检索结果-内蒙古大学图书馆

2004 ieee 11th Digital signal processing workshop and 2nd ieee signal processing Education workshop

作者： Djurić, Petar M. Vemula, Mahesh Bugallo, Mónica F. Dept. of Elec. and Comp. Engineering Stony Brook University Stony Brook NY 11794 United States

ISBN: (纸本)0780384342

In a wireless sensor network, limited power, communication, and computational resources are the major constraints that one has to overcome in their successful deployment and utilization. Binary sensor networks are a class of networks that get around these constraints. There, the sensors transmit only a binary digit on the occurrence of the event of interest, and therefore, the signals that reach the fusion center of these networks are highly compressed and pose challenging problems for recovering the sensed information. In this paper we consider the problem of tracking a vehicle, which moves along a 2-dimensional space, by using a binary sensor network that fuses information by particle filtering. ©2004 ieee.

关键词： Wireless telecommunication systems

来源：评论

学校读者我要写书评

暂无评论

Removal of eye blinking artifacts from EEC incorporating a new constrained BSS algorithm

Removal of eye blinking artifacts from EEC incorporating a n...

引用

2004 sensor array and multichannel signal processing workshop

作者： Shaker, Leor Sanei, Saeid Latif, Mohamed A. Centre for Digital Signal Processing Research King's College London London WC2R 2LS United Kingdom

ISBN: (纸本)0780385454

A robust constrained blind source separation algorithm (C-BSS) has been developed here for an effective removal of eye muscle artifacts from electroencephalograms (EEG). Presently, clinicians reject a data segment if the patient blinked or spoke. The rejected data segment may contain important information that may be masked by the artifact. In the CBSS technique we exploit a reference signals as a constraint. The constrained problem is then converted to an unconstrained problem by means of nonlinear penalty functions weighted by the penalty terms. This leads to the modification of the overall cost function, based on a stocastic gradient algorithm, by incorporating a reference signal. © 2004 ieee.

关键词： Eye movements

来源：评论

学校读者我要写书评

暂无评论

A neuromorphic IC connection between cortical dendritic processing and HMM classification

A neuromorphic IC connection between cortical dendritic proc...

引用

2004 ieee 11th Digital signal processing workshop and 2nd ieee signal processing Education workshop

作者： Hasler, Paul Smith, Paul D. Farquhar, Ethan Anderson, David V. Georgia Inst. Technol. Elec./C.E. Atlanta GA 30332-0250

ISBN: (纸本)0780384342

We show connections between dendritic processing structures and Hidden-Markov Model (HMM) decoding that we arrived through siumultanious circuit design of these systems. From an integrated circuit (IC) toward biology perspective, these simple spreading networks relate well to cable theory and are similar to biological structures such as dendrites and cortical cells. Going in the other direction, from IC to classical digital signal processing (DSP), these structure hold similarities to HMM decoders. In order to implement both structures requires a compact array of variable conductance elements. Using floating-gate transistors we are able to individually vary the conductance of each diffuser element in the array, which dramatically changes the analysis of these arrays. © 2004 ieee.

关键词： Integrated circuits

来源：评论

学校读者我要写书评

暂无评论

Estimating the optimum loading factor against the finite sample size effect in minimum variance beamformers

Estimating the optimum loading factor against the finite sam...

引用

2004 sensor array and multichannel signal processing workshop

作者： Mestre, Xavier Lagunas, Miguel A. Nexus I Building c/Gran Capitá 2-4 2a planta Barcelona 08034 Spain

ISBN: (纸本)0780385454

Diagonal loading is a commonly used technique that improves the robustness of minimum variance beamformers against multiple impairments. In this paper, we concentrate on the application of diagonal loading to mitigate the finite sample size effect. Up to now, the actual loading factor for this problem was chosen via rather ad-hoc approximations. Here, we propose an estimator of this factor that is optimum in the sense that maximizes the asymptotic signal to noise plus interference ratio (SINR) at the output of the beamformer. Our estimator is consistent even when the number of array elements is driven to infinity with the sample size, and consequently has an excellent performance even when the quotient between the number of observations and the number of elements of the array is low. © 2004 ieee.

