检索结果-内蒙古大学图书馆

IEEE International Symposium on Information Theory

作者： Hanxu Hou Kenneth W. Shum Minghua Chen Hui Li Peking University Beijing Beijing CN Institute of Network Coding Chinese University of Hong Kong Hong Kong China Department of Information Engineering Chinese University of Hong Kong Hong Kong China Shenzhen Engineering Laboratory of Converged Networks Technology Shenzhen Key Laboratory of Cloud Computing Technology and App. Shenzhen Graduate School Peking University Shenzhen China

ISBN: (纸本)9781479904440

Regenerating code is a class of storage codes that achieve the optimal trade-off between storage capacity and repair bandwidth, which are two important performance metrics in data storage systems. However, existing constructions of regenerating codes rely on expensive computational operations such as finite field multiplication. The high coding and repair complexity limit their applications in large-scale practical storage systems. In this paper, we show that it is possible to achieve the full potential of regenerating codes with low computational complexity. In particular, we propose a new class of regenerating codes, called BASIC codes, that can achieve two specific points (i.e., minimum-bandwidth and minimum-storage regenerating points) on the storage and repair bandwidth trade-off curve, using only binary addition and shift operations in the coding and repair processes. Although in this paper we focus on constructing and analyzing BASIC codes for two specific exact-repair settings, our framework can be generalized to develop BASIC codes for more general exact- and functional-repair regenerating codes.

关键词： Maintenance engineering Encoding Polynomials Vectors Symmetric matrices Bandwidth Computational complexity

来源：评论

学校读者我要写书评

暂无评论

A POMDP-based optimal spectrum sensing and access scheme for cognitive radio networks with hardware limitation

A POMDP-based optimal spectrum sensing and access scheme for...

引用

IEEE Conference on Wireless Communications and networking

作者： Lingcen Wu Wei Wang Zhaoyang Zhang Department of Information Science and Electronic Engineering Zhejiang Provincial Key Laboratory of Information Network Technology University of Zhejiang Hangzhou China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China

In cognitive radio networks, multiple discontinuous spectrum opportunities are detected by spectrum sensing and utilized together to satisfy the service requirement by spectrum aggregation. In this paper, we develop an analytical framework for joint spectrum sensing and access scheme based on Partially Observable Markov Decision Process (POMDP). Considering the hardware limitations, the spectrum aggregation range is restricted and only a part of channels can be sensed. For obtaining the reward function of POMDP, the channel switch probability is estimated by theoretic deduction. Under this POMDP framework, an optimal spectrum sensing and access scheme is proposed to minimize the channel switch times. Simulation results show that our proposed optimal scheme reduces the times of channel switches significantly.

关键词： Sensors Switches Vectors Probability Bandwidth Joints Markov processes

来源：评论

学校读者我要写书评

暂无评论

Chosen Ciphertext Secure Identity-Based Broadcast Encryption in the Standard Model

引用

Journal of Shanghai Jiaotong university(Science) 2011年第6期16卷 672-676页

作者：孙瑾胡予濮张乐友 Key Laboratory of Computer Network and Information Security Xidian University Department of Application Mathematics Xi'an University of Technology

To give concurrent consideration both the efficiency and the security(intensity of intractable problem) in the standard model,a chosen ciphertext secure identity-based broadcast encryption is *** the chosen ciphertext security model,by using identity(ID) sequence and adding additional information in ciphertext,the self-adaptive chosen identity security(the full security) and the chosen ciphertext security are gained *** reduction of scheme's security is the decisional bilinear Diffie-Hellman(BDH) intractable assumption,and the proof of security shows that the proposed scheme is indistinguishable against adaptive chosen ciphertext attacks in the standard model under the decisional BDH intractable *** the security level is improved,and it is suitable for higher security environment.

关键词： the standard model provably secure broadcast encryption the chosen ciphertext security the self-adaptive chosen identity security

来源：评论

学校读者我要写书评

暂无评论

A primary traffic aware opportunistic spectrum sensing for cognitive radio networks

A primary traffic aware opportunistic spectrum sensing for c...

引用

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Fan Zhang Wei Wang Zhaoyang Zhang Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Hong Kong China Department of Information Science and Electronic Engineering Zhejiang Provincial Key Laboratory of Information Network Technology University of Zhejiang Hangzhou China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China

ISBN: (纸本)9781457713460

Spectrum sensing is adopted to detect the presence of primary users in cognitive radio networks. Considering the sensing overhead, it is not always a good choice that the secondary user senses the channel all the time. In this paper, we propose an opportunistic spectrum sensing decision method according to the primary user's traffic. First, the traffic of primary user is observed and estimated. For estimating the parameters of the primary traffic, the Maximum Likelihood estimation is adopted and the confidence interval is calculated based on finite observed samples. Then, according to the estimated primary traffic information, a decision criterion is proposed for determining whether to sense the channel. The simulation results show that the performance of the proposed opportunistic sensing scheme is much better than that when sensing at every timeslots and very close to that in the ideal case in which the primary traffic information is obtained perfectly.

