GPS软件接收机导航电文提取的研究

Navigation Data Extraction Based on GPS Software Receiver

导航电文提取中最重要的步骤是位同步和帧同步。传统的方法是先进行位同步再进行帧同步,并且算法复杂。文中提出了利用自相关函数直接进行帧同步的算法,该算法在实现帧同步的同时也实现了位同步。利用实际采集的GPS中频信号,基于计算机MATLAB软件平台,分别使用传统的方法和自相关函数算法完成帧同步和位同步。仿真结果表明两种方法均可以有效可靠地获得导航电文,自相关函数的算法更简单快捷。

The most important steps for navigation data extraction are bit synchronization and frame synchronization. The traditional algorithms are complex, and implemented with frame synchronization followed by bit synchronization. A new algorithm is proposed in this paper, which is based on autocorrelation function and could obtain bit synchronization and frame synchronization simultaneously. Traditional algorithms and autocorrelation function algorithm are developed by using real GPS intermediate frequency samples based on MATLAB software of personal computer. Simulation results show that both of these two algorithms could obtain navigation data effectively and reliably, and the autocorrelation algorithm is better than traditional algorithm.