scholarly journals Reduced-Dimension Noncircular-Capon Algorithm for DOA Estimation of Noncircular Signals

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Weihua Lv ◽  
Huapu Sun ◽  
Xiaofei Zhang ◽  
Dazhuan Xu
Keyword(s):  
Computational Cost ◽  
Doa Estimation ◽  
Two Dimensional ◽  
Angle Estimation ◽  
One Dimensional ◽  
Reduced Dimension ◽  
Noncircular Signals ◽  
Simulation Results ◽  
High Computational Cost ◽  
Better Than

The problem of the direction of arrival (DOA) estimation for the noncircular (NC) signals, which have been widely used in communications, is investigated. A reduced-dimension NC-Capon algorithm is proposed hereby for the DOA estimation of noncircular signals. The proposed algorithm, which only requires one-dimensional search, can avoid the high computational cost within the two-dimensional NC-Capon algorithm. The angle estimation performance of the proposed algorithm is much better than that of the conventional Capon algorithm and very close to that of the two-dimensional NC-Capon algorithm, which has a much higher complexity than the proposed algorithm. Furthermore, the proposed algorithm can be applied to arbitrary arrays and works well without estimating the noncircular phases. The simulation results verify the effectiveness and improvement of the proposed algorithm.

scholarly journals Two-Dimensional DOA Estimation for Uniform Rectangular Array Using Reduced-Dimension Propagator Method

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Ming Zhou ◽  
Xiaofei Zhang ◽  
Xiaofeng Qiu ◽  
Chenghua Wang
Keyword(s):  
Estimation Error ◽  
Doa Estimation ◽  
Eigenvalue Decomposition ◽  
Two Dimensional ◽  
Rectangular Array ◽  
Angle Estimation ◽  
Propagator Method ◽  
Reduced Dimension ◽  
2D Doa Estimation ◽  
Uniform Rectangular Array

A novel algorithm is proposed for two-dimensional direction of arrival (2D-DOA) estimation with uniform rectangular array using reduced-dimension propagator method (RD-PM). The proposed algorithm requires no eigenvalue decomposition of the covariance matrix of the receive data and simplifies two-dimensional global searching in two-dimensional PM (2D-PM) to one-dimensional local searching. The complexity of the proposed algorithm is much lower than that of 2D-PM. The angle estimation performance of the proposed algorithm is better than that of estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm and conventional PM algorithms, also very close to 2D-PM. The angle estimation error and Cramér-Rao bound (CRB) are derived in this paper. Furthermore, the proposed algorithm can achieve automatically paired 2D-DOA estimation. The simulation results verify the effectiveness of the algorithm.

scholarly journals DOA Estimation of Noncircular Signals Using Quaternions

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Tianzhen Meng ◽  
Minjie Wu ◽  
Naichang Yuan
Keyword(s):  
Computational Complexity ◽  
Covariance Matrix ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Estimation Problem ◽  
Estimation Accuracy ◽  
Two Dimensional ◽  
Output Vector ◽  
Noncircular Signals ◽  
Simulation Results

The two-dimensional (2D) direction-of-arrival (DOA) estimation problem for noncircular signals using quaternions is considered in this paper. In the framework of quaternions, we reconstruct the conjugate augmented output vector which reduces the dimension of covariance matrix. Compared with existing methods, the proposed one has two main advantages. Firstly, the estimation accuracy is higher since quaternions have stronger orthogonality. Secondly, the dimension of covariance matrix is reduced by half which decreases the computational complexity. Simulation results are presented verifying the efficacy of the algorithm.

Two-Dimensional DOA Estimation for Planar Array Using a Successive Propagator Method

2019 ◽  
Vol 28 (10) ◽  
pp. 1950161 ◽  
Author(s):  
Weiyang Chen ◽  
Xiaofei Zhang ◽  
Chi Jiang
Keyword(s):  
Computational Cost ◽  
Doa Estimation ◽  
Rotational Invariance ◽  
Eigenvalue Decomposition ◽  
Invariance Property ◽  
Two Dimensional ◽  
Propagator Method ◽  
Planar Array ◽  
Esprit Algorithm ◽  
Better Than

