检索结果-内蒙古大学图书馆

IEEE Conference on Vehicular Technology (VTC)

作者： S. Forest D. Haccoun Electrical and Computer Engineering Department École Polytechnique de Montréal Montreal QUE Canada

Adaptive sequence estimation is an equalization procedure used to minimize the effect of severe intersymbol interference in frequency selective fading channels. Unfortunately, conventional adaptive methods suffer from substantial performance degradations under fast channel variations. A new approach to the adaptive sequence estimation problem is considered. A model for a combined channel and sequence estimation (CCSE) is proposed and used to present viable solutions which provide significant improvements in error performance. An analysis of the pairwise distances in the framework of CCSE is also presented, Finally, computer simulation results supporting the theoretical analysis and demonstrating the superiority of the new approach over conventional methods in fast fading channels are presented.

关键词： Frequency estimation Adaptive equalizers Maximum likelihood estimation Fading computer errors Intersymbol interference Automata Degradation computer simulation Viterbi algorithm

来源：评论

学校读者我要写书评

暂无评论

Comprehensive experimental investigation of gate current limitation effects on power GaAs FETs RF performances

Comprehensive experimental investigation of gate current lim...

引用

Microwave, MTT-S International Symposium

作者： N. Constantin F.M. Ghannouchi Electrical and Computer Engineering Department Ecole Polytechnique de Montrèal Montreal QUE Canada

This paper presents for the first time a detailed experimental investigation of gate current limitation effects on power GaAs FETs RF performances. This gate current limitation is entirely accomplished by dynamic compensation of the gate bias voltage. Effects of this current limitation on power added efficiency and output power performance have been examined through an extensive experimental investigation over the entire Smith chart. Comprehensive results are given and allow to determine the optimal resistor value needed for the gate current limitation. The thermal runaway problem is also taken into consideration when selecting the gate resistor.< >

关键词： Gallium arsenide FETs Radio frequency Voltage Resistors Roentgenium Power generation Circuits Impedance Thermal resistance

来源：评论

学校读者我要写书评

暂无评论

Dynamic range requirements for CDMA-based PCS power amplifiers

Dynamic range requirements for CDMA-based PCS power amplifie...

引用

Canadian Conference on Electrical and computer engineering (CCECE)

作者： Guoxiang Zhao F.M. Ghannouchi F. Beauregard Electrical and Computer Engineering Department École Polytechnique de Montréal Montreal QUE Canada

The input average power and peak power for different numbers of multiple channels are estimated for power amplifiers operated in CDMA-based PCS down-link transmitters. Multiple QPSK spread spectrum signals have been simulated, using SPW software (signal processing worksystem). The simulation results for N/spl les/64 are given. The obtained dynamic range requirements are useful for linear power amplifiers designed for CDMA-PCS application.

关键词： Dynamic range Personal communication networks Power amplifiers Quadrature phase shift keying Signal processing Bandwidth Frequency Transmitters Spread spectrum communication Multiaccess communication

来源：评论

学校读者我要写书评

暂无评论

A new current-mode 2-bit pipelined ADC's cell

A new current-mode 2-bit pipelined ADC's cell

引用

Canadian Conference on Electrical and computer engineering (CCECE)

作者： J. Zhu C.J.B. Fayomi M. Sawan Department of Electrical and Computer Engineering École Polytechnique de Montréal Montreal QUE Canada

A new current-mode 2-bit pipelined ADC's cell is presented. Its potential advantages are high-speed, low power/voltage, continuous time mode conversion, less circuit complexity and less die area. A novel cell circuitry based on current-mode has been designed. Primary results of HSPICE simulation show that an 8-bit resolution under 5-V single supply with 100 kHz sinusoidal input is achievable.

关键词： Adders Voltage CMOS technology Complexity theory Signal resolution Power dissipation Digital-analog conversion Throughput Circuit simulation Video signal processing

来源：评论

学校读者我要写书评

暂无评论

A novel CMOS digital clock and data decoder for implanted systems

A novel CMOS digital clock and data decoder for implanted sy...

引用

Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： K. Arabi M. Sawan Department of Electrical and Computer Engineering École Polytechnique de Montréal Montreal QUE Canada

A novel all-digital clock and data separator (DCDS) using a CMOS 1.2 /spl mu/m process is described. The DCDS is intended for an implantable bladder controller and can be used as a standard block for any programmable implanted prosthesis. All components used are digital and therefore unlike analog or hybrid decoders, the presented DCDS is not sensitive to fluctuating process parameters and can operate with different values of power supply. The proposed architecture is very simple and has been designed for low power that is an important parameter for implantable devices. A digital delay line provides the timing reference for the decoder with a programmable resolution. The DCDS meets the jitter-tolerance requirements and satisfies the exigency demand of implanted devices.

关键词： Clocks Decoding Bladder Communication system control Voltage control Biological control systems Prosthetics Implants CMOS process Timing

来源：评论

学校读者我要写书评

暂无评论

High current AC/DC power converters using T-connected transformers

High current AC/DC power converters using T-connected transf...

