基于软件接收机的GPS信号快速捕获算法

GPS SIGNAL FAST ACQUISITION ALGORITHM BASED ON SOFTWARE RECEIVER

针对GPS信号C/A码的捕获,利用多项式拟合估计多普勒频率偏移值,减少了频率搜索范围;将直接求相关值和利用FFT/IFFT变换的算法相结合,用于确定C/A码相位。且在信号处理上利用抽取避免重复采样。仿真结果表明,该算法在同等的定位精度要求下,降低了计算复杂度,提高了C/A码的捕获速度。

In light of GPS signal C/A code acquisition, Doppler frequency shift is estimated by polynomial fitting to reduce frequency searching scope; the method of directly finding correlation is combined with FFT/IFFT algorithm to determine C/A code phase. And data extraction method is used in signal processing to avoid multiple sampling. Simulation results show that this algorithm decreases calculation complexity and increases C/A code acquisition speed in equivalent requirement of locating precision.