检索结果-内蒙古大学图书馆

Investigation of Line Current Harmonics in Cascaded Multi-level Inverter Based Induction Motor Drive and an Adaptive On-line Selective Current Harmonic Elimination algorithm

引用

Research Journal of Applied Sciences, Engineering and Technology 2015年第7期9卷 531-542页

作者： P. Avirajamanjula P. Palanivel Department of EEE M.A.M College of Engineering Anna University India

Multilevel Inverters (MLIs) have drawn increasing attention in numerous applications, especially in drives, distributed energy resources area, utility etc. MLIs have the ability to synthesize a near sinusoidal output voltage wave with minimal Total Harmonic Distortion (THD) in low frequency switching. Even though they offer lower THD, the presence of lower order harmonics is objectionable and harmonics elimination in Multilevel Inverters (MLIs) has been receiving immense attention for the past few decades. Existing Selective Harmonic Elimination (SHE) techniques can eliminate the objectionable lower order voltage harmonics with low switching frequency by solving the Fourier non-linear transcendental equations of the output voltage. The line current harmonics has a direct role to play on the magneto-motive force and results in increase of mismatching of air-gap permeance, vibrations, acoustic noise etc. This study proposes normalized least mean squares (NLMS) algorithm based scheme to eliminate the selected dominant harmonics in load current using only the knowledge of the frequencies to be eliminated. The algorithm is simulated using MATLAB/SIMULINK tool for a three-phase VSI to eliminate the fifth and seventh harmonics. The informative simulation results verify the validity and effectiveness of the proposed algorithm. The system performance is analyzed based on the simulation results considering Total Harmonic Distortion (THD), magnitude of eliminated harmonics and frequency spectrum.

关键词： Frequency spectrum H-bridge inverter load current normalized least mean square algorithm single frequency cancelling filter total harmonic distortion voltage source inverter

来源：评论

学校读者我要写书评

暂无评论

A Channel-Estimate-Based Decision Feedback Equalizer Robust under Impulsive Noise

A Channel-Estimate-Based Decision Feedback Equalizer Robust ...

引用

Underwater Communications networking (UComms)

作者： Pelekanakis, Konstantinos Chitre, Mandar Natl Univ Singapore Acoust Res Lab Singapore 119223 Singapore

ISBN: (纸本)9781479975785

A channel-estimate-based decision feedback equalizer (CEB DFE) robust under impulsive noise is presented for single-input multiple-output (SIMO) underwater acoustic communications. Channel estimation is performed via the improvedproportionate M-estimate affine projection algorithm (IPMAPA), a linear complexity algorithm which is robust against impulsive interference and exploits channel sparseness. The superiority of IPMAPA to the normalized sign algorithm (NSA) and the normalized least-mean-square (NLMS) algorithm is demonstrated by processing data transmitted at 9 kbps over a 1.2km shallow water environment contaminated by snapping shrimp noise.

关键词： channel estimation decision feedback equalisers impulse noise least mean squares methods underwater acoustic communication wireless channels CEB DFE IPMAPA NLMS algorithm NSA SIMO underwater acoustic communication bit rate 9 kbit/s channel estimation-based decision feedback equalizer data processing distance 1.2 km improved proportionate M-estimate affine projection algorithm impulsive interference impulsive noise linear complexity algorithm normalized least mean square algorithm normalized sign algorithm shallow water environment shrimp noise snapping single input multiple output underwater acoustic communication Baseband Channel estimation Decision feedback equalizers Feedforward neural networks Noise Receivers Robustness decision feedback equalisers Impulse noise channel estimation impulsive interference least squares method underwater acoustic communication Baseband feedforward neural nets wireless channels least mean square algorithm Receivers Noise shallow-water environment Robustness

来源：评论

学校读者我要写书评

暂无评论

An Affine Projection algorithm Based DFE with Set-Membership Filtering

An Affine Projection Algorithm Based DFE with Set-Membership...

引用

5th International Conference on Computers and Devices for Communication (CODEC)

作者： Mishra, Ramesh Chandra Bhattacharjee, Ratnajit Mitra, Abhijit Indian Inst Technol Dept EEE Gauhati Assam India Sir JC Bose Sch Engg Dept ECE Hooghly W Bengal India

ISBN: (纸本)9781467326209;9781467326193

A channel equalization technique based on the affine projection algorithms (APA) with set-membership (SM) filtering for updating filters of a decision feedback equalizer (DFE) is proposed for time-varying wireless channels. The performance of the proposed approach is analyzed through simulations. It is shown in the results that this scheme offers advantages of having substantial fewer number of weight updating operations at moderate SNR with almost similar convergence as normal APA based equalizer. The introduced equalizer converges faster with a marginal increase in complexity than the set-membership normalized least mean square (NLMS) algorithm based equalizer.

