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intersymbol Interferences in PN Code Spread-Spectrum Receivers with Adaptive Interference Suppression Filters

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SIMULTANEOUS FREQUENCY AND DIRECTION ESTIMATION OF COHERENT SIGNALS

International Conference on electronics and Information Technology

作者： Wang Yongde dept.of Radio electronics Sichuan University

＜正＞lntersymbol interferences（ISI） in FN code spread-spectrum communication system with adaptive interference suppression filters are inevitable.For two typical suppression fiiters.the linear predictive error filter（PEF） and the transversal filter with symmetric distribution weights（STF）.anaiytical expressions for ISI are obtained in this paper.and a new interference rejection scheme without the ISI.named adaptive sub-optimal filter（ASOF）.is presented.Finally.the performance comparison of three schemes are shown in figures.in the results.when the processing gain is smail.the ISI can not be neglected and the performance of the ASOF is more effective than that of both the PEF and STF with the same number of taps.

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Journal of electronics(China) 2001年第2期18卷 97-104页

作者： Su Xin Chen Tianqi (dept. of Electronic Eng., University of Electronic Science and Technology of China, Chengdu 610054) dept.of Electronic Eng. University of Electronic Science and Technology of ChinaChengdu 610054

A new method is proposed in this paper for simultaneous frequency and direction estimation of coherent signals. The method is based on the rotational invariance techniques and uses an array triplet in motion to estimate the central frequencies and azimuths of coherent signals from narrowband sources. Without searching in the space of frequency-direction, the computational efficiency of the method is improved significantly. Simulation resultsin the typical examples demonstrate the performance of this new method.

关键词： Array triplet Coherent signals Rotational invariance Central frequency and DOA

TARGET DETECTION USING MULTI-RESOLUTION ANALYSIS AND HOLDER CONSTANT

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Journal of electronics(China) 2001年第2期18卷 160-166页

作者： Liu Wenyu Li Hua Zhu Guangxi (dept. of Electron, and Info. Eng., Huazhong University of Science and Technology, Wuhan 430074) dept.of Electron.and Info.Eng. Huazhong University of Science and TechnologyWuhan 430074

Through analyzing the different height parameter of 3D surface between the artificial target and complex background based on the description of average Holder constant of fractional Brownian motion, a novel method of target detection based on wavelet transformation and Holder constant is proposed. The wavelet Holder constants are calculated and linearly interpolated in a series of images, the target is detected by testing the linearity errof The more accurate localization can be achieved using two images of the same region but with difIerent scaling parameters.The application results of this algorithm for target detection are also given, and show that this method has good performance of noise immunity. This method is also suitable for identifying specific targets in complex background.

关键词： Target detection Fractional Brownian motion Wavelet translation Holder constant

LMS Algorithm Based on Subband Decomposition

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LMS Algorithm Based on Subband Decomposition

Relationship between magnetic Barkhausen noise and the stresses, the hardness and the phase content of ferromagnetic materials

1998 International Conference on Communication Technology

作者： Chen Zhiyuan Yue Guangxin dept.of Telecommunications Engineering Beijing University of Posts and Telecommunications

ISBN: (纸本)7800908275

＜正＞In this paper,LMS algorithm based on subband decomposition is proposed,which shows better convergence property over traditional LMS adaptive algorithms.First,based on subband decomposition adaptive filtering including cross filtering and its Wiener optimal solution are presented.Then we give a detailed analysis of LMS algorithm based on subband decomposition and its computational complexity.The simulation results verify the theoretical results that have been obtained.

关键词： computational complexity convergence of numerical methods least mean squares methods adaptive filters channel bank filters LMS algorithm subband decomposition convergence adaptive filtering cross filtering Wiener optimal solution computational complexity

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Journal of Harbin Institute of Technology(New Series) 2005年第1期12卷 67-70页

作者：祁欣侯志灵田建龙 dept. of Physics and electronics Beijing University of Chemical TechnologyBeijing 100029 China

Magnetic Barkhausen Noise (MBN) is a phenomenon of electromagnetic energy emission due to the movement of magnetic domain walls inside ferromagnetic materials when they are locally magnetized by an alternating magnetic field. According to Faraday’s law of electromagnetic induction, the noise can be received by the coil attached to the surface of the material being magnetized and the noise carries the message of the characteristics of the material such as stresses, hardness, phase content, etc. Based on the characteristic of the noise, research about the relationship between the welding stresses in the welding assembly and the noise, the fatigue damage of the plate structure and the noise, and the influence of heat treatment and the variation of phase content to the noise are carried out in this paper.

