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# International Conference on Acoustics, Speech, and Signal Processing

## Filter Results

Displaying Results 1 - 25 of 725
• ### ICASSP 90. 1990 International Conference on Acoustics, Speech and Signal Processing (Cat. No.90CH2847-2)

Publication Year: 1990
| PDF (573 KB)
• ### A fast computational algorithm for the QR-like decomposition of the modified covariance method of linear prediction

Publication Year: 1990
Cited by:  Papers (2)
| | PDF (106 KB)

Summary form only given. A fast QR algorithm for the batch modified covariance method of linear prediction that is the companion to the fast Cholesky algorithm has been developed. A Fortran program that performs the QR solution for the linear prediction parameters has also been developed. The numerical accuracies of the fast QR algorithm and fast Cholesky algorithm solutions for the least-squares ... View full abstract»

• ### Digital prediction with spectral noise shaping

Publication Year: 1990, Page(s):1643 - 1646 vol.3
| | PDF (328 KB)

In order to avoid the coding noise accumulation in successive transcoders, a new fully digital structure is used where all the filters have quantized inputs. Whereas the coding noise spectrum is flat with the CCITT algorithm, with this new structure it presents a spectral shaping which can be further improved in high-frequency region, by filtering the quantizing noise View full abstract»

• ### A comparative study of robust parameter estimation methods

Publication Year: 1990, Page(s):2967 - 2970 vol.5
Cited by:  Papers (1)
| | PDF (296 KB)

The problem of robust system identification when no statistical information is available on the noise, but only a bound on it is known, is addressed. A unified presentation of two classes of ellipsoidal outer-bounding algorithms is made, and a comparison with robust projection algorithms is carried out from a theoretical point of view. It is shown that these two families of algorithms can be writt... View full abstract»

• ### Comparison of two efficient ML algorithms for high resolution sources tracking-time recursive implementation

Publication Year: 1990, Page(s):2963 - 2966 vol.5
Cited by:  Papers (3)
| | PDF (316 KB)

A comparison is made of two fast Newton-Gauss algorithms for implementation of the exact maximum-likelihood (ML) and an approximate ML (AML) previously introduced by the authors (1989). The AML is impeded by the need of an eigenvalue decomposition of the covariance matrix, but it exhibits better robustness and a lower signal-to-noise ratio (SNR) threshold. The availability of efficient ML algorith... View full abstract»

• ### A normalization technique for non-additive noise

Publication Year: 1990, Page(s):2895 - 2898 vol.5
Cited by:  Papers (2)
| | PDF (276 KB)

A normalization technique leading to a constant false alarm receiver in the cases where noise and signal are not additive is presented. The algorithm presented is mainly based on a log transform followed by a fixed and adaptive sorting. Some results obtained on a real signal (neutron noise) are given. They show the superiority of the method over classical smoothing approaches from the noise alone ... View full abstract»

• ### Analysis of algorithms for sensor arrays with invariance structure

Publication Year: 1990, Page(s):2959 - 2962 vol.5
Cited by:  Papers (5)
| | PDF (308 KB)

The problem of estimating signal parameters from sensor array data is addressed. If the array is composed of two identical subarrays, (i.e. one invariance) the ESPRIT algorithm is known to yield parameter estimates in a very cost efficient manner. Recently, the total least squares (TLS) version of ESPRIT has been formulated in a subspace fitting framework. In this formulation, the ESPRIT concept i... View full abstract»

• ### Interference removal using multiple detection hypotheses

Publication Year: 1990, Page(s):2891 - 2893 vol.5
| | PDF (296 KB)

An approach for reducing the impact of strong interfering contacts when using an ambiguity surface for detection and tracking, as is the case in many sonar and radar applications, is presented. The problem of broadband detection from a multibeam line array is considered. The algorithm uses an ambiguity surface generated by integrating existing broadband detection outputs according to predefined hy... View full abstract»

• ### Laplacian pyramid versus wavelet decomposition for image sequence coding

Publication Year: 1990, Page(s):1965 - 1968 vol.4
Cited by:  Papers (7)  |  Patents (3)
| | PDF (420 KB)

