山秀明
信息网络理论与工程,复杂性科学理论及其在网络、通信、雷达中应用(混沌、微分动力系统、协同学、元胞自动机等)。
个性化签名
- 姓名:山秀明
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学术头衔:
博士生导师
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学科领域:
发酵工程
- 研究兴趣:信息网络理论与工程,复杂性科学理论及其在网络、通信、雷达中应用(混沌、微分动力系统、协同学、元胞自动机等)。
山秀明,男,1944年10月生于黑龙江省明水县。1964年9月~1970年2月,清华大学无线电电子学系无线电技术专业学习。1970年3月至今,先后在清华大学电子工程系任助教、讲师、副教授、教授、博士生导师、责任教授。1974年4月13日成为中国共产党正式党员。1974年5月起先后担任过党支部委员、支部书记、清华大学电子工程系党委副书记。现为高速信号处理与网络传输研究所所长,校分学位委员会委员,系学术委员会委员。长时间从事通信、网络、雷达等方面的科学研究。长期对本科生、研究生主讲《信号分析与处理》、《控制理论》、《复杂系统分析导论》等课。1999年,组建跨学科复杂工程系统实验室,2003年建立二级学科《信息网络与复杂系统》。2005年7月负责的《信号与系统》课被评为北京市精品课。研究方向为:信息网络理论与工程,复杂性科学理论及其在网络、通信、雷达中应用(混沌、微分动力系统、协同学、元胞自动机等)。著《航管二次雷达》,合译《统计信号处理及应用导论》。近五年来负责或指导自然科学基金、985项目、国防基金等项目研究十余项,另外策划并参研面向企业的合作项目十余项。35年来,参加过50余项科研工作,获发明专利一项,获省部委科技进步奖多项,清华校内各种奖励10余项。2000年以来,发表文章150余篇。
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532
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成果数
10
【期刊论文】Effect of carrier frequency offset on performance of BLAST-OFDMM systems
山秀明, Liang Wang, Yong Ren and Xiuming Shan
ELECTRONICS LETTERS 4th July 2002 Vol. 38 No.14,-0001,():
-1年11月30日
The effect of carnier frequency offset on the perfomance of BLAST-OFDM systems is presented. Analysis shows that system performance degrades as frequency offiset and channel state information estimation interval increase. Numerical simulations confim this conclusion A pilot channel is recommended for synchronisation and phase-shift adjustment.
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山秀明, 李旲, , 刘旸, 任勇, 焦健, 仇贲
,-0001,():
-1年11月30日
因特网具有复杂的网络拓扑结构,已有的研究发现这种拓扑结构非常有利于病毒的传播。本文采用理论分析和计算机模拟相结合的手段分析了有限规模网络上病毒传播模型的动力学性质。研究表明SIS病毒传播模型在有限规模网络上传播是一个有限状态的马尔科夫过程,病毒传播存在一个瞬时稳态,并分析了瞬时稳态下感染节点密度和存活概率的变化规律。这些结果有助于理解计算机病毒在因特网上传播的现象,并可以为免疫策略的研究提供了一定理论上的帮助
epidemic spreading,, complex networks,, SIS model
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【期刊论文】DRIVING SYNCHRONIZATION OF SPATIOTEMPORAL CHAOS AND ITS APPLICATIONS IN CDMA COMMUNICATIONS
山秀明, REN YONG, XIA YONGXIANG*, SHAN XIUMING and YUAN JIAN
International Journal of Bifurcation and Chaos, Vol. 11, No.12(2001)3117-3124,-0001,():
-1年11月30日
This paper investigates the driving synchronization of spatiotemporal chaos. Using this method, synchronization could be achieved e ciently. By improving the driving sequence generation method, the spatial periodicity in the original system is overcome. Large quantities of chaotic sequences are available, which possess the excellent properties expected in Code Division Multiple Access (CDMA) communications. These chaotic sequences can be used as the spreading sequences in place of the traditional pseudo-noise sequences. We also evaluate the performance of the chaotic CDMA communication systems and compute the average bit error rate caused by the multi-user interference and the noise in the channel. The theoretical and simulation results show the excellent performance of the scheme.
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【期刊论文】Design of a fuzzy controller for active queue management
山秀明, Ren Fengyuan*, Ren Yong, Shan Xiuming
Computer Communications 25(2002)874-883,-0001,():
-1年11月30日
As an effective mechamism acting on the intermediate nodes to support end to end congestion control, active queue management (AQM) takes a trade off between link utilization and delay experienced by data packets. From the point of view of the control theory, it is rational to regard AQM as a typical regulating system. Although proportional integral (PI) controller for AQM outperforms traditional RED algoritlnn, the mismatches in simplified TCP flow modal inevitably degrades the perfomance because the design of PI controller is heavily dependent of the accuracy of the plant, such as, for small buffer the system tends to perform poorly, in this paper, the fuzzy logic controller (FLC) for AQM is designed based on the fuzzy logical control, its superiority is independent of the modal of the plant, which is very suitable to the high variability and uncertainty networks. We present the guidelines and highlights to design the parameters of the FLC. We then compare its performance with the PI controller through sinulations, and investigate the impact of the network configuration and operating parameters on the stability and responsibility. The results show that the FLC is rather robust against the noise and disturbace caused by the round trip time, the llink capacity, the number of the active flows and the non responsive UDP flows, etc., which badly degrade the performance of the PI controller. The transient response and tracldng capability of the FLC is superior to that of the PI controller, which is beneficial to achieve the goals of AQM scheme.
