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Performance of two-way amplify-and-forward relaying with adaptive modulation over Nakagami-m fading channels

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The Journal of China Universities of Posts and Telecommunications 2011年第5期18卷 47-52页

作者： ZHANG yong-liang chang yong-yu DAI Li-yun YANG Da-cheng School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China School of Software and Communication Engineering Jiangxi University of Finance and Economics Nanchang 330013 China

This paper investigates the performance of a two-way amplify-and-forward （AF） relay system with adaptive modulation over independent and non-identical Nakagami-m fading channels. The tight closed-form cumulative distribution function （CDF） expression of the instantaneous end-to-end signal-to-noise ratio （SNR） is provided. Further, approximate closed-form expression for the average spectral efficiency of the two-way AF system with adaptive modulation is obtained. Then, a tight lower bound of outage probability is derived. Finally, we use numerical simulations to verify the tightness of our analytical results.

关键词： two-way relaying adaptive modulation spectral efficiency outage probability

SAGE based iterative receiver for joint synchronization and channel estimation in uplink MIMO-OFDMA systems

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 100-104页

作者： JIANG Zheng QIN Xiao-fang ZHANG Xin chang yong-yu Wireless Theories and Technologies Laboratory Beijing University of Posts and Telecommunications Beijing 100876 China

A new Turbo iterative receiver structure is proposed for the uplink multiple-input multiple-output orthogonal frequency division multiple access （MIMO-OFDMA） systems. The space-alternating generalized expectation-maximization （SAGE） algorithm is naturally embedded in the framework of iterative receiver to perform synchronization and detection usin~ the Turbo detector outputs. In each iteration, the expectation step intends to remove the multiple access interference （MAI） caused by other asynchronous users, and the maximization step is utilized to estimate the required parameters （i.e., timing offset, carrier frequency offset, channel state information, etc.） sequentially for each user. Simulation results show that the proposed algorithm can approach the performance of ideal receiver closely, while the processing complexity is rather lower than the conventional detectors.

关键词： SAGE iterative receiver synchronization channel estimation

Radio resource management strategy for VoIP service in TD-HSDPA system

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The Journal of China Universities of Posts and Telecommunications 2009年第4期16卷 29-33页

作者： HE Da-jiang ,CUI Jie,chang yong-yu,YANG Da-cheng School of Communication and Information Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,China [a]School of Communication and Information Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, the performance of a novel radio resource management （RRM） strategy for voice over IP （VoIP） service will be evaluated in low code rate （LCR） time duplex high speed downlink packet access （TD-HSDPA） system. This novel RRM strategy is studied from the aspects of scheduling algorithm and time slot assignment algorithm. As VolP is delay sensitive service, the delay based proportional fair （DBPF） scheduler is proposed in this article. Smart antenna （SA）, which is adopted in LCR TD-HSDPA, can obtain spatial information from the direction of arrival （DOA） estimation. To exploit this spatial information further, a dynamic time slot allocation （DTA） algorithm is introduced to cooperate with the DBPF scheduler. The performance of the round robin （RR）, proportional fair （PF） with the random time slot allocation （RTA） algorithm will be given to demonstrate the benefits of this novel DBPF with DTA RRM strategy. The system level simulation results prove that the performance of this novel RRM strategy is the best of all the RRM strategies.

关键词： RRM smart antenna VolP DBPF DTA HARQ AMC

Performance analysis of rate-adaptive cooperative MAC based on wireless local area networks

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The Journal of China Universities of Posts and Telecommunications 2009年第5期16卷 78-85页

作者： ZHANG Yang , XU Hong-kun, chang yong-yu, YANG Da-cheng, WANG Ya-feng School 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 Telecommunications Beijing 100876 China

Bi-dimensional Markov chain model based on cooperative medium access control （MAC） of wireless local area networks （WLAN） is considered to reflect system performance accurately. Two basic factors that affect the analysis results are station retry limits and non-saturated transmit probability. A uniform solution considering both factors is proposed. To prove the theoretical analysis, a cooperative MAC （CoopMAC） topology is established and the simulation model is enhanced by changing the cooperative table to the nodes＇ memory with more information added. Meanwhile, the three-way handshake scheme is modified and a handshake threshold is set based on the packet size. Simulation results show the performance analytical model is accurate, and the rate-adaptive cooperative MAC protocol significantly improves the network performance in terms of non-saturated system throughput and delay.

