Method for synchronizing time based on lock phase ring in wireless sensor network

Abstract

The invention features: less energy expenses, less complexity, and compensation function for the drift and offset. It uses PLL (phase locked loop) principal and a single-way broadcast synchronous mechanism to scheme out a solution which simultaneously has the compensation function for the drift and offset and the time synchronization function of radio sensor network.

Description

technical field [0001] The invention belongs to the technical field of time synchronization in wireless sensor networks. Background technique [0002] Time synchronization in a wireless sensor network (WSN, Wireless Sensor network) means that all or some nodes in the network have the same time reference, that is, different nodes keep the same clock, or nodes can convert each other's clocks to local clocks. The factors that cause clock inconsistency among sensor network nodes mainly include: out-of-synchronization caused by clock frequency drift caused by external environmental changes such as temperature, pressure, and power supply voltage. The initial values ​​of the clocks of different nodes are also different. On the one hand, the initial values ​​set during the development process are different; on the other hand, in order to save energy, nodes usually rely on external observed events to frequently sleep and start. Causes a difference in the initial value of the clock i...

AI Technical Summary

Problems solved by technology

[0028] From the analysis of the synchronization principles of various existing algorithms, except for TS / MS, almost all algorithms are based on offset compensation. Some algorithms, such as RBS and FTSP, combine drift compensation technology, but without exception The drift is estimated by performing linear regression processing on multiple sample data, and the space complexity of the corresponding algorithm is relatively large

Tiny-Snyc in TS / MS uses two data points to determine four constraint boundaries. Although the overhead is small, it cannot give the best estimate of relative drift and relative offset. Mini-Sync uses complex algorithms to deterministically delete Data points that do not affect the accuracy, but need to save useful historical data to obtain the optimal estimate. The storage of 40 triple data points suggested by the proposer of TS / MS is not small for wireless sensor network nodes with limited resources. s expenses

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