DOA estimation using an array of sensors requires precise knowledge of the wavelength λ of the incident signal. This paper considers the case when A is unknown or imprecisely known and shows that an inherent ambiguit...
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Near field acoustic holography (NAH) is an experimental technique for analysing sound fields near sources. A simulation study has been carried out, and this paper examines and compares i) classical planar NAH based on...
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Near field acoustic holography (NAH) is an experimental technique for analysing sound fields near sources. A simulation study has been carried out, and this paper examines and compares i) classical planar NAH based on spatial transforms (single layer NAH), ii) a similar technique based on measurements in two parallel planes (double layer NAH), and iii) a method that avoids spatial transforms and thus leakage by using statistical considerations (SONAH). The source is a point driven panel that generates a complicated sound field. The influence of reflections and background noise from other sources is examined. The results indicate improved accuracy in localisation and characterisation of a sound source with double layer array processing in the presence of sources from the 'wrong' side of the measurement array. An investigation of the influence of transducer mismatch errors on the global accuracy of the NAH calculations shows that NAH with single and double layer arrays are affected in a similar manner.
In blind array processing, the array manifold is unknown but, under the signal independence assumption, the signal parameters can be estimated by recourse to higher-order information. The author considers the 4th-orde...
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An alternate paradigm is presented for multi-dimensional adaptive array processing which provides a unique highly-parallelizable algorithm for distributed processing architectures. The principle is to perform interfer...
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In feedforward active noise control (ANC) systems, the misplacement of the reference microphone may violate the causality constraint and degrade the ANC system's performance. This paper applies the microphone arra...
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ISBN:
(纸本)9788361402282
In feedforward active noise control (ANC) systems, the misplacement of the reference microphone may violate the causality constraint and degrade the ANC system's performance. This paper applies the microphone array technique to feedforward ANC system to solve the unknown noise source problem. The generalized cross-correlation (GCC) and steering response power (SRP) methods based on microphone array are used to estimate the noise source location. Then the ANC system selects the proper reference microphone for noise control algorithm. The simulation results show that the SRP method can estimate the noise source direction with 84% accuracy. The proposed microphone array integrated ANC system can dramatically improve the system performance.
Whether in business or science, multi-dimensional arrays are a common abstraction in data analytics and many systems exist for efficiently processingarrays. As dataset grow in size, it is becoming increasingly import...
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ISBN:
(纸本)9781450306140
Whether in business or science, multi-dimensional arrays are a common abstraction in data analytics and many systems exist for efficiently processingarrays. As dataset grow in size, it is becoming increasingly important to process these arrays in parallel. In this paper, we discuss different types of array operations and review how they can be processed in parallel using two different existing techniques. The first technique, which we call merge, consists in partitioning an array, processing the partitions in parallel, then merging the results to reconcile computations that span partition boundaries. The second technique, which we call overlap, consists in partitioning an array into subarrays that overlap by a given number of cells along each dimension. Thanks to this overlap, the array partitions can be processed in parallel without any merge phase. We discuss when each technique can be applied to an array operation. We show that even for a single array operation, a different approach may yield the best performance for different regions of an array. Following this observation, we introduce a new parallel array processing technique that combines the merge and overlap approaches. Our technique enables a parallel array processing system to mix-and-match the merge and overlap techniques within a single operation on an array. Through experiments on real, scientific data, we show that this hybrid approach outperforms the other two techniques. Copyright 2011 ACM.
Limiting the analysis to the exploitation of the second order statistics of the complex data, the optimal SpatioTemporal (ST) receivers in stationary contexts are Linear and Time Invariant (TI). However, for (quasi)-c...
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Limiting the analysis to the exploitation of the second order statistics of the complex data, the optimal SpatioTemporal (ST) receivers in stationary contexts are Linear and Time Invariant (TI). However, for (quasi)-cyclostationary observations, it is now well-known that the optimal ST complex receivers become (poly)-periodic (PP) and, under some conditions of non circularity, Widely Linear (WL). Using these results and the fact that PP filtering is equivalent to FREquency SHifted (FRESH) filtering, the purpose of this paper is to present a new ST, PP and WL receiver structure, very useful for applications such as passive listening or source separation, taking into account the potential (quasi)-cyclostationarity and non circularity properties of the observations. This new cyclic receiver may be implemented either blindly or from the a priori knowledge or estimation of the useful signal steering vector. The performance computation of this new cyclic receiver shows off the great interest of the latter in cyclostationary contexts and its great capability of interferences rejection even from a one sensor reception.
A novel space-time array processing strategy for adaptive airborne MTI radar is presented via the application of a multichannel least squares predictive transform (PT) signal modeling procedure. The crux of the techni...
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Optimum array processing is generally studied and used in the case of perfectly known wavefronts. In sonar and in presence of non-rigid arrays or in shallow water, the wavefronts may be randomly distorted. This articl...
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The fourth order cumulants have been shown to increase the effective aperture of an antenna compared to second order cumulants. In this paper, we investigate the potential benefits of fourth order array processing met...
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