This paper describes the problem caused by near-field sound sources. Formerly, the authors proposed a 2-ch passive subtractive beamformer with a single sharp notch for noise reduction. It is obvious that the single sh...
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ISBN:
(纸本)0780385454
This paper describes the problem caused by near-field sound sources. Formerly, the authors proposed a 2-ch passive subtractive beamformer with a single sharp notch for noise reduction. It is obvious that the single sharp notch is insufficient for dealing with near-field, non-point sound sources. To solve this problem, this paper presents the hybrid subtractive beamformer that is realized as a cascade connection of single subtractive beamformers. The number of connections depends on frequency to minimize the negative effect caused by spatial aliasing when an objective signal is assumed as a wide-band speech signal. The experimental results verifies that the hybrid beamformer has an advantage in reducing signal distortion over the original single subtractive beamformer.
In this paper we study the performance of time-reversal multiple signal classification (TR-MUSIC) for computational TR applications. The analysis builds upon classical results on first-order perturbation of singular v...
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ISBN:
(纸本)9781479914814
In this paper we study the performance of time-reversal multiple signal classification (TR-MUSIC) for computational TR applications. The analysis builds upon classical results on first-order perturbation of singular value decomposition. The closed form of mean-squared error (MSE) matrix of TR-MUSIC is derived for a narrowband multistatic co-located scenario and is compared with both numerical simulations and the Cramer-Rao lower bound. 1
Increasing the number of sources to be processed from a given array of sensors is an important problem in sensorarraysignalprocessing and of interest to many researchers. This problem has also been tackled with the...
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ISBN:
(纸本)9781728119465
Increasing the number of sources to be processed from a given array of sensors is an important problem in sensorarraysignalprocessing and of interest to many researchers. This problem has also been tackled with the virtual array based approach where the covariance and cumulant lags provide a virtual sensor. Here, an important parameter which affects the parameter estimation accuracy and latency is weight function. The weight function is defined as the frequency of occurrence of each virtual sensor in the virtual array. We provide the close-form expression of virtual array corresponding to linear array. We have also analytically evaluated the weight function of virtual array and have also studied the effect of the weight function on parameter estimation. Simulation results show the parameter estimation accuracy is significantly improve with high weight function.
Direction-of-arrival (DOA) estimation is an interesting research topic with various applications. Existing algorithms provide superior estimation performance, at the cost of accurate quantified measurements. In this p...
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ISBN:
(纸本)9781728119465
Direction-of-arrival (DOA) estimation is an interesting research topic with various applications. Existing algorithms provide superior estimation performance, at the cost of accurate quantified measurements. In this paper, we stress the problem of 2D DOA estimation for uniform rectangular array using one-bit measurements. The relationship between the covariance matrices of one-bit measurement and that of the accurately quantified measurement is analyzed in detail, from which we find the existing tensor algorithm can be directly applied. As a result, a one-bit parallel factor analysis (PARAFAC) estimator is proposed. Simulation results show the effectiveness of the proposed method.
Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate opti...
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ISBN:
(纸本)1424403081
Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate options for combining the radar and telecom functions of the deep space network (DSN) into a single large transmit array of small parabolic reflectors will be discussed. In particular the effect of combing the radar and telecom functions on the sizes of individual antenna apertures and the corresponding spacing between the antenna elements of the array will be analyzed. A heterogeneous architecture for the DSN large transmit array is proposed to meet the radar and telecom requirements while considering the budget, scheduling, and strategic planning constrains.
In this paper, we propose a new approach to sensor localization problems, based on recent developments in machine leaning. The main idea behind it is to consider a matrix regression method between the ranging matrix a...
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ISBN:
(纸本)9781424422401
In this paper, we propose a new approach to sensor localization problems, based on recent developments in machine leaning. The main idea behind it is to consider a matrix regression method between the ranging matrix and the matrix of inner products between positions of sensors, in order to complete the latter. Once we have learnt this regression from information between sensors of known positions (beacons), we apply it to sensors of unknown positions. Retrieving the estimated positions of the latter can be done by solving a linear system. We propose a distributed algorithm, where each sensor positions itself with information available from its nearby beacons. The proposed method is validated by experimentations.
This paper presents a new two dimentional(2D) sparse array called the augmented L-shaped nested array based on the concept of fourth-order difference co-array. By properly choosing the relative positions of two L-shap...
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ISBN:
(纸本)9781538647523
This paper presents a new two dimentional(2D) sparse array called the augmented L-shaped nested array based on the concept of fourth-order difference co-array. By properly choosing the relative positions of two L-shaped nested arrays, one could obtain a virtual planar array containing a large-scale hole-free uniform rectangular co-array. As a result, the degree of freedom could be greatly enhanced. Many theoretical properties are derived and simulations are included by considering the fourth-order cumulants of quasi-stationary signal to validate the superior performance of the proposed array in comparison with other 2D sparse arrays.
Passive radars offer several advantages over the conventional radar systems by using a source of illumination that is independent from the receivers and primarily used in other purposes. The second generation digital ...
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ISBN:
(纸本)9781467310710
Passive radars offer several advantages over the conventional radar systems by using a source of illumination that is independent from the receivers and primarily used in other purposes. The second generation digital television standard DVB-T2 is a good alternative to be utilized as an illuminating system. Passive radar receivers should be able to detect the target echo at very low signal-to-noise ratios. In this paper, a novel detection method for the DVB-T2signal is proposed that fulfills these conditions. Distributions of test statistic are established and the performance of the method is verified with simulations. It is shown that the proposed method is suitable for passive radar systems and can be used without the exact knowledge of the transmitted signal waveform.
Source location accuracy can be dramatically degraded by the inaccuracy in the sensor positions. The sensor position errors need to be taken into account in order to improve the source location estimate. This paper pr...
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ISBN:
(纸本)1424403081
Source location accuracy can be dramatically degraded by the inaccuracy in the sensor positions. The sensor position errors need to be taken into account in order to improve the source location estimate. This paper presents an algorithm based on the Taylor-series technique to estimate the location of an emitting source in the presence of random sensor position errors, where the data measurements are angle-of-arrivals (AoAs). The proposed algorithm jointly estimates the source andsensor positions iteratively by using Taylor-series linearization. Simulation results indicate that the proposed method approaches the CRLB accuracy for both near-field and far-field sources.
The classic DSP sampling property: "(Uniform) sampling of a bandlimited signal leads to (perfect) replication in the spectral domain." does not hold in the vertex Graph signalprocessing (GSP) model. Samplin...
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ISBN:
(纸本)9798350344820;9798350344813
The classic DSP sampling property: "(Uniform) sampling of a bandlimited signal leads to (perfect) replication in the spectral domain." does not hold in the vertex Graph signalprocessing (GSP) model. Sampling uniformly in GSP does not lead to perfect replicas, but rather distorted replicas [1]. In [2], we introduced a Step 1-Step 2 Companion Model Method, S2CM2, as a way to introduce new GSP concepts. The GSP companion model is closest to the DSP time model (with different boundary conditions), making it easier to extend DSP concepts. In this paper, we consider GSP sampling in the companion model. We show that GSP sampling theory in the companion model is similar to DSP sampling theory by illustrating the four sampling steps: Subsampling, Decimation, Upsampling, Interpolation, in the companion model.
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