We consider the problem of two-dimensional (2D) direction of arrival (DOA) estimation for planar array, and propose a successive propagator method (PM)-based algorithm. The rotational invariance property of the propagator matrix is exploited to obtain the initial angle estimations, while the accurate estimates can be achieved through successive one-dimensional and local spectrum-peak searches. The proposed algorithm can obtain automatically paired 2D-DOA estimations, and it requires no eigenvalue decomposition of the covariance matrix of received data, which remarkably reduces the computational cost compared with traditional 2D-PM algorithm. In addition, the DOA estimation performance of the proposed algorithm is better than estimation of signal parameters via rotational invariance technique (ESPRIT) algorithm and PM algorithm, and is close to 2D-PM algorithm which requires 2D spectrum-peak search. Numerical simulations demonstrate the effectiveness and improvement of the proposed algorithm.

scholarly journals Two-Dimensional DOA Estimation in Compressed Sensing with Compressive-Reduced Dimension-lp-MUSIC

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Weijian Si ◽  
Xinggen Qu ◽  
Lutao Liu ◽  
Zhiyu Qu
Keyword(s):  
Compressed Sensing ◽  
Estimation Method ◽  
Doa Estimation ◽  
Superior Performance ◽  
Two Dimensional ◽  
Improve Performance ◽  
Performance Simulation ◽  
Pair Matching ◽  
Reduced Dimension ◽  
Simulation Results

This paper presents a novel two-dimensional (2D) direction of arrival (DOA) estimation method in compressed sensing (CS) to remove the estimation failure problem and achieve superior performance. The proposed method separates the steering vector into two parts to construct two corresponding noise subspaces by introducing electric angles. Then, electric angles are estimated based on the constructed noise subspaces. In order to estimate the azimuth and elevation angles in terms of estimates of electric angles, arc-tangent operations are exploited. The arc-tangent is a one-to-one function and allows the value of the argument to be larger than unity so that the proposed method never fails. The proposed method can avoid pair matching to reduce the computational complexity and extend the number of snapshots to improve performance. Simulation results show that the proposed method can avoid estimation failure occurrence and has superior performance as compared to existing methods.

The Method of Two-Dimensional Stretching to Reduce Residual Stress in Quenched Thin-Walled Aluminum Alloy

2015 ◽  
Vol 1095 ◽  
pp. 523-526
Author(s):  
Kun Qi Wang ◽  
Wei Zheng ◽  
Dan Dan Na
Keyword(s):  
Thermal Analysis ◽  
Residual Stress ◽  
Aluminum Alloy ◽  
Steady State ◽  
Two Dimensional ◽  
One Dimensional ◽  
Thin Walled ◽  
Simulation Results ◽  
Transient Thermal ◽  
Better Than

This study aims to reduce the residual stress of quenched thin-walled aluminum alloy. The method of two-dimensional stretching was proposed to further reduce the residual stress in the alloy. The steady-state and transient thermal analysis were used in ANSYS workbench15.0. Static structural was used to simulate one-dimensional and two-dimensional stretching. The simulation results show that two-dimensional stretching method is better than one-dimensional stretching, and it can eliminate the residual stress up to 92.6% when the amount of stretching in length and width is controlled in 2.5%.

A Dynamic Adaptive Wavelet Method for Solution of the Schrodinger Equation

2015 ◽  
Vol 06 (01) ◽  
pp. 1450001 ◽  
Author(s):  
Ratikanta Behera ◽  
Mani Mehra
Keyword(s):  
Schrödinger Equation ◽  
Computational Efficiency ◽  
Schrodinger Equation ◽  
Computational Cost ◽  
Two Dimensional ◽  
Wavelet Method ◽  
Adaptive Wavelet ◽  
One Dimensional ◽  
Grid Adaptation ◽  
Adaptive Wavelet Method

In this paper, we present a dynamically adaptive wavelet method for solving Schrodinger equation on one-dimensional, two-dimensional and on the sphere. Solving one-dimensional and two-dimensional Schrodinger equations are based on Daubechies wavelet with finite difference method on an arbitrary grid, and for spherical Schrodinger equation is based on spherical wavelet over an optimal spherical geodesic grid. The method is applied to the solution of Schrodinger equation for computational efficiency and achieve accuracy with controlling spatial grid adaptation — high resolution computations are performed only in regions where a solution varies greatly (i.e., near steep gradients, or near-singularities) and a much coarser grid where the solution varies slowly. Thereupon the dynamic adaptive wavelet method is useful to analyze local structure of solution with very less number of computational cost than any other methods. The prowess and computational efficiency of the adaptive wavelet method is demonstrated for the solution of Schrodinger equation on one-dimensional, two-dimensional and on the sphere.