关键词： performance analysis cooperative MAC bi-dimensional Markov Chain non-saturated transmit station retry limit

ASP-Based Programs of Best Linear Unbiased Prediction-Estimated Breeding Values in Breeding Stock

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Animal Husbandry and Feed Science 2010年第10期2卷 4-6,16页

作者： FAN Qiang TIAN chang-yong yu Mei-zi Liaoning Agricultural College Yingkou 115009 China

In order to improve the breeding effect of livestock, the data were read from an Excel file with Active Server Page （ASP） programs, and the breeding values of breeding stock were calculated by best linear unbiased p... 详细信息

关键词： Best linear unbiased prediction Active Server Paget Excel Breeding stock Breeding value

存在反馈周期和反馈时延的自适应调制MIMO系统

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维普期刊数据库

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电子与信息学报 2007年第2期29卷 301-304页

作者：宋扬常永宇杨大成北京邮电大学电信工程学院北京100876

该文研究了反馈信道信息存在的反馈周期和时延对自适应调制MIMO系统的影响,分析了基于奇异值分解的等效并行衰落信道特性,并且给出了接收机的检测方法和一种简化的检测顺序。研究表明,等效并行衰落信道在一定的时间间隔内具有较大的相关... 详细信息

该文研究了反馈信道信息存在的反馈周期和时延对自适应调制MIMO系统的影响,分析了基于奇异值分解的等效并行衰落信道特性,并且给出了接收机的检测方法和一种简化的检测顺序。研究表明,等效并行衰落信道在一定的时间间隔内具有较大的相关性;接收机采用迫零和干扰消除方法可明显提高系统性能。

关键词： MIMO 自适碰调制反馈分配算法

无循环前缀SFBC-OFDM系统的Turbo均衡

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北京邮电大学学报 2009年第6期32卷 62-66页

作者：陈哲常永宇杨大成北京邮电大学信息与通信工程学院北京100876

为了提高传输效率,对无循环前缀(CP)的空频分组码正交频分复用(SFBC-OFDM)系统进行了研究,提出一种基于软信息反馈的Turbo均衡算法.同时提出了符号间干扰删除、软循环重构、对角化SFBC译码以及MMSE频域均衡器,通过多次迭代抑制系统中出... 详细信息

为了提高传输效率,对无循环前缀(CP)的空频分组码正交频分复用(SFBC-OFDM)系统进行了研究,提出一种基于软信息反馈的Turbo均衡算法.同时提出了符号间干扰删除、软循环重构、对角化SFBC译码以及MMSE频域均衡器,通过多次迭代抑制系统中出现的各种干扰.仿真结果表明,该算法可有效改善无CP的SFBC-OFDM的误码性能.

关键词：正交频分复用 Turbo均衡空频分组码

Massive MIMO网络中低复杂度的MMSE检测方法

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北京邮电大学学报 2016年第6期39卷 57-61页

作者：汪彬常永宇权威张戬北京邮电大学信息与通信工程学院北京100876 华为技术有限公司北京研究所北京100085

设计出大规模多入多出(massive MIMO)网络中一种有效、低复杂度的最小均方误差(MMSE)接收机结构.该接收机基于最陡下降和最小均方算法,能够避免大规模矩阵求逆运算.数学推导结果证明,这2种算法应用于MMSE检测时是收敛的.此外,分析了影... 详细信息

设计出大规模多入多出(massive MIMO)网络中一种有效、低复杂度的最小均方误差(MMSE)接收机结构.该接收机基于最陡下降和最小均方算法,能够避免大规模矩阵求逆运算.数学推导结果证明,这2种算法应用于MMSE检测时是收敛的.此外,分析了影响收敛速度的因素.仿真结果表明,应用于Massive MIMO网络中时该接收机收敛速度较快,切实可行.

关键词：大规模多入多出最小均方误差最陡下降最小均方

关于非规则LDPC码的基于度分布HARQ性能研究

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电子与信息学报 2009年第4期31卷 989-992页

作者：许成鑫常永宇杨大成北京邮电大学电信工程学院北京100876

该文提出了一种非规则LDPC码字基于度分布HARQ技术的改进方案。该方案在选择重传信息的过程中,不仅考虑了节点度分布的影响,而且考虑了非规则LDPC码字自身的不均等错误保护特性。与原始的基于度分布的HARQ方案相比,该方案使系统的误比... 详细信息

该文提出了一种非规则LDPC码字基于度分布HARQ技术的改进方案。该方案在选择重传信息的过程中,不仅考虑了节点度分布的影响,而且考虑了非规则LDPC码字自身的不均等错误保护特性。与原始的基于度分布的HARQ方案相比,该方案使系统的误比特率和吞吐量指标得到了明显改善。

关键词：非规则LDPC码 HARQ 度分布不均等错误保护