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Acoustics, Speech and Signal Processing, 1998. Proceedings of the 1998 IEEE International Conference on

15-15 May 1998

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  • Proceedings of the 1998 IEEE International Conference on Acoustics, Speech and Signal Processing [front matter]

    Publication Year: 1998, Page(s):i - lxiii
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  • A new subband perceptual audio coder using CELP

    Publication Year: 1998, Page(s):3661 - 3664 vol.6
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (307 KB)

    This paper presents an audio coding system which uses filter banks to decompose, in the frequency domain, the audio signal into constant width subbands. A specific compression is applied in each subband. This compression is achieved by means of CELP coders. In order to obtain a high audio quality, psychoacoustic models allocate dynamically the number of bits needed in each subband. A particular ca... View full abstract»

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  • Extraction of detailed image regions for content-based image retrieval

    Publication Year: 1998, Page(s):3713 - 3716 vol.6
    Cited by:  Papers (2)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (708 KB)

    We present a technique for coarsely extracting the regions of natural color images which contain directional detail, e.g., edges, texture, etc., which we then use for image database indexing. As a measure of color activity, we use a perceptually modified distance measure based on the sum-of-angles criterion. We then apply histogram thresholding techniques to separate the image into smooth color re... View full abstract»

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  • Author index

    Publication Year: 1998, Page(s):A1 - A12
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  • A bottle model for head-related transfer functions

    Publication Year: 1998, Page(s):3533 - 3536 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    We describe a parsimonious model for the direction-dependent transfer function of the pinna. The model describes the transfer function with reference to resonators located in particular physical positions relative to the ear canal. The purpose of the work is to provide a parametric model that permits identification with moderate data-gathering, and filter specification for any direction without th... View full abstract»

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  • A new test of stationarity and its application to teletraffic data

    Publication Year: 1998, Page(s):3449 - 3452 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (396 KB)

    In this contribution we generalize the test of sphericity as a test of stationarity for time-series. The sphericity statistics is in our case a measure of distance between the empirical correlations calculated on two contiguous segments of the same process. We prove that under the hypothesis of stationarity the logarithm of the sphericity converges in distribution to a quadratic form in a multidim... View full abstract»

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  • Convergence properties of blind algorithms for base station CDMA receivers

    Publication Year: 1998, Page(s):3181 - 3184 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    In this paper, the blind estimation of wireless CDMA receiver coefficients from the second order statistics of the signals is considered. Although many algorithms have been proposed so far, their performance analysis has always been carried out assuming perfect receiver coefficients estimation and/or under time-invariant conditions. In this article, we present some decision-directed blind algorith... View full abstract»

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  • Fast computation of efficient decision feedback equalizers for high speed wireless communications

    Publication Year: 1998, Page(s):3493 - 3496 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    Decision feedback equalization (DFE) structures have been proposed for the efficient equalization of wireless channels with long postcursor response, which is a bottleneck problem for high speed communications over multipath channels with large delay spread. These structures are equivalent to the conventional DFE, but remove postcursor intersymbol interference (ISI) prior to feedforward filtering.... View full abstract»

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  • On the implementation of adaptive equalizers for wireless ATM with an extended QR-decomposition-based RLS-algorithm

    Publication Year: 1998, Page(s):3445 - 3448 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    An extended quadratic residue (QR)-decomposition (QRD)-based RLS-algorithm is introduced, applicable for equalization, allowing an estimate of the transmitted symbol, when it is a-priori unknown. To achieve low-cost implementations strength reduction and square-root free Givens-rotations are applied. Several QRD-based RLS-algorithms are compared in terms of the number of mathematical operations. T... View full abstract»

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  • The effects of local scattering on direction of arrival estimation with MUSIC and ESPRIT

    Publication Year: 1998, Page(s):3333 - 3336 vol.6
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    In wireless communication scenarios, multipath propagation from local scatterers in the vicinity of mobile sources may cause angular spreading as seen from a base station antenna array. This paper studies the effects of such local scattering on direction of arrival (DOA) estimation with the MUSIC and ESPRIT algorithms. Previous work has considered rapidly time-varying scenarios, and concluded that... View full abstract»

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  • Implementation of linear multiuser detectors for asynchronous CDMA systems by linear multi-stage interference cancellation

    Publication Year: 1998, Page(s):3225 - 3228 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    The decorrelating and the linear, minimum mean-squared error (MMSE) detectors for asynchronous code-division multiple-access communications ideally are infinite memory-length detectors. Finite memory approximations of these detectors require the inversion of a correlation matrix whose dimension is given by the product of the number of active users and the length of the processing window. With incr... View full abstract»

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  • Head-related transfer function modeling in 3-D sound systems with genetic algorithms

    Publication Year: 1998, Page(s):3529 - 3532 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    Head-related transfer functions (HRTFs) describe the spectral filtering that occurs between a source sound and the listener's eardrum. Since HRTFs vary as a function of the relative source location and subject, practical implementation of 3D audio must take into account a large set of HRTFs for different azimuths and elevations. Previous work has proposed several HRTF models for data reduction. Th... View full abstract»

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  • On the use of explicit speech modeling in microphone array applications

    Publication Year: 1998, Page(s):3613 - 3616 vol.6
    Cited by:  Papers (11)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    This paper addresses the limitations of current approaches to distant-talker speech acquisition and advocates the development of techniques which explicitly incorporate the nature of the speech signal (e.g. statistical non-stationarity, method of production, pitch, voicing, formant structure, and source radiator model) into a multi-channel context. The goal is to combine the advantages of spatial ... View full abstract»

