扩频调制的伪码跟踪技术分析  

Analysis on Pseudocode Tracking Technology for Spread Spectrum Modulation

作　　者：张丽娜[1] ZHANG Li’na(The 54th Research Institute of CETC,Shijiazhuang 050081,China)

机构地区：[1]中国电子科技集团公司第五十四研究所,河北石家庄050081

出　　处：《无线电工程》2018年第5期397-400,共4页Radio Engineering

基　　金：国家高技术研究发展计划("863"计划)基金资助项目(2015AA015701)

摘　　要：在直接序列扩频传输系统中,接收端通常利用匹配滤波器实现扩频信号的初始同步,利用伪码跟踪环实现本地码字对其相位的精确跟踪。伪码跟踪的准确性直接影响解扩的性能。伪码跟踪中采用归一化的鉴相算法,通过合理的环路参数、相干累加长度和非相干累加次数设计,可以提高伪码跟踪的准确性。针对直接序列扩频信号,通过理论和仿真分析得到了码跟踪环中的相干累加长度和非相干累加次数这2个关键参数与载波频差、扩频比以及误码率之间的关系,可以为扩频码定时跟踪的设计提供依据。In the DSSS system,the receiver usually uses matched filter to implement initial acquisition of DSSS signal,and pseudocode tracking loop to implement accurate phase tracking.The accuracy of pseudocode tracking affects the performance of despread.This paper uses the normalized phase-detecting algorithm and designs the reasonable loop parameter,right coherent accumulation length and number of non-coherent accumulation to improve the performance of pseudocode tracking.For DSSS signals,the theoretical and simulation analysis are done to obtain such two key parameters of code tracking as coherent accumulation length and number of non-coherent accumulation,and the relation between these two parameters and the demod condition of SNR,carrier offset as well as spread factor,which can be used for design basis of spreading code timing tracking.

关 键 词：直接序列扩频 伪码跟踪环 相干累加 

分 类 号：TN763[电子电信—电路与系统]