Implementation of a set of pyramid transforms in a hierarchical approach for a real television sequence which consists of a 3-D data information set is presented. The investigation is based on several visual and objective comparative criteria, including the relevance to the motion information. Several pyramid transforms for image sequence coding are investigated and compared. The nonorthogonal pyr... View full abstract»

• ### On a high resolution array processing method non-based on the eigenanalysis approach

Publication Year: 1990, Page(s):2955 - 2958 vol.5
Cited by:  Papers (25)
| | PDF (308 KB)

A concept for array processing was recently introduced under the name of propagator'. The properties of this concept have since been proven useful for source bearing estimation problems in difficult situations. The propagator is a linear operator which can easily be extracted from the cross-spectral matrix of the signals received on the array without any eigendecomposition of this matrix. It is s... View full abstract»

• ### Instantaneous frequency estimation using the cross Wigner-Ville distribution with application to nonstationary transient detection

Publication Year: 1990, Page(s):2887 - 2890 vol.5
Cited by:  Papers (6)
| | PDF (312 KB)

A method based on an iterative procedure incorporating time-frequency distributions (TFDs) is proposed for instantaneous frequency (IF) estimation of rapidly time-varying signals. This method is then applied to the problem of adaptively detecting a transient of unknown waveshape in white Gaussian noise. For this type of adaptive detection, the signal's time-frequency representation is first estima... View full abstract»

• ### Word juncture modeling using phonological rules for HMM-based continuous speech recognition

Publication Year: 1990, Page(s):737 - 740 vol.2
Cited by:  Papers (2)  |  Patents (1)
| | PDF (388 KB)

Between-word context-dependent phones have been proposed to provide a more precise phonetic representation of word junctures. This technique makes it possible to accurately model soft pronunciation changes (changes in which a phone undergoes a comparatively small alteration). However, hard pronunciation changes (changes in which a phone is completely deleted or replaced by a different phone) are m... View full abstract»

• ### A signal subspace beamformer

Publication Year: 1990, Page(s):2815 - 2818 vol.5
Cited by:  Papers (2)
| | PDF (268 KB)

It is shown that it is possible to approximate a maximum-likelihood method, leading to a very high performance subspace algorithm. This has all the advantages of subspace methods (i.e. inexpensive), but with much better threshold performance than existing methods such as MUSIC. The method is applicable to arbitrary array geometry, and is demonstrated on both linear and curved arrays with limited s... View full abstract»

• ### Direction finding using an interpolated array

Publication Year: 1990, Page(s):2951 - 2954 vol.5
Cited by:  Papers (40)  |  Patents (25)
| | PDF (328 KB)

A direction-finding technique is developed which uses the outputs of a virtual array computed from the real array using a linear interpolation procedure. The geometry of the virtual array is under the control of the designer. Using a linear virtual array, an extension of the root-MUSIC algorithm to arbitrary array geometries is developed View full abstract»

• ### Parallel architecture for real-time speech recognition in Spanish

Publication Year: 1990, Page(s):977 - 980 vol.2
| | PDF (248 KB)

Parallel processing with an architecture based on transputers and its application to speech recognition in Spanish are evaluated. Furthermore, real-time performance viability has been proved with an effective processing environment that allows the development and evaluation of recognition algorithms using different structures and topologies. Pruning algorithms have proved to reduce significantly t... View full abstract»

• ### Multiple-channel detection using generalized coherence

Publication Year: 1990, Page(s):2883 - 2886 vol.5
Cited by:  Papers (11)
| | PDF (260 KB)

The properties and performance of the generalized coherence (GC) estimate as a statistic for detecting the presence of a common but unknown signal on several noisy channels are examined. The H 0 distribution function of the GC estimate derived in earlier work is applied to develop detection thresholds corresponding to a range of false alarm probabilities for various numbers of ... View full abstract»

• ### Blur identification using bispectrum

Publication Year: 1990, Page(s):1961 - 1964 vol.4
Cited by:  Papers (11)
| | PDF (312 KB)

Blur identification methods based on the bispectrum of an observed noisy and blurred image are proposed. Blur identification is addressed, in the case of uniform blurs, by zero-crossing detection in a particular cross section of the bispectrum of the observed image. The identification of general finite-impulse-response blurs is considered. The blurred image is represented by a nonminimum phase ARM... View full abstract»

