基于GPS软件接收机平台的弱信号捕获算法研究

为了解决GPS弱信号的捕获问题,以GPS软件接收机为平台,首先建立了消除考虑多普勒频移对码片传输影响的精确GPS信号模型;在此基础上,采用了一种相干/非相干积分相结合的改进型块数据捕获算法实现了对弱信号的有效捕获。该算法综合考虑了非相干积分引起的噪声影响,并提出一种易于工程实现的非相关积分损耗补偿方法。最后,通过一组实测数据,验证了改进的相干/非相干相结合捕获算法,补偿了由于非相关积分带来的积分损耗,能够有效地实现对弱信号的捕获。

Weak signal acquisition algorithm based on GPS software receiver platform

In order to capture the weak GPS signals,the refined GPS signal model to eradicate the effect of Doppler shift on the C/A code transmission is established on GPS software receiver platform.Based on this,an improved data acquisition algorithm based on coherent/incoherent integral is given to acquire the weak signals efficiently.This algorithm considers synthetically the noise caused by incoherent integral and a method to compensate the incoherent integral loss used in a practial engineering is proposed.The testing experiments are carried out and the results indicate that this weak signal acquisition algorithm improves the performance in acquiring low S/N GPS signal significantly.