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Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

science in china(Series F) 2009年第8期52卷 1418-1427页

作者： yu xiangbin1,2. bi guangguo3 & xu weiye4 1 college of information science and technology,{2., nanjing 2.0016, china 2.Department of Electronic Engineering, City university of Hong Kong, Hong Kong, china 3 National Mobile Communications Research Laboratory, Southeast university, nanjing 2.0096, china 4 Department of Communication Engineering, nanjing Institute of {12., nanjing 2.1167, china college of information {2. and technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Electronic Engineering City University of Hong Kong Hong Kong China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China Department of Communication Engineering Nanjing Institute of Technology Nanjing 211167 China

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

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Performance of multiuser CDMA system with space-time block coding in MIMO Rayleigh fading channels

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science in china(Series F) 2009年第12期52卷 2296-2307页

作者： yu xiangbin DONG Tao bi {2. college of information {2. and technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China School of information science and {2. Sun Yat-sen University Guangzhou 510275 China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China

In this paper, by introducing orthogonal space-time coding scheme, the multiuser CDMA systems with different space time codes are given, and corresponding system performance is investigated over Rayleigh fading channel. A low-complexity multiuser receiver scheme is developed for space-time coded CDMA systems. The scheme can make full use of the complex orthogonality of space-time coding to simplify the high decoding complexity of the existing scheme. Compared to the existing scheme with exponential decoding complexity, it has linear decoding complexity. Based on the performance analysis and mathematical calculation, average bit error rate （BER） of the system is derived in detail, and tight closed-form approximation expressions of BER are attained. Simulation results on average BER are in agreement with the theory analysis. The results show that the proposed scheme can achieve almost the same performance as the existing scheme. Moreover, on the condition of same system throughput and concatenation of channel code, the given full-rate space-time coded CDMA system has lower BER than the full-diversity space-time coded CDMA systems.

关键词： space-time block coding code division multiple access (CDMA) full diversity full rate multiple input multiple output (MIMO)

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Performance of orthogonal STBC-MIMO with variable-power adaptive modulation and delayed feedback in Nakagami fading channels

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science china({2. sciences) 2013年第10期56卷 81-90页

作者： yu xiangbin CHEN XiaoMin bi {2. RUI yun college of information {2. and technology Nanjing University of Aeronautics and Astronautics National Mobile Communications Research Laboratory Southeast University Shanghai Advanced Research Institute Chinese Academic of Science

A variable-power(VP)adaptive modulation(AM)scheme with space-time block code(STBC)is developed in MIMO systems,and the corresponding performance is investigated in Nakagami fading *** optimum switching thresholds are derived so that the spectrum efciency(SE)under an average power and a target bit error rate(BER)constraint is *** the switching thresholds,average BER and SE are further *** a result,closed-form expressions are ***,the exact and approximate BER expressions of VP AM and constant-power(CP)AM systems with delayed feedback are respectively *** results show that the theoretical SE and BER can match the corresponding simulation *** results indicate that VP-AM with STBC provide higher spectrum efciency than the CP counterparts,and has slighter bite error rate performance degradation when the normalized delay is less than 0.01.

关键词： orthogonal space-time coding adaptive modulation variable power delayed feedback Nakagami fading

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Adaptive Energy-Efficient Power Allocation for DAS with Imperfect Channel State information and Antenna Selection

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china Communications 2016年第7期13卷 127-134页

作者： weiye xu Min Lin yu Yang {2. yu college of Communications Engineering PLA University of Science and TechnologyNanjingChina information Security Center Beijing University of Posts and TelecommunicationsBeijingChina nanjing university of {2. science and technology NanjingChina college of Electronic and information Engineering Nanjing University of Aeronautics and AstronauticsNanjingChina School of Communication Engineering Nanjing Institute of TechnologyNanjingChina.

Considering that perfect channel state information(CSI) is difficult to obtain in practice,energy efficiency(EE) for distributed antenna systems(DAS) based on imperfect CSI and antennas selection is investigated in Rayleigh fading channel.A novel EE that is defined as the average transmission rate divided by the total consumed power is *** accordance with this definition,an adaptive power allocation(PA) scheme for DAS is proposed to maximize the EE under the maximum transmit power *** solution of PA in the constrained EE optimization does exist and is unique.A practical iterative algorithm with Newton method is presented to obtain the solution of *** proposed scheme includes the one under perfect CSI as a special case,and it only needs large scale and statistical *** a result,the scheme has low overhead and good *** theoretical EE is also derived for performance evaluation,and simulation result shows the validity of the theoretical ***,EE can be enhanced by decreasing the estimation error and/or path loss exponents.