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  • A new blind zeroforcing equalizer for multichannel systems

    Publication Year: 1998, Page(s):3177 - 3180 vol.6
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    Blind channel equalization has been a very active research topic due to its potential application in mobile communications and digital TV systems. In this paper, we present a new blind zero-forcing equalizer that utilizes second order statistics from the multi-channel configuration. The algorithm is simple and relies only on nullspace decomposition. It can actively select the desired delay of the ... View full abstract»

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  • Two-stage code reference beamformer in mobile communications

    Publication Year: 1998, Page(s):3309 - 3312 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    This paper addresses a new architecture for blind adaptive beamforming when dealing with frequency hopping (FH) modulation in cellular mobile communications systems. The proposed code reference beamformer (CRB) takes advantage of the inherent frequency diversity to estimate beforehand the noise plus interference correlation matrix, which is employed as the first part of the framework. Then, a seco... View full abstract»

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  • H equalization of communication channels

    Publication Year: 1998, Page(s):3489 - 3492 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    As an alternative to existing techniques and algorithms, we investigate the merit of the H-infinity approach to the equalization of communication channels. We first look at causal H-infinity equalization problem and then look at the improvement due to finite delay. By introducing the risk sensitive property, we compare the average performance of the central H-infinity equalizer with the MMSE equal... View full abstract»

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  • Computational reduction during idle transmission in DSL modems

    Publication Year: 1998, Page(s):3441 - 3444 vol.6
    Cited by:  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    This document describes two methods for reducing computational requirements during idle transmission in remote access systems incorporating digital subscriber line (DSL) modems, including asymmetrical DSL (ADSL) systems. These methods save processing power during idle transmission by generating an idle signal using low-complexity techniques. The generated idle signal is made spectrally compatible ... View full abstract»

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  • Design of neural network quantizers for a distributed estimation system with communication constraints

    Publication Year: 1998, Page(s):3469 - 3472 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    We consider the problem of quantizer design in a distributed estimation system with communication constraints at the channels in the case where the observation statistics are unknown and one must rely on a training set. The method that we propose applies a variation of the cyclic generalized Lloyd algorithm (CGLA) on every point of the training set and then uses a neural network for each quantizer... View full abstract»

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  • Decoupled direction finding: detection

    Publication Year: 1998, Page(s):3329 - 3332 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    Antenna arrays are likely to be an important feature of future mobile communication systems. With an antenna array, mobile users can be separated by a spatial filtering procedure allowing several users on the same carrier frequency. The uplink part (mobile to base) not only can, but is better solved without using any spatial knowledge in terms of direction of arrival (DOA). However, DOA estimation... View full abstract»

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  • Efficient implementation of linear multiuser detectors

    Publication Year: 1998, Page(s):3221 - 3224 vol.6
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    A recursive algorithm for updating linear detectors in code-division multiple-access systems is proposed. Based on this algorithm, a window-based implementation with a signal-based criterion for determining the window length is developed. Performance analysis and numerical experiments are conducted that show the merits of the proposed implementation method View full abstract»

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  • Optimal object allocation for multimedia broadcast

    Publication Year: 1998, Page(s):3717 - 3720 vol.6
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    With the arrival of terrestrial digital TV, a distribution network able to deliver up to 19 Mbits/s in each of the physical transmission channels will become available. Using the adopted data broadcast protocols, simultaneous transmission of multimedia documents to large population segments can be achieved. While these protocols describe methods for recognizing files in data streams, no method is ... View full abstract»

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  • Multi-microphone noise cancellation for improvement of hearing aid performance

    Publication Year: 1998, Page(s):3633 - 3636 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    A scheme for binaural pre-processing of speech signals for input to a standard linear hearing aid has been investigated. The system is based on that of Toner & Campbell (1993) who applied the least mean squares (LMS) algorithm in sub-bands to speech signals from various acoustic environments and signal to noise ratios (SNR). The processing scheme attempts to take advantage of the multiple inpu... View full abstract»

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  • Automatic classification of environmental noise events by hidden Markov models

    Publication Year: 1998, Page(s):3609 - 3612 vol.6
    Cited by:  Papers (18)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    The automatic classification of environmental noise sources from their acoustic signatures recorded at the microphone of a noise monitoring system (NMS) is an active subject of research nowadays. This paper shows how hidden Markov models (HMMs) can be used to build an environmental noise recognition system based on a time-frequency analysis of the noise signal. The performance of the proposed HMM-... View full abstract»

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  • Blind 2-D RAKE receivers based on RLS-type space-time adaptive filtering for DS-CDMA system

    Publication Year: 1998, Page(s):3173 - 3176 vol.6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (380 KB)

    We previously presented a blind 2-D RAKE receiver for CDMA that cancels strong multi-user access interference and optimally combines multipath. The weight vector yielding the optimum signal to interference plus noise ratio for bit decisions is the “largest” generalized eigenvector of the spatio-frequency (spatio-temporal) correlation matrix pencil. However, the eigen-analysis based alg... View full abstract»

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  • A fast blind source separation for digital wireless applications

    Publication Year: 1998, Page(s):3305 - 3308 vol.6
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB)

    The problem of blindly estimating multiple digital co-channel communication signals using an antenna array is studied in the presence of multipath fading. We develop a fast sequential-estimation algorithm for separating multi-user signals based on the geometric observation made by Kansen and Xu (see Proc. ICASSP'96, p.1085-8, Atlanta, GA, 1996). When the signals are constrained to a finite alphabe... View full abstract»

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