无源定位中雷达信号的时差提取
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摘要
无源时差定位又称为双曲线定位,是一种重要的无源定位方法,它通过处理三个或更多个接收站采集到的信号到达时间数据,从而对辐射源进行定位。时差定位系统具有精度高、定位快等优点,在工程中得到了广泛的应用。但是时差定位系统的精度主要取决于时延估计的精度,因此,研究快速、准确的时延估计方法成为时差定位系统中一个十分重要的课题。
实际工程中雷达信号的传播环境十分复杂,信号在传播过程中要受到反射、散射以及各种杂波的影响,因此接收机接收到的信号往往具有信噪比比较低、信号模型复杂等特点。现在常用的几种时延估计方法,只适用于信号为平稳信号,噪声为加性高斯白噪声这样比较简单的情况。像雷达信号这样复杂的传播模型,这些常用的时延估计方法就不适用了。
大部分的雷达信号都是非平稳信号,但它们都具有循环平稳特性,所谓循环平稳信号是指相关函数为时间的周期函数的一大类非平稳信号。基于这样的特点本文给出了基于循环平稳性的时延估计方法。该方法不仅能够有效的进行信号的时延估计,而且该方法还可以对某些信号的参数进行估计;在抗噪性方面该方法不仅能够抑制加性平稳噪声,而且还能够抑制乘性平稳噪声。该方法计算量较小,易于工程实现,能够满足雷达对抗的实时性要求。
正弦信号、线性调频信号、多项式相位信号、相位编码信号是雷达信号中常用的几种信号,对这几种信号的研究是雷达信号处理中非常重要的内容,也是实际工程的需要。因此,本文选择上述几种信号作为研究对象,对这几种信号的时延估计算法进行了建模和理论推导,给出了时延估计算法的具体表达式,并进行了计算机仿真。
文章的最后进行了全文总结,指出了有待下一步研究的问题。本文提供的方法为循环平稳信号处理方法在雷达信号处理方面的应用提供了一个很好的思路和方法。
Time difference of arrival (TDOA) location system, namely the hyperbola location, is an important passive location method.Using the time difference of signals arrived to three or more different stations, we can determine the position of the target wanted to be located.Because of its high precision and fast location advantages, it is widely used in practice.But its precision depends on time delay estimation, so researching fast and exact time delay estimation method become a hot topic in TDOA location system.
The special radar signal environment is very complex in electronic warfare, so the received signals always have low signal noise ratio (SNR) and complex model.Under this kind of environment, the estimation precision of time delay and the capability of restraining noise fallen down in the conventional methods.
Most radar signals are non-stationary signals, but they are cyclostationary signals,namely, the correlation function of radar signals is periodic function of time. Based on the cyclostationary characteristic, a novel time delay estimation method has been proposed in this thesis.
The reseach work focused on the time delay estimation of the common practical radar singnals, including harmonics signal, chirp signal, polynomial phase signal, and phase-shift keying signal.The new algorithm for different radar signals are deduced in detail respectively, and simulation results are presented.The results proved that the new method is efficient for time delay and some other parameters estimation. At the same time, it can restrain multiplicative and additive noise.
Generally, a nice idea and method are proposed for radar signal processing. Meanwhile, there is still a lot of work worth further research with great effort.
实际工程中雷达信号的传播环境十分复杂,信号在传播过程中要受到反射、散射以及各种杂波的影响,因此接收机接收到的信号往往具有信噪比比较低、信号模型复杂等特点。现在常用的几种时延估计方法,只适用于信号为平稳信号,噪声为加性高斯白噪声这样比较简单的情况。像雷达信号这样复杂的传播模型,这些常用的时延估计方法就不适用了。
大部分的雷达信号都是非平稳信号,但它们都具有循环平稳特性,所谓循环平稳信号是指相关函数为时间的周期函数的一大类非平稳信号。基于这样的特点本文给出了基于循环平稳性的时延估计方法。该方法不仅能够有效的进行信号的时延估计,而且该方法还可以对某些信号的参数进行估计;在抗噪性方面该方法不仅能够抑制加性平稳噪声,而且还能够抑制乘性平稳噪声。该方法计算量较小,易于工程实现,能够满足雷达对抗的实时性要求。
正弦信号、线性调频信号、多项式相位信号、相位编码信号是雷达信号中常用的几种信号,对这几种信号的研究是雷达信号处理中非常重要的内容,也是实际工程的需要。因此,本文选择上述几种信号作为研究对象,对这几种信号的时延估计算法进行了建模和理论推导,给出了时延估计算法的具体表达式,并进行了计算机仿真。
文章的最后进行了全文总结,指出了有待下一步研究的问题。本文提供的方法为循环平稳信号处理方法在雷达信号处理方面的应用提供了一个很好的思路和方法。
Time difference of arrival (TDOA) location system, namely the hyperbola location, is an important passive location method.Using the time difference of signals arrived to three or more different stations, we can determine the position of the target wanted to be located.Because of its high precision and fast location advantages, it is widely used in practice.But its precision depends on time delay estimation, so researching fast and exact time delay estimation method become a hot topic in TDOA location system.
