In presence of general array error in a uniform circular arrays (UCAs), estimation of azimuth and elevation for a Source is proposed. Based on array manifold in UCAs, the spatial frequency that is related to DOA is ga...
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ISBN:
(纸本)0780385454
In presence of general array error in a uniform circular arrays (UCAs), estimation of azimuth and elevation for a Source is proposed. Based on array manifold in UCAs, the spatial frequency that is related to DOA is gained and theoretical expression for its asymptotic variance and the Cramer-Rao Bound (CRB) of estimation is derived. The ambiguous problem is analyzed. The azimuth and elevation of source are estimated by Weight Total Least Squares. The results of simulation show that the performance of the estimation is close to the CRB.
This paper is concerned with a new accelerated RLS adaptive beamforming algorithm applied to fast moving mobile terminals. The proposed algorithm is based on the internal model principle by approximately expressing th...
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ISBN:
(纸本)0780385454
This paper is concerned with a new accelerated RLS adaptive beamforming algorithm applied to fast moving mobile terminals. The proposed algorithm is based on the internal model principle by approximately expressing the parameter changes in terms of polynomial time functions, and can rapidly track the multipath fading environment. We show that the amount of calculation of the proposed algorithm is almost the same as that of the ordinary RLS adaptive beamforming, and its effectiveness is examined in numerical simulations.
In this paper we evaluate the performance of a Tripole array for estimation of the polarization and one dimensional direction of arrival (DOA). We employ a model based on far-field calculations of a Tripole antenna an...
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ISBN:
(纸本)0780385454
In this paper we evaluate the performance of a Tripole array for estimation of the polarization and one dimensional direction of arrival (DOA). We employ a model based on far-field calculations of a Tripole antenna and completely polarized electromagnetic waves carrying Gaussian distributed signals. The analysis of the performance is based on calculations of the Cramer-Rao Lower Bound (CRLB) for the polarization and DOA estimators. It is seen that the Tripole array is suitable for polarization estimation with or without knowledge of the DOA. It is also seen that the quality of the DOA estimate depends strongly on the polarization state.
In this paper, we propose a method for estimating the number of sources based on the eigenvectors of the covariance matrix of a narrowband array. The proposed method provides the same detection sensitivity as AIC and ...
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ISBN:
(纸本)0780385454
In this paper, we propose a method for estimating the number of sources based on the eigenvectors of the covariance matrix of a narrowband array. The proposed method provides the same detection sensitivity as AIC and MDL, but appears to be much more robust to signal and noise model perturbations. Unlike AIC and MDL that do not make use of the procedure used in calibrating the antenna array, the proposed method can use the calibrated antenna responses to take into account the existing nonidealities present in the antenna array, and hence outperforming AIC and MDL methods in practice.
We present a definition of a dual-frequency dual-wavenumber cross-spectrum of two nonstationary and inhomogeneous harmonizable random fields, which is in fact a generalization of the Loeve (dual-frequency) cross-spect...
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ISBN:
(纸本)0780385454
We present a definition of a dual-frequency dual-wavenumber cross-spectrum of two nonstationary and inhomogeneous harmonizable random fields, which is in fact a generalization of the Loeve (dual-frequency) cross-spectrum of two random processes. Furthermore, a geometric argument shows that a proper normalization yields a natural measure of cross-coherence, and application of the Cauchy-Schwarz inequality results in a necessary and sufficient condition for full cross-coherence. Finally, estimators of the cross-spectrum and the cross-coherence based on the multitaper approach are suggested, and tested on synthetic arrayprocessing data.
Recently, a maximum likelihood estimate has been proposed for road vehicle speed based on two onmidirectional microphones. We undertake a broadband analysis in a stochastic setting in order to expose the effect of inp...
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ISBN:
(纸本)0780385454
Recently, a maximum likelihood estimate has been proposed for road vehicle speed based on two onmidirectional microphones. We undertake a broadband analysis in a stochastic setting in order to expose the effect of input SNR, target speed, bandwidth, and observation time in the SNR at the output of the modified crosscorrelator on which the estimate is based. The use of 1-bit quantized signals, which provides an important hardware simplification, is also considered and seen to result in mild performance degradation.
Speech is dramatically degraded when a distant microphone is used in real environments. One of the possible solutions is to use a microphone array to improve the quality of the recorded speech signal. In this paper we...
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ISBN:
(纸本)0780385454
Speech is dramatically degraded when a distant microphone is used in real environments. One of the possible solutions is to use a microphone array to improve the quality of the recorded speech signal. In this paper we present a robust beamformer that integrates the directional noise reduction capability of a modification of the Generalized Sidelobe Canceller with adaptive blocking matrix and the great performance of the Wiener postfiltering techniques against low-correlated noises. Experimental results show that the proposed integrated adaptive Wiener-filtering beamformer is at least as robust to directional and uncorrelated noise as conventional postfiltering of the output and presents a lower level of degradation of the speech signal.
We discuss dispersive wave propagation and show that the Wigner distribution is a powerful approach because it simplifies the issues immensely. We show that the spatial time-frequency arrayprocessing formulation of A...
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ISBN:
(纸本)0780385454
We discuss dispersive wave propagation and show that the Wigner distribution is a powerful approach because it simplifies the issues immensely. We show that the spatial time-frequency arrayprocessing formulation of Amin et al. can be viewed as a projection of a Wigner distribution in space, wavenumber, time and frequency. We also show that there is a very simple yet illuminating and accurate approximation between the Wigner distribution of a wave at two different spatial points. In particular, the Wigner distributions of the wave at two different locations are related by a frequencydependent time-shift that depends explicitly on the dispersion relation, in a very straight forward way.
We propose a novel direction-of-arrival (DOA) estimation method, which uses sensors of the receiving array, for spatially non-symmetric distributed sources characterized by multipath fading. Specifically, the probabil...
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ISBN:
(纸本)0780385454
We propose a novel direction-of-arrival (DOA) estimation method, which uses sensors of the receiving array, for spatially non-symmetric distributed sources characterized by multipath fading. Specifically, the probability density function (PDF) of a non-symmetric distribution is modeled as the summation of two Gaussian PDFs. The proposed algorithm is based on a covariance fitting and accurately estimates the DOA for a non-symmetricaly distributed source by determining the scaling ratio between the two Gaussians. Furthermore, the degree of angular spread is also evaluated by using these estimated parameters.
In this paper, we develop and evaluate distributed implementations of source localization estimators from energy-based measurements obtained via an ad-hoc network of acoustic sensors. The distributed locally construct...
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ISBN:
(纸本)0780385454
In this paper, we develop and evaluate distributed implementations of source localization estimators from energy-based measurements obtained via an ad-hoc network of acoustic sensors. The distributed locally constructed algorithms that we present produce at each node a sequence of esLimates approximating a desired source localization algorithm. As our investigation reveals, the localization performance of these distributed algorithms depends on the type of desired localization algorithm, the network topology and the number of communication and fusion steps employed in these approximations.
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