一种精度改进的短时匹配滤波器和FFT的高速捕获算法

针对传统的短时相关和FFT(Fast Fourier Transform:快速傅里叶变换)相结合的高速信号捕获算法的优点以及不足之处,在该算法的基础上,提出了一种可以获得更高的捕获精度并且不需要大量增加FFT点数方法。该方法在获得相同的伪码精度的条件下,可以大大提高对载波多普勒频移的估计。仿真结果证明了该方法的正确性。更精确地捕获精度保证了GPS接收机能成功地进入跟踪状态。

An Accuracy Improved Signal Acquisition Algorithm Based on Short Time Matched Filter and FFT

Short Time Matched Filter (STMF) and FFT algorithm is one of the fastest algorithms for GPS signal acquisition. However, this algorithm has lower acquisition accuracy and is more complex to realize. In this paper, an improved method is proposed based on the traditional STMF FFT algorithm. The proposed algorithm has higher frequency acquisition accuracy and need fewer data points for FFT operation. Simulation results show that this method has better frequency acquisition accuracy than the traditional method , which ensures the GPS loop can be easy turn to tracking.