检索结果-内蒙古大学图书馆

A novel channel estimation method for clipped OFDM systems based on virtual pilots

Journal of Computational Information Systems 2012年第5期8卷 1905-1912页

作者： Xie, Yongsheng Zhou, Leilei Fu, Yaoxian Key Lab. of Wireless Sensor Network and Communication Shanghai Institute of Microsystem and Information Technology CAS Shanghai 200050 China

Data as well as pilot symbols are nonlinearly distorted due to signal clipping in practical OFDM systems. The distortion inflicted on pilot symbols has great negative effect on the channel estimation. To solve this issue, a novel iterative channel estimation algorithm based on virtual pilots is introduced for clipped OFDM systems in this paper. The algorithm iteratively estimates nonlinear distortion of data symbols, and subsequently uses it for data detection. Then part or all of the detected data symbols are used as virtual pilots to perform more precise channel re-estimation. The MSE of channel estimation is derived theoretically. Simulation results show that the proposal improves the performance remarkably with moderate complexity increase at the receiver. In particular, compared to traditional algorithm, the BER performance of this method increases by 0.3 dB. © 2012 Binary Information Press.

关键词： Peak to average power ratio

来源：评论

学校读者我要写书评

暂无评论

Single-channel Speech Separation by l0 Optimization Using Quasi-KLT Bases

引用

电子学报(英文版) 2012年第3期21卷 535-540页

作者： GUO Haiyan YANG Zhen ZHU Weiping YE Lei College of Engineering Nanjing Agricultural University Nanjing 210031 China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology (Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper deals with single-channel speech separation. First, it is proved that when the sparse bases of the signal sources satisfy certain conditions, all the sources can be perfectly separated from a single mixture by l0 optimization. Then, a special case where the single mixture is generated by two independent speech sources is studied in more detail. It is revealed that the ideal quasi- KLT bases constructed from the original sources satisfy the sufficient conditions for perfect separation of mixed signals. Considering the fact that the ideal quasi-KLT bases cannot be obtained in practice, template-matching based quasi- KLT bases generated from the single mixture are also pro- posed to perform single-channel speech separation. Finally, simulation results demonstrating the effective performance of single-channel separation of two speech sources by l0op- timization using the template-matching based quasi-KLT bases are presented.

关键词：语音分离 KLT 优化单通道模板匹配混合物充分条件信号分离

来源：评论

学校读者我要写书评

暂无评论

Dynamical QoS self-configuration approach of cognitive networks based on end-link cooperation policy

引用

Journal of Computational Information Systems 2012年第11期8卷 4685-4693页

作者： Qi, Jin Zhang, Shunyi Sun, Yanfei Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China Institute of Information and Network Technology Nanjing University of Posts and Telecommunication Nanjing 210003 China

To solve the problem of rapid QoS declining under network situation as well as improve the judging and dynamical adjusting ability that network system towards user QoS, in this paper, we proposed a dynamical self-configuration approach for guaranteeing QoS in cognitive networks (CNs). Through utilizing the active property of CNs while introducing end-link cooperation policy based on decisionmaking, the user priority has been determined and dynamically corrected. The simulation result represents that the proposed approach has better performance than traditional best of effort service, enabling to guarantee the user QoS under congestion status effectively. © 2012 Binary Information Press.

关键词： Quality of service

来源：评论

学校读者我要写书评

暂无评论

Cognitive networks multi-constraint QoS routing algorithm based on autonomic ant colony algorithm

引用

Journal of Computational Information Systems 2012年第8期8卷 3429-3436页

作者： Qi, Jin Zhang, Shunyi Sun, Yanfei Key Lab. of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China Institute of Information and Network Technology Nanjing University of Posts and Telecommunication Nanjing 210003 China

This paper focused on the study of cognitive networks (CNs) oriented multi-parameter constraint Quality of Service (QoS) routing optimization. With the foundation of CNs multi-parameter QoS routing requirement, referring to the shortcomings of basic ant colony algorithm, we brought improvements to the four aspects of pheromone initialization, pheromone evaporation factor adjustment, pheromone update method and state transition rules, proposed the CNs multi-constraint QoS routing algorithm based on autonomic ant colony (AAC) algorithm. The simulation result represents that the proposed algorithm has relatively good optimization ability and fast convergence speed, can effectively solving the multi-constraint QoS routing problem faced by CNs. © 2012 Binary Information Press.

关键词： Cost functions

来源：评论

学校读者我要写书评

暂无评论

Wavelet Transform-Based Distributed Compressed Sensing in wireless sensor networks

引用

China communications 2012年第2期9卷 1-12页

作者： Hu Haifeng Yang Zhen Bao Jianmin Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications Nanjing 210003 P. R. China National Mobile Communications Research Laboratory Southeast University Nanjing 210096 P. R. China

wireless sensor networks(WSN) are mainly characterized by a potentially large number of distributed sensor nodes which collectively transmit information about sensed events to the *** this paper,we present a Distributed Wavelet Basis Generation(DWBG) algorithm performing at the sink to obtain the distributed wavelet basis in *** on this basis,a Wavelet Transform-based Distributed Compressed Sensing(WTDCS) algorithm is proposed to compress and reconstruct the sensed data with spatial ***,we make a detailed analysis of relationship between reconstruction performance and WTDCS algorithm parameters such as the compression ratio,the channel Signal-to-Noise Ratio(SNR),the observation noise power and the correlation decay parameter by *** simulation results show that WTDCS can achieve high performance in terms of energy and reconstruction accuracy,as compared to the conventional distributed wavelet transform algorithm.

