基于FFT校频的分段匹配滤波器性能分析

Performance Analysis for PN Code Acquisition with PMF Based on FFT

为了对动态PN码捕获中使用的分段匹配滤波器的设计进行指导,在建立其数学模型的基础上,分析了分段数、FFT点数与载波频偏对滤波器性能的影响。结果表明,增加分段数可以减小载波频偏对相关峰的影响;增加FFT点数可以提高频偏校正的精度;在环境噪声为高斯白噪声情况下,存在最佳的分段数和FFT点数组合,可以用最小运算量达到最佳捕获效果。

The common technique of dynamic long PN code acquisition is partial matched filter（PMF） based on FFT.To guide the design of PMF and based on the building of mathematical model,the paper analyzes the effect of different parameter to the filter performance.Simulation result shows that increasing the number of segments can reduce the impact of frequency offset while it also amplified the noise and the accuracy can be improved by increasing the FFT points.At last it gets the conclusion that the best fixed numbers of sections and the FFT points are existing in Gaussian white noise conditions.