关键词： Robustness (control systems)

来源：评论

学校读者我要写书评

暂无评论

Near field imaging of subsurface targets using active arrays and elastic waves

Near field imaging of subsurface targets using active arrays...

引用

2004 ieee 11th Digital signal processing workshop and 2nd ieee signal processing Education workshop

作者： Alam, Mubashir McClellan, James H. Ctr. of Signal and Image Processing Sch. of Elec. and Comp. Engineering Georgia Institute of Technology Atlanta GA 30332-0250

ISBN: (纸本)0780384342

This paper presents a time-reversal based approach for detecting the positions of subsurface passive targets like landmines. The measurements are made by using sources and sensors placed on the surface. The imaging algorithm will use the seismic waves reflected from the targets, and measured on the surface. A time reversal based algorithm is used, which utilizes the possible link between the time-reversal matrix and the covariance matrix used in standard array processing. It will be shown that the time-reversal matrix can be used to estimate the near field DOA and range parameters using a 2-D MUSIC approach. © 2004 ieee.

关键词： Imaging techniques

来源：评论

学校读者我要写书评

暂无评论

Rooting versus joint diagonalization in 2-D harmonic retrieval

Rooting versus joint diagonalization in 2-D harmonic retriev...

引用

2004 sensor array and multichannel signal processing workshop

作者： Pesavento, Marius Böhme, Johann F. Signal Theory Group Ruhr University Bochum D-44780 Germany

ISBN: (纸本)0780385454

We address the problem of estimating the harmonics of a two-dimensional exponential mixture. A new algorithms that exploits the multiple-invariance structure is proposed. Unlike previous ESPRIT type methods for two- or multi-dimensional harmonic estimation that are based on joint diagonalization the new algorithm uses polynomial rooting to efficiently obtain the parameters of interest. We reveal a close relations to the recently proposed MD-RARE and show that in the new algorithm, referred to as the rooted multiple-invariance MD-ESPRIT, the degrees of the characteristic polynomials are reduced by a factor two compared to the MD-RARE polynomials. This leads to lower computational complexity and improved numerical stability of the estimation procedure. ©2004 ieee.

关键词： Problem solving

来源：评论

学校读者我要写书评

暂无评论

Distributed classification of Gaussian space-time sources in wireless sensor networks

引用

ieee JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2004年第6期22卷 1026-1036页

作者： D'Costa, A Ramachandran, V Sayeed, AM Univ Wisconsin Dept Elect & Comp Engn Madison WI 53706 USA

Distributed signal processing techniques for classification of objects are studied assuming knowledge of sensor measurement statistics. The spatio-temporal signal field generated by an object is modeled as a bandlimited stationary ergodic Gaussian field. The model. suggests a simple abstraction of correlation between node measurements: it partitions the network into disjoint spatial coherence regions over which the signal remains strongly correlated, whereas the signal in distinct coherence regions is approximately uncorrelated. The size of coherence regions is determined by spatial signal bandwidths. It is shown that this partitioning imposes a structure on optimal distributed classification algorithms that is naturally suited to the communication constraints of the network: local high-bandwidth exchange of feature vectors within each coherence region to improve the measurement signal-to-noise ratio (SNR), and global low-bandwidth exchange of local decisions across coherence regions to stabilize the inherent variability in the signal. Classifier performance is analyzed for both soft and hard decision fusion across coherence regions assuming noise-free, as well as noisy communication links between nodes. Under mild conditions, the probability of error of all classification schemes (soft, hard, noisy) decays exponentially to zero with the number of independent node measurements.-the error exponent depends on both the measurement and communication SNRs and decreases from soft to hard to noisy, fusion. Numerical results based on real data illustrate the remarkable advantage of multiple sensor measurements in distributed decision making.

