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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 {3. 2009年第6期16卷 11-16页

作者： CHENG tie-zheng,yuan Chao-wei {3. of information and Communication engineering,beijing university of posts and telecommunications,beijing 100876,china [a] school of information and Communication engineering beijing university of posts and {3. 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

Transmit-reference UWB system based on m-sequence codes

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The Journal of china Universities of posts and {3. 2010年第1期17卷 25-31页

作者： ZHAO lin-li,lü tie-jun,qiao yong-wei {3. of information and Communication engineering,beijing university of posts and telecommunications,beijing 100876,china [a] school of information Communication engineering Beijing University of Posts telecommunications Beijing 100876 China

In this article, a novel transmit-reference （TR） signaling scheme is proposed for ultra-wideband （UWB） system, where by invoking m-sequence codes the reference and data pulses can be transmitted side by side to increase the data rate. This structure enables demodulation with a simple and practical autocorrelation receiver despite existence of severe inter-pulse interference （IPI） To evaluate detection performance of the new designs, closed-form expression for bit error probability （BRP） is theoretically derived and simulation results confirm the analytical results. In addition, the proposed scheme can be extended to M-ary systems to further improve the data rate and power efficiency.

关键词： UWB TR IPI m-sequence M-ary

Novel THP algorithms with minimum BER criterion for MIMO broadcast communications

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The Journal of china Universities of posts and {3. 2009年第4期16卷 71-77页

作者： YUN Xiang,l tie-jun school of {3. and Communication engineering,beijing university of posts and telecommunications,beijing 100876,china [a]school of information and Communication engineering beijing university of posts and {3. 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

Stratigraphic framework and sedimentary evolution during the Cryogenian-Ediacaran transition in northeastern Sichuan Basin,South china

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Petroleum Science 2024年第2期21卷 823-835页

作者： Yi Zhang Hong-wei Kuang yong-Qing liu Qiang Shi Dong-Ge Wang Ke-Ning Qi Yu-Chong Wang Da-wei {3. Xiao-Shuai Chen li-zhi Wu Meng Tian long Chen Yi wei liao-yuan Song Jian li Zi-Gang Wu Yun-Qian liu Xuan-Chun liu An-Qing Chen zhi-wei liao Institute of Geology Chinese Academy of Geological SciencesBeijing100037China State Key laboratory of Coal Mine Disaster Dynamics and Control School of Resources and Safety EngineeringChongqing UniversityChongqing400044China No.205 Geological Team Chongqing Bureau of Geology and Minerals ExplorationChongqing401121China Chongqing Institute of Geological Survey Chongqing401122China Key laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu610059SichuanChina

The northeastern Sichuan area in the northern Yangtze margin has unique Ediacaran geological records,especially the Doushantuo Formation(DST),and become a hot research area in recent ***,the Cryogenian-Ediacaran(C-E)boundary has not been precisely identified,which restricts the in-depth study of geological information during this crucial transitional period and is unfavorable for a systematic and complete understanding of the Yangtze Block and even the global paleogeographic *** study conducted stratigraphy,sedimentology,and chronostratigraphy to establish the stratigraphic framework and sedimentary evolution of the C-E transition strata in northeastern *** results showed that the Ediacaran sediments,without the cap dolomite,unconformably overlaid the Cryogenian sediments in the studied *** Member II of the DST,characterized by 50-160 m of red-green sandstone(approximately equivalent to the original Chengkou“Guanyinya Formation”),directly overlaid the Cryogenian sediments and displayed a 623.2.3.Ma maximum depositional age from the detrital zircon U-Pb *** stratigraphic correlations indicate that the C-E transition strata in northeastern Sichuan had a consistent lithological association and sedimentary sequence characteristics but differed from the Three ***,the upper Nantuo massive glacial diamictites transition to the icebergs rafted lonestone-bearing mudstones at the top,then change upward to DST barrier coast *** proposed DST of the northeastern Sichuan Basin was divided into three lithostratigraphic members without the regional Member I cap dolomite:(i)Member II purple-red,gray-green sandstone strata,(ii)MemberⅢblack mudstone strata,and(iii)Member IV P-Mn bearing *** the C-E transition,the study area experienced(i)the global deglaciation stage in the terminal Marinoan glaciation and(ii)the filling-leveling up stage with clastic rocks in the early ***,the early Ediacaran

关键词： Marinoan glaciation Doushantuo formation Cap dolomite Deglacial and coastal deposits Detrital zircon U-Pb dating

Resource scheduling scheme with QoS support in two-hop relay-enhanced OFDMA systems

