基于信道模型的短波时差测量克拉美罗界分析  

Cramer-Rao lower bound analysis of shortwave time difference measurements based on channel model

作　　者：王君明 周晨[1] 李琛 吕明杰 乔玮 朱建桦 WANG Junming;ZHOU Chen;LI Chen;LYU Mingjie;QIAO Wei;ZHU Jianhua(School of Electronic Information,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学电子信息学院,湖北武汉430072

出　　处：《湘潭大学学报（自然科学版）》2024年第1期35-43,共9页Journal of Xiangtan University(Natural Science Edition)

基　　金：国家自然科学基金(41574146,41774162,42074187,41804026,41931075);国家环境重点研发项目(6142403180204)。

摘　　要：短波时差定位的关键在于高精度时差的提取.电离层的复杂性使得基于互相关的传统时差测量估计算法不能提取短波信号中的时延信息,该文利用国际参考电离层(IRI)模型获取电离层的电子密度信息,以数值型三维射线追踪的方法构建Vogler信道模型,得到短波信号的时延估计,并推导了在多普勒扩展不影响信号相关性时的短波时差测量克拉美罗界(CRLB).仿真结果表明,短波时差测量CRLB与采样时间、电波频率、输入信噪比有关,且冬季的时差测量CRLB低于夏季.The key of time difference location is to extract time difference with high precision.Due to the complexity of ionosphere,the traditional time difference estimation algorithm based on cross correlation cannot extract the time delay information of short wave signal,in this paper,the ionospheric electron density information is obtained by using the international reference ionospheric model,the Vogler channel model is constructed by using the numerical ray tracing method,and the time delay estimation of shortwave signal is obtained.The Cramer-Rao lower bound(CRLB)of shortwave time difference measurement is derived under the background that the signal correlation is not affected by Doppler extension.The simulation results show that CRLB is related to sampling time,radio frequency and input signal-to-noise ratio,and the CRLB of time difference measurement in winter is lower than that in summer.

关 键 词：Vogler信道 短波时差测量 多普勒扩展 克拉美罗界 

分 类 号：TN011[电子电信—物理电子学]