基于双PLL的大频偏直扩信号的载波跟踪  

Carrier Recovery of DS-SS Signal with Large Frequency Offset Based on Dual PLL

作　　者：刘燕丽[1] 张天骐[1] 张伟[2] 马国宁[2] 苗圃[1] 

机构地区：[1]重庆邮电大学信号处理与片上系统研究所,重庆400065 [2]中国工程物理研究院电子工程研究所,四川绵阳621900

出　　处：《电视技术》2009年第S2期146-149,共4页Video Engineering

基　　金：国家自然科学基金-中物院NSAF联合基金项目(10776040);国家自然科学基金项目(60602057);重庆市科委自然科学基金项目(CSTC2006BB2373);重庆市教委自然科学基金项目(KJ060509;KJ080517);重庆邮电大学自然科学基金项目(A2006-04;A2006-86)

摘　　要：针对直接序列扩频通信中的载波恢复问题,提出了一种基于自适应算法设计的双PLL载波跟踪方法。该方法采用两个PLL,一个用来产生由频偏引起的相偏,另一个则用来跟踪接收到的扩频信号载波的相偏。在高动态环境下,应用此环路可以迅速地捕获到存在大频偏的调制载波信号的相位。双PLL中所使用的LPF和NCO均可通过软件编程来实现其功能,而且环路中所使用的参数可以通过计算机仿真来调整。仿真结果表明,该方法有良好的跟踪效果。For the problem of carrier recovery in DS-SS communication,the model of dual PLL is presented,which is designed based on the auto -adapted algorithm.Two PLL are used in this method,one of which is used to track the phase produced by the frequency offset,and the other is used to track the phase of carrier.In high dynamic environment,using this dual PLL can rapidly track the phase of modulated carrier which occurrences frequency offset to a great extent in the course of communication.The LPF and NCO used in the dual PLL both can implement their function through software.Also the parameters used in the dual PLL can adjust through simulation.The computer simulation shows that the dual PLL has the favorable effect.

关 键 词：PN码 双PLL 低通滤波器 数控振荡器 载波恢复 

分 类 号：TN914.42[电子电信—通信与信息系统]