基于时间压扩的GPS信号多普勒算法实现与验证

Implementation and Verification of GPS Signal Doppler Algorithm Based on Time Companding

为了设计可靠的GPS模拟源,多普勒效应的模拟是必须解决的问题。以推导GPS中频信号的数学模型为基础,分析了GPS信号生成过程中的关键技术,展示了GPS模拟源的实现流程,提出一种改进的GPS模拟源的多普勒算法。该方法基于传播时延的时间压扩特性,通过计算少量等间隔时刻精确信号传播时延,结合三阶多项式,可以计算出任意采样时刻的传播时延,并能够实现信号的动态多普勒。经过软件接收机和OEMStar硬件接收机对生成的信号验证,结果表明用该方法生成的信号具有较强可用性,达到了预期要求。

In order to design a reliable GPS signal simulator,simulation of the GPS Doppler effect must be solved. Based on the mathematical model of IF GPS signal,this paper analyzes the key technology in the process of GPS signal generation,shows the structure of GPS signal simulator and proposes an improved algorithm of GPS Doppler effect. This algorithm is based on the time companding of signal transmission delay. When algorithm gets few number of uniformly-spaced transmission delay,it can calculate transmission delay of random sampling time by using three order polynomial and realizes dynamic Doppler effect.After the verification of generated signal by GPS software receiver and OEMStar hardware receiver,the result shows that the signal generated in this way has good availability,and meets the expected requirements.