基于码部分相关性的GPS信号捕获算法

Acquisition algorithm for GPS signal based on partial correlation of C/A code

为提高GPS信号的捕获速度,减少捕获时间,从C/A码的部分相关性出发,提出一种基于1024点FFT的码相位捕获算法.将输入数据按1024点进行分段,对每段1024点分别采用FFT算法进行捕获.仿真结果表明,该算法既保证了码相捕获精度,又有效降低了计算量,提高了捕获速度.可以利用现有的1024点FFT核完成设计,对系统硬件要求较低.该算法对GLONASS、GALILEO、北斗导航系统的信号捕获也具有很好的借鉴作用.

To improve the acquisition speed for GPS signal while decreasing the acquisition time, an phase acquisition algorithm based on 1024 fast Fourier transform （FFT） was developed con sidering the partial correlation of the C/A code. The input data were done in subsection in every 1024 points, and the coarse C/A code phase was calculated by using 1024 FFT. Simulation results show that the algorithm guarantees computational preci sion, while decreasing the computational complexity and im proving acquisition speed. The design can be realized by using existing 1024 point FFT IP core in GPS receiver, which has a relatively low requirement to hardware. The proposed algorithm can also give good reference to GLONSS of Russia, Galileo of Europe and Beidou Navigation System of China in signal acquisinon.