关键词： Affine projection algorithm Decision feedback equalizer normalized least mean square algorithm Set-membership

来源：评论

学校读者我要写书评

暂无评论

Identification of fNIRS based Brain Activity using Adaptive algorithm

Identification of fNIRS based Brain Activity using Adaptive ...

引用

1st International Conference on Robotics and Artificial Intelligence (ICRAI)

作者： Kamran, M. Ahmad Hong, Keum-Shik Mannan, Malik M. Naeem Pusan Natl Univ Dept Cognomechatron Engn Pusan South Korea

ISBN: (纸本)9781467348843;9781467348850

Functional near infrared spectroscopy (fNIRS) is non-invasive brain imaging techniques that detects the cortical activity by measuring the change in the concentration of oxyhemoglobin and de-oxy hemoglobin. It uses near infrared light of two wave lengths, 760 nm and 830 nm. NIRS is emerging neuro imaging modality with high temporal resolution. The advantage of NIRS system over other neuro imaging modalities is low cost, portable, safe and somehow results in short period of time. The scalp remains intact throughout the experiment. In this study we present a method for identification of brain activity by using fNIRS data. The general linear model has been used in study with predicted blood oxygen level dependent (BOLD) response signal and its delayed versions. The normalized least mean square (NLMS) algorithm has been used for identification of unknown parameters in the model recursively. A one way t-test has been performed for the significance of results.

关键词： General linear model (GLM) blood oxegen level dependent normalized least mean square algorithm adaptive filtering

来源：评论

学校读者我要写书评

暂无评论

MIMO Channel Equalization Using Set-membership Affine Projection algorithm

MIMO Channel Equalization Using Set-membership Affine Projec...

引用

IEEE Region 10 Conference (TENCON) - Sustainable Development through Humanitarian Technology

作者： Mishra, R. C. Bhattacharjee, R. Mitra, A. Indian Inst Technol Guwahati Dept EEE Gauhati Assam India Sir J C Bose Sch Engg Dept ECE Hooghly W Bengal India

ISBN: (纸本)9781467348232;9781467348225

A multiple-input multiple-output (MIMO) channel equalization scheme for time-varying wireless channels is proposed. The proposed equalization technique uses set-membership affine projection (SM-AP) algorithm for updating filter weights of a decision feedback equalizer (DFE). The performance of the proposed scheme is investigated through simulations using wireless channel models recommended by International Telecommunication Union for Radiocommunication Sector (ITU-R). The results show that the proposed scheme achieves a fast convergence speed. The convergence performance of this scheme has also been studied for different projection order and compared with the convergence performance of set-membership normalized least mean-square (SM-NLMS) algorithm based MIMO-DFE. The proposed equalizer has low complexity and works well even in frequency-selective channels.

关键词： Affine projection algorithm Decision feedback equalizer Multiple-input multiple-output systems normalized least mean square algorithm Set-membership filtering

来源：评论

学校读者我要写书评

暂无评论

An affine projection algorithm based DFE with set-membership filtering

An affine projection algorithm based DFE with set-membership...

引用

International Conference on Computers and Devices for Communication (CODEC)

作者： Ramesh Chandra Mishra Ratnajit Bhattacharjee Abhijit Mitra Department of EEE Indian Institute of Technology Guwahati Assam India Department of ECE Sir J. C. Bose School of Engineering West Bengal India

ISBN: (纸本)9781467326193

关键词： Affine projection algorithm Decision feedback equalizer normalized least mean square algorithm Set-membership decision feedback equalisers Projection algorithms least mean square algorithm Equalizers HELIOS DEVICES Filtration ALASKA POWER ADMINISTRATION based

来源：评论

学校读者我要写书评

暂无评论

Nonlinear Acoustic System Identification using a Combination of Volterra and Power Filters

Nonlinear Acoustic System Identification using a Combination...

引用

10th International Symposium on Signals, Circuits and Systems (ISSCS)

作者： Contan, Cristian Topa, Marina Kirei, Botond Homana, Ioana Tech Univ Cluj Napoca Fac Elect Telecommun & Informat Technol Cluj Napoca Romania

ISBN: (纸本)9781457702013

The paper proposes a nonlinear system identification method that uses a combination of adaptive linear, Volterra and power filters. Adaptation of the kernels is made using a normalized least mean square algorithm. The method is applied in echo cancellation, where several sources of nonlinearities exist: the overdriven amplifier, the small loudspeaker at high volume, the room with different absorbent walls. Functions with nonlinear characteristics are chosen to model these distortions. The evaluation is made in terms of Echo Return Loss Enhancement. Results show that the overall convex combination approach performs better or at least as well as the best single adaptive filter.

