无人机GPS信号的快速捕获与算法改进

摘要

无人机在空中侦察、监视、通信、反潜以及电子干扰等领域发挥的作用日趋重要,GPS技术已经成为无人机快速,安全,有效地执行任务的关键技术.传统的GPS信号捕获算法,每搜索一个多普勒频点需要进行两次FFT和一次IFFT,运算量大且实时性差.文中利用C/A码功率谱对称性的特点,通过减少参与循环的FFT点数的方法对传统的FFT算法做了改进并利用MATLAB进行了仿真,仿真结果表明,改进后的捕获方法能够在满足捕获精度的条件下,可以更快的完成捕获任务,有效地提升了导航定位的实时性.%UAV plays an increasingly important role in the air reconnaissance,surveillance,communications,anti-submarine and electronic interference,however,GPS technology has become a critical technology on UAV quickly,safely and effectively performing the mission.The traditional FFT acquisition algorithm requires two FFT and one IFFT to search for a Doppler frequency which needs large computing and has a bad real-time.In this paper,based on C/A code power spectral symmetry features,Traditional FFT algorithm has been improved by reducing the FFT points involved in the cycle method.Matlab simulation results show that the new acquisition algorithm can be faster to complete capture under meeting capture accurancy.effectively enhancing real-time navigation and positioning.