关键词： Chernoff bounds distributed classification error exponents sensor networks signal modeling

来源：评论

学校读者我要写书评

暂无评论

Estimating time-frequency distributions and scattering functions using the Rihaczek distribution

Estimating time-frequency distributions and scattering funct...

引用

2004 sensor array and multichannel signal processing workshop

作者： Farden, David C. Scharf, Louis L. ECE Department North Dakota State University Fargo ND 58105 ECE and Statistics Departments Colorado State University Fort Collins CO 80523-1373

ISBN: (纸本)0780385454

In this paper we study two problems: estimation of time-frequency distributions (TFDs) and estimation of wireless or radar scattering functions (SFs). We show that the most general quadratic, delay- and modulation-invariant estimator of each may be written as a convolution of a Rihaczek TF density with a TF kernel. This representation complements other equivalent representations and establishes a fundamental connection between the analysis of the two problems. However, the representation also illustrates a fundamental difference in design for the two problems. For TFD estimation, the Rihaczek TF density is the raw Rihaczek for the time series and the kernel is designed to convolve in time and frequency for smoothing. For SF estimation, the kernel is the true SF and the Rihaczek TF density is that for a transmitter signal designed to deconvolve in time and frequency for inversion. In each case, the Fourier transform identities in a four-corners diagram allow for kernel or Rihaczek design in the transformed space of ambiguity functions. Design in this space then produces spectrograms and interferograms for TFD estimation, and ideal transmitter signals for SF estimation. © 2004 ieee.

关键词： sensors

来源：评论

学校读者我要写书评

暂无评论

Distributed space-time codes for cooperative wireless networks in the presence of different propagation delays and path losses

Distributed space-time codes for cooperative wireless networ...

引用

2004 sensor array and multichannel signal processing workshop

作者： Mietzner, Jan Hoeher, Peter A. Faculty of Engineering University of Kiel Kaiserstrasse 2 D-24143 Kiel Germany

ISBN: (纸本)0780385454

The application of a distributed space-time coding scheme in a simulcast network is considered. A key challenge is addressed which is particularly crucial in the downlink: Since the distances between the individual transmitting nodes and the receiving node are typically different, the transmitted signals are subject to different propagation delays and to different path losses. The influence of these effects on the system performance is investigated for the example of a specific space-time coding scheme, based on simulative and analytical results. Specifically, the issue of equalization/detection at the receiver is addressed, and a joint equalizer/detector algorithm of practicable complexity is proposed for large relative propagation delays. ©2004 ieee.

关键词： Wireless telecommunication systems

来源：评论

学校读者我要写书评

暂无评论

signal processing for radio astronomical arrays

Signal processing for radio astronomical arrays

引用

2004 sensor array and multichannel signal processing workshop

作者： Van Der Veen, Alle-Jan Leshem, Amir Boonstra, Albert-Jan Delft Univ. of Technology Dept. Electrical Eng. DIMES Mekelweg 4 2628 CD Delft Netherlands Bar-Ilan University Dept. Electrical Eng. Tel-Aviv Israel ASTRON P.O Box 2 7990 AA Dwingeloo Netherlands

ISBN: (纸本)0780385454

Radio astronomy forms an interesting application area for array signal processing techniques. Current synthesis imaging telescopes consist of a small number of identical dishes, which track a fixed patch in the sky and produce estimates of the time-varying spatial covariance matrix. The observations are distorted by RFI, e.g., radio, TV, radar and satellite signals. We describe some of the tools that array signal processing offers to filter out the interference, based on eigenvalue decompositions and factor analysis, a more general technique applicable to partially calibrated arrays. We consider spatial filtering techniques using projections, and discuss how a reference antenna pointed at the interferer can improve the performance. We also consider image formation and its relation to beamforming. Finally, we briefly discuss some future radio telescopes, which will consist of distributed phased arrays with 10,000s to 100,000s of elements. ©2004 ieee.

关键词： Radio astronomy

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：