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IEEE Signal Processing Letters

Issue 12 • Dec. 2002

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Displaying Results 1 - 19 of 19
  • Code-constrained blind detection of CDMA signals in multipath channels

    Publication Year: 2002, Page(s):389 - 392
    Cited by:  Papers (39)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (379 KB) | HTML iconHTML

    In this letter, a constant-modulus-algorithm-based multiuser detection scheme is proposed for a communication system under multipath propagation. To mitigate channel distortion and multiuser interference, we integrate multiple constraints into the optimization criterion. According to our analysis, the ability of the detector to remove all interference is ensured in the absence of noise when the co... View full abstract»

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  • An AV-based RAKE-like receiver for DS-CDMA systems

    Publication Year: 2002, Page(s):393 - 396
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (291 KB) | HTML iconHTML

    Previously, several detectors based on auxiliary vector (AV) filters were presented to suppress multi-access interference (MAI) in direct-sequence/code-division-multiple-access (DS-CDMA) systems. Knowing the signature waveform of the desired user, these AV-based detectors are a class of promising candidates for MAI suppression due to their superior performance and low computational complexity. How... View full abstract»

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  • A residual echo cancellation scheme for hands-free telephony

    Publication Year: 2002, Page(s):397 - 399
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (383 KB) | HTML iconHTML

    A residual echo cancellation scheme based on the autoregressive (AR) analysis is proposed for hands-free telephony. Residual echo is whitened by the inverse filter using the estimated AR coefficients. Removing the speech characteristics of the residual echo signal, the noise reduction system successfully reduces the power of residual echo as well as that of ambient noise. In a car cabin, the propo... View full abstract»

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  • Binary LUM smoothing

    Publication Year: 2002, Page(s):400 - 403
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (322 KB) | HTML iconHTML

    In this letter, valuable simplification and analysis related to Boolean lower-upper middle (LUM) smoothers are provided. Thus, a class of nonlinear order-statistic LUM smoothers can be implemented as stack filters fast and effectively. An acquisition of the proposed method lies in the simple determination of the binary output according to the configuration of binary samples inside the filter windo... View full abstract»

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  • Self-organizing codebooks for trellis-coded VQ

    Publication Year: 2002, Page(s):404 - 406
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (215 KB) | HTML iconHTML

    Because of its computational complexity, vector quantization (VQ) can work only on relatively small vectors, which severely limits its encoding performance. Trellis-coded VQ (TCVQ) circumvents this problem by using VQ in combination with a trellis encoding strategy, thus treating very large blocks of data at once. TCVQ is based on a size-N VQ codebook which is recursively partitioned to form two (... View full abstract»

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  • Sequential modeling for identifying CpG island locations in human genome

    Publication Year: 2002, Page(s):407 - 409
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (195 KB) | HTML iconHTML

    We consider several sequential processing algorithms for identifying genes in human DNA, based on detecting CpG ("C proceeds G") islands. The algorithms are designed to capture the underlying statistical structure in a DNA sequence. Sequential processing using a Markov model and a hidden Markov model are shown to identify most CpG islands in annotated (marked) DNA subsequences available from publi... View full abstract»

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  • Application of bit-plane decomposition steganography to JPEG2000 encoded images

    Publication Year: 2002, Page(s):410 - 413
    Cited by:  Papers (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (378 KB) | HTML iconHTML

    This letter presents a steganography method based on a JPEG2000 lossy compression scheme and bit-plane complexity segmentation (BPCS) steganography. It overcomes the lack of robustness of bit-plane-based steganography methods with respect to lossy compression of a dummy image: a critical shortcoming that has hampered deployment in a practical scenario. The proposed method is based on a seamless in... View full abstract»

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  • Direction estimation of coherent signals using spatial signature

    Publication Year: 2002, Page(s):414 - 417
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (429 KB) | HTML iconHTML

    A computationally efficient spatial signature-based (SS) method is proposed for estimating the directions of arrival of coherent narrowband signals impinging on a uniform linear array. The normalized SS of the coherent signals is blindly estimated from the principal eigenvector of array covariance matrix and then is used to estimate the directions with a modified Kumaresan-Prony method, where a li... View full abstract»

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  • Multicodebook split vector quantization of LSF parameters

    Publication Year: 2002, Page(s):418 - 421
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (244 KB) | HTML iconHTML

    A multicodebook quantization method for improving the performance of the split vector quantization (SVQ) is described. In the proposed method, multiple codebooks having different sizes are trained, and the minimal-size codebook and its codeword satisfying the condition based on the spectral distortion are determined. Several clustering techniques for reducing total bit rate and the analysis of the... View full abstract»

