摘要： 为实现无线传感器网络高精度的时间同步功能，提出一种基于Zigbee技术的硬件时钟同步方法。采用跨层思想提取接收信号强度指示值信号作为同步触发信号，设计复杂可编程逻辑器件的硬件电路时钟模块实现计时，并配合软件算法完成整个网络的时间同步，在保证低能耗和复杂度的基础上，提高时间同步精度。对同步精度进行理论研究和测试分析，结果表明，该方法可使系统节点间达到10 μs级的时钟同步精度，满足多数无线传感器网络要求。

关键词: 无线传感器网络, 时间同步, 跨层设计, 接收信号强度指示值触发信号, 复杂可编程逻辑器件时钟模块, XBee无线通信模块

Abstract: A method of high precise time synchronization with hardware for Wireless Sensor Network(WSN) based on Zigbee technology is proposed to realize synchronous functions. Based on the method of cross-layer design, Received Signal Strength Indicator(RSSI) signal is extracted to be acted as synchronous trigger signal. With the use of Complex Programmable Logic Device(CPLD) hardware circuit, a design of time module for real-time demand in the system is achieved for timing. With the software synchronous algorithm, the system can achieve the synchronization function. Problems about the contradictions between low power, low cost and high accuracy in the traditional time synchronization in sensor wireless networks are solved. Theory analysis and experiments about system precision are done to show that time accuracy between nodes can reach the range of 10 μs and the synchronization met most needs of WSN.

Key words: Wireless Sensor Network(WSN), time synchronization, cross-layer design, Received Signal Strength Indicator(RSSI) trigger signal, Complex Programmable Logic Device(CPLD) time clock module, XBee wireless communication module

中图分类号: 

• TN925