The Design Of ZigBee Wireless Sensor Network With Precision Time Synchronization

High-speed train test environment is different from other common test environment. totally enclosed design of high-speed train makes a lot of time can only be tested using a wireless sensor network. Meanwhile.train runing with a high speed,Tunnel Operation,Top of the high-voltage electricity to the GPS signal by the impact of synchronization between the sensor network becomes particularly inconvenient.In high-speed train sensor networks, a design was proposed to build a data acquisition system, which using the zigbee wireless sensor monitoring network. The system is based on TI'sOpen Source Zigbee Stack and use of ultra-low power wireless communication module JN5139. microcontroller use C8051F023. Briefly discusses the importance of precision clock signals for Synchronization between sensor networks. And that the Precision clock signals Play a positive role on data processing and data fusion. Another design was proposed to build a frequency adjustable waveform generator.based on the chip of AD9851(DDS) Atmega8 and FE-5680A rubidium atomic frequency standard. The hardware and software realization are mostly presented. The field debugging results showed that system's performance could meet the design's demand.In this thesis, we design a precision rubidium atomic clock applied to the ZigBee wireless sensor acquisition system. The main work accomplished as follows:1,Analysis Synchronization software and synchronization algorithm Which Commonly used in wireless sensor acquisition system.2,Designed a Adjustable precision clock based on the FE-5680A Rubidium oscillator and DDS (direct digital synthesis) chip AD9851.3,Programming a PC Program to change frequency of the clock.with a Intuitive interface, and easy to use.4,Designed a wireless sensor acquisition system based on ZigBee.5,System programming and debugging.