The special radar signal environment is very complex in electronic warfare, so the received signals always have low signal noise ratio (SNR) and complex model.Under this kind of environment, the estimation precision of time delay and the capability of restraining noise fallen down in the conventional methods.
Most radar signals are non-stationary signals, but they are cyclostationary signals,namely, the correlation function of radar signals is periodic function of time. Based on the cyclostationary characteristic, a novel time delay estimation method has been proposed in this thesis.
The reseach work focused on the time delay estimation of the common practical radar singnals, including harmonics signal, chirp signal, polynomial phase signal, and phase-shift keying signal.The new algorithm for different radar signals are deduced in detail respectively, and simulation results are presented.The results proved that the new method is efficient for time delay and some other parameters estimation. At the same time, it can restrain multiplicative and additive noise.
Generally, a nice idea and method are proposed for radar signal processing. Meanwhile, there is still a lot of work worth further research with great effort.
引文
1. 单月辉,孙仲康.不断发展的无源定位技术.航空电子对抗,2001,23(6):36-42
2. 徐汉林.时差无源三站精确定位技术研究.电子对抗技术,1998,13(1):15-23
3. 张正明 辐射源无源定位研究:[博士学位论文].西安:西安电子科技大学,2000
4. Carter G C, Knapp C H.The generalized correlation method for estimation of time delay IEEE Trans Acoustics speech , signal processing,1976, 24(4):320-327.
5. Piersol A G . Time delay estimation using phase data . IEEE Trans on ASSP,1981,29(3):471-477
6. Nikias C L, Pan R.Time delay estimation in unknown Gaussian spatially correlated noise IEEE Trans on ASSP,1988,36(11):1706-1714
7. Chan Y T Riley J M, Plant J B.A Parameter estimation approach to time delay estimation and signal detection.IEEE Trans on ASSP ,1980,28(1):8-16
8. Chan Y T Riley J M, Plant J B.Modeling of the delay and its application to estimation and signal detection,IEEE Trans on ASSP,1981,29(3):577-581
9. Reed F A, Fintuch P L, Bershad N J.Time delay estimation using the LMS adaptive filter-static behavior.IEEE Trans on ASSP ,1981,29(3):651-571
10. 邱天爽.LMS 自适应时间延迟估计.海洋技术,1993,(12)1-13
11. Youn D H,Ahmed N,Carter G C.On using the LMS algorithm for time delay estimation.IEEE Trans on ASSP,1982,30(5):789-801
12. WA.Gardner . The spectral correlation theory of cyclostationary time-series . Signal Processing,1986,11(4):13-36
13. 张贤达,保铮.非平稳信号分析与处理.国防工业出版社,1999
14. 张贤达.现代信号处理(第二版).清华大学出版社,2002
15. 王宏禹.现代谱估计.东南大学出版社.1991
16. 胡广书.数字信号处理一理论、算法与实现.清华大学出版社,1997
17. H C SO . Time-delay estimation for sinusoidal signals . IEEE Proc-Radar, Sonar Naving,2001,148(6):318-324
18. G.B. Giannakis,G.T. Zhou.Harmonics in multiplicative and additive noise: Parameter estimation using cyclic statistics.IEEE Trans. SP,1995,43(9):2217-2221
19. G.T.Zhou,G.B. Giannakis.Harmonics in multiplicative and additive noise: Performance analysis of cyclic estimators.IEEE Trans. SP,1995,43(6):1445-1460
