on synchronization accuracy in wireless networks, for the event-triggered node interaction method The average consistency time synchronization method has not yet solved the clock synchronization problem under the influence of the above factors. It provides an event-based node interaction strategy suitable for this scenario. The trigger condition maintains an appropriate convergence speed, so that the node only meets the trigger condition. The communication overhead is reduced by broadcasting to neighbor nodes; at the same time, under the proposed event-triggered interaction strategy, the relative frequency offset is estimated by the sequential least squares method, and the proportional integrator is used to update the frequency offset value of the logical clock, so that all nodes Robust to time delay and time-varying frequency offset, enabling global clock synchronization

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