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Indoor massive multiple-input multiple-output channel characterization and performance evaluation

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Frontiers of Information Technology & Electronic Engineering 2017年第6期18卷 773-787页

作者： Jian-zhi LI Bo AI Rui-si HE Qi WANG Mi YANG Bei ZHANG Ke GUAN Dan-ping HE Zhang-dui ZHONG Ting ZHOU Nan LI State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China Engineering University of Armed Police Force Telecommunication Engineering DepartmentXi'an 710086China Key Laboratory of Wireless Sensor Network and Communication Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China ZTE Corporation Beijing 100191China

We present a measurement campaign to characterize an indoor massive multiple-input multiple-output (MIMO) channel system, using a 64-element virtual linear array, a 64-element virtual planar array, and a 128-element virtual planar array. The array topologies are generated using a 3D mechanical turntable. The measurements are conducted at 2, 4, 6, 11, 15, and 22 GHz, with a large bandwidth of 200 MHz. Both line-of-sight (LOS) and non-LOS (NLOS) propagation scenarios are considered. The typical channel parameters are extracted, including path loss,shadow fading, power delay profile, and root mean square (RMS) delay spread. The frequency dependence of these channel parameters is analyzed. The correlation between shadow fading and RMS delay spread is discussed. In addition, the performance of the standard linear precoder—the Matched filter, which can be used for intersymbol interference (ISI) mitigation by shortening the RMS delay spread, is investigated. Other performance measures,such as entropy capacity, Demmel condition number, and channel ellipticity, are analyzed. The measured channels,which are in a rich-scattering indoor environment, are found to achieve a performance close to that in independent and identically distributed Rayleigh channels even in an LOS scenario.

关键词： Massive MIMO Channel modeling 5G Shadow fading Delay spread Matched filter Entropy capacity Condition number Channel ellipticity

Signal Processing for Fast Fault Detection in HVDC Grids

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CSEE Journal of Power and Energy Systems 2018年第4期4卷 469-478页

作者： Willem Leterme Mike Barnes Dirk Van Hertem EnergyVille/Electa research group Electrical Engineering Department ESATKU LeuvenBelgium Power Conversion Research Group School of Electrical and Electronic EngineeringUniversity of ManchesterManchester M139PLUK

For multiterminal or meshed Voltage Source Converter(VSC)High-voltage Direct Current(HVDC)systems,high speed protection against DC faults is essential,as power electronic components cannot withstand the rapidly increasing fault currents which would otherwise result.Recently proposed DC fault detection methods were developed based on time domain simulations in EMT-type software,which requires considerable modeling and computational efforts and results in methods specifically designed for the HVDC grid under study.To simplify the initial design of DC fault detection methods,this paper proposes general guidelines based on fundamental theory and offers a reduced modeling approach.Furthermore,the impact of non-ideal measurements is investigated and a method to choose the filters that optimally discriminate these fault signals from noise,is proposed.The approach was evaluated in a case study on fault detection in a realistically dimensioned HVDC grid.The paper shows that the initial design of fast fault detection methods can be based on the relatively simple proposed guidelines and reduced models.The paper furthermore shows that a sufficiently high sampling frequency and a filter matched to the fault signal enable fault detection within hundreds of microseconds and discrimination of DC faults from transients not related to DC faults.

关键词： HVDC Matched filter measurement power system faults power system transients

Robust digital receiver for EPC sensor network

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Journal of Systems Engineering and Electronics 2013年第1期24卷 44-51页

作者： Cheng Jin Sung Ho Cho Department of Electronics and Computer Engineering Hanyang University

A robust digital receiver based on a Matched filter （MF） is proposed for the radio frequency identification （RFID） reader system to enhance the reliability of signal processing in the electronic product code （EPC） sensor network （ESN）. The performance of the proposed receiver is investigated by examining the anti-collision algorithm in the EPC global Class1 Generation2 protocol. The validity and usefulness are demonstrated by both computer simulations and experiments. Based on the verification results, comparing with the conventional zero crossing detector （ZCD） based receiver, the proposed receiver is very robust against strong amplitude distortions and considerable frequency deviations happening on the backscattered signal from a passive tag.

关键词： electronic product code （EPC） sensor network （ESN） signal distortion Matched filter radio frequency identification （RFID） receiver.

Research on Multi-target Signal Separation and Processing Method

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Research on Multi-target Signal Separation and Processing Me...

