检索结果-内蒙古大学图书馆

ON THE SENSITIVITY OF TRANSVERSAL RLS ALGORITHMS TO RANDOM PERTURBATIONS IN THE FILTER COEFFICIENTS

IEEE TRANSACTIONS ON ACOUSTICS SPEECH AND signal processing 1988年第11期36卷 1781-1783页

作者： ARDALAN, S Center for Communications and Signal Processing Department of Electrical and Computer Engineering North Carolina State University Raleigh NC USA

The author investigates the sensitivity of the RLS algorithm to random perturbations about the optimum filter coefficients. Expressions are derived for the mean and variance of the deviation from the optimum error power for the prewindowed growing memory and the experimentally windowed ( lambda >1) RLS algorithm. The results show that the variance of the deviation for correlated signals increases compared to uncorrelated white signals by a term related to the sum of the square of the off-diagonal elements of the sample autocorrelation matrix. For lambda >1, the deviations are bounded and inversely proportional to 1- lambda . For lambda =1, the deviations are unbounded and increase linearly with the number of iterations.

关键词： Restless Legs Syndrome Filter coefficient Deviation Transverse Inverse Proportion Sum of squares algorithms perturbation iterative methods Variance

来源：评论

学校读者我要写书评

暂无评论

ARMA BISPECTRUM APPROACH TO NONMINIMUM PHASE SYSTEM-IDENTIFICATION

引用

IEEE TRANSACTIONS ON ACOUSTICS SPEECH AND signal processing 1988年第4期36卷 513-524页

作者： NIKIAS, CL Communications and Digital Signal Processing (CDSP) Center for Research and Graduate Studies Department of Electrical and Computer Engineering Northeastern University Boston MA USA

An identification procedure is proposed for a nonGaussian white-noise-driven, linear, time-invariant, nonminimum-phase FIR (finite-impulse response) system. The method is based on parametric modeling of the third moments of the output sequence and uses causal and anticausal autoregressive moving-average (ARMA) models. The magnitude and phase response of the system are expressed in terms of the AR parameters of the ARMA models. In particular, the AR part of the causal ARMA model captures the minimum-phase component of the system, and the AR part of the anticausal ARMA captures the maximum-phase component. Both sets of parameters are obtained by solving overdetermined linear systems of equations. A model-order-selection criterion based on third-order moments is proposed. The ARMA bispectrum approach is compared to more conventional approaches for magnitude and phase reconstruction. It is demonstrated that the proposed identification procedure exhibits improved modeling performance. The method does not require knowledge of the non-Gaussian noise distribution.< >

关键词： System identification Autoregressive processes Autocorrelation Equations Yield estimation Finite impulse response filter Parametric statistics Linear systems Ear White noise

来源：评论

学校读者我要写书评

暂无评论

TIME-DELAY ESTIMATION IN UNKNOWN GAUSSIAN SPATIALLY CORRELATED NOISE

引用

IEEE TRANSACTIONS ON ACOUSTICS SPEECH AND signal processing 1988年第11期36卷 1706-1714页

作者： NIKIAS, CL PAN, RL Communications and Digital Signal Processing (CDSP) Center for Research and Graduate Studies Department of Electrical and Computer Engineering Northeastern University Boston MA USA

A novel class of methods that estimate the difference in arrival time between signals corrupted by spatially correlated Gaussian noise sources of unknown cross correlation is presented. The methods are based on the idea of comparing the similarities between the two sensor measurements in higher-order spectrum domains (bispectrum) rather than in the cross-correlation domain. It is demonstrated that estimation techniques based on higher-order cumulants suppress the effect of correlated Gaussian noise sources and therefore exhibit improved performance over generalized cross-correlation methods. Results are reported for different types of signals, lengths of data records, and signal-to-noise ratios.< >

关键词： Delay effects Delay estimation Gaussian noise Biomedical measurements Geophysical measurements Sonar applications Random processes Digital signal processing signal to noise ratio Noise measurement

