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Robust Tomlinsion-Harashima precoding design with outdated CSIT

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The Journal of China Universities of posts and telecommunications 2010年第2期17卷 59-62页

作者： WANG Xu-zhen ,NIU Kai,HE Zhi-qiang,YU Guang-wei,WU Wei-ling Key Laboratory of Universal Wireless Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,China [a] Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

The channel state information at transmitter （CSIT） acquisition plays a key role in the multi-input multi-output （MIMO） system, especially for the precoding schemes. However it is unrealizable to acquire perfect CSIT in practice. In this article, an effective and practical dynamic CSIT model is introduced to acquire imperfect channel state information. For practicability, the channel temporal and spatial correlations are considered and the channel estimate and its error covariance are obtained by utilizing the outdated channel state information. Based on the dynamic CSIT mode, closed-form solution of robust Tomlinsion-Harashima precoding （THP） is derived by a Lagrangian approach. Numerical simulations are presented to demonstrate the performance.

关键词： channel estimation imperfect CSIT robust THP

Investing and Pricing with Supply Uncertainty in Electricity Market:A General View Combining Wholesale and Retail Market

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China Communications 2015年第3期12卷 20-34页

作者： LI Xiaobo GAO Li WANG Gongpu GAO Feifei WU Qingwei beijing university of posts and telecommunications school of Digital Media and Design Arts Beijing University of Posts and Telecommunications school of Computer and Information Technology Beijing Jiaotong University Department of Automation Tsinghua UniversityState Key Lab of Intelligent Technologies and SystemsTsinghua National Laboratory for Information Science and Technology(TNList)

Renewable energy,such as wind and solar energy,may vary signifi cantly over time and locations depending on the weather and the climate *** leads to the supply uncertainty in the electricity(power) market with renewable energy integrated to power *** this paper,electricity in the market is classified into two types:stablesupply electricity(SSE) and unstablesupply electricity(USE).We investigate the investment and pricing strategies under the electricity supply uncertainty in wholesale and retail electricity *** particular,our model combines the wholesale and retail market and capture the dominant players,i.e.,consumers,power plant(power operator),and electricity *** derive the market behaviors of these players,we formulate the market decision problems as a multistage Stackelberg *** solving the game model,we obtain the optimal,with closedform,wholesale investment and retail pricing strategy for the *** also obtain the energy supplier's best price mechanism numerically under certain *** fi nd the price of SSE being about 1.4.times higher than that of USE will benefi t energy supplieroptimally,under which power plant's optimal strategy of investing is to purchase USE about 4.5 times much more than SSE.

关键词： electricity supply with uncertainty electricity investment electricity pricing wholesale market retail market Stackelberg game

A Content Based Search Algorithm for Motion Estimation

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The Journal of China Universities of posts and telecommunications 2000年第3期7卷 25-27页

作者： SHI Ke wei, CAI An ni, SUN Jing ao (school of Telecommunication Engineering, beijing university of posts and telecommunications, beijing 100876, P.R.China) asteur.ivic.ve

The basic search algorithm to implement Motion Estimation ( ME ) in the H .263 encoder is a full search. It is simple but time consuming. Traditional search algorithms are fast, but may cause a fall in image quality or an increase in bit rate in low bit rate applications. A fast search algorithm for ME with consideration on image content is proposed in this paper. Experiments show that the proposed algorithm can offer up to 70 percent savings in execution time with almost no sacrifice in PSNR and bit rate, compared with the full search.

关键词： motion estimation video coding H .263 content based

Cooperative HARQ protocol and diversity analysis of systems with multiple incremental relays

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The Journal of China Universities of posts and telecommunications 2009年第5期16卷 8-13页

作者： FAN Bin , WANG Wen-bo, LIN Yi-cheng, ZHENG Kan Wireless Signal Processing and Network Lab, Key Laboratory of Universal Wireless Communication, Ministry of Education, beijing university of posts and telecommunications, beijing 100876, China [a]Wireless Signal Processing and Network Lab Key Laboratory of Universal Wireless Communication Ministry of Education beijing university of posts and telecommunications beijing 100876 China

Wireless networks contain an inherent distributed spatial diversity that can be exploited by relays. Relay networks can take advantage of the broadcast-oriented nature of wireless transmission, but require more radio resource to transmit data for their multi-hop traits. Fortunately, incremental relaying technique, which can choose direct or multi-hop transmission adaptively, can efficiently utilize resource. In this article, the incremental transmission with amplify-and-forward （AF） relays is focused on. A practical hybrid-automatic retransmission request （HARQ） protocol is designed, and the related optimal relay selection strategy is proposed. To analyze the cooperative diversity of system with the proposed protocol, the capacity lower bound is deduced. Simulation and analytical results indicate that by adopting the optimal relay selection strategy, the system with the proposed HARQ protocol can achieve an order of cooperative diversity that equals the aggregated number of the relay and source nodes.

