This paper addresses the problem of source localization and waveform estimation in array processing applications. We present two nonparametric user parameter free algorithms, namely the iterative adaptive approach (IA...
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ISBN:
(纸本)9781424429400
This paper addresses the problem of source localization and waveform estimation in array processing applications. We present two nonparametric user parameter free algorithms, namely the iterative adaptive approach (IAA) and the maximum likelihood based IAA (IAA-ML). Both IAA and IAA-ML can work with arbitrary array geometries and uncorrelated as well as coherent sources. We extend IAA and IAA-ML to yield sparse results by, using the Bayesian information criterion (BIC). Further improvements in performance can be achieved by employing the last step of the parametric RELAX algorithm initialized by the estimates of IAA and IAA-ML with BIC. Our simulations demonstrate that IAA and IAA-ML show better performance than the most competitive sparse signal representation approaches in the literature: M-FOCUSS, M-SBL and l(1)-SVD.
array antennas are becoming ubiquitous in many commercial and military systems. This allows for electronic steering of the antenna in one or more directions simultaneously. However, by combining the individual array e...
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ISBN:
(纸本)9781728114163
array antennas are becoming ubiquitous in many commercial and military systems. This allows for electronic steering of the antenna in one or more directions simultaneously. However, by combining the individual array element signals at the array, these systems fail to take full advantage of the array capabilities. The newest array antennas are capable of supporting I/Q digital inputs and outputs for each element. This creates new processing challenges, and the need for a new architecture to enable capabilities such as very fast adaptation rates with very high independent beam counts.
A technique is proposed for estimating the parameters of 2D uniform motion of multiple moving objects in a scene, based on long-sequence image processing and the application of a recently developed multi-line fitting ...
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ISBN:
(纸本)0819414778
A technique is proposed for estimating the parameters of 2D uniform motion of multiple moving objects in a scene, based on long-sequence image processing and the application of a recently developed multi-line fitting algorithm. Plots of the vertical and horizontal projections versus frame number give new images in which uniformly moving objects are represented by skewed band regions, with the angles of the skew from the vertical being a measure of the velocities of the moving objects. For example, vertical bands will correspond to objects with zero velocity. A recently developed algorithm called SLIDE (subspace-based line detection) can be used to efficiently determine the skew angles. SLIDE exploits the temporal coherence between the contributions of each of the moving patterns in the frame projections to enhance and distinguish a signal subspace that is defined by the desired motion parameters. A similar procedure can be used to determine the vertical velocities. Some further steps must then be taken to properly associate the horizontal and vertical velocities.
This paper presents a novel algorithm for designing beam-space transformation with robust interference suppression, reducing the computation complexity, and improving the performance of applied signal processing algor...
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ISBN:
(纸本)9781728116792
This paper presents a novel algorithm for designing beam-space transformation with robust interference suppression, reducing the computation complexity, and improving the performance of applied signal processing algorithms. This approach constructs an objective function that addresses multiple performance criteria simultaneously including the in-sector estimation accuracy and the out-of-sector interference rejection capability, and then utilizes a numerical optimization paradigm to search for the solution. The algorithm is flexible, robust and data independent, which performs well in harsh environment involving a small number of snapshots and highly correlated/coherent sources. Simulation results confirm its effectiveness in the presence of strong moving interference.
array processing by means of using the difference coarray as a virtual uniform linear array (VULA) has become a popular approach, mainly due to the claim of obtaining O (N-2) degrees of freedom (DOF) from a N element ...
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ISBN:
(纸本)9781728168135
array processing by means of using the difference coarray as a virtual uniform linear array (VULA) has become a popular approach, mainly due to the claim of obtaining O (N-2) degrees of freedom (DOF) from a N element sparse array. In this work we seek to understand if and how this type of nonlinear array processing (NAP) approach could be used for direction of arrival (DOA) estimation and adaptive beamforming from the perspective of a pulsed radar system. More specifically, our study seeks to validate some of the theoretical aspects and challenges of NAP through an experimental emulation of the receive side of a monostatic 6 element nested array radar.
