To estimate the direction-of-arrival （DOA） of wideband coherent signals, a new method by modifying the orthogonality of the projected suhspaces method is proposed. And it can deal with randomly position perturbed ar...To estimate the direction-of-arrival （DOA） of wideband coherent signals, a new method by modifying the orthogonality of the projected suhspaces method is proposed. And it can deal with randomly position perturbed arrays by using the Toeplitz method. This method needn＇t the primary information of DOA for focusing matrix and the sector dividing of interpolated method, which improving the precision of estimation and reducing the computational complexity. Simulations illustrate the effectiveness of this method.展开更多
A phase-derived velocity measurement method is proposed in a wideband coherent system,based on a precise echo model considering the inner pulse Doppler effect caused by fast moving targets.The Cramer-Rao low band of v...A phase-derived velocity measurement method is proposed in a wideband coherent system,based on a precise echo model considering the inner pulse Doppler effect caused by fast moving targets.The Cramer-Rao low band of velocity measurement precision is deduced,demonstrating the high precision of the proposed method.Simulations and out-field experiments further validate the effectiveness of the proposed method in high-precision measurement and micro-motion extraction for targets with weak reflection intensity.Compared with the long-time integration approaches for velocity measurement,the phase-derived method is easy to implement and meets the requirement for high data rate,which makes it suitable for micro-motion feature extraction in wideband systems.展开更多
In order to solve the problem of coherent signal subspace method(CSSM) depending on the estimated accuracy of signal subspace, a new direction of arrival(DOA) estimation method of wideband source, which is based on it...In order to solve the problem of coherent signal subspace method(CSSM) depending on the estimated accuracy of signal subspace, a new direction of arrival(DOA) estimation method of wideband source, which is based on iterative adaptive spectral reconstruction, is proposed. Firstly, the wideband signals are divided into several narrowband signals of different frequency bins by discrete Fourier transformation(DFT). Then, the signal matched power spectrum in referenced frequency bins is computed, which can form the initial covariance matrix. Finally, the linear restrained minimum variance spectral(Capon spectral) of signals in other frequency bins are reconstructed using sequential iterative means, so the DOA can be estimated by the locations of spectral peaks. Theoretical analysis and simulation results show the proposed method based on the iterative spectral reconstruction for the covariance matrices of all sub-bands can avoid the problem of determining the signal subspace accurately with the coherent signal subspace method under the conditions of small samples and low signal to noise ratio(SNR), and it can also realize full dimensional focusing of different sub-band data, which can be applied to coherent sources and can significantly improve the accuracy of DOA estimation.展开更多
For the frequency difference of arrival （FDOA） esti-mation in passive location, this paper transforms the frequency difference estimation into the radial velocity difference estimation, which is difficult to achieve...For the frequency difference of arrival （FDOA） esti-mation in passive location, this paper transforms the frequency difference estimation into the radial velocity difference estimation, which is difficult to achieve a high accuracy due to the mismatch between the sampling period and the pulse repetition interval. The proposed algorithm firstly estimates the point-in-time that each pulse arrives at two receivers accurately. Secondly two time of arrival （TOA） sequences are subtracted. And final y the radial ve-locity difference of a target relative to two stations with the least square method is estimated. This algorithm only needs accurate estimation of the time delay between pulses and is not influenced by parameters such as frequency and modulation mode. It avoids transmitting a large amount of data between two stations in real time. Simulation results corroborate that the performance is bet-ter than the arithmetic average of the Cramer-Rao lower bound （CRLB） for monopulse under suitable conditions.展开更多
本文提出了一种新的宽带信号DOA(Direction of Arrival)快速估计方法。该方法既不需要对阵列观测输出进行“聚焦”变换,也不需要对阵列输出的协方差矩阵进行特征值分解,从而使得该方法运算量比常用的宽带空间谱估计方法要小很多。计算...本文提出了一种新的宽带信号DOA(Direction of Arrival)快速估计方法。该方法既不需要对阵列观测输出进行“聚焦”变换,也不需要对阵列输出的协方差矩阵进行特征值分解,从而使得该方法运算量比常用的宽带空间谱估计方法要小很多。计算机仿真试验证实了方法的有效性。展开更多
本文针对动态信噪比环境超宽带(UWB,Ultra WideBand)信号的非相干捕获,提出了一种基于遗传算法的信号捕获方案.以遗传算法结合在线估计接收信噪比,搜索积分窗口长度与定时位置的参数组合,实现系统要求的比特错误概率.该方法解决了传统...本文针对动态信噪比环境超宽带(UWB,Ultra WideBand)信号的非相干捕获,提出了一种基于遗传算法的信号捕获方案.以遗传算法结合在线估计接收信噪比,搜索积分窗口长度与定时位置的参数组合,实现系统要求的比特错误概率.该方法解决了传统捕获方案在未知信噪比条件下积分长度无法择优选取以及捕获门限难于设定的问题.仿真结果表明,基于遗传算法的二维参数捕获方法与传统Look and Jump by Ksteps算法相比有效的提高了未知信噪比条件下的系统捕获性能,拓展了UWB非相干系统的应用范围.展开更多
文摘To estimate the direction-of-arrival （DOA） of wideband coherent signals, a new method by modifying the orthogonality of the projected suhspaces method is proposed. And it can deal with randomly position perturbed arrays by using the Toeplitz method. This method needn＇t the primary information of DOA for focusing matrix and the sector dividing of interpolated method, which improving the precision of estimation and reducing the computational complexity. Simulations illustrate the effectiveness of this method.