关键词： cooperative HARQ AF incremental relay diversity gain

VCO clock synchronization loop combined with dispersion equalization in optical coherent receivers

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The Journal of China Universities of posts and telecommunications 2010年第5期17卷 122-128页

作者： FAN Yang-yang,CHEN Xue,ZHOU Xian,ZHOU Wei-qin,ZHU Hai,LI Zhi-yu Key Laboratory of Information Photonics and Optical Communications,Ministry of Education,beijing university of posts and telecommunications,beijing 100876,China [a] Key Laboratory of Information Photonics Optical Communications Ministry of Education Beijing University of Posts telecommunications Beijing 100876 China

In optical coherent receivers,the timing error detector （TED） in synchronization loop can not work normally when signal is distorted by large *** paper proposes a novel clock synchronization scheme which adds a butterfly-structured adaptive equalizer to the loop to fulfill synchronizations,equalizations and polarization de-multiplexing of two polarization states simultaneously under the control of single voltage-controlled oscillator （VCO）.Simulink simulation demonstrates the rationality and the feasibility of the combined loop with single VCO.

关键词： optical coherent receiver synchronization dispersion equalization

Pruning Redundant Alarm Correlation Patterns

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The Journal of China Universities of posts and telecommunications 2002年第2期9卷 45-48页

作者： CHEN Yue, LIN Qi ning, TU Zhi yun (Business Management school, beijing university of posts and telecommunications, beijing 100876, P.R.China) Business Management school Beijing University of Posts and Telecommunications Beijing 100876 P.R.China

Efficient methods exist for discovering association rules fromlarge collections of data. The number of discovered rules can,however, be so large. At the same time it is well known that manydiscovered associations are redundant or minor variations of *** existence may simply be due to chance rather than truecorrelation. Thus, those spurious and insignificant rules should beremoved. In this paper, we propose a novel technique to over- Comethis problem. The technique firstly introduces the newconcept-structure rule cover, and then present a Quantitative methodto prune redundant correlation patterns. The user can now obtain acomplete picture of the do- Main without being overwhelmed by a hugenumber of rules.

关键词： alarm correlation structural rule cover correlation logic minimumsupport

Identifying online traffic based on property of TCP flow

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The Journal of China Universities of posts and telecommunications 2009年第3期16卷 84-88页

作者： HONG Min-huo,GU Ren-tao,WANG Hong-xiang,SUN Yong-mei,JI Yue-feng Key Laboratory of Optical Communications and Lightwave Technologies,beijing university of posts and telecommunications,beijing 100876,China [a]Key Laboratory of Optical Communications and Lightwave Technologies beijing university of posts and telecommunications beijing 100876 China

Classification of network traffic using port-based or payload-based analysis is becoming increasingly difficult when many applications use dynamic port numbers, masquerading techniques, and encryption to avoid detection. In this article, an approach is presented for online traffic classification relying on the observation of the first n packets of a transmission control protocol （TCP） connection. Its key idea is to utilize the properties of the observed first ten packets of a TCP connection and Bayesian network method to build a classifier. This classifier can classify TCP flows dynamically as packets pass through it by deciding whether a TCP flow belongs to a given application. The experimental results show that the proposed approach performs well in online Internet traffic classification and that it is superior to naive Bayesian method.

关键词： network traffic classification inter-arrival time TCP flow Bayesian network

A Distributed Intranet/Web Solution to Integrated Management of Access Networks

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The Journal of China Universities of posts and telecommunications 2002年第1期9卷 35-39页

作者： LIU Ting, SHOU Guo chu, GUO Zhi gang (Continuing Education school, beijing university of posts and telecommunications, beijing 100876, P.R. China) Continuing Education school Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

In this article, we describe the present situation of accessnetwork management, enumerate a few prob- lems during the developmentof network management systems, then put forward a distributedIntranet/Web solution named iMAN to the integrated management ofaccess networks, present its architecture and protocol stack, and de-scribe its application in practice.

关键词： Intranet/Web access network network management iMAN

Combining Digital Watermarks with Two-Color Bitmap Image

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The Journal of China Universities of posts and telecommunications 2000年第Z1期 31-35页

作者： SAAD A Amer, YANG Yi-xian (Information Security Center, beijing university of posts and telecommunications, beijing 100876, P.R. China)

A technology for combining digital watermarks with two-color bitmap image based on the threshold watermarking method is presented. Our technology doesn’t add any thing to the digital media, but combines the watermarks in two-color bitmap image by looking for some characteristic values in the bitmap and uses the relationship between the watermarks and the characteristic values to prove the copyright protection. The choice of the characteristic values depends on the choice of a cryptographic key known by the owner of the bitmap. The benefit of using a cryptographic key is to combine the watermarks with the bitmap in a high secure way.

关键词： digital watermarks information hiding copyright protection