• ### Applications of truncated QR methods to sinusoidal frequency estimation

Publication Year: 1990, Page(s):2571 - 2574 vol.5
Cited by:  Papers (2)
| | PDF (280 KB)

Three truncated QR methods are proposed for sinusoidal frequency estimation: (1) truncated QR without column pivoting (TQR); (2) truncated QR with pre-ordered columns, (TQRR); and (3) truncated QR with column pivoting (TQRP). It is demonstrated that the benefit of truncated singular value decomposition (TSVD) for high-frequency resolution is achievable under the truncated QR approach with much low... View full abstract»

• ### Soft constrained minimum variance beamforming

Publication Year: 1990, Page(s):2811 - 2814 vol.5
Cited by:  Papers (15)
| | PDF (340 KB)

The mean-squared error between the desired and actual response is constrained, resulting in a quadratic constraint on the weights. The constraint is purposely chosen to permit signal distortion with the goal of achieving improved interference cancellation, motivating the term soft constrained' beamforming. The soft constrained minimum variance (SCMV) philosophy represents a trade of bias (signal ... View full abstract»

• ### ESPRIT with perturbed subarrays

Publication Year: 1990, Page(s):2947 - 2950 vol.5
| | PDF (252 KB)

The effectiveness of the ESPRIT direction-finding algorithm in the presence of array perturbations is addressed. For the single-signal case, expressions are found for the errors in the angle of arrival due to element location perturbations, element gain and phase errors, and subarray rotations. Results are also presented for the multiple signal situation. For random location perturbations, the var... View full abstract»

• ### Non-Euclidean locally monotonic regression

Publication Year: 1990, Page(s):1201 - 1204 vol.3
Cited by:  Papers (2)
| | PDF (428 KB)

The concept of locally monotonic regression is extended by considering metrics on rn that are different from the Euclidean metric. The existence of regressions for a large class of metrics is shown. Algorithms that show the computability of locally monotonic regressions are given. A general algorithm that computes regressions for the lp metrics is given; con... View full abstract»

• ### Image coding using vector quantization in the wavelet transform domain

Publication Year: 1990, Page(s):2297 - 2300 vol.4
Cited by:  Papers (57)  |  Patents (3)
| | PDF (352 KB)

A two-step scheme for image compression that takes into account psychovisual features in space and frequency domains is proposed. A wavelet transform is first used in order to obtain a set of orthonormal subclasses of images; the original image is decomposed at different scales using a pyramidal algorithm architecture. The decomposition is along the vertical and horizontal directions and maintains... View full abstract»

• ### An improved analysis of ΣΔ modulators with bandlimited Gaussian inputs

Publication Year: 1990, Page(s):1691 - 1694 vol.3
Cited by:  Papers (1)
| | PDF (308 KB)

Three results on ΣΔ modulation are presented. First, a change of variables is presented that demonstrates that two of the parameters in a ΣΔ modulator do not affect the system performance. Second, a successive parameterization approach is used to determine the probability density function (PDF) at the input to the quantizer of a second-order ΣΔ modulator. Third,... View full abstract»

• ### VLSI design of multi-rate arrays for DSP algorithm

Publication Year: 1990, Page(s):1049 - 1052 vol.2
Cited by:  Papers (7)
| | PDF (252 KB)

Multirate arrays where the data transmission rate at different paths varies are introduced. Using a multirate clock, transparent data or data with small delays are propagated K times faster than the computed data, achieving a speedup of a factor of K as compared to systolic arrays. A new synthesis method for a class of nonuniform recurrence equations named DURE (directional unifo... View full abstract»

• ### Optimum space-time processing for semi-stationary signals in spatially correlated noise

Publication Year: 1990, Page(s):2879 - 2882 vol.5
| | PDF (364 KB)

The problem of optimum space-time processing for multiple Gaussian source signals transmitted through a slowly-varying linear channel and monitored with a passive array of sensors in the presence of spatially correlated noise is addressed. To solve this problem, a new class of linear systems (LS), referred to as semistationary, is introduced. These LS are characterized by time-frequency representa... View full abstract»