电子学报 ›› 2019, Vol. 47 ›› Issue (4): 798-805.DOI: 10.3969/j.issn.0372-2112.2019.04.005

• 学术论文 • 上一篇    下一篇

窄带跳频信号的无模糊时差估计算法

姚山峰, 欧阳鑫信, 贺青   

  1. 盲信号处理重点实验室, 四川成都 610041
  • 收稿日期:2018-03-05 修回日期:2018-09-14 出版日期:2019-04-25
    • 作者简介:
    • 姚山峰 男,1986年生于四川安岳,硕士.现为盲信号处理重点实验室助理研究员,主要研究方向为无源定位与统计信号处理.E-mail:sephyao@163.com;欧阳鑫信 男,1987年生于江西吉安,博士.现为盲信号处理重点实验室助理研究员,主要研究方向为参数估计与无源定位.E-mail:ouyxxwork@163.com;贺青 男,1984年生于四川成都,博士.现为盲信号处理重点实验室助理研究员,主要研究方向为无源定位与阵列信号处理.E-mail:kinghe919@163.com

Unambiguous TDOA Estimation Algorithm of Narrowband Frequency Hopping Signal

YAO Shan-feng, OUYANG Xin-xin, HE Qing   

  1. National Key Laboratory of Science and Technology on Blind Signal Processing, Chengdu, Sichuan 610041, China
  • Received:2018-03-05 Revised:2018-09-14 Online:2019-04-25 Published:2019-04-25

摘要: 针对跳频信号的高精度时差估计问题,分析了跳频信号相关函数的模糊特性,提出了基于多跳相干积累的跳频信号时差估计方法.多跳相关函数中存在周期副峰,将导致时差估计出现周期模糊,提出了两种消除模糊的方法——单跳时差平均法与相关函数包络拟合法.两种方法获得的时差粗值可以确定在相关主峰附近小范围精确搜索的搜索区间,在此区间内进行时差估计可以消除周期模糊.单跳时差平均法通过对单跳时差估计进行非相干平均获得时差粗值.相关函数包络拟合法通过搜索到的多个周期峰值,进行包络拟合获得时差粗值.仿真表明,两种算法性能明显优于常规的互模糊函数法,均能降低无模糊时差估计对相关输出信噪比的要求,提高无模糊时差估计所要求的频率间隔.相关函数包络拟合法性能更优,但运算量更大.

关键词: 跳频信号, 时差模糊, 单跳时差平均, 相关函数包络拟合, 模糊消除

Abstract: In order to estimate the time difference of arrival (TDOA) of frequency hopping signal accurately,the ambiguous characteristic of the correlation function is analyzed,and the TDOA estimation method of frequency hopping signal based on multi-hop coherent integration is investigated.The periodic peaks in the multi-hop correlation function will lead to ambiguous estimation of the TDOA;so two approaches to eliminate ambiguity are proposed:the approach of ambiguity elimination by TDOA averaging of single-hop (TASH) and by envelope fitting of correlation function (EFCF).Ambiguity elimination is achieved through fine peak searching between a small interval nearby the main peak,and the small interval is determined by the coarse TDOA obtained by means of TASH or EFCF.The difference between TASH and EFCF is that the first approach obtains the coarse TDOA by incoherent averaging of TDOA estimation of single-hop,while the second approach obtains the coarse TDOA by the envelope of correlation function which is fitted by using multiple periodic peaks found by whole searching.Numerical simulations demonstrate that the performance of the two proposed methods is obviously superior to the conventional CAF,and the requirement for the correlation output SNR of unambiguous estimation can be reduced,the frequency interval for unambiguous estimation can be increased.The EFCF has better performance but greater computational complexity.

Key words: frequency hopping signal, TDOA ambiguity, TDOA averaging of single-hop (TASH), envelope fitting of correlation function (EFCF), ambiguity elimination

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