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Novel limited feedback scheme under the MIMO broadcast system

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The Journal of china Universities of Posts and telecommunications 2009年第6期16卷 11-16页

作者： CHENG Tie-zheng,YUAN Chao-wei school of information and {2. {3.,beijing University of Posts and telecommunications,beijing 100876,china [a] school of information and {2. {3. beijing University of Posts and telecommunications beijing 100876 china

By deducing the distribution of the normalized channel covariance matrix,a novel limited feedback scheme is proposed under multiple users（MU） multiple-input multiple-output（MIMO） broadcast channel（BC） *** proposed scheme has advantages in three ***,it has no constraints on the number of users or ***,each user＇s feedback bits are independent of the number of receiving ***,the proposed scheme avoids the storage of large-size codebook on the *** results show that the performance of the proposed scheme is close to the perfect channel state information（CSI） case and it just needs a small number of feedback bits.

关键词： MIMO broadcast channel limited feedback normalized channel covariance

Robust multiuser MIMO scheduling algorithms with imperfect CSI

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Science china(information Sciences) 2012年第4期55卷 815-826页

作者： MAO JunLing 1,3.GAO JinChun 1,3.LIU YuanAn 1,3.XIE Gang 2.3.& ZHANG Jian 1,3.1 school of Electronic engineering,{2. University of Posts and telecommunications,beijing 100876,china 2.school of information and communication engineering,{2. University of Posts and telecommunications,beijing 100876,china 3.Key Lab of Universal Wireless communications,Ministry of Education,{2. University of Posts and telecommunications,beijing 100876,china 1. school of Electronic engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Lab of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

Robust multiuser multiple-input-multiple-output (MIMO) scheduling algorithms are proposed in this *** imperfect channel state information (CSI),traditional scheduling algorithms for the multiuser MIMO system based on the zero forcing precoding scheme will lose some performance due to the multi-user interference (MUI).In order to improve the system average throughput,we study the robust multiuser MIMO scheduling problem with imperfect *** the average capacity formula,we derive a robust factor which can transform the robust multiuser MIMO scheduling problem into the traditional one,thus most existing non-robust scheduling algorithms can be robust if this factor is *** results show that compared with the traditional algorithms,the proposed robust algorithms can improve the system average throughput significantly under the CSI error environment.

关键词： multiuser MIMO (MU-MIMO) scheduling robust imperfect CSI

Novel THP algorithms with minimum BER criterion for MIMO broadcast communications

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The Journal of china Universities of Posts and telecommunications 2009年第4期16卷 71-77页

作者： YUN Xiang,L Tie-jun school of information and {2. {3.,beijing University of Posts and telecommunications,beijing 100876,china [a]school of information and {2. {3. beijing University of Posts and telecommunications beijing 100876 china

In this article, two novel Tomlinson-Harashima precoding （THP） algorithms are proposed at the downlink broadcast channel of multi-user multiple-input multiple-output （MIMO） systems. The optimality criterion is the minimization of the bit error rate （BER） at the receiver with a constraint on the overall transmitted power. In these algorithms, transmit power allocation （TPA） matrix is introduced to the traditional THP algorithms as part of the precoding matrix. This leads to a power loading operation based on substreams signal to interference-plus-noise ratio （SINR） and results in improvement of the error rate performance compared with traditional THP algorithms. When the precoding loss factor is considered, further performance improvement is achieved by the enhanced algorithm.

关键词： MIMO system THP minimum bit-error rate (MBER) broadcast communication

Generalized quantum state sharing of the arbitrary two particles state

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 2064-2068页

作者： WANG Chuan 1,2.ZHANG Yong 1,2.& JIN GuangSheng 1,2.1 {3. of Science,beijing University of Posts and {2.,beijing 100876,china 2.Key Laboratory of Optical communication and Lightwave Technologies,beijing University of Posts and {2.,beijing 100876,china 1. school of Science Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Optical Communication and Lightwave Technologies Beijing University of Posts and Telecommunications Beijing 100876 China

This paper has proposed a generalized quantum state sharing protocol of an arbitrary two-particle state using non-maximally GHZ states and generalized Bell state *** sender Alice performs two-particle generalized Bell state measurements on her two particles in the state sharing process and the controller takes measurements on his particles and transfers the quantum information to the receiver with entanglement swapping by the cooperation of the other *** is found that the use of nonmaximally entangled state in quantum state sharing has enabled the secure sharing of the quantum state.

关键词： quantum state sharing quantum entanglement arbitrary two particles state

Error exponents for two-hop Gaussian multiple source-destination relay channels

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Science china(information Sciences) 2012年第2期55卷 348-359页

作者： DENG PanLiang1,3.LIU YuanAn1,3.XIE Gang2.3.WANG XiaoYu1,3.TANG BiHua1,3.& SUN JianFeng1,3.1school of Electronic engineering,{2. University of Posts and telecommunications,beijing 100876,china 2.0} of information and communication engineering,{2. University of Posts and telecommunications,beijing 100876,china 3.ey Laboratory of Universal Wireless communication,Ministry of Education,beijing 100876,china 1. school of Electronic engineering Beijing University of Posts and Telecommunications Beijing 100876 China3. Key Laboratory of Universal Wireless Communication Ministry of Education Beijing 100876 China2. School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

We investigate the two-hop multiple source-destination relay channels using the rate splitting trans-mission scheme where each source can split its message into private and public *** determine the system error probability via integrated exponent function under amplify-and-forward(AF)and decode-and-forward(DF)relay *** most significant difference between AF and DF system error probability evaluations lies in a minimized cut-set bound of transmission rate under the DF *** are many cases among transmission rate intervals for different system parameters(*** power)and it is extremely complex to derive the system error probability for the DF *** obtain a relatively simple result,which unifies various cases by a few *** results show that the system error probability decreases with the increase of the public ***,in order to draw deep insight into the reliability requirement of each source node in this network,we provide the error exponent region(EER)for different source nodes to show the trade-off of error probability among source nodes.

