小快拍条件下利用样本协方差矩阵代替统计协方差矩阵会带来较大误差,导致传统DOA估计算法不能准确估计目标方位。通过分析发现在不同阵元数与快拍数之比情况下,不管相干源还是独立源,样本协方差矩阵都具有明显的谱分离特性,在此基础上提出了采用小快拍的主特征空间目标波达方向估计方法,该方法利用导向向量与噪声子空间正交,且与信号子空间平行的特性,使用导向向量与主特征空间相乘再取反余弦构造出目标DOA估计幅度。仿真与水池试验中阵元数与样本数之比为1时依然可以准确将多个目标分辨出;海试数据验证中,阵元数与样本数之比也同样为1时,2个相邻目标可以正确分辨出,而MUSIC算法则有伪目标出现。
Abstract
Sample covariance matrix (SCM) with small sample instead of a array covariance matrix will bring great error, which leads to the traditional algorithm can not accurately estimate the direction of arrival (DOA) of targets. It is found that the sample covariance matrix has obvious spectral separation property with different ratio of elements number to samples number regardless of coherent source or independent source, and then a DOA estimation method based on main feature space was proposed using small number of snapshots. It is well known that the steering vector is orthogonal to the noise subspace and parallel to the signal subspace. Steering vector and the main feature space of SCM were multiplied, and then the inverse cosine was taken to construct the targets DOA estimation amplitude. In the simulation and water tank experiment, when the ratio of the number of sensors to the number of samples is 1, the proposed method can still distinguish multi targets correctly; in the sea trial, when the above ratio is 1, it can identify 2 adjacent targets clearly, while the MUSIC algorithm has a pseudo target.
关键词
样本协方差矩阵 /
谱分离特性 /
主特征空间 /
波达方向估计 /
小快拍
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Key words
sample covariance matrix(SCM) /
spectral separation /
main feature space /
direction of arrival(DOA) estimation /
small number of snapshots
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参考文献
[1] 王永良,陈辉,彭应宁,等.空间谱估计理论与算法[M].北京:清华大学出版社,2004:2~5.
Wang Yong-liang, Chen Hui, Peng Ying-ning, et al. Theory and algorithm of spatial spectrum estimation[M].BeiJing:Tsinghua Press, 2004:2~5.
[2] Carlson B D. Covariance matrix estimation errors and diagonal loading in adaptive arrays[J]. IEEE Transactions on Aerospace Electronic Systems, 1988, 24(4):397-401.
[3] Chen Y, Wiesel A, Eldar Y C, et al. Shrinkage Algorithms for MMSE Covariance Estimation[J]. IEEE Transactions on Signal Processing, 2010, 58(10):5016-5029.
[4] Pillai S U, Kwon B H. Forward/Backward spatial smoothing techniques for coherent signal Identification[J]. IEEE Transactions on Acoustics Speech & Signal Processing, 1989, 37(1):8-15.
[5] Evans J E, Sun D F, Johnson J R. Application of Advanced Signal Processing Techniques to Angle of Arrival Estimation in ATC Navigation and Surveillance Systems[J]. Calculation, 1982.
[6] Gershman A B, Bã¶Hme J F. Improved DOA estimation via pseudorandom resampling of spatial spectrum[J]. IEEE Signal Processing Letters, 1997, 4(2):54 - 57.
[7]Vasylyshyn V. Removing the outliers in root-MUSIC via pseudo-noise resampling and conventional beamformer[J]. Signal Processing, 2013, 93(12):3423-3429.
[8] Qian C, Huang L, So H C. Improved Unitary Root-MUSIC for DOA Estimation Based on Pseudo-Noise Resampling[J]. IEEE Signal Processing Letters, 2014, 21(2):140-144.
[9] Shaghaghi M, Vorobyov S A. Subspace Leakage Analysis and Improved DOA Estimation With Small Sample Size[J]. Signal Processing IEEE Transactions on, 2015, 63(12):3251-3265.
[10] Bai Z D, Silverstein J W. No eigenvalues outside the support of the limiting spectral distribution of large-dimensional sample covariance matrices[J]. Annals of probability, 1998: 316-345.
[11] Bai Z D, Silverstein J W. Exact separation of eigenvalues of large dimensional sample covariance matrices[J]. Annals of probability, 1999: 1536-1555.
[12] 李华, 白志东, 肖玉山. 大维随机矩阵的渐进特征[J]. 东北师大学报(自然科学版),2014,46 (4): 1-8.
Li Hua,Bai Zhi-dong,Xiao Yu-shan. The asymptotic properties of the large dimension random matrix[J]. Journal of Northeast Normal University (Natural Science Edition), 2014 ,46(4): 1-8.
[13] Mestre X, Lagunas M Á. Modified subspace algorithms for DoA estimation with large arrays[J]. Signal Processing, IEEE Transactions on, 2008, 56(2): 598-614.
[14] Stergiopoulos S, Sullivan E J. Extended towed array processing by an overlap correlator[J]. The Journal of the Acoustical Society of America, 1989, 86(1): 158-171.
[15] Chavali V, Wage K E, Buck J R. Coprime processing for the Elba Island sonar data set[C]//, 48th Asilomar Conference on Signals, Systems and Computers. California.: IEEE, 2014: 1864-1868.
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脚注
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