An effective DOA estimation method of coherent signals based on reconstruct weighted noise subspace

In this article, a difference-coarray-based direction of arrival (DOA) method is introduced, which utilizes the uniform linear array (ULA) in a novel fashion to address the problem of DOA estimation for coherent signals. Inspired by the coarray-based estimators employed in cases of sparse arrays, we convert the sample covariance matrix of the observed signals into the difference coarray domain and process the signals using a spatial smoothing technique. The proposed method exhibits good accuracy and robustness in both the uncorrelated and coherent cases. Numerical simulations verify that the ULA difference coarray- (UDC-) based method can achieve good DOA estimation accuracy even when the SNR is very low. In addition, the UDC-based method is insensitive to the number of snapshots. Under extremely challenging conditions, the proposed UDC-ES-DOA method is preferred because of its outstanding robustness, while the UDC-MUSIC method is suitable for most moderate cases of lower complexity. Due to its demonstrated advantages, the proposed method is a promising and competitive solution for practical DOA estimation, especially for low-SNR or snapshot-limited applications.

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DOA Estimation Method in Multipath Environment for Passive Bistatic Radar

International Journal of Antennas and Propagation ◽

10.1155/2019/7419156 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Panhe Hu ◽

Qinglong Bao ◽

Zengping Chen

Keyword(s):

Signal To Noise Ratio ◽

Estimation Method ◽

Doa Estimation ◽

Estimation Accuracy ◽

Bistatic Radar ◽

Spatial Difference ◽

Coherent Signals ◽

Vhf Radar ◽

Multipath Environment ◽

Passive Bistatic Radar

Direction-of-arrival (DOA) estimation in multipath environment is an important issue for passive bistatic radar (PBR) using frequency agile phased array VHF radar as illuminator of opportunity. Under such scenario, the main focus of this paper is to cope with the closely spaced uncorrelated and coherent signals in low signal-to-noise ratio and limited snapshots. Making full use of the characteristics of moduli of eigenvalues, the DOAs of the uncorrelated signals are firstly estimated. Afterwards, their contributions are eliminated by means of spatial difference technique. Finally, in order to improve resolution and accuracy DOA estimation of remaining coherent signals while avoiding the cross-terms effect, a new beamforming solution based iterative adaptive approach (IAA) is proposed to deal with a reconstructed covariance matrix. The proposed method combines the advantages of both spatial difference method and the IAA algorithm while avoiding their shortcomings. Simulation results validate its effectiveness; meanwhile, the good performances of the proposed method in terms of resolution probability, detection probability, and estimation accuracy are demonstrated by comparison with the existing methods.

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Fast DOA Estimation Based on the Transform Domain Weighted Noise Subspace Fitting Algorithm for Generalized Sparse Array

International Journal of Antennas and Propagation ◽

10.1155/2021/9952575 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Chunxi Liu ◽

Zhikun Chen ◽

Dongliang Peng

Keyword(s):

Estimation Method ◽

Estimation Algorithm ◽

Doa Estimation ◽

Transform Domain ◽

Music Algorithm ◽

Sparse Array ◽

Estimation Algorithms ◽

Noise Subspace ◽

Fitting Algorithm ◽

Array Aperture

Compared with uniform arrays, a generalized sparse array (GSA) can obtain larger array aperture because of its larger element spacing, which improves the accuracy of DOA estimation. At present, most DOA estimation algorithms are only suitable for the uniform arrays, while a few DOA estimate algorithms that can be applied to the GSA are unsatisfactory in terms of computational speed and accuracy. To compensate this deficiency, an improved DOA estimation algorithm which can be applied to the GSA is proposed in this paper. First, the received signal model of the GSA is established. Then, a fast DOA estimation method is derived by combining the weighted noise subspace algorithm (WNSF) with the concept of “transform domain” (TD). Theoretical analysis and simulation results show that compared with the traditional multiple signal classification (MUSIC) algorithm and the traditional WNSF algorithm, the proposed algorithm has higher accuracy and lower computational complexity.

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New DOA Estimation Method for Wideband Coherent Signals in the Presence of Correlated Noise

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.263-266.157 ◽

2012 ◽

Vol 263-266 ◽

pp. 157-161 ◽

Cited By ~ 1

Author(s):

Jin Zhang ◽

Yun Xiang Mao ◽

Jian Yun Zhang

Keyword(s):

Numerical Simulation ◽

Antenna Array ◽

Covariance Matrix ◽

Estimation Method ◽

Direction Of Arrival ◽

Doa Estimation ◽

Correlated Noise ◽

Linear Antenna ◽

Coherent Signals ◽

Linear Antenna Array

With a uniform linear antenna array, a new direction-of-arrival (DOA) estimation method is proposed for wideband coherent signals in the presence of unknown correlated noise but with structured covariance matrix. Based on this proposed structure, i.e. Hermitian Toeplitz, a spatial differencing operation that exploits this symmetry is applied to remove the effect of the unknown noise and a new matrix is constructed accordingly at each frequency bin. Following this step, a focusing operation is performed to give the corresponding aligned covariance matrix. Finally, an eigenstructure-based DOA estimation method is applied. The validity of the method is supported by numerical simulation under various conditions.

