GPS接收机信号捕获方法的改进与实现

Improvement and implementation of GPS signal acquisition method

在GPS卫星定位中,由于卫星和接收机之间的相对运动产生高达10kHz的多普勒频移,同时大多数情况下卫星信号容易被遮挡,接收到的信号都比较弱,需要有一种有效的捕获方法实现GPS信号的捕获。分析了已有捕获方法的特点和缺陷,提出了一种改进的基于循环相关的捕获方法,并进行验证,表明该方法能实现相对弱信号的快速捕获。

In GPS satellite position, since the relative movement between the GPS satellites and the GPS receivers will cause the Doppler frequency shifts that can reach 10kHz and the signals from the GPS satellites will be blocked, the received GPS signals will be very weak, and it is essential to obtain an effective method to acquire such weak signals. The performances and shortcomings of the traditional acquisition methods were analyzed, and then an improved acquisition method based on circular correlation was presented. The testing results show that the modified method can fast acquire weak signals under the realistic application environment.