Image Segmentation Research Based on GA and Improved Otsu Algorithm

2017 ◽  
Vol 7 (2) ◽  
pp. 533
Author(s):  
Xiaoqun Qin
Keyword(s):  
Genetic Algorithm ◽  
Image Segmentation ◽  
Two Dimensional ◽  
One Dimensional ◽  
Otsu Method ◽  
Segmented Object ◽  
The Face ◽  
Image Segmentation Algorithm ◽  
Small Dispersion ◽  
Better Than

<p>In the face of the problem of high complexity of two-dimensional Otsu adaptive threshold algorithm, a new fast and effective Otsu image segmentation algorithm is proposed based on genetic algorithm. This algorithm replaces the segmentation threshold of the traditional two - dimensional Otsu method by finding the threshold of two one-dimensional Otsu method, it reduces the computational complexity of the partition from O (L4) to O (L). In order to ensure the integrity of the segmented object, the algorithm introduces the concept of small dispersion in class, and the automatic optimization of parameters are achieved by genetic algorithm. Theoretical analysis and experimental results show that the algorithm is not only better than the original two-dimensional Otsu algorithm, but also it has better segmentation effect.</p>

Person Localization System Using Privacy-Preserving Sensor

2011 ◽  
Vol 103 ◽  
pp. 622-627 ◽  
Author(s):  
Shota Nakashima ◽  
Hui Min Lu ◽  
Kohei Miyata ◽  
Yuhki Kitazono ◽  
Serikawa Seiichi
Keyword(s):  
Low Cost ◽  
Video Camera ◽  
Brightness Distribution ◽  
Privacy Preserving ◽  
Two Dimensional ◽  
Texture Image ◽  
Localization System ◽  
One Dimensional ◽  
Two Dimensional Image ◽  
Simulation Results

A privacy-preserving sensor for person localization has been developed. In theory, the sensor can be constructed with a line sensor and cylindrical lens because only a one-dimensional brightness distribution is needed. However, a line sensor is expensive. In contrast, CMOS area sensors are low cost and are increasing in sensitivity according to recent rapid advancement in the technology. Therefore, we covered the CMOS area sensor physically so that it behaved as a line sensor, we substituted CMOS sensors for the line sensors in practice. The proposed sensor obtains a one-dimensional horizontal brightness distribution that is approximately equal to the integration value of each vertical pixel line of the two-dimensional image. It is impossible to restore the two-dimensional detail texture image from one-dimensional brightness distribution, although it obtains enough information to detect a person’s position and movement status. Thus, the privacy is protected. Moreover, the appearance of the proposed sensor is very different from the conventional video camera, so the psychological resistance of having a picture taken is reduced. In this work, we made the privacy preserving sensor practically, and verified whether a person’s state was able to be detected. The simulation results show that the proposed sensor can detect a present person’s state responsively without violating privacy.

Research of Active Detection Technology Using Vector Array on Small Platform

2011 ◽  
Vol 128-129 ◽  
pp. 682-685
Author(s):  
Xue Li Sheng ◽  
Jia Lu ◽  
Chun Yan Sun ◽  
Ji Dan Mei ◽  
Long Xiang Guo ◽  
...  
Keyword(s):  
Signal Processing ◽  
Acoustic Pressure ◽  
Doa Estimation ◽  
Vibration Velocity ◽  
Active Sonar ◽  
Detection Technology ◽  
Simulation Results ◽  
Active Detection ◽  
Small Platform ◽  
Better Than

Active sonar on small platform which uses vector array is selected in this paper as research object, the methods of signal and DOA estimation and the performance of these methods are discussed. Vector array comprehensive copy correlator and vector array comprehensive adaptive copy correlator which use acoustic pressure and vibration velocity at the same time are proposed in this paper. The performance of signal processing and the precision of DOA estimation can be improved by these methods. Simulation results present that the performance of the proposed methods are better than conventional copy correlator. In addition, vector array comprehensive adaptive copy correlator has higher gain than vector array comprehensive copy correlator in multi-path channel.

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