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The Journal of china Universities of posts and {3. 2010年第4期17卷 26-30页

作者： lIU wei ,JI Hong,lI Ting school of information and Telecommunication {3.,beijing university of posts and telecommunications,beijing 100876,china [a] school of information Telecommunication engineering Beijing University of Posts telecommunications Beijing 100876 China

As the system performance is obviously improved by introducing the concept of relay into the traditional orthogonal frequency division multiple access （OFDMA） systems, resource scheduling in relay-enhanced OFDMA systems is worthy of being studied carefully. To solve the optimization problem of achieving the maximum throughput while satisfying the quality of service （QoS） and guaranteeing the fairness of users, a novel resource scheduling scheme with QoS support for the downlink of two-hop relay-enhanced OFDMA systems is proposed. The proposed scheme, which is considered both in the first time sub-slot between direct link users and relay stations, and the second time sub-slot among relay link users, takes QoS support into consideration, as well as the system throughput and the fairness for users. Simulation results show that the proposed scheme has good performance in maximizing system throughput and guaranteeing the performance in the service delay and the data loss rate.

关键词： relay OFDMA QoS resource scheduling

User-perceived e-mail service QoS parameters and measurement

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The Journal of china Universities of posts and {3. 2010年第3期17卷 85-90页

作者： lI yong-zhi , lIU Feng, lEI Zhen-ming, CHEN ling school of {3. and Communication engineering, 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

Synchronization of MIMO OFDM systems by perfect complete generalized complementary orthogonal loosely synchronous code groups

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The Journal of china Universities of posts and {3. 2009年第2期16卷 1-7页

作者： WANG Jian YANG Xun lI Dao-ben school of information engineering,{3. university of posts and telecommunications,beijing 100876,china [a]school of information engineering beijing university of posts and {3. beijing 100876 china

This article proposes a time/frequency synchronization algorithm in the multiple input multiple output （MIMO） systems, in which the perfect complete generalized complementary orthogonal loosely synchronous code groups are used as the synchronization sequence. The synchronization algorithm is divided into four stages： 1） synchronization in time domain by signal autocorrelation; 2） synchronization in frequency domain by fast Fourier transform （FFT）; 3. multipath dissociation using coherent detection and fine time synchronization; 4） fine frequency offset estimation by phase rotation. As per the perfect complete generalized complementary orthogonal loosely synchronous code groups, the cross-correlation and out-of-phase auto-correlation for any relative shift between any two codes is always zero. This ideal property makes the time/frequency synchronization algorithm simple and efficient. The simulation results show that even in the multipath fast fading channel with low signal noise ratio （SNR）, the MIMO system can get synchronized both in the time domain and frequency domain with high stability and reliability.

关键词： MIMO OFDM synchronization complementary orthogonal code loosely synchronous (lS) code

Resource allocation based on genetic algorithm for multi-hop OFDM system with non-regenerative relaying

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The Journal of china Universities of posts and {3. 2009年第5期16卷 25-32页

作者： SHI Jie , XU Wen-jun, HE zhi-qiang, NIU Kai, WU wei-ling {3. of information and Telecommunication engineering, beijing university of posts and telecommunications, beijing 100876, china [a]school of information and Telecommunication engineering beijing university of posts and {3. beijing 100876 china

This article investigates resource allocation in multi-hop orthogonal frequency division multiplexing （OFDM） system with amplifying-and-forwarding relaying to maximize the end-to-end capacity, Most existing methods for multi-hop system focus on power allocation or subcarrier selection separately, but joint resource allocation is rarely considered due to the absence of effective interaction schemes. In this work, a novel joint resource allocation methodology is proposed based on Partheno genetic algorithm （PGA）, which produces excellent subcarrier allocation set （referred to as individual in PGA） with higher capacity by evolution operator generation by generation. In addition, an adaptive power allocation is also designed to evaluate the fitness of PGA and further enhance the system capacity. Both theoretical analysis and simulated results show the effectiveness of the proposed joint strategy. It outperforms the traditional method by as much as 40% capacity improvement for 3.hop relaying system when system power is high, and obtains much more capacity enhancement percent under conditions of low system power.

关键词： multi-hop OFDM system non-regenerative relaying genetic algorithm power allocation subcarrier selection resource allocation

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 {3.,beijing university of posts and telecommunications,beijing 100876,china 2 school of information and Communication {3.,beijing university of posts and telecommunications,beijing 100876,china 3.Key lab of Universal Wireless Communications,Ministry of Education,beijing 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