20. William A G., Chih-Kang C.Signal-selective time-difference of arrival estimation for passive location of man-made signal source in highly corruptive environments, part Ⅰ theory and method.IEEE Tran-Signal processing ,1992,40(5):1168-1184
21. William A G, Chih-Kang C.Signal-selective time-difference of arrival estimation for passive location of man-made signal source in highly corruptive environments, partⅡalgorithms and performance.IEEE Tran-Signal processing,1992,40(5):1185-1197
22. Petar M, Steven M K.Parameter estimation of chirp signals.IEEE Tran-Signal processing, Dec 1990,38(12):121-128
23. 黄知涛 基于循环平稳特性的低截获概率信号的截获技术研究:[博士学位论文].长沙:国防科技大学,2000
24. 毛用才 几种复高阶循环平稳信号的参数估计研究:[博士学位论文].西安:西安电子科技大学 1999
25. S.Shanmsunder, G B Giannakis.estimating random amplitude polynomial phase signals: A Cyclostationary approach.IEEE Tran Signal processing,1995,43(2):492-505
26. S.Peleg, B Porat.estimation and classification of polynomial phase signals.IEEE Tran Information theory,1991,37(2):422-430
27. G Zhou,G B Giannakis.on polynomial signals with time-varying amplitudes.IEEE Tran Signal processing,1996,44(4):848-861
28. S Barbarossa, V Petrone.analysis of polynomial phase signals by the integrated generalized ambiguity function.IEEE Tran Signal processing,1997,45(2):316-327
29. A V Dandawate, G B Giannakis.Asymptotic theory of mixed time averages and kth-order cyclic-moment and cumulant statistics.IEEE Tran inform theory,1995,28(5):162-170
30. WA. Gardner.Introduction to Random Processes with Applications to Signals and Systems NewYork: Macmillan, 1985
31. WA. Gardner, WA. Brown and C.K. Chen.Spectral correlation of modulated signals. Part II-Digital modulation.IEEE Trans. Commun,1987,35(6):595-601
32. WA. Gardner, C.M. Spooner.Detection and source location of weak cyclostationary signals: Simplifications of the maximum-likelihood receiver.IEEE Trans. Com,1993,41(6):
33 F Gini, G.B. Giannakis.Frequency offset and timing estimation in slowly varing fading channels :a cyclostationary approach.IEEE trans. Com.,1995,46(8):400-411
34 S.C. Rezeanu, R.E. Ziemer, M.A. Wickert.Joint maximum-likelihood parameter estimation for burst DS spread-spectrum transmission.IEEE trans,1997,45(2):227-238
35 冯小平.扩频通信信号的到达时差估计方法.西安电子科技大学学报,2000,27(1):17-20
36 黄春琳,姜文利,周一宇.低截获概率雷达信号的循环谱相关函数检测方法分析,国防科技大学学报,2001,23(4):102-106
37 柳征,黄知涛,周一宇.调幅调频信号的循环平稳性分析,系统工程与电子技术,2002,24(1):21-27
38 张仔兵,李立萍,肖先赐.MPSK信号的循环谱检测及码元速率估计,系统工程与电子技术,2005,27(5):803-806
39 丁鹭飞,耿富录.雷达原理(第三版).西安电子科技大学出版社,2002.
40 赵国庆.雷达对抗原理.西安电子科技大学出版社,1999
41 曹志刚,钱亚生.现代通信原理.清华大学出版社,2001
42 张志涌.精通MATLAB(6.5版).北京航空航天大学出版社,2003
43 孙仲康.单多基地有源无源定位技术.国防工业出版社,1996
44 Simon Haykin.自适应滤波器原理(第四版).电子工业出版社,2003
45 沈风麟,叶中付,钱玉美.信号统计分析与处理.中国科学技术大学出版社,2000
2. 徐汉林.时差无源三站精确定位技术研究.电子对抗技术,1998,13(1):15-23
3. 张正明 辐射源无源定位研究:[博士学位论文].西安:西安电子科技大学,2000
4. Carter G C, Knapp C H.The generalized correlation method for estimation of time delay IEEE Trans Acoustics speech , signal processing,1976, 24(4):320-327.
