检索结果-内蒙古大学图书馆

A Novel Neural-Fuzzy Method to Search the Optimal Step Size for nlms Beamforming

IEEE LATIN AMERICA TRANSACTIONS 2015年第2期13卷 402-408页

作者： Tupacyupanqui, W. O. Miyatake, M. N. Meana, H. P. Inst Politecn Nacl Comunicac & Elect Mexico City DF Mexico Inst Politecn Nacl Secc Postgrad & Invest Escuela Super Ingn Mecan & Elect Mexico City DF Mexico

This paper presents a novel algorithm based on neural networks and fuzzy logic to generate membership functions and search an approximation of the optimal step-size for Normalized Least Mean Squares (nlms) beamforming systems. The proposed method makes a new error curve, Error Ensemble Learning (EEL), based on the final estimated value of the adaptive algorithm's mean-square-error. A fuzzy clustering method individually assigns membership values to each EEL curve coordinates. This information is fed into a neural network to generate membership functions for a fuzzy inference system. The final estimation of the optimal step-size is obtained using a group of Mamdani linguistic propositions and the centroid defuzzification method. Simulation results show that a useful approximation of the optimal step-size is obtained for different interference conditions;the evaluation results also show that a higher directivity is achieved in the radiation beam pattern.

关键词： Adaptive filters Beamforming Fuzzy logic Neural networks nlms algorithm

来源：评论

学校读者我要写书评

暂无评论

An Efficient nlms-based VLSI Architecture for Robust FECG Extraction and FHR Processing 27

An Efficient NLMS-based VLSI Architecture for Robust FECG Ex...

引用

27th IEEE International Conference on Electronics, Circuits and Systems (IEEE ICECS)

作者： da Costa, Patricia U. L. Paim, Guilherme Rocha, Leandro da Costa, Eduardo Almeida, Sergio Bampi, Sergio Catholic Univ Pelotas UCPel Grad Program Elect Engn & Comp Pelotas RS Brazil Fed Univ Rio Grande do Sul UFRGS Grad Program Microelect PGMicro Porto Alegre RS Brazil

ISBN: (纸本)9781728160443

This work presents an efficient nlms-based VLSI architecture to extract the fetal electrocardiogram (FECG) and detect the fetal heart rate (FHR), using the adaptive filter strategy. The efficient nlms-based architecture herein investigated can robustly cancel the high-noised mother-related ECG signals, enabling the FHR measurement. We used the Improved Fetal Pan and Tompkins algorithm (IFPTA) to detect fetal R-peak and calculate the FHR. Our nlms-based VLSI architecture effectively detects the R-peaks in the extracted FECG with 93.2% accuracy with the only 2.4 mW of total power dissipation.

关键词： nlms algorithm FHR detetion FECG extration

来源：评论

学校读者我要写书评

暂无评论

Comparison of LMS and nlms Adaptive Filters with a Non-Stationary Input

Comparison of LMS and NLMS Adaptive Filters with a Non-Stati...

引用

44th Asilomar Conference on Signals, Systems and Computers

作者： Eweda, Eweda Ajman Univ Sci & Technol Dept Elect Engn Ajman U Arab Emirates

ISBN: (纸本)9781424497218

The tracking performances of the LMS and nlms algorithms are compared when the input of the adaptive filter is nonstationary. The analysis is done in the context of tracking a Markov plant. A periodic scenario of the variation of the input power is considered. The steady-state peak mean square deviation is used as the tracking performance measure. It is found that one algorithm outperforms the other depending on the values of the rate of variation of the input power, the minimum input power, the noise variance, and the mean square plant parameter increments.

关键词： Adaptive Filtering LMS algorithm nlms algorithm Tracking

来源：评论

学校读者我要写书评

暂无评论

An introduction to EIP-nlms post-processing method for cross-talk cancellation in BSS outputs

An introduction to EIP-NLMS post-processing method for cross...

引用

2nd International Conference on Computer and Automation Engineering (ICCAE)

作者： Noohi, Tahereh Shabani, Hasti Kahaei, Mohammad Hossein Iran Univ Sci & Technol Tehran Signal & Syst Modeling Lab Sch Elect Engn Tehran Iran

ISBN: (纸本)9781424455690

In this paper, we propose a new post-processing method to suppress the residual cross-talk of Blind Source Separation (BSS) outputs. This method relies on the existence of the so called Exclusive Inactivity Periods (EIPs) in the source signals during which all sources are active except one. After detecting EIPs, we use the Normalized Least-Mean-Square (nlms) algorithm to estimate the cross-talk in these regions. Simulation results show the ability of the proposed method in suppressing the residual cross-talk without distorting the target signal and improving the SIR about 3 dB compared to the nlms post-processing [5].

