GPS接收机中晶振误差的模拟方法

GPS(Global Positioning System)接收机中参考频率源的性能对接收机整体性能有着诸多影响。该文对在GPS接收机中使用最多的晶振的误差特性和性能影响进行了分析，在此基础上提出了一种模拟晶振频率误差的方法，即首先确定晶振在给定取样时间间隔上各主要随机误差成分的Allan(阿仑)方差参数，由此反演产生相应的各项晶振频率误差模拟序列并进行叠加。文中给出了计算机数值模拟的方法，并对仿真实验结果进行了分析，从而为GPS接收机设计、性能评估和测试平台如GPS信号模拟器的研制提供有关的理论支持和设计方法。

A Method for Simulating the Crystal Oscillator Errors in GPS Receiver

The frequency source in Global Positioning System (GPS) receiver has a great many influence on the whole performance of the receiver. Based on the analysis of error characteristics and performance effect of the mostly used crystal oscillator, a method to simulate the frequency error of crystal oscillator is proposed. The major idea is to determine the Allan variance parameter of each main stochastic error component at the given sampling interval at first, then to deduct a set of corresponding frequency error series and superpose them together. The computer numerical simulation approach and the experimental results are given. This research provides related both theoretical reference and practical design for the development of an integrated design, test and evaluation platform such as a GPS signal simulator.