基于数字锁相原理的GPS高精度同步时钟产生新方法  

New Method of Generating GPS High Accuracy Synchronous Clock Based on the Digital Phase-lock Principle

作　　者：李泽文[1,2] 姚建刚[1] 曾祥君[2] 邓丰[2] 楚湘辉[2] 

机构地区：[1]湖南大学电气与信息工程学院,湖南省长沙市410082 [2]长沙理工大学电气与信息工程学院,湖南省长沙市410114

出　　处：《电力系统自动化》2009年第18期82-86,共5页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50577001);教育部新世纪优秀人才计划资助项目(NECT-04-0781);湖南省教育厅科技项目(07C088)~~

摘　　要：在分析时钟误差的基础上,根据全球定位系统(GPS)秒时钟无累计误差和晶振秒时钟无随机误差的特点,提出了一种利用GPS秒时钟同步晶振秒时钟实现高精度时钟的新方法。该方法根据数字锁相原理,通过测量GPS秒时钟与晶振秒时钟间的相位差来控制晶振秒时钟的分频系数,实时消除晶振秒时钟的累计误差,从而产生高精度秒时钟。实验结果表明,在GPS正常工作时能够保证其精度稳定在20ns;GPS信号失效1h的情况下,秒时钟精度仍能稳定在100ns。根据此方法研制了具有较高性价比的高精度时钟发生装置,成功应用于行波定位系统中。Based on an analysis of the errors for a clock and by taking into account the characteristic that the GPS second clock is free from cumulative errors and the crystal oscillator clock is free from random errors, a new method is proposed to implement the highly accurate clock by the synchronization of a crystal oscillator second clock with GPS second clock. According to the digital phase-lock principle, the method is used to control the frequency dividing coefficient by measuring the actual phase difference between the crystal oscillator second clock and the one pulse per second （1PPS） of GPS to eliminate the cumulative errors of the crystal oscillator second clock in real time, thereby generating the high accuracy second clock. Experimental results show, when the GPS receiver works normally, that the synchronous second clock accuracy can be maintained at 20 ns, while if the GPS signal becomes ineffective for one hour, the accuracy of the synchronous second clock can still be stabilized at 100 ns. A high accuracy clock generating device with a fairly high price performance ratio has been developed using this method and successfully applied in a traveling wave locating system.

关 键 词：全球定位系统 高精度时钟 晶振 GPS秒时钟 复杂可编程逻辑器件 

分 类 号：TN967.1[电子电信—信号与信息处理]