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IEEE Signal Processing Letters

Issue 2  Part 2 • Date Feb. 2004

 This issue contains several parts.Go to:  Part 1 

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Displaying Results 1 - 25 of 48
  • Table of contents

    Publication Year: 2004, Page(s): 01
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  • IEEE Signal Processing Letters Society Information

    Publication Year: 2004, Page(s): 0_2
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  • Leaky zero-forcing adaptive equalization

    Publication Year: 2004, Page(s):129 - 131
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB) | HTML iconHTML

    Zero-forcing equalizer adaptation schemes are attractive because of their simplicity. We study their steady-state solution, and find that it is more poorly conditioned than that of least mean-square adaptation schemes. A simple yet effective solution to this problem, based on tap leakage, is proposed, analyzed, and exemplified for an idealized digital optical storage system. View full abstract»

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  • Variable step-size NLMS and affine projection algorithms

    Publication Year: 2004, Page(s):132 - 135
    Cited by:  Papers (230)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB) | HTML iconHTML

    This letter proposes two new variable step-size algorithms for normalized least mean square and affine projection. The proposed schemes lead to faster convergence rate and lower misadjustment error. View full abstract»

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  • Subspace leaky LMS

    Publication Year: 2004, Page(s):136 - 139
    Cited by:  Papers (4)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB) | HTML iconHTML

    The least mean squared (LMS) adaptive filtering algorithm may experience uncontrolled parameter drift when its input signal is not persistently exciting, leading to serious consequences when implemented with finite word-length. Though so-called "tap-leakage" modifications of LMS have been proposed to mitigate this drift, they inevitably introduce parameter bias which degrades mean-squared error pe... View full abstract»

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  • Observations on adaptive vector filters for noise reduction in color images

    Publication Year: 2004, Page(s):140 - 143
    Cited by:  Papers (7)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB) | HTML iconHTML

    In a series of papers, Plataniotis et al. proposed a number of filters for noise reduction in color images where the noise type is unknown. In this letter, those filters with a unified notation are summarized, and it is shown that they are essentially variants of the same filtering procedure. It is also shown that the class of adaptive vector filters can be considered as interpolants between the a... View full abstract»

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  • Recursive least squares implementation of the quadratically constrained IIR filter

    Publication Year: 2004, Page(s):144 - 147
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB) | HTML iconHTML

    To avoid the bias in the equation error (EE) method, the unit norm constrained EE approach was introduced. In order to get faster convergence, the implementation of the EE with the unit norm constraint using recursive least squares via variable loading is presented. View full abstract»

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  • The behavior of the modified FX-LMS algorithm with secondary path modeling errors

    Publication Year: 2004, Page(s):148 - 151
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (200 KB) | HTML iconHTML

    In active noise control there has been some research based in the modified filtered-X least mean square (LMS) algorithm (MFX-LMS). When the secondary path is perfectly modeled, this algorithm is able to perfectly eliminate it's effect. It is also easily adapted to allow the use of fast algorithms such as the recursive least square, or algorithms with good tracking performance based on the Kalman f... View full abstract»

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  • A memory-efficient and high-speed sine/cosine generator based on parallel CORDIC rotations

    Publication Year: 2004, Page(s):152 - 155
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB) | HTML iconHTML

    The sine/cosine function generator is based on parallelization of the original CORDIC algorithm by predicting all the rotation directions directly from the binary bits of the initial input angle. Unlike previous approaches that require complicated circuits or exponentially increased ROM, our proposed architecture has a relatively simple prediction scheme through an efficient angle recoding. The cr... View full abstract»

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  • A novel algorithm for computing the 1-D discrete Hartley transform

    Publication Year: 2004, Page(s):156 - 159
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB) | HTML iconHTML

    An efficient split algorithm for calculating the one-dimensional discrete Hartley transforms, by using a special partitioning in the frequency domain, is introduced. The partition determines a fast paired transform that splits the 2r-point unitary Hartley transform into a set of 2r-n-point odd-frequency Hartley transforms, n=1:r. A proposed method of calculation of the 2... View full abstract»

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  • Bandpass variable-bandwidth filter for reconstruction of signals with known boundary in time-frequency domain

    Publication Year: 2004, Page(s):160 - 163
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB) | HTML iconHTML

    A bandpass variable-bandwidth filter (BPVBF) is proposed for the reconstruction of the signal whose boundaries are known in time-frequency domain (TFD). The behaviors of the ideal BPVBF are investigated in TFD. Simulation results show that the ideal BPVBF rejects noise in the outside of a region of interest in TFD and produces the reliable reconstruction of signals. View full abstract»

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  • Efficient single-bit ternary digital filtering using sigma-delta modulator

    Publication Year: 2004, Page(s):164 - 166
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (112 KB) | HTML iconHTML

    Efficient filtering of sigma-delta bit-streams using a finite-impulse response (FIR)-like digital filter is presented. The filter combines a lowpass sigma-delta modulator system and a ternary FIR filter. Unlike conventional FIR filters, the combination of the two components allows a bit stream to be filtered, with the output being retained in single-bit format. View full abstract»

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  • An enhanced generalized Lloyd algorithm

    Publication Year: 2004, Page(s):167 - 170
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (168 KB) | HTML iconHTML

    Vector quantization is an effective means of data compression for it maps a set of real numbers into a single integer. In this letter an enhanced generalized Lloyd algorithm (GLA) for vector quantizer design is presented. Experiment results show that the proposed scheme outperforms the conventional GLA and recently reported modification of the K-means algorithm. Moreover, the achievement in coding... View full abstract»

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  • Polynomial-based filters with odd number of polynomial segments for interpolation

    Publication Year: 2004, Page(s):171 - 174
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB) | HTML iconHTML