基金Supported by the National Natural Science Foundation of China(61301189)111 Project of China(B14010)
文摘A phase-derived velocity measurement method is proposed in a wideband coherent system,based on a precise echo model considering the inner pulse Doppler effect caused by fast moving targets.The Cramer-Rao low band of velocity measurement precision is deduced,demonstrating the high precision of the proposed method.Simulations and out-field experiments further validate the effectiveness of the proposed method in high-precision measurement and micro-motion extraction for targets with weak reflection intensity.Compared with the long-time integration approaches for velocity measurement,the phase-derived method is easy to implement and meets the requirement for high data rate,which makes it suitable for micro-motion feature extraction in wideband systems.
基金supported by the National Natural Science Foundation of China(61671352)the open foundation of Key Laboratory of Cognitive Radio and Information Processing,Ministry of Education(Guilin University of Electronic Technology)(CRKL160206)Xi’an University of Science and Technology Doctor(after)Start Gold Project(2017QDJ018)
文摘In order to solve the problem of coherent signal subspace method(CSSM) depending on the estimated accuracy of signal subspace, a new direction of arrival(DOA) estimation method of wideband source, which is based on iterative adaptive spectral reconstruction, is proposed. Firstly, the wideband signals are divided into several narrowband signals of different frequency bins by discrete Fourier transformation(DFT). Then, the signal matched power spectrum in referenced frequency bins is computed, which can form the initial covariance matrix. Finally, the linear restrained minimum variance spectral(Capon spectral) of signals in other frequency bins are reconstructed using sequential iterative means, so the DOA can be estimated by the locations of spectral peaks. Theoretical analysis and simulation results show the proposed method based on the iterative spectral reconstruction for the covariance matrices of all sub-bands can avoid the problem of determining the signal subspace accurately with the coherent signal subspace method under the conditions of small samples and low signal to noise ratio(SNR), and it can also realize full dimensional focusing of different sub-band data, which can be applied to coherent sources and can significantly improve the accuracy of DOA estimation.
基金supported by the National Natural Science Foundationof China(61201208)
文摘For the frequency difference of arrival （FDOA） esti-mation in passive location, this paper transforms the frequency difference estimation into the radial velocity difference estimation, which is difficult to achieve a high accuracy due to the mismatch between the sampling period and the pulse repetition interval. The proposed algorithm firstly estimates the point-in-time that each pulse arrives at two receivers accurately. Secondly two time of arrival （TOA） sequences are subtracted. And final y the radial ve-locity difference of a target relative to two stations with the least square method is estimated. This algorithm only needs accurate estimation of the time delay between pulses and is not influenced by parameters such as frequency and modulation mode. It avoids transmitting a large amount of data between two stations in real time. Simulation results corroborate that the performance is bet-ter than the arithmetic average of the Cramer-Rao lower bound （CRLB） for monopulse under suitable conditions.
文摘本文针对动态信噪比环境超宽带(UWB,Ultra WideBand)信号的非相干捕获,提出了一种基于遗传算法的信号捕获方案.以遗传算法结合在线估计接收信噪比,搜索积分窗口长度与定时位置的参数组合,实现系统要求的比特错误概率.该方法解决了传统捕获方案在未知信噪比条件下积分长度无法择优选取以及捕获门限难于设定的问题.仿真结果表明,基于遗传算法的二维参数捕获方法与传统Look and Jump by Ksteps算法相比有效的提高了未知信噪比条件下的系统捕获性能,拓展了UWB非相干系统的应用范围.
