检索结果-南通市图书馆

Extended Mapping Transformation Method and Its Applications to Nonlinear Partial Differential Equation（s）

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第3X期44卷 473-478页

作者： zhao Hong BAI cheng-lin Physics Science and Information Engineering School Liaocheng University Liaocheng 252059 China

In this paper, we extend the mapping transformation method through introducing variable *** means of the extended mapping transformation method, many explicit and exact general solutions with arbitrary functions for some nonlinear partial differential equations, which contain solitary wave solutions, trigonometric function solutions, and rational solutions, are obtained.

关键词： nonlinear partial differential equations extended mapping transformation method exact solutions

Precoding with interference suppression sequence scheme for OFDM-based cognitive radio systems

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 59-64页

作者： zhao cheng-lin ZHANG Kun SUN Xue-bin JIANG Ting Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

Orthogonal frequency division multiplexing （OFDM） is considered to be one of the promising schemes for cognitive radios （CR） systems, due to its flexibility in spectrum shaping. However, the traditional way of spectrum-notching failed to suppress out-of-band leakage enough, resulting in interference with licensed users （LUs）. A novel spectrum shaping scheme is proposed in this article, where a precoder with interference suppression sequence （ISS） is for the first time introduced for shaping the spectrum of OFDM signals in OFDM-based CR systems. The precoder matrix together with ISS matrix is obtained by minimizing the power of out-of-band interference, which results in the sufficient interference suppression of OFDM signal to LUs Analysis and simulation results show that the proposed scheme can significantly suppress the interference power to LUs at a little cost of precoding efficiency. Meanwhile, the peak-to-average-power-ratio （PAPR） is invariable and the bit-error-rate （BER） performance over Rayleigh fading channel is improved.

关键词： OFDM cognitive radio precoding spectrum shaping

Study on coexistence between DCS1800 and TDD-LTE systems in multi-mode terminals

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2014年第6期21卷 24-29页

作者： ZHENG Zhi-hui zhao cheng-lin Li Bin TAO Hong-bo School of Telecommunication Engineering Beijing University of Posts and Telecommunications The State Radio Monitoring Center Testing Center

It＇s well known that the mobile stations will comprise a wide range of radio access technologies（RAT）, providing user with flexible and efficient access to multi-media service and high data rate communications. Although much work has been done for coexistence analysis between different systems base stations（BS）, most of them have not addressed the interference within multi-mode terminal. Hence, for filling the gap, The authors in the article present coexistence studyies of digital cellular system at 1 800 MHz（DCS1800） and time division duplex long term evolution（TDD-LTE） network in multi-mode terminal with multi-service provisioning. A new system model for coexistence was introduced and how deterministic analysis can be done within the terminal was explained. The interference evaluation model was given based on relations between reference sensitivity and signal-to-noise ratio（SNR）, which is also deduced. The system simulation methodology was provided and assumption used in simulation was given. Simulation results were shown with different system parameters. Numeric results indicate that multi-mode terminal is mainly affected by local interference. The minimum antenna isolation required for a health system operation was provided.

关键词： TDD-LTE systems coexistence analysis multi-mode terminal deterministic analysis sensitivity degradation

Deepen spectrum notch and reduce PAPR in OFDM systems via combining subcarriers precoding with tone reservation

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2011年第3期18卷 80-84页

作者： zhao cheng-lin LIU De-qiang SUN Xue-bin JIANG Ting School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In orthogonal frequency division multiplexing （OFDM） systems, spectrum notch can be generated to mitigate interference to other narrow-band services by turning off corresponding subcarriers. However, the inter-carrier interference may limit considerably the produced notch depth. Another problem in OFDM is the high peak-to-average power ratio （PAPR）. In this paper, a technique combining subcarriers precoding with tone reservation is proposed to deepen spectrum notch and simultaneously reduce peak-to-average power ratio. Simulation results show that this presented joint algorithm can produce satisfied results to solve these problems at the expense of a moderate loss in bit error rate （BER） performance.

关键词： OFDM, spectrum notch, PAPP subcarriers precoding, tone reservation

Abundant Multisoliton Structure of(3+1)-Dimensional Breaking Soliton Equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2004年第10期42卷 561-564页

作者： zhao Hong BAI cheng-lin Department of Communication Engineering,Liaocheng University,Liaocheng 252059,China Department of Communication Engineering Liaocheng University Liaocheng 252059 China

Using the extended homogeneous balance method,we obtained abundant exact solution structures of th-dimensional breaking soliton *** means of the leading order term analysis,the nonlinear transformationof the(3+1)-dimensional breaking soliton equation are given first,and then some special types of single solitary wawsolutions and the multisoliton solutions are constructed.

