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MBGM: A Graph-Mining Tool Based on MapReduce and BSP

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zte communications 2014年第4期12卷 16-22页

作者： Zhenjiang Dong Lixia Liu Bin Wu Yang Liu zte Corporation Beijing University of Posts and Telecommunications

This paper proposes an analytical mining tool for big graph data based on MapReduce and bulk synchronous parallel （BSP） com puting model. The tool is named Mapreduce and BSP based Graphmining tool （MBGM）. The core of this mining system are four sets of parallel graphmining algorithms programmed in the BSP parallel model and one set of data extractiontransformationload ing （ETE） algorithms implemented in MapReduce. To invoke these algorithm sets, we designed a workflow engine which optimized for cloud computing. Finally, a welldesigned data management function enables users to view, delete and input data in the Ha doop distributed file system （HDFS）. Experiments on artificial data show that the components of graphmining algorithm in MBGM are efficient.

关键词： cloud computing parallel algorithms graph data analysis data mining social network analysis

Line-of-Sight MIMO for Next-Generation Microwave Transmission Systems

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zte communications 2012年第4期10卷 33-38页

作者： Xianwei Gong Zhifeng Yuan Jun Xu Liujun Hu Wireless Technology Advance Research Team ZTE

Line-of-sight MIMQ （LoS MIMO） is not applicable in scattering wireless transmission scenarios, but it may be applied in LoS microwave transmission scenarios if antenna spacing （within transmit and/or receive arrays） is suitable and there is one hop distance. LoS MIMQ can improve channel capacity and performance of a transmission system. In this paper, we discuss factors affecting channel capacity and performance in LoS MIMO. We also discuss the feasibility LoS MIMO applications.

关键词： line of sight MIMO microwave channel capacity

Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model

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zte communications 2024年第1期22卷 34-40页

作者： SUN Yunqi JIAN Mengnan YANG Jun ZHAO Yajun CHEN Yijian State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen 518055China zte Corporation Shenzhen 518057China

Degree of freedom(DOF)is a key indicator for spatial multiplexing layers of a wireless ***,the channel of a multiple-input multiple-output(MIMO)half-wavelength dipole array has a DOF that equals the antenna ***,recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is *** utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO(HMIMO)channel and give a upper bound of the DOF with strong mutual *** numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system.

关键词： channel model degree of freedom holographic MIMO mutual coupling

Facial Landmark Localization by Gibbs Sampling

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zte communications 2014年第4期12卷 23-29页

作者： Bofei Wang Diankai Zhang Chi Zhang Jiani Hu Weihong Deng zte Corporation Beijing University of Posts and Telecommunication

In this paper, we introduce a novel method for facial landmark detection. We localize facial landmarks according to the MAP crite rion. Conventional gradient ascent algorithms get stuck at the local optimal solution. Gibbs sampling is a kind of Markov Chain Monte Carlo （MCMC） algorithm. We choose it for optimization because it is easy to implement and it guarantees global conver gence. The posterior distribution is obtained by learning prior distribution and likelihood function. Prior distribution is assumed Gaussian. We use Principle Component Analysis （PCA） to reduce the dimensionality and learn the prior distribution. Local Linear Support Vector Machine （LLSVM） is used to get the likelihood function of every key point. In our experiment, we compare our de tector with some other wellknown methods. The results show that the proposed method is very simple and efficient. It can avoid trapping in local optimal solution.

关键词： facial landmarks MAP Gibbs sampling MCMC LL-SVM

Digital Signal Processing for Optical Access Networks

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zte communications 2014年第4期12卷 40-48页

作者： Jianjun Yu Optics Labs ZTE (TX) Inc.

In this paper, we investigate advanced digital signal process ing （DSP） at the transmitter and receiver side for signal pre equalization and postequalization in order to improve spec trum efficiency （SE） and transmission distance in an optical access network. A novel DSP scheme for this optical super Nyquist filtering 9 Quadrature Amplitude Modulation （9 QAM） like signals based on muhimodulus equalization with out post filtering is proposed. This scheme recovers the Ny quist filtered Quadrature PhaseShift Keying （QPSK） signal to a 9QAMlike one. With this technique, SE can be increased to 4 b/s/Hz for QPSK signals. A novel digital superNyquist signal generation scheme is also proposed to further suppress the Nyquist signal bandwidth and reduce channel crosstalk without the need for optical prefiltering. Only optical cou plers are needed for superNyquist wavelengthdivisionmulti plexing （WDM） channel multiplexing. We extend the DSP for shorthaul optical transmission networks by using highorder QAMs. We propose a highspeed Can＇ierless Amplitude/Phase 64 QAM （CAP64 QAM） system using directly modulated la ser （DML） based on direct detection and digital equalization. Decisiondirected least mean square is used to equalize the CAP64QAM. Using this scheme, we generate and transmit up to 60 Gbit/s CAP64QAM over 20 km standard single mode fiber based on the DML and direct detection. Finally, several key problems are solved for real time orthogonalfre quencydivisionmultiplexing （OFDM） signal transmission aml processing. With coherent detection, up to 100 Glfit/s 16 QAMOFDM realtime transmission is possible.