关键词： error exponent error exponent region rate splitting multiple source-destination relay channel

Reverse reconciliation for continuous variable quantum key distribution

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Science china(Physics,Mechanics & Astronomy) 2010年第1期53卷 100-105页

作者： LU ZhiXin 1,2., YU Li 1,2., LI Kang 1,2., LIU BingCan 1,2.3., LIN JianGui 1,2., JIAO RongZhen 1,2.& YANG BoJun 1,2. school of Science, beijing University of Posts and {2., beijing 100876, china 2.Key Laboratory of {13. Photonics and Optical communication, Ministry of Education, beijing University of Posts and {2., beijing 100876, china 3.Department of Fundamental Courses, Academy of Armored Force engineering, beijing 100072. china 1. school of Science Beijing University of Posts and Telecommunications Beijing 100876 China2. Key Laboratory of Information Photonics and Optical Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China3. Department of Fundamental Courses Academy of Armored Force Engineering Beijing 100072 China

An efficient and practical post-processing technique based on reverse reconciliation for continuous variable quantum key distribution is proposed and simulated with low-density parity check (LDPC) codes. MultiLevel Coding/ MultiStage Decoding, which fully utilizes optimization technique such as vector quantization and iterative decoding and the optimal channel coding most close to the Shannon limit, was used to realize efficient reverse reconciliation algorithm. Simulation results showed that the proposed method can improve the secure key distribution rate to 2.2.kb/s and the coding efficiency to 0.89 over 2. km in single-mode optical fiber. Moreover, there still is room for much improvement.

关键词： quantum communication key distribution reverses reconciliation low-density parity check codes

Location based spectrum sensing performance analysis over fading channels in cognitive radio networks

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The Journal of china Universities of Posts and telecommunications 2010年第5期17卷 26-31页

作者： YAO Hai-peng,ZHOU Zheng,SUN Xuan,LI Bin school of information and {2. {3.,beijing University of Posts and telecommunications,beijing 100876,china [a] school of information communication engineering Beijing University of Posts telecommunications Beijing 100876 China

This paper analyzes the spectrum sensing performance over fading channel,in which a licensee and multiple unlicensed users coexist and operate in the licensed channel in a local *** overall average probabilities of detection and false alarm by jointly taking the fading and the locations of all secondary users into account are derived,and a statistical model of cumulate interference is *** on the cumulate interference,a closed-form expression of outage probability at the primary user’s receiver according to a specific distribution of the fading is ***,the sensing parameters so as to minimize the total spectrum sensing error and maximize the average opportunistic throughput are *** is noted that the overall average performance analysis and results here enable to benchmark the design of specific spectrum sensing algorithms.

关键词： spectrum sensing cognitive radio cumulate interference outage probability

User-perceived e-mail service QoS parameters and measurement

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The Journal of china Universities of Posts and telecommunications 2010年第3期17卷 85-90页

作者： LI Yong-zhi , LIU Feng, LEI Zhen-ming, CHEN Ling school of information and {2. {3., beijing University of Posts and telecommunications, beijing 100876, china [a] school of information communication engineering Beijing University of Posts telecommunications Beijing 100876 China

A group of quality of service （QoS） parameters of electronic mail （e-mail） traffic are proposed from users＇ perspective. These parameters cover three fields： delay, throughput and usability. Concept and algorithm of each parameter are presented and its effect on user perceptions is described. In order to evaluate the effectiveness of these parameters, an active measurement system is implemented. Measured results show that the group of QoS parameters we proposed can be used to get a comprehensive view of user-perceived e-mail service QoS.

关键词： user perceptions e-mail service QoS active measurement

A new method of discovering new meteor showers from the IMO single-station video meteor database

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Science china(Physics,Mechanics & Astronomy) 2008年第8期51卷 1170-1178页

作者： LI Jun1,2.& ZHU Jin3.1 No.2.Middle school of {3.,{3. 100010,china 2.school of Journalism and communication,Tsinghua University,{3. 100084,china 3.{3. Planterium,{3. 100044,china 1. No.2.Middle school of beijing Beijing 100010 China 2. school of Journalism and communication Tsinghua University Beijing 100084 China 3. beijing Planterium Beijing 100044 China

It has been found that unknown meteor showers could be efficiently discovered from the single station video meteor database of the International Meteor Organization(IMO) by assuming the geocentric velocity and adjusting it within the dynamically permitted range. The mean geocentric velocities of new meteor showers can be obtained,as well as the coordinates of the radiants. The activity period and maximum time can also be obtained if there are sufficient shower meteors. All single station video meteor observations between February 13.and 17(from 2.00 to 2.05) in IMO's database are processed with this method. As a result,two new meteor showers,one near RA=2.5.10°,Dec=41.82. in Hercules and the other near RA=2.3.03.,Dec=17.04° in Serpenids,are discovered. Some dynamical characteristics of the new meteor showers are also determined. Considering the random nature on the selection of period in this work,it is expected that there are some more potential new meteor showers in IMO's video database.

关键词： single-station video meteor database the process of single-station video meteor database discovery of new meteor showers