来源：评论

学校读者我要写书评

暂无评论

ARMA MODELING OF 4TH-ORDER CUMULANTS AND PHASE ESTIMATION

引用

CIRCUITS SYSTEMS AND signal processing 1988年第3期7卷 291-325页

作者： NIKIAS, CL PAN, R 1. Communications and Digital Signal Processing Center for Research and Graduate Studies Department of Electrical and Computer Engineering Northeastern University 02115 Boston MA USA

A new procedure is proposed for ARMA modeling of fourth-order cumulants and trispectrum estimation of non-Gaussian stationary random processes. The new procedure is applied to the identification of nonminimum phase systems for both phase and magnitude response estimation. It is demonstrated by means of comprehensive simulation examples that the ARMA approach exhibits improved performance over conventional trispectrum methods. ARMA model order selection criteria based on fourth-order cumulants are presented and their performance evaluated. The computational complexity of the ARMA and conventional trispectrum methods is also examined. The new procedure does not require knowledge of the non-Gaussian distribution.

关键词： signal processing

来源：评论

学校读者我要写书评

暂无评论

Connections between three-dimensional inverse scattering and linear least-squares estimation of random fields

引用

Acta Applicandae Mathematicae 1988年第3期13卷 267-289页

作者： Yagle, Andrew E. Communications and Signal Processing Laboratory Department of Electrical Engineering and Computer Science The University of Michigan Ann Arbor United States

The three-dimensional Schrödinger equation inverse scattering problem with a nonspherically-symmetric potential is related to the filtering problem of computing the linear leastsquares estimate of the three-dimensional random field on the surface of a sphere from noisy observations inside the sphere. The relation consists of associating an estimation problem with the inverse scattering problem, and vice-versa. This association allows equations and quantities for one problem to be given interpretations in terms of the other problem. A new fast algorithm is obtained for the estimation of random fields using this association. The present work is an extension of the connections between estimation and inverse scattering already known to exist for stationary random processes and one-dimensional scattering potentials, and isotropic random fields and radial scattering protentials. © 1988 Kluwer Academic Publishers.

关键词： AMS subject classifications (1980): 35R30, 93E11, 35L20 fast algorithms Inverse scattering linear least-squares estimation random fields

来源：评论

学校读者我要写书评

暂无评论

THE COMPLEX CEPSTRUM OF HIGHER-ORDER CUMULANTS AND NONMINIMUM PHASE SYSTEM-IDENTIFICATION

引用

IEEE TRANSACTIONS ON ACOUSTICS SPEECH AND signal processing 1988年第2期36卷 186-205页

作者： PAN, R NIKIAS, CL Communications and Digital Signal Processing (CDSP) Center for Research and Graduate Studies Department of Electrical and Computer Engineering Northeastern University Boston MA USA Dept. of Electr. & Comput. Eng. Northeastern Univ. Boston MA USA

A computationally efficient identification procedure is proposed for a nonGaussian white-noise-driven linear, time-invariant, nonminimum phase system. The method is based on the idea of computing the complex cepstrum of higher order cumulants of the system output. In particular, the differential cepstrum parameters of the nonminimum phase impulse response are estimated directly from higher-order cumulants by least-squares solution or two-dimensional FFT operations. The method reconstructs the minimum-phase and maximum-phase impulse response components separately. It is flexible enough to be applied on autoregressive (AR), moving average (MA), or ARMA system without a priori knowledge of the type of the system. Benchmark simulation examples demonstrate the effectiveness of the method even with short length data records.< >

关键词： Cepstrum System identification White noise Phase estimation signal processing signal reconstruction Convolution Frequency Transfer functions Data communication

来源：评论

学校读者我要写书评

暂无评论

Applications of adaptive least square filtering to image restoration 3

Applications of adaptive least square filtering to image res...

引用

Visual communications and Image processing III 1988

作者： Chellali, Mohamed Ingle, Vinay K. Northeastern University Electrical and Computer Engineering Department Communication and Digital Signal Processing Center BostonMA02115 United States

Images in real life are inhomogeneous while the transmission channels are time varying, hence, adaptive schemes are suitable for tracking slow variations on system identification and inverse filtering. In this paper we report theoretical and experimental study of the application of adaptive filtering to two dimensional signals. In particular, we focus on the recursive least square transversal filter applied to image restoration. A multichannel extension of the well known one dimensional recursive least square (RLS) algorithm is presented. Finally simulation results on real world images are given. © 1988 SPIE. All rights reserved.

