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A class of discounted models for singular diffusion control

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Chinese science Bulletin 2000年第5期45卷 405-408页

作者： LIU Kunhui, QIN Mingda & LU Chuanlai1. College of sciences, Northern Jiaotong university, beijing 10004., China 2. Department of Mathematics and Mechanics, beijing university of science and Technology, beijing 100083 .China 3. Department of Information Engineering, beijing university of posts and telecommunications, beijing 100876, China Correspondence should be addressed to Lu Chuanlai College of sciences Northern Jiaotong University Beijing China Department of Mathematics and Mechanics Beijing University of Science and Technology Beijing China Department of Information Engineering Beijing University of Posts and Telecommunications Beijing China

A kind of discounted problems for singular diffusion control have been studied. The drift and diffusion coefficients of state process are nonlinear. The class of models has been basically extended from a corresponding one established by Karatzes et al. before. By applying some analysis methods different from earlier works, the sufficient and necessary conditions of the existence of optimal control have been obtained. If an optimal control exists, it is a 'transient reflection' of state process for two lines.

关键词： stochastic control variational equation singular stochastic control.

A novel adaptive spectrum forming filter:Application in cognitive ultra-wideband

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science China(Information sciences) 2010年第12期53卷 2584-2599页

作者： LI Bin ,ZHOU Zheng & ZOU WeiXia Key Lab of Universal Wireless Communications,MOE.Wireless Network Lab,beijing university of posts and telecommunications,beijing 100876,China 1. Key Lab of Universal Wireless Communications MOE. Wireless Network Lab Beijing University of Posts and Telecommunications Beijing 100876 China

Ultra wideband impulse radio(UWB-IR) has important applications in high data rate communications,high precision positioning and penetrating target *** with cognitive radio(CR),UWB can also greatly alleviate the current spectrum ***,the existing UWB waveforms are faced with two *** spectrum utilization of UWB signal is rather low,which reduces the communication ***,it appears difficult for UWB-IR to avoid spectrum collision with other incumbent *** UWB will inevitably interfere other legal wireless *** by these considerations,we model the UWB waveform design into an interpolation *** on radial basis function neural network,a novel UWB pulse is presented in this *** UWB pulse is then realized though reasonable simplification on the already proposed theoretical *** designed UWB pulses can adaptively track the external spectral environment where UWB devices work and reconfigure its emission spectrum according to the state of primer users without any modification on *** frequency utilization is maximized when there is no active primary *** adequate spectrum avoidance has also been achieved without much spectrum utilization degradation within the non-primary *** and analysis show that our UWB-IR pulse is much superior to the other existing UWB signals in the frequency utilization,spectrum avoidance and in the transmission performance.

关键词： UWB-IR cognitive radio pulse design RBF network spectrum efficiency spectrum avoidance

An improved dynamic user equipment power saving mechanism for LTE system and performance analysis

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science China(Information sciences) 2010年第10期53卷 2075-2086页

作者： XU HaiBo, TIAN Hui , HUANG Bo & ZHANG Ping Key Laboratory of Universal Wireless Communications, Ministry of Education beijing university of posts and telecommunications, beijing 100876, China 1. Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In order to minimize the power consumption of user equipments (UEs), and further to support various services and transmissions of large amount of data, the power saving mechanisms have been investigated for most remarkable wireless systems. In this paper, an improved dynamic discontinuous reception (D-DRX) scheme is presented for LTE system, which is able to adaptively adjust the inactivity timer and the sleep period of UEs’ receivers. Moreover, theoretical analysis based on the Markov chain is provided for the D-DRX scheme. Several numerical examples quantitatively show that the D-DRX scheme can capture various packet arrival patterns and scheduling behaviors of system to make a better tradeoff between power saving and packet delay by considering the length of packet queue.

关键词： power saving DRX Markov chain LTE-advanced

Subsection-filtering method applied in optoelectronic signal processing of the liquid drop analyzer

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Subsection-filtering method applied in optoelectronic signal...

Performance Analysis of Channel Assignment with Prioritized Handoff Procedures in GSM

2010 International Conference on Display and Photonics

作者： HUANG Jia-yong SONG Qing WU Di LIU Jing ZHANG Chun-song Automation school beijing university of posts and telecommunications beijing 100876 China beijing Univ. of posts and telecommunications (China)

ISBN: (纸本)9780819482402

Liquid drop fingerprint can be obtained through fiber-capacitive drop analysis technology as the fiber signal changes with the drop volume which can be represented by the capacitive signal during the drop ***,if the fiber or capacitive signals are filtered by the normal low-pass filter method,the fingerprint would be distorted because of the capacitive signal’s saw-tooth style and fiber signal’s periodically abrupt *** the paper the subsection-filtering method is explored and analyzed,in which firstly separates the signals according to drop growth period and then filters every subsection *** improves that it is an effective way to solve the signal distortion problem, which usually happens when filters the fiber or capacitive signal during the signal mutation period.