关键词： Sensors Maximum likelihood estimation Channel estimation Cognitive radio Wireless sensor networks Educational institutions Parameter estimation

来源：评论

学校读者我要写书评

暂无评论

NPS: Non-periodic sensing for opportunistic spectrum access

NPS: Non-periodic sensing for opportunistic spectrum access

引用

2010 International Conference on Wireless Communications and Signal Processing, WCSP 2010

作者： Zhang, Ning Wang, Wei Zhang, Zhaoyang Department of Information Science and Electronic Engineering Key Laboratory of Integrate Information Network Technology Zhejiang University Hangzhou 310027 China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu 610031 China

ISBN: (纸本)9781424475551

One of the most challenging issues in cognitive radio networks is when and how often to sense the availability of licensed spectrum. Adopting the fixed sensing period to detect signals, the conventional periodic spectrum sensing method is inefficient or even not able to satisfy the various demands of secondary users. In this paper, we propose a non-periodic sensing (NPS) mechanism, which reduces the sensing overhead based on the users' data rate requirement and the spectrum availability statistics. Based on the theoretic framework of NPS, we propose three specific NPS methods-Demand-oriented method, Max-oriented method and Mix method-to schedule the spectrum sensing adaptively. The simulation results shows the improvement on the sensing efficiency compared with the periodic sensing approach. ©2010 IEEE.

关键词： Cognitive radio

来源：评论

学校读者我要写书评

暂无评论

Optimal resource allocation for cognitive radio networks with imperfect spectrum sensing

Optimal resource allocation for cognitive radio networks wit...

引用

2010 IEEE 71st Vehicular technology Conference, VTC 2010-Spring

作者： Wu, Kejian Wang, Wei Luo, Haiyan Yu, Guanding Zhang, Zhaoyang Department of Information Science and Electronic Engineering Key Laboratory of Integrate Information Network Technology Zhejiang University Hangzhou310027 China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu610031 China

In this paper, an optimal resource allocation scheme is proposed for multi-user multi-channel cognitive radio networks under imperfect spectrum sensing. The channel dynamic model and the sensing errors are considered together to derive the metric of mean delay for each user-channel combination based on the vacation queueing model. Finally, the optimal resource allocation is determined according to the average system delay by bipartite graph matching. The simulation results indicate that the proposed mean delay metric can represent the transmission performance successfully. © 2010 IEEE.

关键词： Queueing theory

来源：评论

学校读者我要写书评

暂无评论

Performance test of network simulation based on split-object model

Performance test of network simulation based on split-object...

引用

International Forum on Information technology and applications

作者： Wu, Ping Wu, Bin Dept. Network Management Center Yunnan Academy of Scientific and Technical Information Kunming 650051 China Computer Technology Application Key Laboratory Kunming University of Science and Technology Kunming 650051 China

ISBN: (纸本)9780769541150

The network simulation (NS) is an important issue in the study of network technology. However, The error between the network performance simulation on split-object model and the true network environment is considerable apparent. In order to obtain the NS result approaching the reality, in this paper, we analyze the structure of split-object mode and find reasons to cause the error. According to the definition of NS performance's index, we remodel the split-object model by choosing the proper function and equation in the control theory and deducing the logical coefficent in them. We further evaluate the efficiency and the availability of the new model under NS-2 platform. The results show that the new mode is more suitable for network simulation with higher accuracy. © 2010 IEEE.

关键词： mathematical analysis network simulation performance test split-object model network analog Performance Tests mathematical analysis Control Theory object information model networking Techniques

来源：评论

学校读者我要写书评

暂无评论

NPS: Non-periodic sensing for opportunistic spectrum access

NPS: Non-periodic sensing for opportunistic spectrum access

引用

International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Ning Zhang Wei Wang Zhaoyang Zhang Department of Information Science and Electronic Engineering Key Laboratory of Integrate Information Network Technology University of Zhejiang Hangzhou China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China

关键词： Sensors Cognitive radio Schedules Simulation Laboratories Availability

来源：评论

学校读者我要写书评

暂无评论

Prediction-Based Spectrum Aggregation with Hardware Limitation in Cognitive Radio networks

Prediction-Based Spectrum Aggregation with Hardware Limitati...

引用

IEEE Conference on Vehicular technology (VTC)

作者： Furong Huang Wei Wang Haiyan Luo Guanding Yu Zhaoyang Zhang Department of Information Science and Electronic Engineering Key Laboratory of Integrate Information Network Technology University of Zhejiang Hangzhou China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China

In cognitive radio networks, multiple spectrum opportunities can be used together to satisfy the service requirement by spectrum aggregation. In this paper, an admission control algorithm and a spectrum assignment strategy are proposed in order for both increasing the spectrum aggregation aware access capacity and decreasing the channel switch times when the channel states change. Considering different bandwidth requirement of secondary users, the proposed greedy admission algorithm takes limited aggregation capability into account. The channel switch times of secondary users at sensing moments is minimized based on the prediction of primary activities and the corresponding channel state transitions. The concept of outage probability is introduced into the scheme to indicate the probability of channel switch. The numerical results show the performance improvement of the proposed algorithms.

关键词： Hardware Cognitive radio Switches Bandwidth Chromium Admission control Laboratories Frequency Availability Information science

来源：评论

学校读者我要写书评

暂无评论

Optimal Resource Allocation for Cognitive Radio networks with Imperfect Spectrum Sensing

Optimal Resource Allocation for Cognitive Radio Networks wit...

引用

IEEE Conference on Vehicular technology (VTC)

作者： Kejian Wu Wei Wang Haiyan Luo Guanding Yu Zhaoyang Zhang Department of Information Science and Electronic Engineering Key Laboratory of Integrate Information Network Technology University of Zhejiang Hangzhou China Key Laboratory of Information Coding and Transmission Southwest Jiaotong University Chengdu China

关键词： Resource management Cognitive radio Laboratories Delay estimation Bipartite graph Availability Measurement Switches Information science Computer errors

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：