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Tensor Approach to DOA Estimation of Coherent Signals with Electromagnetic Vector-Sensor Array

Sensors ◽

10.3390/s18124320 ◽

2018 ◽

Vol 18 (12) ◽

pp. 4320 ◽

Cited By ~ 2

Author(s):

Ming-Yang Cao ◽

Xingpeng Mao ◽

Xiaozhuan Long ◽

Lei Huang

Keyword(s):

Estimation Method ◽

Doa Estimation ◽

Parameters Estimation ◽

Estimation Accuracy ◽

Coherent Signals ◽

Rectangular Array ◽

Vector Sensor ◽

Electromagnetic Vector Sensor ◽

Vector Sensors ◽

Uniform Rectangular Array

This paper addresses the direction-of-arrival (DOA) estimation problem using a uniform rectangular array with electromagnetic vector-sensors in correlated/coherent signal environments. The polarization information is separated from the steering matrix to decorrelate the signals. By developing a tensorial structured received measurements of the array, we propose a tensor-based eigenvector DOA estimation method. Then we apply the forward-backward averaging to the tensor since it obeys the centro-Hermitian structure. In addition, a tensor-based polarization parameters estimation method is presented. The proposed algorithms are superior to the state-of-the-art algorithms in terms of estimation accuracy of coherent signals while only demand a modest computation burden comparing with the latter ones. Simulation results are given to demonstrate the effectiveness of the proposed methods under different scenarios.

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DOA Estimation Method for CHAOS Radar System

Journal of Science and Technology Issue on Information and Communications Technology ◽

10.31130/ict-ud.2019.84 ◽

2019 ◽

Vol 17 (12.2) ◽

pp. 35

Author(s):

Hán Trọng Thanh ◽

Nguyen Thanh Chuyen ◽

Nguyen Xuan Quyen

Keyword(s):

Antenna Array ◽

Estimation Method ◽

Matrix Pencil ◽

Doa Estimation ◽

Sampling Frequency ◽

Radar System ◽

Linear Antenna ◽

Coherent Signals ◽

Security Systems ◽

Simulation Results

CHAOS signal has been drawing a lot of research interest recently due to its performance in security systems. In this paper, an approach to estimate the direction of target for Distributed Chaos Radar System using Total Forward - Backward Matrix Pencil (TFBMP) algorithm. This algorithm works directly on signal samples of signals received by M – element Uniform Linear Antenna array. Therefore, the correlation between the received signals does not significantly impact on its performance and efficiency. This fact permits us to estimate not only wideband incoherent signals but also wideband coherent signals. Furthermore, this algorithm can also extract the Direction Of Arrival (DOA) with only one snapshot of signal, which means that the sampling frequency in real time receivers can be considerably reduced. The simulation results for DOA of incoming CHAOS signals using the proposed approach will be shown and analyzed to verify its performance.

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An Efficient DOA Estimation Method for Passive Surveillance System Based on Troposcatter

Mathematical Problems in Engineering ◽

10.1155/2021/6650278 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Xinping Mi ◽

Zan Liu ◽

Xihong Chen ◽

Qiang Liu

Keyword(s):

Surveillance System ◽

Estimation Method ◽

Doa Estimation ◽

Superior Performance ◽

Invariance Property ◽

Good Resolution ◽

Passive Surveillance ◽

Rank Deficiency ◽

Noise Subspace ◽

Passive Surveillance System

Direction of arrival (DOA) estimation plays an important role in the passive surveillance system based on troposcatter. Rank deficiency and subspace leakage resulting from multipath propagation can deteriorate the performance of the DOA estimator. In this paper, characteristics of signals propagated by troposcatter are analyzed, and an efficient DOA estimation method is proposed. According to our new method, the invariance property of noise subspace (IPNS) is introduced as the main method. To provide precise noise subspace for INPS, forward and backward spatial smoothing (FBSS) is carried out to overcome rank deficiency. Subspace leakage is eliminated by a two-step scheme, and this process can also largely reduce the computational load of INPS. Numerical simulation results validate that our method has not only good resolution in condition of closely spaced signals but also superior performance in case of power difference.

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Direction of Arrival Estimation for Coherent Signals in GPS Receiver

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.195-196.109 ◽

2012 ◽

Vol 195-196 ◽

pp. 109-114

Author(s):

Yue Cui ◽

Kai Hua Liu ◽

Jun Feng Wang

Keyword(s):

Estimation Method ◽

Direction Of Arrival ◽

Doa Estimation ◽

Gps Receiver ◽

Coherent Signals ◽

Difference Matrix ◽

Low Snr ◽

Strong Interference ◽

Orthogonal Subspace ◽

Effectiveness And Efficiency

A new direction of arrival (DOA) estimation method is proposed for coherent GPS signals, which applies to the GPS receiver with rich multipath, strong interference and low SNR. In this method, the interference is first suppressed by projecting the received signal onto the interference orthogonal subspace. Afterwards, the noise is eliminated by the spatial difference matrix. Then, the coherent GPS signals are decorrelated by the reconstructed Toeplitz matrix, and the DOA estimation is improved by a new constructed matrix. The proposed method can obtain more accurate DOA estimation for coherent GPS signals with strong interference and low SNR in the GPS receiver. Simulation results demonstrate the effectiveness and efficiency of the proposed method.

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