关键词： Blind Source Separation post-processing Exclusive Inactivity Periods (EIPs) nlms algorithm

来源：评论

学校读者我要写书评

暂无评论

A Variable Step-Size Partial-Update Normalized Least Mean Square algorithm for Second-Order Adaptive Volterra Filters

引用

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2020年第12期39卷 6073-6097页

作者： Mayyas, Khaled Afeef, Liza Jordan Univ Sci & Technol Dept Elect Engn Irbid 22110 Jordan

Partial-update (PU) algorithms offer reduced computational complexity to adaptive second-order Volterra filters (SOV) in nonlinear systems while retaining acceptable performance. In this paper, a new selective partial-update technique for the normalized LMS (nlms) SOV algorithm is proposed, which requires lesser number of comparison operations per iteration than existing methods while providing close performance to the standard M-Max nlms-SOV algorithm. Convergence properties of the proposed algorithm are enhanced by making the algorithm step-size time varying based on the natural logarithm function. Simulation experiments compare the proposed algorithm with existing PU and variable step-size nlms-SOV algorithms, which illustrate the advantageous properties of the new algorithm. The proposed algorithm achieves both lower steady-state misalignment and faster convergence speed when compared with the fixed step-size full-update nlms-SOV algorithm. Simulations also show that comparison operations overhead of the proposed algorithm is reduced significantly compared to that of the standard M-Max nlms-SOV algorithm.

关键词： Adaptive second-order Volterra filters nlms algorithm Partial-update algorithms Variable step size Computational complexity

来源：评论

学校读者我要写书评

暂无评论

Controllable Sparse Antenna Array for Adaptive Beamforming

引用

IEEE ACCESS 2019年 7卷 6412-6423页

作者： Shi, Wanlu Li, Yingsong Zhao, Luyu Liu, Xiaoguang Harbin Engn Univ Coll Informat & Commun Engn Harbin 150001 Heilongjiang Peoples R China Chinese Acad Sci Natl Space Sci Ctr Key Lab Microwave Remote Sensing Beijing 100190 Peoples R China Xidian Univ Key Lab Antennas & Microwave Technol Xian 710071 Shaanxi Peoples R China Univ Calif Davis Elect & Comp Engn Davis CA 95616 USA

We propose an l(0)-norm constrained normalized least-mean-square (Cnlms) adaptive beamforming algorithm for controllable sparse antenna arrays. To control the sparsity of the antenna array, an l(0)-norm penalty is used as a constraint in the Cnlms algorithm. The proposed algorithm inherits the advantages of the Cnlms algorithm in beamforming. The l(0)-norm constraint can force the quantities of antennas to a certain number to control the sparsity by selecting a suitable parameter. In addition, the proposed algorithm accelerates the convergence process compared with the existing algorithms in sparse array beamforming, and its convergence is presented in this paper. To reduce the computation burden, an approximating l(0)-norm method is employed. The performance of the proposed algorithm is analyzed through simulations for various array configurations.

关键词： l(0)-norm sparse controllable array nlms algorithm constrained adaptive beamforming

来源：评论

学校读者我要写书评

暂无评论

A new adaptive algorithm for target detection in hyperspectral images

引用

INFRARED PHYSICS & TECHNOLOGY 2019年第0期99卷 222-230页

作者： Bakhshi, Gholamreza Shahtalebi, Kamal Momeni, Mehdi Univ Isfahan Dept Elect Engn Hezar Jerib Ave Esfahan 81744 Iran Univ Isfahan Dept Geomat Engn Hezar Jerib Ave Esfahan 81744 Iran

In this paper, a novel adaptive algorithm for target detection in hyperspectral images (HSIs) is proposed. In a general classification, the proposed method belongs to the category of those methods which are not based on the statistical moments of the observed HSI (e.g. correlation or covariance matrix). The main processing burden of the proposed method is over a known set of spectral signatures. Assuming a linear spectral mixing model, the proposed method takes a set of spectral signatures which one of them relates to the target material and the others relate to the background materials. Based on an adaptive approach, the normalized least mean square (nlms) adaptive algorithm is engaged to estimate a weight vector which is almost orthogonal to the background materials spectral signature whereas it makes an absolutely non-orthogonal pair with the target material spectral signature. The estimated weight vector is multiplied by the observed HSI to make the final decision. One synthetic and two real hyperspectral images are considered to evaluate the performance of the proposed method. The evaluation results show that the proposed method outperforms its counterparts.