(, AQM), , Congestion Control, Flow Control, Fuzzy Logic Control
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【期刊论文】Cross-Layer Design Improves TCP Performance in Multihop Ad Hoc Networks
山秀明, Yongkang XIAO†a). Xiuming SHAN†‡, Nonmebers, and Yong REN†‡, Member
IEICE TRANS. COMMUN., VOL. E88-B, NO.8 AUGUST 2005,-0001,():
-1年11月30日
TCP performance in the IEEE 802.1-based multihop ad hoc networks is extremely poor, because the congestion conrtol mechanism of TCP cannot effectively deal with te problem of packet drops caused by mobility and shared channel contention among wireless nodes. In this paper, we present a cross-layer method, which adaptively adjusts the TCP maximum window size according to the number of RTS (Request To Send) retry counts of the MAC layer at the TCP sender, to control the number of TCP packets in the network and thus decrease the channel contention. Our simulation results show that this mehod can remarkably improve TCP throughput and its stability.
multihop ad hoc networks,, IEEE 802., 11 MAC protocol,, TCP,, congestion conrtol mechanism cross-laver dsion
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【期刊论文】Blind Frequency Offset Correction Algorithm for DWMT System
山秀明, Yang Cao, Yong Ren and Xiuming Shan
,-0001,():
-1年11月30日
Abstract-Discrete Wavelet Multi-carrier Transceiver (DWMT) system, which can be viewed as a kind of OFDM, has many advantages because it uses wavelet as its base functions. In this paper we present a new sub-carrier frequency synchronize method for DWMT systems with little assistant information. The essential ideal of this arithmetic is: when an orthogonal multi-carrier system is of perfect frequency synchronize, the demodulated signals of different sub-carriers are independent of each other. Whereas when frequency offset exists, every demodulated signal is constructed by several modulated signals' projects on the demodulating frequency. So the adjacent demodulated signals consist of the element of the same modulated signal, and these demodulated signals are correlated with each other. The degree what they correlated with each other is a function of the sub-carrier relative frequency offset. Since that little assistant information is used in this algorithm, the spectrum efficiency can be largely increased. Simulation result show that if the number of the sub-carrier of the DWMT system is bigger than 1000, the relative frequency offset can be limited in 2%.
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【期刊论文】An Efficient Decoding Algorithm for Low-Density Parity-Check Codes
山秀明, Yang CAO†a), Xiuming SHAN†, Nonmembers, and Yong REN†, Regular Membe
IEICE TRANS. FUNDAMENTALS, VOL. E85-A, NO.1 JANUARY 2002,-0001,():
-1年11月30日
We present a simple decoding algorithm that modifies soft bit-flipping algorithm for decoding LDPC codes. In our method, a new parameter is explored to distinguish the variables (symbols) belonging to the same number of unsatisfied constraints. A token is also assigned in the method to avoid repeated flipping of the same variable, rather than using a constant taboo length. Our scheme shows a similar computational load as the taboo-based algorithm, while having a similar decoding performance as the belief propagation algorithm.
LDPC codes,, iterative decoding,, bit-flipping,, belief propagation and bipartite graph.,
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山秀明, Liang WANG†, Xiuming SHAN†, Nonmembers, and Yong REN†, Regular Member
IEICE TRANS. COMMUN., VOL. E86-B, NO.8 AUGUST 2003,-0001,():
-1年11月30日
Carrier frequency and symbol timing errors may greatly degrade the performance of the orthogonal frequency division mulitplexing (OFDM) system, especially in multipath environment, In this paper, wer explore the cyclostationarity of OFDM signals, which only relies on second order statistics, to estimated the synchronization offset, First, a coarse carrier fre-quency offset estimator for multipath environment is developed using the second order statistics of the received OFDM signal. It has a wide capture range though not accurated. Second, we intoduce a new synchronization algorithm based on cyclosta-tionarity and matched filter theories, which can get the macimal estimation SNR in multipath environment, Both estimators uti-lize channel stte information to achieve better estimation per-formanc and are non-pilot aided. They can be combined to form a whole OFDM synchronizer for multipath environment.Finally, simulations confirm the performance of the estimation algorithm.
orthogonal frequency division multiplixing (, OPDM), ,, cyclostationarity,, synchronization,, multipath channel
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【期刊论文】A New Approach for Evaluating Clipping Distortion in DS-CDMA Systems
山秀明, Jian WANG†a), Xiuming SHAN, Nonmembers, and Yong RENy, Member
IEICE TRANS. COMMUN., VOL.E88-B, NO.2 FEBRUARY 2005,-0001,():
-1年11月30日
A new theoretical approach for the evaluation of the in-band nonlinear distortione ects on the performance of DS-CDMA systems is presented. Rather than widely used models of treating the e ects of nonlinear distortion as additive Gaussian noise, the new approach is based on the asymptotic clipping and shot noise theories, which o er important insights into true nature of clipping process and can be further extended to many communications systems with high PAPR and peak-limited nonlinearities.
DS-CDMA,, nonlinearities,, impulse noise
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【期刊论文】A linear feedback synchronization theorem for a class of chaotic systems
山秀明, Feng Liu a, *, Yong Ren a, Xiuming Shan a, Zulian Qiu b
F. Liu et al. Chaos, Solitons and Fractals 13 (2002) 723-730,-0001,():
-1年11月30日
A new synchronization theorem for a class of chaotic systems is presented in this paper. We take the last state variable of drive system as the driving scalar signal. Its linear feedback gain is a function of a free parameter. It is also proved that the global syn-chronization can be attained through simple linear output error feedback. This approach is illustrated by Chua's circuit and a 4D hyperchaotic system.
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