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  • Context-adaptive smoothing for concatenative speech synthesis

    Publication Year: 2002, Page(s):422 - 425
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (220 KB) | HTML iconHTML

    In text-to-speech synthesis, spectral smoothing is often employed to reduce artifacts at unit-joining points. A context-adaptive smoothing method is proposed in this letter, where the amount of smoothing is determined according to context information. Discontinuities at unit boundaries are predicted by a regression tree, and smoothing factors are computed by using predicted discontinuities and rea... View full abstract»

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  • Two-dimensional non-Gaussian autoregressive model order determination

    Publication Year: 2002, Page(s):426 - 428
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB) | HTML iconHTML

    A two-dimensional (2-D) autoregressive (AR) model driven by a non-Gaussian zero-mean independent identically distributed 2-D sequence is considered. The input sequence is not observed. The signal observations may be contaminated by additive Gaussian noise. We consider the problem of model order determination using higher order cumulants of the 2-D signal. We show that the necessary information to ... View full abstract»

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  • Block adaptive interference suppression in DS-CDMA systems

    Publication Year: 2002, Page(s):429 - 431
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (298 KB) | HTML iconHTML

    In this letter, we introduce interference suppression in direct-sequence code-division multiple-access systems using the minimum-mean-square-error criterion based on a block adaptive filtering algorithm. Simulation results show that the proposed implementations of the block algorithm requires much lower computation as compared to recursive least square (RLS) algorithms while maintaining comparable... View full abstract»

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  • Adaptive RLS algorithm for blind source separation using a natural gradient

    Publication Year: 2002, Page(s):432 - 435
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (288 KB) | HTML iconHTML

    By using the natural gradient on the Stiefel manifold to minimize a nonlinear principle component analysis criterion, this letter proposes a new adaptive recursive-least-squares (RLS) algorithm with prewhitening for blind source separation (BSS), which makes full use of the orthogonality constraint of the separating matrix. Simulations show that the new natural-gradient-based RLS algorithm has fas... View full abstract»

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  • Performance of the hierarchical LMS algorithm

    Publication Year: 2002, Page(s):436 - 437
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (265 KB) | HTML iconHTML

    Woo (2001) introduced the hierarchical least mean-square (HLMS) adaptive filter algorithm, and demonstrated that it may converge faster than least mean-squares (LMS). This letter reports that the HLMS algorithm may converge to a biased impulse response, not only for colored input (as has previously been shown to be the case for the hierarchical least squares algorithm) but also for white input. We... View full abstract»

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  • Bivariate shrinkage with local variance estimation

    Publication Year: 2002, Page(s):438 - 441
    Cited by:  Papers (307)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1310 KB) | HTML iconHTML

    The performance of image-denoising algorithms using wavelet transforms can be improved significantly by taking into account the statistical dependencies among wavelet coefficients as demonstrated by several algorithms presented in the literature. In two earlier papers by the authors, a simple bivariate shrinkage rule is described using a coefficient and its parent. The performance can also be impr... View full abstract»

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  • Optimized support vector machines for nonstationary signal classification

    Publication Year: 2002, Page(s):442 - 445
    Cited by:  Papers (18)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (342 KB) | HTML iconHTML

    This letter describes an efficient method to perform nonstationary signal classification. A support vector machine (SVM) algorithm is introduced and its parameters optimized in a principled way. Simulations demonstrate that our low-complexity method outperforms state-of-the-art nonstationary signal classification techniques. View full abstract»

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  • List of reviewers

    Publication Year: 2002, Page(s):446 - 449
    Request permission for commercial reuse | PDF file iconPDF (148 KB)
    Freely Available from IEEE
  • Author Index

    Publication Year: 2002, Page(s):450 - 453
    Request permission for commercial reuse | PDF file iconPDF (197 KB)
    Freely Available from IEEE
  • Subject Index

    Publication Year: 2002, Page(s):453 - 463
    Request permission for commercial reuse | PDF file iconPDF (237 KB)
    Freely Available from IEEE

Aims & Scope

The IEEE Signal Processing Letters is a monthly, archival publication designed to provide rapid dissemination of original, cutting-edge ideas and timely, significant contributions in signal, image, speech, language and audio processing.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
James E. Fowler
Dept Electrical & Computer Engineering
Associate Director                         
Distributed Analytics and Security Institute
Mississippi State University
Mississippi State, MS 39762 USA
fowler@ece.msstate.edu