圆周移位在伪码补零BDS信号捕获算法中的应用

D1导航电文中加入了NH码,且D2导航电文的速率也比GPS信号的快很多,使得BDS的信号结构增加了捕获难度。采用伪码补零的方法可以对BDS信号进行有效捕获,但是该方法积分时间较长导致捕获耗时变长。本文提出了一种基于圆周移位的改进伪码补零算法,将搜索中复杂的载波剥离运算用计算量很小的频谱序列的搬移操作来代替,使算法复杂度大幅下降。试验结果表明,该方法可以有效减少运算量和捕获耗时。

Pseudo Code Zero-Padding BDS Signal Acquisition Algorithm Based on Circumference Shift

A unique NH code is added in D1 navigation message of BDS,and the speed of the D2 navigation message is much faster than that of the GPS.This unique signal structure increases the difficulty of satellite signal acquisition.BDS signal can be acquired effectively by the method of zero-padding pseudo code.However,this acquisition method is quite time-consuming due to the integration process.So in this paper an improved pseudo code zero-padding method based on circumference shift is presented.The complex carrier stripping operation is replaced by the operation of the frequency spectrum move with a small calculation amount.The complexity of the algorithm is significantly decreased.The experimental results show that the improved algorithm can effectively reduce the calculation amount and the acquisition time.