引用

Canadian Conference on Electrical and computer engineering (CCECE)

作者： C. Guimaraes G. Olivier G.-E. April Department of Electrical and Computer Engineering École Polytechnique de Montréal Montreal QUE Canada

This paper presents a new high current low voltage AC/DC power converter family using T connected transformers and nonconventional zigzag series connection of the primary windings. Six, 12, 18 and 24 pulses have been theoretically analyzed and simulated with EMTP package. Experimental results confirm the analytical and simulation results. Due to its simplicity and the absence of interphase transformers, the 12-pulse power converter appears to be a very attractive alternative to more conventional configurations, especially for urban transit applications.

关键词： Analog-digital conversion Phase transformers Pulse transformers Rectifiers Analytical models Low voltage Bridge circuits Pulse circuits Semiconductor diodes Thyristors

来源：评论

学校读者我要写书评

暂无评论

Shielding of an electric line source by a finite ground plane and a narrow metal strip

Shielding of an electric line source by a finite ground plan...

引用

IEEE International Symposium on Electromagnetic Compatibility (EMC)

作者： N. Grignon J.-J. Laurin Poly-Grames Research Laboratory Department of Electrical and Computer Engineering Ecole Polytechnique de Montrèal Montreal QUE Canada Poly-Grams Research Laboratory Department of Electrical and Computer Engineering Ecole Polytechnique de Montrèal Montreal QUE Canada

The article discusses the performance of a finite-width image plane in the shielding of an electric line source. The effect on the shielding effectiveness of a metallic substrate and superstrate laid under and above the line source and image plane is studied in detail. The results are obtained by solving the electric-field integral equation with the point matching method for the case of two-dimensional geometry. For the 30 cm-wide image plane used in the simulations, it is shown that over the 30-1000 MHz frequency band, a narrow strip can reduce the maximum radiated electric field by about 25 dB when the line source is centered over the image plane. Without the strip, the maximum radiated field can increase by up to 12 dB when the source is moved from the center to the edge of the image plane. A noteworthy effect obtained by the addition of the strip on top of the edge-positioned line source is a 14 dB reduction of the maximum radiated field. This fully compensates for the 12 dB increase obtained by moving the strip-less line source from the center to the edge of the image plane.

关键词： Strips Frequency Integral equations Geometry Current density Laboratories Electromagnetic radiation Shunt (electrical) Numerical analysis Moment methods

来源：评论

学校读者我要写书评

暂无评论

Fading channel performance analysis for the decoding of convolutional codes

Fading channel performance analysis for the decoding of conv...

引用

Canadian Conference on Electrical and computer engineering (CCECE)

作者： J. Belzile F. Gagnon D. Haccoun Department of Electrical Engineering École de Technologie Supérieure Montreal QUE Canada Department of Electrical and Computer Engineering École Polytechnique de Montréal Montreal QUE Canada

In this paper the performance of convolutional decoding over fading channels is explored, The decoding algorithm used are the Viterbi and bidirectional algorithms. By estimating a "decoder weight spectrum" for the decoder, an "equivalent free distance" may be observed. Furthermore, using this "decoder weight spectrum" useful estimations of the error probabilities are obtained and compared to computer simulation results in the case of very slow and very fast fading. The resultant curves are shown to be very tightly related.

关键词： Fading Performance analysis Decoding Convolutional codes Rician channels Autocorrelation Viterbi algorithm Error probability Additive white noise AWGN

来源：评论

学校读者我要写书评

暂无评论

PHASE-VELOCITY EQUALIZATION IN MICROSTRIP COUPLERS BY PARTIAL DIELECTRIC OVERLAYS

引用

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 1995年第5期9卷 249-252页

作者： KOUKI, AB KHEBIR, A GHANNOUCHI, FM Department of Electrical and Computer Engineering Ecole Polytechnique de Montreal 333 Queen Mary Boulevard 2nd Floor Montreal Quebec H3V 1A2 Canada

The effects of a partial isotropic dielectric overlay on the isolation, coupling, and impedance of a microstrip 10-dB coupler are studied. Results as functions of the overlay's width, height, and dielectric constant are presented. It is found that a better coupler design can be achieved through proper choice of these three parameters. (C) 1995 John Wiley & Sons, Inc.

关键词： DIRECTIONAL COUPLERS DIELECTRIC OVERLAYS PHASE VELOCITY EQUALIZATION

来源：评论

学校读者我要写书评

暂无评论

A free-space reflectometer for surface impedance measurement of materials in the Ku-band

A free-space reflectometer for surface impedance measurement...

引用

IEEE International Symposium on Electromagnetic Compatibility (EMC)

作者： H. Mercier J.-J. Laurin Poly-GRAMES Research Laboratory Department of Electrical and Computer Engineering École Polytechnique de Montréal Montreal QUE Canada

This paper presents a free-space reflectometer that has been developed to measure surface impedance of planar materials in the Ku-band (12.5 to 18 GHz). The set-up uses a microwave lens made of metal plates to create an equiphase wavefront arriving at normal incidence on the sample surface. Thus, the TEM wave assumption can be made to extract the impedance of the sample, which is not the case for other free-space methods using lenses. It also has the advantage of requiring small sample size (17 cm/spl times/17 cm). The system has been validated with plexiglass. The maximal error on the reflection coefficient was 0.02 for the amplitude over the 5.5 GHz bandwidth. The accuracy of the system makes it suitable for shielding effectiveness measurement and characterization of conductive polymers or thin metallic layers.

关键词： Impedance measurement Lenses Surface waves Equations Surface impedance Optical materials Optical reflection Frequency Dielectrics Laboratories

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：