In the present research the typical triangle on formative research was extended to a double triangle for an overall career programme (here expander/ compressor) and funnel proposal was explored in a single course (as ...
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In the present research the typical triangle on formative research was extended to a double triangle for an overall career programme (here expander/ compressor) and funnel proposal was explored in a single course (as a "fractal" method). array processing and ElectroEncephaloGram (EEG) techniques have been incorporated into a Digital Signal processing (DSP) course and research projects. The present research question was: is it possible to insert array sensing on formative research in an undergraduate course of DSP? From over eight years, two semesters with different homework loads (homogeneous triangle vs expander-compressor-supplier distributions) were analysed in detail within the DSP evaluations and students chose between experimental applied analysis and a formative research project. Results showed that cognitive load was influenced positively in the expander-compressor-supplier distribution, showing that an increase of the efficiency undertook more undergraduate research on array processing and the decrease of the number of formative applied projects. Over a longer term (48 months) students undertook more undergraduate research works on array processing and DSP techniques.
The optimal array for detecting the signal from a desired direction but contaminated by receiver noise and strong interference from different sources with unknown arriving-angles is re-examined. The well-known optimal...
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ISBN:
(纸本)1424403081
The optimal array for detecting the signal from a desired direction but contaminated by receiver noise and strong interference from different sources with unknown arriving-angles is re-examined. The well-known optimal array is obtained by inverting the covariance matrix of interference and noise to maximize the signal to interference and noise ratio (SINR). In practice, the covariance matrix is unknown and has to be estimated by a sample covariance matrix. The optimal array is thus estimated by inverting the sample covariance matrix. This procedure has been employed in optimal array research without challenge. However, it is shown in this paper that the estimated optimal array fails to yield the highest SINR in the case of unknown arriving-angles. Instead the highest SINR can be achieved by optimally estimating the arriving-angles of interference followed by a constrained matched filter, which maximizes the signal to noise ratio subject to canceling the interference from the estimated arriving-angles. In order to reduce the computational burden, an angle-tracking system for multiple targets is adopted to achieve the optimal estimation of arriving-angles. The resulting system of angle-tracking adaptive array offers the highest SINR at a computational burden only on the order of N . M-2 multiplications within a radar range-cell Delta tau, rather than N-3 multiplications in the well-known but questionable estimated optimal array. Here N is the number of sensors in the array and M the number of interference sources. Typically, N = 1,000 in a planar radar array, M = 2 similar to 10 and Delta tau = 1 mu S. Numerical simulations confirm the theoretical results.
This paper presents a version of MUSIC algorithm for linear vector-sensor arrays based on a complexified quaternionic (biquatemionic) modelization of the output three-components vector-signals. A way of computing the ...
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ISBN:
(纸本)9781424404681
This paper presents a version of MUSIC algorithm for linear vector-sensor arrays based on a complexified quaternionic (biquatemionic) modelization of the output three-components vector-signals. A way of computing the eigenvalue decomposition of a biquaternion valued matrix is introduced and the subspace decomposition of the biquaternionic spectral matrix of the observations is used to define the biquaternionic MUSIC estimator (BQ-MUSIC). Performances of the BQ-MUSIC are compared with classical long-vector technique.
A new iterative procedure for estimating the direction of arrival of plane waves in the presence of noise with an unknown correlation structure can also be used to separate line spectra from a wide class of smooth spe...
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A new approach is proposed for estimating the direction-of-arrival (DOA) of the cyclostationary coherent signals impinging on a uniform linear array (ULA) by utilizing the spatial smoothing (SS) technique. In order to...
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A new approach is proposed for estimating the direction-of-arrival (DOA) of the cyclostationary coherent signals impinging on a uniform linear array (ULA) by utilizing the spatial smoothing (SS) technique. In order to improve the robustness of the DOA estimation by exploiting the cyclic statistical information sufficiently and handling the coherence effectively, we give a cyclic algorithm with multiple lag parameters and the optimal subarray size. The performance is verified and compared with the conventional methods through numerical examples.
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