    In many signal processing applications, it is beneficial to use polynomial-based interpolation filters. Actual implementations of these filters can be performed effectively by using the Farrow structure or its modifications. In the literature only polynomial-based filters having even number of polynomial pieces N have been considered. This letter presents a modification of the implementation form ... View full abstract»

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  • Mean frequency estimation of narrowband signals

    Publication Year: 2004, Page(s):175 - 178
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB) | HTML iconHTML

    This letter shows that the single frequency approximation for a narrowband lowpass signal embedded in white noise using the Pisarenko harmonic decomposition algorithm is approximately the power-weighted mean frequency of the signal. Experimental results indicate that this method is superior to a commonly used Fourier transform based mean frequency estimation method. View full abstract»

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  • Discrete frequency-coding waveform design for netted radar systems

    Publication Year: 2004, Page(s):179 - 182
    Cited by:  Papers (55)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (136 KB) | HTML iconHTML

    A novel method is proposed to design discrete frequency-coding waveforms (DFCWs) for the netted radar systems. Some of the designed results are presented and they indicate that the proposed algorithm is effective for the DFCW design. View full abstract»

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  • AR model estimation from quantized signals

    Publication Year: 2004, Page(s):183 - 185
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (92 KB) | HTML iconHTML

    This letter investigates the deviation of least squares AR-model estimates induced by linear quantization of the observable signal under modeling. Model correction is attained by describing the undesirable bias as a function of the number of bits used to represent the signal. Sensitivity considerations are employed to explain the behavior of the deviations on the generator filter poles. Numerical ... View full abstract»

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  • A modified dichotomous search frequency estimator

    Publication Year: 2004, Page(s):186 - 188
    Cited by:  Papers (58)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (144 KB) | HTML iconHTML

    The estimation of the frequency of a sinusoidal signal has been dealt with extensively in the literature. In this letter, we examine the dichotomous search of the periodogram peak algorithm. We provide an insight into the need to pad the data with zeros in order to achieve a performance that is comparable to the Cramer-Rao lower bound (CRB). We also propose a modified dichotomous search estimator ... View full abstract»

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  • A non-Gaussian problem that arises in fused detection in clutter

    Publication Year: 2004, Page(s):189 - 192
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB) | HTML iconHTML

    A common model for sonar clutter is that of the transmitted signal convolved with a colored Gaussian process relating to the sea-bottom profile. Rather surprisingly, this noise becomes strongly non-Gaussian if there are multiple realizations and if a realistic random phase is introduced - the univariate statistics remain Gaussian, but the joint probability density function is not. In this letter, ... View full abstract»

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  • Separability and axial symmetry of M-D polynomials and maximum-entropy M-D random Processes

    Publication Year: 2004, Page(s):193 - 196
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (160 KB) | HTML iconHTML

    In multidimensional system and signal analysis it is often assumed that an M-dimensional (M-D) polynomial is separable. The following properties are presented to show rationales of the separability assumption. First, if an M-D polynomial is separable, it is axially symmetric. Second, if the autocorrelation generating function of an M-D deterministic sequence with the support in the first 2... View full abstract»

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  • The CRB for parameter estimation in irregularly sampled continuous-time ARMA systems

    Publication Year: 2004, Page(s):197 - 200
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (152 KB) | HTML iconHTML

    We derive novel and compact formulas for the Cramer-Rao bound (CRB) associated with the identification of the parameters in a continuous-time autoregressive moving-average (ARMA) model, given nonuniformly sampled data. Our approach is based on a state-space formulation of the ARMA model, which facilitates a derivation of the CRB in closed form. Numerical examples illustrate our results. View full abstract»

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  • Robust adaptive local polynomial Fourier transform

    Publication Year: 2004, Page(s):201 - 204
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB) | HTML iconHTML

    A robust form of the local polynomial Fourier transform (LPFT) is introduced. This transform can produce a highly concentrated time-frequency (TF) representation for signals embedded in an impulse noise. Calculation of the adaptive parameter in the proposed transform is based on the concentration measure. A modified form, calculated as a weighted sum of the robust LPFT, is proposed for multicompon... View full abstract»

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  • Analysis-ready multiwavelets (armlets) for processing scalar-valued signals

    Publication Year: 2004, Page(s):205 - 208
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB) | HTML iconHTML

    The notion of armlets is introduced in this letter as a precise formulation of orthonormal multiwavelets that guarantee wavelet decomposition with highpass output not being effected by polynomial perturbation of the input. A mathematical scheme for constructing armlets is given, and it is shown that the notions of armlets and balanced multiwavelets are different. In particular, while balanced wave... View full abstract»

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  • Detection of asynchronous CDMA with unknown user waveforms

    Publication Year: 2004, Page(s):209 - 211
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (120 KB) | HTML iconHTML

    We propose a procedure for detection of short code asynchronous code division multi-access (CDMA) without knowledge of user waveforms, symbol timing, or the number of users. The only a priori information used is the symbol duration. The source waveforms and timing are acquired by a modified iterative least squares with projection (ILSP) algorithm. A minimal mean-squared-error (MMSE) receiver is th... View full abstract»

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  • Near-far resistance of multicarrier CDMA communication systems

    Publication Year: 2004, Page(s):212 - 215
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (176 KB) | HTML iconHTML

    In this letter, the near-far resistance of the minimum mean square error (MMSE) detector is derived for multicarrier code division multiple access (MC-CDMA) communication systems both with cyclic prefix (CP) and without CP. It is shown that the near-far resistance of MC-CDMA without CP is the same as that of the direct sequence CDMA (DS-CDMA) while MC-CDMA with CP has better performance on near-fa... View full abstract»

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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.

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Meet Our Editors

Editor-in-Chief
Peter Willett
University of Connecticut
Storrs, CT 06269
peter.willett@uconn.edu