关键词： Hyperspectral images Linear spectral mixing model Target detection Adaptive algorithms nlms algorithm

来源：评论

学校读者我要写书评

暂无评论

Acoustic feedback cancellation in hearing aids using dual adaptive filtering and gain-controlled probe signal

引用

BIOMEDICAL SIGNAL PROCESSING AND CONTROL 2019年第0期52卷 1-13页

作者： Akhtar, Muhammad Tahir Albu, Felix Nishihara, Akinori Nazarbayev Univ Sch Engn Dept Elect & Comp Engn Astana Kazakhstan Valahia Univ Targoviste Dept Elect Targoviste 130082 Romania Tokyo Inst Technol Meguro Ku Tokyo 1528552 Japan

In this paper, we propose a probe signal-based adaptive filtering method for acoustic feedback cancellation (AFC) in hearing aids. The proposed method consists of two adaptive filters. The first adaptive filter is excited by the receiver (loudspeaker) signal, and uses the microphone signal as its desired response. The first adaptive filter shows a fast convergence speed, however, it may converge to a biased solution at the steady-state because its input and desired response are correlated with each other. The second adaptive filter is excited by an internally generated (uncorrelated) probe signal. The two adaptive filters are adapted using a delay-based normalized least mean square (nlms) algorithm. A strategy is devised to exchange the coefficients of two adaptive filters such that the both adaptive filters give a good (unbiased) estimate of the acoustic feedback path. Furthermore, we propose to vary the gain of the probe signal, such that a high level probe signal is injected during the transient state, and a low level probe signal is used after the AFC system has converged. The computer simulations demonstrate that the proposed method achieves good modeling accuracy, preserves good speech quality, and maintains high output SNR at the steady-state. (C) 2019 The Author(s). Published by Elsevier Ltd.

关键词： Hearing aids Acoustic feedback nlms algorithm Probe signal

来源：评论

学校读者我要写书评

暂无评论

Cyclic frequency distinction and its application in modulation parameter estimation: An adaptive approach

引用

AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2018年 84卷 13-20页

作者： Rahimzadeh, Fatemeh Shahtalebi, Kamal Parvaresh, Farzad Univ Isfahan Dept Elect Engn Esfahan *** Iran

Cyclic frequency detection of cyclostationary signals and its application in modulation parameters estimation is the aim of this paper. A simple frequency shifted (FRESH) model is structured. The normalized least mean square (nlms) algorithm is engaged to estimate the unknown weights of the considered model. The norm of the parameter estimate is related to the model accuracy. A high (low) value indicates that the FRESH structure is based on an accurate (inaccurate) cyclic frequency and the weight estimate of the nlms algorithm converges to a nonzero (zero) vector. Accordingly for two given values which only one of them is the true cyclic frequency of the received signal, two FRESH structures are considered and simultaneously two nlms algorithms are executed. If the norm of the weight estimate of the first algorithm exceeds the resulted norm of the second one, according to the proposed method, the first given value is the true cyclic frequency and vice versa. The method is used to estimate the modulation parameters of three different problems: chip rate estimation of a spread spectrum signal, carrier frequency and bit rate estimation of BPSK and QPSK signals, and symbol rate estimation of OFDM signals.

关键词： Chip rate Cyclic frequency Cyclostationary nlms algorithm Symbol duration

来源：评论

学校读者我要写书评

暂无评论

Beamforming with a Simple Adaptive Partial Feedback Method in Cooperative Cognitive Radio Networks

引用

WIRELESS PERSONAL COMMUNICATIONS 2017年第3期95卷 3167-3184页

作者： Asgarian, Mina Shahtalebi, Kamal Sabahi, Mohamad Farzan Univ Isfahan Dept Elect Engn Esfahan *** Iran

This paper focuses on beamforming problem in a cooperative cognitive radio communication system where primary users (PUs) coexist with a secondary user (SU). An adaptive partial feedback structure for computing the channel state information is proposed. PUs and SU receivers execute their associated normalized least mean square adaptive algorithms. The output of each algorithm contains an estimate of the related channel coefficients. The receivers also reply the quantized step-size values of their algorithms via feedback channel to the transmitter, which empower it to execute these algorithms simultaneously. The transmitter iteratively employs the feedback information to estimate the channel weights and uses them for its beamforming scheme, in such a way that the SU receiver's channel gain is maximized while the interference on PUs is maintained below a predefined level. Analysis of the proposed method shows that, with a simple modification, the required bits in feedback channel are considerably reduced. The method is applicable for time-varying systems. Besides, when the cross correlation matrix is the only available channel information between primary and secondary networks, a simple and compatible beamforming scheme is proposed. Simulation results evaluate the reasonable performance of the proposed method.

关键词： Cognitive radio Optimal beamforming scheme Partial feedback nlms algorithm Channel state information

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：