关键词： Acoustics Adaptation models Adaptive filters Maximum likelihood detection Nonlinear filters Nonlinear systems Power filters Volterra filter adaptive filters adaptive linear filter convex combination approach echo cancellation echo return loss enhancement echo suppression least mean squares methods nonlinear acoustic system identification nonlinear filters nonlinear systems normalized least mean square algorithm overdriven amplifier power filter power filters

来源：评论

学校读者我要写书评

暂无评论

Variable step-size normalized LMS algorithm by approximating correlation matrix of estimation error

引用

SIGNAL PROCESSING 2010年第9期90卷 2792-2799页

作者： Cho, Hyeonwoo Kim, Sang Woo Pohang Univ Sci & Technol Div Elect & Comp Engn Pohang 790784 Gyungbuk South Korea

In this letter, we propose a variable step-size normalized least mean square (NLMS) algorithm. We study the relationship among the NLMS, recursive least square and Kalman filter algorithms. Based on the relationship, we derive an equation to determine the step-size of NLMS algorithm at each time instant. In steady state, the convergence of the proposed algorithm is verified by using the equation, which describes the relationship among the mean-square error, excess mean-square error, and measurement noise variance. Through computer simulation results, we verify the performance of the proposed algorithm and the change in the variable step-size over iterations. (C) 2010 Elsevier B.V. All rights reserved.

关键词： Variable step-size normalized least mean square algorithm Kalman filter Recursive least square State-space equation

来源：评论

学校读者我要写书评

暂无评论

normalized LMS digital filter for chromatic dispersion equalization in 112-Gbit/s PDM-QPSK coherent optical transmission system

引用

OPTICS COMMUNICATIONS 2010年第6期283卷 963-967页

作者： Xu, Tianhua Jacobsen, Gunnar Popov, Sergei Li, Jie Wang, Ke Friberg, Ari T. Royal Inst Technol SE-16440 Stockholm Sweden Acreo AB SE-16440 Kista Sweden Tianjin Univ Tianjin 300072 Peoples R China

High bit rates optical communication systems pose the challenge of their tolerance to linear and nonlinear fiber impairments. Coherent optical receivers using digital signal processing techniques can mitigate the fiber impairments in the optical transmission system, including the chromatic dispersion equalization with digital filters. In this paper, an adaptive finite impulse response filter employing normalized least mean square algorithm is developed for compensating the chromatic dispersion in a 112-Gbit/s polarization division multiplexed quadrature phase shift keying coherent communication system, which is established in the VPI Simulation platform. The principle of the adaptive normalized least mean square algorithm for signal equalization is analyzed theoretically, and at the meanwhile, the taps number and the tap weights in the adaptive finite impulse response filter for compensating a certain fiber chromatic dispersion are also investigated by numerical simulation. The chromatic dispersion compensation performance of the adaptive filter is analyzed by evaluating the behavior of the bit-error-rate versus the optical signal-to-noise ratio, and the compensation results are also compared with other present digital filters. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Coherent optical receiver Digital signal processing Chromatic dispersion equalization Polarization division multiplexed quadrature phase shift keying normalized least mean square algorithm Adaptive finite impulse response filter

来源：评论

学校读者我要写书评

暂无评论

Generalized normalized gradient descent algorithm based on estimated a posteriori error

Generalized normalized gradient descent algorithm based on e...

引用

10th International Conference on Advanced Communication Technology

作者： Hur, Minsung Choi, Jin Yong Baek, Jong-Seob Seo, JongSoo Yonsei Univ Sch Elect & Elect Engn Seoul 120749 South Korea

ISBN: (纸本)9788955191356

A normalized-least-mean-square (NLMS) algorithm is used to adapt to an unknown system by minimizing the error between the desired signal and the signal resulting from the adaptive filter. A small positive constant value is used to ameliorate the problem of its diverging when the input power is small. Moreover, it can be a variable, where Generalized normalized Gradient Descent (GNGD) algorithm can be used to update the value based on the a priori error. The Steady-State mean square Error (SSMSE) performance of the algorithm is expected to improve by using a posteriori error instead of the a priori error. In this paper, a GNGD algorithm based on estimated a posteriori error is derived for use in coefficient update using NLMS algorithm. With simulation results, it is shown that using a posteriori error for updating the small constant value within channel equalizer coefficient update process decreases the algorithm's SSMSE performance sensitivity to varying initial step size.

关键词： A posteriori error generalized normalized gradient descent algorithm normalized least mean square algorithm

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：