关键词：磁性材料铁磁体巴克豪森效应噪音磁畴 A/D转换

An improved spectral performance of SPWM inverter based on the time-sequence of chaos

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Journal of Harbin Institute of Technology(New Series) 2007年第1期14卷 59-63页

作者：李冠林陈希有刘洪臣杨伟 dept. of Electrical Engineering Harbin Institute of Technology dept. of Electrical and electronics Engineering Dalian University of Technology

A novel approach for improving the spectral performance of sinusoidal Pulse Width Modulation (SPWM) inverter is presented. By varying the carrier frequency according to chaotic time-sequence, the discrete spectrum of the output voltage is transformed into the continuous spectrum, which could reduce the acoustic noise concentrated at specific tones in an inverter-driven electric machine. Fourier analysis shows that the harmonic at the fixed frequency has been restrained effectively and the distribution of the spectrum is in a wider range. Besides, a novel variable is introduced for the evaluation of the output voltage spectrum in SPWM inverter. Simulations and experiments with DSP confirm the advantages of the novel approach. Experimental results show the annoying acoustic noise has been translated into some enjoyable sound like a fall or water flowing when this novel method is applied.

关键词：变极器 SPWM 谐波时间序列混沌无间断供电

Electromagnetic Modeling of Arbitrary Composite PEC Object with Fast Multipole Method

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Electromagnetic Modeling of Arbitrary Composite PEC Object w...

Admission control with long-range dependence traffic input

2004 3rd International Conference on Computational Electromagnetics and Its Applications

作者： Dong Jian Chai ShunLian Mao JunJie dept.of Electric Engineer＆Science National Uni.of Defence Tec

ISBN: (纸本)0780385624

＜正＞Multilevel fast multipole method is combined with the surface integral equation method to solve the electromagnetic characteristic of large complex PEC target in this paper.Much attention is paid to deal with the modeling of complex junction structures.The method of determining the number of basic function and unknown at the surf ace junction is presented.

关键词： computational electromagnetics electric field integral equations magnetic field integral equations computing electromagnetics EFIE MFIE combined field integral equation CFIE PEC object electromagnetic modeling arbitrary composite PEC object multilevel fast multipole method surface integral equation method complex PEC target complex junction structures surface junction basic functions

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Journal of Harbin Institute of Technology(New Series) 2005年第4期12卷 396-399页

作者：饶云华邹雪城 School of electronics Information Wuhan University Wuhan 430079 China dept. of electronics Science and Technology Huazhong Univ. of Science and Technology Wuhan 430074 China

The admission control scheme is investigated for a FIFO self-similar queuing system with Quality of Service (QoS) performance guarantees. Since the self-similar queuing system performance analysis is often carried out under the condition of infinite buffer, it is difficult to deduce the upper boundary of buffer overflow probability. To overcome this shortcoming, a simple overflow condition is proposed, which defines a buffer overflow occurrence whenever the arrival rate exceeds the service rate. The analytic formula for the buffer overflow probability upper boundary is easily obtained under this condition. The required bandwidth upper boundary with long-range dependence input and determined overflow probability is then derived from this formula. Based on the above analytic formulas, the upper boundaries of the admission control regions for homogeneous and heterogeneous long-range dependence traffic sources are separately obtained. Finally, an effective admission control scheme for long-range dependence input is proposed. Simulation studies with real traffic have confirmed the validity of these results.

关键词：自相似队列系统 QoS 网络系统交易输入溢出概率

PERFORMANCE OF NON-COHERENT RECEIVER WITH UWB PPM SIGNAL IN MULTIPATH CHANNELS

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Journal of electronics(China) 2007年第4期24卷 448-454页

作者： Wu Jianjun Xiang Haige electronics dept Peking University Beijing100871 China

Mainly due to its implementation simplicity, the non-coherent Ultra-Wide Band (UWB) receiver is attractive for lower data rate applications, which gains much attention again in recent years. In this paper, a General Likelihood Ratio Test (GLRT) based non-coherent receiver on UWB Pulse-Position-Modulation (PPM) signal in multipath channels is derived, and a novel structure is proposed as well. Subsequently, the closed-form expressions of asymptotic error-rate performance related to the non-coherent receiver are also derived and verified.

关键词：超宽频带非连贯性信号通信信道