为了提高任意阵列的波达方向(direction of arrival,DOA)估计性能,从对子阵阵元选取进行优化的角度出发,提出了基于最优子阵划分旋转不变信号参数估计技术(estimation of signal parameters via rotational invariance techniques,ESPR...为了提高任意阵列的波达方向(direction of arrival,DOA)估计性能,从对子阵阵元选取进行优化的角度出发,提出了基于最优子阵划分旋转不变信号参数估计技术(estimation of signal parameters via rotational invariance techniques,ESPRIT)的任意线阵高精度DOA估计算法.该算法首先利用虚拟插值阵列ESPRIT(virtual interpolated array ESPRIT,VIA-ESPRIT)得到精度较低的DOA粗估计.其次以DOA粗估计为参考对任意阵列进行相位补偿,使其具备旋转不变性.然后根据ESPRIT算法原理对构建旋转不变方程的子阵划分进行优化,并通过优化后子阵间的旋转不变性得到高精度的DOA估计.此外,本文还分析了子阵划分对算法估计性能的影响,给出了子阵最优选取的近似计算方法.计算机仿真结果验证了所提算法的有效性,并表明其性能逼近克拉美·罗界(Cramer-Rao bound,CRB).展开更多
Aim To extract harmonic frequencies of helicopter acoustic signal as features for hel icopter identification. Methods Estimation of signal parameters via rotational invariance techniques(ESPRIT) was selected to ext...Aim To extract harmonic frequencies of helicopter acoustic signal as features for hel icopter identification. Methods Estimation of signal parameters via rotational invariance techniques(ESPRIT) was selected to extract harmonic frequencies from really measured helicopter acoustic signal and an algorithm based on the SVD TLS was used. Results ESPRIT correctly extracted harmonic frequencies of helicopter using the data of limited length under the variousflight conditions. Conclusion ESPRIT is an effective method of extracting harmonic frequencies and using harmonic frequencies of helicopter acoustic signal to recognize helicopter is feasible.展开更多
有效的射频干扰(Radio frequency interference,RFI)抑制技术是超宽带合成孔径雷达(Ul-tra-wideband synthetic aperture radar,UWB-SAR)成像质量的重要保证。通过对超宽带回波信号的特性分析,得出RFI具有短时间内平稳的特性,这样便可...有效的射频干扰(Radio frequency interference,RFI)抑制技术是超宽带合成孔径雷达(Ul-tra-wideband synthetic aperture radar,UWB-SAR)成像质量的重要保证。通过对超宽带回波信号的特性分析,得出RFI具有短时间内平稳的特性,这样便可借助谱估计方法对其进行估计。旋转不变技术估计信号参数方法(Estimation of signal parameters via rotational invariance techniques,ESPRIT)是谱估计中一种频率估计性能较好、运算量较小的方法,文章对该算法在UWB-SAR RFI抑制中的应用进行了研究分析,并通过仿真实验表明该算法对RFI具有良好的抑制性能。展开更多
文摘为了提高任意阵列的波达方向(direction of arrival,DOA)估计性能,从对子阵阵元选取进行优化的角度出发,提出了基于最优子阵划分旋转不变信号参数估计技术(estimation of signal parameters via rotational invariance techniques,ESPRIT)的任意线阵高精度DOA估计算法.该算法首先利用虚拟插值阵列ESPRIT(virtual interpolated array ESPRIT,VIA-ESPRIT)得到精度较低的DOA粗估计.其次以DOA粗估计为参考对任意阵列进行相位补偿,使其具备旋转不变性.然后根据ESPRIT算法原理对构建旋转不变方程的子阵划分进行优化,并通过优化后子阵间的旋转不变性得到高精度的DOA估计.此外,本文还分析了子阵划分对算法估计性能的影响,给出了子阵最优选取的近似计算方法.计算机仿真结果验证了所提算法的有效性,并表明其性能逼近克拉美·罗界(Cramer-Rao bound,CRB).
文摘Aim To extract harmonic frequencies of helicopter acoustic signal as features for hel icopter identification. Methods Estimation of signal parameters via rotational invariance techniques(ESPRIT) was selected to extract harmonic frequencies from really measured helicopter acoustic signal and an algorithm based on the SVD TLS was used. Results ESPRIT correctly extracted harmonic frequencies of helicopter using the data of limited length under the variousflight conditions. Conclusion ESPRIT is an effective method of extracting harmonic frequencies and using harmonic frequencies of helicopter acoustic signal to recognize helicopter is feasible.
文摘有效的射频干扰(Radio frequency interference,RFI)抑制技术是超宽带合成孔径雷达(Ul-tra-wideband synthetic aperture radar,UWB-SAR)成像质量的重要保证。通过对超宽带回波信号的特性分析,得出RFI具有短时间内平稳的特性,这样便可借助谱估计方法对其进行估计。旋转不变技术估计信号参数方法(Estimation of signal parameters via rotational invariance techniques,ESPRIT)是谱估计中一种频率估计性能较好、运算量较小的方法,文章对该算法在UWB-SAR RFI抑制中的应用进行了研究分析,并通过仿真实验表明该算法对RFI具有良好的抑制性能。