5. Piersol A G . Time delay estimation using phase data . IEEE Trans on ASSP,1981,29(3):471-477
6. Nikias C L, Pan R.Time delay estimation in unknown Gaussian spatially correlated noise IEEE Trans on ASSP,1988,36(11):1706-1714
7. Chan Y T Riley J M, Plant J B.A Parameter estimation approach to time delay estimation and signal detection.IEEE Trans on ASSP ,1980,28(1):8-16
8. Chan Y T Riley J M, Plant J B.Modeling of the delay and its application to estimation and signal detection,IEEE Trans on ASSP,1981,29(3):577-581
9. Reed F A, Fintuch P L, Bershad N J.Time delay estimation using the LMS adaptive filter-static behavior.IEEE Trans on ASSP ,1981,29(3):651-571
10. 邱天爽.LMS 自适应时间延迟估计.海洋技术,1993,(12)1-13
11. Youn D H,Ahmed N,Carter G C.On using the LMS algorithm for time delay estimation.IEEE Trans on ASSP,1982,30(5):789-801
12. WA.Gardner . The spectral correlation theory of cyclostationary time-series . Signal Processing,1986,11(4):13-36
13. 张贤达,保铮.非平稳信号分析与处理.国防工业出版社,1999
14. 张贤达.现代信号处理(第二版).清华大学出版社,2002
15. 王宏禹.现代谱估计.东南大学出版社.1991
16. 胡广书.数字信号处理一理论、算法与实现.清华大学出版社,1997
17. H C SO . Time-delay estimation for sinusoidal signals . IEEE Proc-Radar, Sonar Naving,2001,148(6):318-324
18. G.B. Giannakis,G.T. Zhou.Harmonics in multiplicative and additive noise: Parameter estimation using cyclic statistics.IEEE Trans. SP,1995,43(9):2217-2221
19. G.T.Zhou,G.B. Giannakis.Harmonics in multiplicative and additive noise: Performance analysis of cyclic estimators.IEEE Trans. SP,1995,43(6):1445-1460
20. William A G., Chih-Kang C.Signal-selective time-difference of arrival estimation for passive location of man-made signal source in highly corruptive environments, part Ⅰ theory and method.IEEE Tran-Signal processing ,1992,40(5):1168-1184
21. William A G, Chih-Kang C.Signal-selective time-difference of arrival estimation for passive location of man-made signal source in highly corruptive environments, partⅡalgorithms and performance.IEEE Tran-Signal processing,1992,40(5):1185-1197
22. Petar M, Steven M K.Parameter estimation of chirp signals.IEEE Tran-Signal processing, Dec 1990,38(12):121-128
23. 黄知涛 基于循环平稳特性的低截获概率信号的截获技术研究:[博士学位论文].长沙:国防科技大学,2000
24. 毛用才 几种复高阶循环平稳信号的参数估计研究:[博士学位论文].西安:西安电子科技大学 1999
25. S.Shanmsunder, G B Giannakis.estimating random amplitude polynomial phase signals: A Cyclostationary approach.IEEE Tran Signal processing,1995,43(2):492-505
26. S.Peleg, B Porat.estimation and classification of polynomial phase signals.IEEE Tran Information theory,1991,37(2):422-430
27. G Zhou,G B Giannakis.on polynomial signals with time-varying amplitudes.IEEE Tran Signal processing,1996,44(4):848-861
28. S Barbarossa, V Petrone.analysis of polynomial phase signals by the integrated generalized ambiguity function.IEEE Tran Signal processing,1997,45(2):316-327
29. A V Dandawate, G B Giannakis.Asymptotic theory of mixed time averages and kth-order cyclic-moment and cumulant statistics.IEEE Tran inform theory,1995,28(5):162-170
30. WA. Gardner.Introduction to Random Processes with Applications to Signals and Systems NewYork: Macmillan, 1985
31. WA. Gardner, WA. Brown and C.K. Chen.Spectral correlation of modulated signals. Part II-Digital modulation.IEEE Trans. Commun,1987,35(6):595-601
32. WA. Gardner, C.M. Spooner.Detection and source location of weak cyclostationary signals: Simplifications of the maximum-likelihood receiver.IEEE Trans. Com,1993,41(6):
33 F Gini, G.B. Giannakis.Frequency offset and timing estimation in slowly varing fading channels :a cyclostationary approach.IEEE trans. Com.,1995,46(8):400-411
34 S.C. Rezeanu, R.E. Ziemer, M.A. Wickert.Joint maximum-likelihood parameter estimation for burst DS spread-spectrum transmission.IEEE trans,1997,45(2):227-238
35 冯小平.扩频通信信号的到达时差估计方法.西安电子科技大学学报,2000,27(1):17-20
36 黄春琳,姜文利,周一宇.低截获概率雷达信号的循环谱相关函数检测方法分析,国防科技大学学报,2001,23(4):102-106
37 柳征,黄知涛,周一宇.调幅调频信号的循环平稳性分析,系统工程与电子技术,2002,24(1):21-27
38 张仔兵,李立萍,肖先赐.MPSK信号的循环谱检测及码元速率估计,系统工程与电子技术,2005,27(5):803-806
39 丁鹭飞,耿富录.雷达原理(第三版).西安电子科技大学出版社,2002.
40 赵国庆.雷达对抗原理.西安电子科技大学出版社,1999
41 曹志刚,钱亚生.现代通信原理.清华大学出版社,2001
42 张志涌.精通MATLAB(6.5版).北京航空航天大学出版社,2003
43 孙仲康.单多基地有源无源定位技术.国防工业出版社,1996
44 Simon Haykin.自适应滤波器原理(第四版).电子工业出版社,2003
45 沈风麟,叶中付,钱玉美.信号统计分析与处理.中国科学技术大学出版社,2000