关键词： extended homogeneous balance method breaking soliton equation soliton solutions

Performance analysis of 3G systems in presence of UWB interference

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2011年第2期18卷 120-124页

作者： SUN Xue-bin GAO Ming-liang ZHOU Zheng zhao cheng-lin LIU Wei School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China China Mobile Research Institute (China) Beijing 100053 China

In this paper,the impact of the interference from multiple ultra wideband（UWB） transmitters to a 3rd-generation（3G） terminal is evaluated under UWB emission power limit regulations of federal communications commission（FCC）,european telecommunications standards institute（ETSI） and Japan respectively.A three-dimensional interference model is presented where a discrete spatial distribution of UWB transmitters is *** is assumed that a mobile terminal and a large number of UWB devices exist in one room simultaneously.A parameter which characterizes the link budget degradation at the victim receiver is defined to measure the UWB interference to 3G *** maximum acceptable density of UWB transmitters and the minimum acceptable distance between UWB transmitters and the 3G terminal are analyzed under different link budget *** simulation results demonstrate that the performance of time division-synchronous code division multiple access（TD-SCDMA） is the best,the one of code division multiple access 2000（CDMA2000） is the worst and the one of wideband code division multiple access（WCDMA） lies between them in presence of UWB interference.

关键词： UWB TD-SCDMA CDMA2000 WCDMA interference

EMPIRICAL LIKELIHOOD RATIO CONFIDENCE INTERVALS FOR VARIOUS DIFFERENCES OF TWO POPULATIONS

在线全文

学校读者我要写书评

暂无评论

Systems Science and Mathematical Sciences 2000年第1期13卷 23-30页

作者： QIN Yong song zhao lin cheng (Department of Statistics and Finance, University of Science and Technology of China, Hefei 230026, China) 中国科学技术大学统计与金融系安徽合肥 230026 中国科学技术大学统计与金融系安徽合肥

******etriccontexts.O...II--31hasintroducedempiricallikelihoodratiostatistics... 详细信息

******etriccontexts.O...II--31hasintroducedempiricallikelihoodratiostatistics...

关键词： Empirical likelihood semi-empirical likelihood hypotheses tests Wilks’ theorem.

在线全文

学校读者我要写书评

暂无评论

奇异系统的不定号二次型指标最优控制问题

自动化学报 2006年第2期32卷 271-278页

作者：马树萍程兆林山东大学数学与系统科学学院济南250100

讨论奇异系统的不定号LQ问题(二次型指标中的权矩阵含有负特征值的最优控制问题)．首先指出问题的可解性,并给出了问题等价转化为奇异系统的奇异LQ问题的充要条件．然后基于等价的奇异系统奇异LQ问题,给出问题存在唯一最优控制-轨线对... 详细信息

讨论奇异系统的不定号LQ问题(二次型指标中的权矩阵含有负特征值的最优控制问题)．首先指出问题的可解性,并给出了问题等价转化为奇异系统的奇异LQ问题的充要条件．然后基于等价的奇异系统奇异LQ问题,给出问题存在唯一最优控制-轨线对的充分条件．最后用一个算例说明结论的正确性．

关键词：不定号二次型指标最优控制奇异系统

在线全文

学校读者我要写书评

暂无评论

时滞相关型离散时变时滞奇异系统的鲁棒镇定

控制与决策 2006年第5期21卷 536-540页

作者：马树萍程兆林山东大学数学与系统科学学院济南250100

讨论含参数不确定的离散时变时滞奇异系统的时滞相关的鲁棒状态反馈稳定化问题.在一系列等价变换下,阐述了其和一个不确定正常线性离散时变时滞系统的鲁棒状态反馈稳定化问题的等价关系;利用矩阵不等式方法,给出一个对所有容许的不确定... 详细信息

讨论含参数不确定的离散时变时滞奇异系统的时滞相关的鲁棒状态反馈稳定化问题.在一系列等价变换下,阐述了其和一个不确定正常线性离散时变时滞系统的鲁棒状态反馈稳定化问题的等价关系;利用矩阵不等式方法,给出一个对所有容许的不确定,使得闭环系统正则、因果且稳定的时滞相关鲁棒状态反馈稳定化控制器存在的充分条件以及无记忆状态反馈控制器的一个解.

关键词：离散奇异系统时变时滞时滞相关不确定性鲁棒稳定化