关键词： digital signal processing high spectrum efficiency super-Ny-quist coherent optical transmission

Ultra-Lightweight Face Animation Method for Ultra-Low Bitrate Video Conferencing

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zte communications 2023年第1期21卷 64-71页

作者： LU Jianguo ZHENG Qingfang State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen 518055China zte Corporation Shenzhen 518057China

Video conferencing systems face the dilemma between smooth streaming and decent visual quality because traditional video compression algorithms fail to produce bitstreams low enough for bandwidth-constrained *** ultra-lightweight face-animation-based method that enables better video conferencing experience is proposed in this *** proposed method compresses high-quality upperbody videos with ultra-low bitrates and runs efficiently on mobile devices without high-end graphics processing units(GPU).Moreover,a visual quality evaluation algorithm is used to avoid image degradation caused by extreme face poses and/or expressions,and a full resolution image composition algorithm to reduce unnaturalness,which guarantees the user *** show that the proposed method is efficient and can generate high-quality videos at ultra-low bitrates.

关键词： talking heads face animation video conferencing generative adversarial network

同方期刊数据库

An Improved Color Cast Detection Method Based on an AB-Chromaticity Histogram

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zte communications 2013年第1期11卷 41-43页

作者： Ping Lu Xia Jia Tirui Wu Pre-Research Department of zte Corporation

AB-chromaticity histogram analysis works well most of the time, but it may not work well when the color cast is not severe. To overcome this problem, we propose an improved, two-step automatic cast-detection method. First, we compute the RGB color variance to evaluate the quality of the input image. If this variance is very small, we extract near-neutral color areas and compute the local ab-chromaticity histogram. We use this local ab-chromaticity histogram to evaluate the quality of the input image. This method has been tested in zte＇ s video surveil- lance system. The results show that the proposed method pro- duces better results based on subjective evaluation and is more efficient in various conditions.

关键词： color cast AB-chromaticity histogram near-neutral color areas

Hierarchical Template Matching for Robust Visual Tracking with Severe Occlusions

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zte communications 2012年第4期10卷 54-59页

作者： Lizuo Jin Tirui Wu Feng Liu Gang Zeng School of Automation Southeast University zte Corporation

To tackle the problem of severe occlusions in visual tracking, we propose a hierarchical template-matching method based on a layered appearance model. This model integrates holistic- and part-region matching in order to locate an object in a coarse-to-fine manner. Furthermore, in order to reduce ambiguity in object localization, only the discriminative parts of an object＇ s appearance template are chosen for similarity computing with respect to their cornerness measurements. The similarity between parts is computed in a layer-wise manner, and from this, occlusions can be evaluated. When the object is partly occluded, it can be located accurately by matching candidate regions with the appearance template. When it is completely occluded, its location can be predicted from its historical motion information using a Kalman filter. The proposed tracker is tested on several practical image sequences, and the experimental results show that it can consistently provide accurate object location for stable tracking, even for severe occlusions.

关键词： visual tracking hierarchical template matching layeredappearance model occlusion analysis

Field Transmission of 100G and Beyond:Multiple Baud Rates and Mixed Line Rates Using Nyquist-WDM Technology

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zte communications 2012年第3期10卷 28-38页

作者： Zhensheng Jia Jianjun Yu Hung-Chang Chien Ze Dong Di Huo zte USA MorristownNJ 07960USA

In this paper, we describe successful joint experiments with Deutsche Telecom on long-haul transmission of 100G and beyond over standard single mode fiber （SSMF） and with in-line EDFA-only amplification. The transmission link consists of 8 nodes and 950 km installed SSMF in DT＇ s optical infrastructure. Laboratory SSMF was added for extended optical reach. The first field experiment involved transmission of 8 x 216.8 Gbit/s Nyquist-WDM signals over 1750 km with 21.6 dB average loss per span. Each channel, modulated by a 54.2 Gbaud PDM-CSRZ-QPSK signal, is on a 50 GHz grid, which produces a net spectral efficiency （SE） of 4 bit/s/Hz. We also describe mixed-data-rate transmission coexisting with 1T, 400G, and 100G channels. The 400G channel uses four independent subcarriers modulated by 28 Gbaud PDM-QPSK signals. This yields a net SE of 4 bit/s/Hz, and 13 optically generated subcarriers from a single optical source are used in the 1T channel with 25 Gbaud PDM-QPSK modulation. The 100G signal uses real-time coherent PDM-QPSK transponder with 15% overhead of soft-decision forward-error correction （SD-FEC）. The digital post filter and 1 -bit maximum-likelihood sequence estimation （MLSE） are introduced at the receiver DSP to suppress noise, linear crosstalk, and filtering effects. Our results show that future 400G and 1T channels that use Nyquist WDM can transmit over long-haul distances with higher SE and using the same QPSK format.

关键词： coherent detection field trial coherent optical OFDM Nyquist WDM MLSE