作者： Hong Lv Jun Li Hongfeng Xu Quanling Sun AnHui JianZhu University

Nowadays,intelligent cities and transportation are being implemented in major cities around the world.In unmanned vehicles,autonomous identification and separation of moving targets is the essential and important part of intelligent transportation.This paper proposes a multi-object separation algorithm in order to solve the security problems that can promote smart transportation.This paper deals with multi-target signals based on MATLAB.In terms of distance,between the cars（targets） that can be separated,multiple targets are separated by Matched filter and FFT algorithm,then the performance of the research is expressed by distance resolution.The separable target distance is up to 200 m,and the resolution is up to 0.6 m;in the terms of speed,multiple targets are separated by the Doppler transform,then the performance of the research is reflected in the form of speed resolution.The speed at which the separated target can be identified is up to 200 km/h,and the resolution is up to 1.8 km/h,otherwise,both stationary and moving targets can be identified.Finally,all the results are obtained by MTALAB simulation.

关键词： Multi-object separation Matched filter FFT algorithm

RESEARCH ON LFM SIGNALS IN STEEL MATERIALS

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RESEARCH ON LFM SIGNALS IN STEEL MATERIALS

2012全国压电和声波理论及器件技术研讨会

作者： Chang-zheng LI Fang-fang SHI Bi-xing ZHANG Institute of Acoustics Chinese Academy of Sciences The Yellow River Institute of Hydraulic Research

Linear frequency signal（LFM） signal is first used in radar fields due to its remarkable properties,such as wide bandwidth,high energy and high signal-to noise ration.LFM excitation has recently been introduced in medical ultrasonic scanning,and much exciting results were obtained by research staffs.However,there is Utile study aiming to inspect solid materials utilizing coded excitation,In the present study,LFM signal were distinguished with pulsed compression method even merged noise.LFM signal with large time-bandwidth product can be designed theoretically,but the limited bandwidth of a transducer will lead to energy loss.Several coded signals were used to excite transducer,then the received signals’ amplitude and spectrum were analyzed.The results show that the amplitude will decrease when the frequency exceed the transducer’s bandwidth.In order to investigate the transmitting law in solid materials,the waveform and spectrum were analyzed after LFM signals penetrating steel materials with different thickness.Through the analysis,it is found that wave at high frequency band attenuates much quickly than wave at low frequency band.The results of investigations of the field structure in a steel plate are provided.The results of measured pressure field distributions before and after compression were compared with the recorded signals using short pulse excitation.The characteristics of waveform and spectrum were analyzed with LFM coded excitation.The SNR of LFM signal at output side will be improved with pulsed compression method.At the same time,the range resolution increase after Matched filter.The sound field on the surface of a steel plate was measured using several LFM coded signal excavating.This paper shows the feasibility of inspecting steel material with LFM signals.

关键词： LFM pulse compression coded excitation Matched filter material inspected

Detection in presence of Noise with Passive Radar Networking

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Detection in presence of Noise with Passive Radar Networking

2011 World Congress on Engineering and Technology(CET 2011)

作者： Darwin R.Becerra College of Astronautics Nanjing University of Aeronautics and Astronautics （NUAA） Nanjing-P.R.China

Very recent radar systems are monostatic i.***.the transmitter and receiver are co-located.However,when a target is illuminated by electromagnetic radiation scattering occurs in all directions.Hence a single receiver can only intercept a very small portion of this energy and much of the signal and its information are lost.Multistatic topologies with a strong Constant False Alarm Rate （CFAR） overcome this limitation and offer the potential to extend the capabilities and performance of current radar systems.In this paper,an introduction to the concept of netted radars is provided.An initial categorization of the types of possible radar networks is introduced.Additionally the ambiguity function is described for bistatic geometry and is used as the basis for target detection in presence of noise in a passive radar system.

关键词： components:Passive Radar Radar Networking Ambiguity Function CFAR Matched filter

TOA Estimation Method Using Fourth Order Cumulants

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TOA Estimation Method Using Fourth Order Cumulants

2000年第16届世界计算机大会

作者： Liu Ying Shuxun Wang 20 Nanhu Street Department of Communications Engineering ChangChun Posts and Telecommunications institute 142 Renmin Street Institute of Information Science and Engineering JiLin University of Technology

＜正＞This paper is concerned with the active identification of a multipath propagation channel.The correlation method and a frequency domain deconvolution are used to convert the TOA（time of arrival） estimation problem to an estimation of frequency.In the case of stationary Gaussian noise （after the de-convolution）,a new approach was proposed by the use of the higher order cumulants of the measurements data.The noise was suppressed and the TOA estimation can be obtained correctly.Finally simulation examples are presented to illustrate the effectiveness of this approach.

关键词： higher-order cumulant multipath propagation Matched filter TOA（time of arrival） estimation