关键词： Fiber-capacitive drop analysis liquid drop fingerprint subsection filter zero-phase filter signal mutation

来源： cnki会议评论

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The Journal of China Universities of posts and telecommunications 2001年第2期8卷 45-50页

作者： WANG Xiao xia, XIN Zhan hong (school of Business, beijing university of posts and telecommunications, beijing 100876, P.R.China) school of Business Beijing University of Posts and Telecommunications

A mathematical model of channel assignment with prioritized handoff procedures is given according to the physical handoff process in GSM networks with some reasonable simplifications and assumptions, and a numerical calculation is applied to the model. A simulation model is established to verify the results of the mathematical model. The results show that the overall loss probability is increased with the number of channel reservation increasing, although the probability of forced termination can be reduced. Therefore, three queuing schemes are proposed: (1) queuing for handoff calls without channel reservation, and the queuing rule is “First come, first served”; (2) queuing for handoff calls without channel reservation, and the queuing rule is “First come to the threshold, first served”; (3) queuing for new calls with one channel reserved for handoff calls. Simulations are also made for the three queuing schemes, the results indicate that the third one is the best, and it is also easy to realize. The optimal queuing length and the maximum waiting time are suggested for the third scheme.

关键词： performance analysis queuing system teletraffic theory GSM handoff channel reservation

RPPK modulation with high data rates

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science China(Information sciences) 2010年第2期53卷 344-354页

作者： LI Bin , ZHOU Zheng & ZOU WeiXia Key Laboratory of Universal Wireless Communications, Ministry of Education Wireless Network Laboratory, beijing university of posts and telecommunications, beijing 100876, China 1. Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China2. Wireless Network Laboratory Beijing University of Posts and Telecommunications Beijing 100876 China

With the development of communication technology, the precious frequency spectrum is becoming more and more crowded. Exploiting the particular filter with zero group delay, ultra narrow band (UNB) modulation is intended for acquiring the high frequency efficiency. Unfortunately, this UNB filter is confronted with great challenges from the classical communication theories. The validation on its realization is also difficult. This paper proposes a novel UNB modulation, namely random pulse position keying (RPPK). It is demonstrated from analysis that there is no inessential discrete spectral line in modulated signal’s power density spectrum (PDS), and the UNB filter has been successfully avoided. Consequently, RPPK is rather explicit in theory and simple in implementation. As is shown by the simulation, the frequency utilization of RPPK can even reach 100 bits/s/Hz. Its optimum receiving performance is slightly inferior to BPSK, yet is much superior to that of other UNB modulations such as VMSK/2. Moreover, multi-access and confidentiality are additional benefits to UNB users.

关键词： UNB modulation frequency utilization efficiency RPPK PDS

Fast Implementation of MSSNR TEQ for DMT Systems

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The Journal of China Universities of posts and telecommunications 2003年第4期10卷 65-70页

作者： DING Jia-xin,ZHOU Zheng(school of Telecommunication Engineering, beijing university of posts and telecommunications, beijing 100876, P.R. China) school of Telecommunication Engineering Beijing University of Posts and Telecommunications 北京 100876

The major approaches to the Time-Domain Equalizer (TEQ) design in DMT systemsare summarized. After pointing out that the optimal design method of Maximum ShorteningSignal-to-Noise Ration (MSSNR) TEQ can't be real-time implemented by DSP, we present a suboptimalMSSNR TEQ design method, which reduces the computational complexity greatly by using a new method toestimate the optimal delay Δ and a proposed step-by-step algorithm to compute the TEQ taps. Theresults of simulations show the validity of the suboptimal method.

关键词： discrete multitone modulation time-domain equalizer shortening SNR optimaldelay

A Certain Kind of Non-Degenerate Solvable Lie Algebra on C

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The Journal of China Universities of posts and telecommunications 1998年第2期5卷 60-64页

作者： Mo Jiao (Department of Basic science. beijing university of posts and telecommunications, beijing, 100876, P. R. China)

This paper deals with the non-degenerate solvable Lie algebra. They are divided into the direct sum of root subspaces under certain conditions. Some properties of these subspaces are shown in this paper.

关键词： ideal direct sum root subspace

Analysis and experimentation of key technologies in service-oriented optical internet

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science China(Information sciences) 2011年第2期54卷 215-226页

作者： JI YueFeng, REN DanPing, LI Hui, LIU XueJun & WANG ZhengZhong Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, beijing university of posts and telecommunications, beijing 100876, China 1. Key Laboratory of Information Photonics and Optical Communications Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

To satisfy diverse bandwidth-intensive applications envisioned in the internet of the future, research on a distributed optical internet, enabling efficient utilization of geographically distributed resources, has become attractive. The deployment of such a network, however, has its own technical challenges, including network architecture, resource management, and high-speed transmission. To address these issues, a service-oriented-architecture-based distributed optical internet architecture is proposed. Thereafter, key technologies of an optical internet, such as optical multicasting, distributed resource control, and high-speed transmission, are analyzed and investigated. The proposed schemes are verified through experimentation and simulation.

关键词： optical internet service-oriented distributed optical networks optical multicasting optical transmission