基于GPS软件接收机的C/A码捕获算法

Acquisition algorithm of C/A code based on GPS software receiver

为了尽量减少导航电文数据比特跳变带来的影响,在基于FFT的并行码相位搜索算法的基础上,采用两相邻毫秒数据进行捕获,再利用DFT细化频率估计,得到C/A码相位和较精确的载波频率。利用实际采集的数据进行实验,结果证实了该方法能快速有效地对C/A码进行捕获,为后续跟踪环路提供了良好的初始条件。

This paper presented an acquisition method, using the two adjacent millisecond data to acquire the initial phase of the C/A code and the carrier Doppler frequency, then the frequency resolution is improved by using DFT. The experimental results show that the proposed method can acquire the GPS signal correctly and quickly, in addition, a good initial condition is provided to the traeking loop.