关键词： Image reconstruction

来源：评论

学校读者我要写书评

暂无评论

Multistage adaptive vector quantization with least squares approximation

Multistage adaptive vector quantization with least squares a...

引用

Visual communications and Image processing III 1988

作者： Sun, H. Hsu, H. Manikopoulos, C.N. Department of Electircal Engineering Fairleigh Dickinson University TeaneckNJ07666 United States Center for Communications and Signal Processing Department of Electrical Engineering New Jersey Institute of Technology NewarkNJ07102 United States

In this paper, we propose an image coding scheme, multistage adaptive vector quantization with least sqaures approximation. In this scheme, an image of size 2n × 2n is first partitioned into 2m × 2m blocks (mm × 2m block is further partitioned into four 2m × 2m-1 blocks, and each of those blocks is also approximated by a 2 × 2 matrix with least squares method. This procedure is continued from the top level of 2m × 2m blocks to the bottom level of 4 × 4 blocks. To achieve a more efficient transmission, the vector quantization is applied to the 4 or 8 dimensional vector set on level-by-level basis. The residual errors due to quantization at each level are fedforward and included in the next level. Thus, it is possible to reprocess at the lower levels, the information lost at the higher level. The simulation results demonstrate that very well reconstructed images can be obtained at the bit rate as low as 0.7 bits/pixel. © 1988 SPIE. All rights reserved.

关键词： Least squares approximations

来源：评论

学校读者我要写书评

暂无评论

Performance analysis of a receiver directed CDMA packet radio network

Performance analysis of a receiver directed CDMA packet radi...

引用

IEEE International Conference on communications (ICC)

作者： H. Xie L. Merakos Department of Electrical and Computer Engineering Communications and Digital Signal Processing Center Northeastern University Boston MA USA

A multihop packet radio network using receiver-directed code-division multiple access (CDMA) is considered. The network is modeled as a system of interacting queues, and sufficient conditions for the stability of the queueing system model are obtained. Under an independence assumption, approximate results for the mean packet delay in a symmetric network are given. The results are used to characterize the throughput-delay performance of a symmetric network using frequency-hop spread-spectrum signalling.< >

关键词： Performance analysis Receivers Multiaccess communication Packet radio networks Stability Spread spectrum communication Frequency Network topology Delay Telecommunication traffic

来源：评论

学校读者我要写书评

暂无评论

ARMA estimation using the general order two channel fast transversal filter (FTF) algorithm

ARMA estimation using the general order two channel fast tra...

引用

International Conference on Acoustics, Speech, and signal processing (ICASSP)

作者： L.J. Faber S.H. Ardalan Center for Communications and Signal Processing Department of Electrical and Computer Engineering North Carolina State University Raleigh NC USA

The general order, multichannel FTF algorithm is a generalization of the multichannel FTF algorithm in which the orders of the input channels can be independently specified. The algorithm is applied to a special case of a two-input-channel, joint process estimator. One of the input channels is defined as the unit-delayed joint process signal; the configuration is an 'equation error' form for least squares (LS) pole-zero ARMA (autoregressive moving-average) system identification. This form is also used in decision-directed equalization and echo cancellation. For this special two-channel case, a computational savings of 2N+1 operations per recursive update is identified, where N is the total number of filter taps. The saving is proven using the concepts of projection onto a vector space. The reduction is available with any of the order-N 'fast' LS algorithms including the fast Kalman (FK) and FAEST algorithms; this had not been recognized for similar application of the FK algorithm to decision-directed equalization. A summary of the modified algorithm is given, with an operations count for each step.< >

关键词： Transversal filters Finite impulse response filter signal processing algorithms IIR filters signal processing Equations System identification Decision feedback equalizers Kalman filters Autoregressive processes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：