基于相位估计器的直接序列快捕方法

Rapid Acquisition for DS/SS Systems Using a Phase Estimator

该文提出一种基于直接序列扩频系统(DS／SS)的码相位估计器。它能根据输入信号与一个特殊序列不同相位下的互相关值,相当准确、有效地估计出本地伪随机序列的改进方向和大小,成倍地缩短了捕获的时间。理论分析和计算机模拟表明,对于周期511以上的伪随机码而言,该算法在正常工作条件下平均捕获时间仅为常规捕获方法的一半。

In this paper, a phase estimator of serial search acquisition is proposed for Direct-Sequences Spread- Spectrum（DS/SS） systems. According to the cross correlation between the PN signal and the auxiliary signals with the different phases, an exact and valid estimation of improving direction and magnitude for the local PN generator is given, by which half the mean acquisition can be reduced. Analysis in theory and numerical results show that the proposed method can achieve acquisition at least two times faster than the conventional serial search method for the PN sequences which periods are more than 511 in normal operating condition.