关键词： distributed antenna system energy efficiency adaptive power allocation imperfect channel state information antenna selection

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大数据驱动的双线融合课程教学质量评价体系构建

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江苏科技信息 2024年第10期41卷 56-60页

作者：王筱纶许钰滕汶松刘梦凡杨长荻南京航空航天大学经济与管理学院江苏南京211106

随着政策引导和MOOC课程兴起,双线融合课程成为高校教学实践新常态。文章基于CIPP评价模式,将定量和定性方法相结合,收集政策公告、理论文献、人工智能问答3类文本,通过高频词分析和语义网络图提取双线融合课程质量3级评价指标。接着,... 详细信息

随着政策引导和MOOC课程兴起,双线融合课程成为高校教学实践新常态。文章基于CIPP评价模式,将定量和定性方法相结合,收集政策公告、理论文献、人工智能问答3类文本,通过高频词分析和语义网络图提取双线融合课程质量3级评价指标。接着,利用信效度检验和层次分析法计算指标权重,构建系统的教学质量评价体系。最后,运用多主体问卷和模糊综合评价法,针对线上比重不同的两门课程进行数据对比,提出相应改进策略。

关键词：双线融合课程 CIPP评价模式教学评价指标数据驱动

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Was Wuhan the early epicenter of the COVID-19 pandemic?——a critique

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National science Review 2023年第4期10卷 19-21页

作者： Yanan Cao Lingling Chen Hua Chen yupeng Cun Xiaofeng Dai Hongli Du Feng Gao Fengbiao Guo Yalong Guo Pei Hao Shunmin He Shunping He XiongLei He Zheng Hu Boon-Peng Hoh Xin Jin Qian Jiang Qinghua Jiang Asifullah Khan Hong-Zhi Kong Jinchen Li Shuai Cheng Li Ying Li Qiang Lin Jianquan Liu Qi Liu Jian Lu xuemei Lu Shujin Luo Qinghua Nie Zilong Qiu Tieliu Shi Xiaofeng Song Jianzhong Su Sheng-ce Tao Chaolong Wang Chuan-Chao Wang Guo-Dong Wang Jiguang Wang Qi Wu Shaoyuan Wu Shuhua xu yu xue Wenjun Yang Zhaohui Yang Kai Ye yuan-Nong Ye Li yu Fangqing Zhao Yiqiang Zhao Weiwei Zhai Dandan Zhang Liye Zhang Houfeng Zheng Qi Zhou Tianqi Zhu Ya-ping Zhang Ruijin Hospital Shanghai Jiao Tong University college of Life science and {2. Guangxi University Beijing Institute of Genomics Chinese Academy of Sciences Children's Hospital of Chongqing Medical university Wuxi School of Medicine Jiangnan University School of biology and biological Engineering South China University of Technology Department of Physics School of ScienceTianjin University School of Pharmaceutical sciences Wuhan University Institute of Botany Chinese Academy of Sciences Institut Pasteur of Shanghai Chinese Academy of Sciences Institute of biophysics Chinese Academy of Sciences Institute of Hydrobiology Chinese Academy of Sciences School of Life sciences Sun Yat-sen University Institute of Synthetic biology Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Faculty of Medicine and Health sciences University College Sedaya International School of Medicine South China University of Technology Department of Medical Genetics Capital Institute of Pediatrics School of Life science and technology Harbin Institute of Technology Department of biochemistry Abdul Wali Khan University Xiangya Hospital Central South University Department of Computer science City University of Hong Kong college of Life science and {2. Foshan University South china Sea Institute of Oceanology Chinese Academy of Sciences college of Ecology Lanzhou University School of Life sciences and technology Tongji University School of Life sciences Peking University Kunming Institute of Zoology Chinese Academy of Sciences college of Animal science South China Agricultural University Institute of Neuroscience Chinese Academy of Sciences School of Life sciences East China Normal University nanjing university of {2. and astronautics Wenzhou Institute University of Chinese Academy of Sciences Institute of Systems biomedicine Shanghai Jiao Tong University Tongji Medical college Huazhong University of Science and Technology School of Life sciences Xiamen University Division of Life science and Department of

Recently, Worobey et al.(2.2.) published a report entitled ‘The Huanan Seafood Wholesale Market in Wuhan was the early epicenter of the COVID-19 pandemic’ that succinctly summarizes their study [1]. A pre-print version of this study had earlier elicited a series of highprofile media coverages [2.3]. All these reports deliver a social-political message that the Huanan market is the epicenter of COVID-19.

关键词： SARS-COV-2 ORIGIN

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直升机桨叶形态光纤监测与重建方法研究

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强度与环境 2023年第2期50卷 54-59页

作者：吴亚星曾捷岳应萍徐云涛王云嵩杨宇孙阳阳骆梦醒南京航空航天大学机械结构力学及控制国家重点实验室南京210016 中国飞机强度研究所全尺寸飞机结构静力/疲劳航空科技重点实验室西安710065 陆军工程大学国防工程学院南京210007

针对新研制直升机不同任务模式,实现飞行过程中桨叶形态变化的实时监测与精确调控,对于提升飞行品质与保障飞行安全至关重要。为此,提出了一种基于坐标变换理论与光纤应变感知信息的直升机桨叶形态监测与重建方法,并给出了相应光纤Brag... 详细信息

针对新研制直升机不同任务模式,实现飞行过程中桨叶形态变化的实时监测与精确调控,对于提升飞行品质与保障飞行安全至关重要。为此,提出了一种基于坐标变换理论与光纤应变感知信息的直升机桨叶形态监测与重建方法,并给出了相应光纤Bragg光栅传感器布局形式。建立了NACA2.12.叶构型有限元模型,根据数值仿真结果,验证了坐标变换理论形态重建效果。在此基础上,构建了基于光纤传感器的直升机桨叶动、静态变形监测与形态重建系统。桨叶整体形态重建均方根平均误差为0.370,桨叶桨尖位移静态变形辨识平均相对误差约为5.754%,动态变形辨识平均相对误差约为7.908%。研究表明,本文所提方法能够为未来智能旋翼形态自适应精确调控提供技术支撑。

关键词：坐标变换理论直升机桨叶光纤Bragg光栅传感器

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