关键词： WSN distributed compressed sensing distributed wavelet transform

来源：评论

学校读者我要写书评

暂无评论

Provably Secure General Aggregate Signcryption Scheme in the Random Oracle Model

引用

China communications 2012年第11期9卷 107-116页

作者： Qi Zhenghua Ren Xunyi Yang Geng College of Computer Nanjing University of Posts and TelecommunicationsNanjing 210003P.R.China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003P.R.China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of EducationJiangsu ProvinceNanjing 210003P.R.China

To reduce the size of certificate chains and the ciphertext size in secure routing protocols, a General Aggregate Signcryption Scheme (GASC) is presented. In GASC, an identity-based signcryption algorithm and an aggregate signature algorithm are combined in a practical and secure manner to form the general aggregate signcryption scheme's schema and concept, and a new secure, efficiently general aggregate signcryption scheme, which allows the aggregation of n distinct signcryptions by n distinct users on n distinct messages, is proposed. First, the correction of the GASC scheme is analyzed. Then, we formally prove the security of GASC in the random oracle models IND-CCA2 and EUF-CMA under the DBDHP assumption and the DLP assumption, respectively. The results show that the GASC scheme is not only secure against any probabilistic polynomial-time IND-GASC-CCA2 and EUF-GASC-CMA adversary in the random oracle models but also efficient in pairing ê computations. In addition, the GASC scheme gives an effective remedy to the key escrow problem, which is an inherent issue in IBC by splitting the private key into two parts, and reduces the communication complexity by eliminating the interaction among the senders (signers) before the signcryption generation.

关键词： identity-based cryptography signcryption aggregate signature bilinear pairing

来源：评论

学校读者我要写书评

暂无评论

Homomorphic Signature for Identity Authentication in Cloud Computing

Homomorphic Signature for Identity Authentication in Cloud C...

引用

中国密码学会2012年会

作者： Zhiwei Wang Wei Zhang Danwei Chen College of Computer Nanjing University of Posts and TelecommunicationsNanjingJiangsu 210003China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks NanjingJiangsu 210003 Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Post

In this paper,we introduce a new kind of homomorphic signature,which is suitable for identity authentication in cloud computing.A user firstly computes the full signature on its all identity attributes,and sends the full signature to the intermediate channel server (the intermediate channel server should check and verify it).During the valid period of his full signature,if the user wants to require a cloud service on a special identity (only involves part of identity attributes),he only needs to securely send a {0,1}n vector to the intermediate channel *** intermediate channel server who doesn't know the secret key can compute the partial signature on the special identity,and then sends it to the cloud *** give a formal secure definition of this homomorphic signature,and construct a scheme from GHR *** prove that our scheme is secure under GHR signature.

关键词： homomorphic signature identity authentication cloud computing GHR signature strong RSA assumption

来源：评论

学校读者我要写书评

暂无评论

Throughput and energy efficiency optimization of ARQ protocols for exploiting cooperative communication in wireless sensor networks

引用

Journal of Convergence Information technology 2012年第19期7卷 39-47页

作者： Wang, Haiyong Yang, Geng Chen, Zhengyu Xu, Jian Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China School of Computer Science and Technology Nanjing University of Posts and Telecommunications Nanjing 210003 China

In wireless sensor networks (WSNs) where the nodes operate on batteries, for which replacement and recharging is almost impossible. So it is critical to prolon g the network lifetime by minimizing the total energy consumption, while satisfying given throughput requirements. With this objective in mind, an automatic retransmission request (ARQ) protocol for exploiting cooperative communication is introduced and a generalized model is proposed for analyzing the throughput and energy efficiency of the scheme. The numerical results reveal that the throughput and energy efficiency of the scheme is much better than that of the traditional ARQ scheme.

关键词： Energy efficiency

来源：评论

学校读者我要写书评

暂无评论

FoVs correlation model for wireless multimedia sensor networks based on three-dimensional perception

引用

Advances in Information Sciences and Service Sciences 2012年第3期4卷 27-34页

作者： Han, Chong Sun, Lijuan Xiao, Fu Guo, Jian Wang, Ruchuan College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Jiangsu Province Nanjing 210003 China

wireless multimedia sensor networks have become the focus of research in a wide variety of areas in recent years. The camera sensor nodes observe the phenomenon at different locations in the field, and the spatially proximal cameras could have highly overlapped field of views (FoVs). Based on the three-dimensional sensing model of camera sensor node, a FoVs correlation model was proposed in this paper. Then, a grid-based and a relative position-based approach were respectively designed to calculate the correlation coefficient between two cameras. Simulation results and algorithm complexity analysis demonstrate that the relative position-based method has highly efficiency and nearly reduces two orders of magnitude of time complexity to the former.

关键词： sensor nodes

来源：评论

学校读者我要写书评

暂无评论

An efficient coverage control algorithm for three-dimensional underwater sensor networks

引用

Advances in Information Sciences and Service Sciences 2012年第10期4卷 393-399页

作者： Xiao, Fu Yang, Yang Sun, Li Wang, Ruchuan Nanjing University of Posts and Telecommunications Nanjing 210003 China Provincial Key Laboratory for Computer Information Processing Technology Soochow University Suzhou 215006 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China

Strategy of sensor nodes deployment is directly related to the cost and performance for underwater wireless sensor networks, which is largely determined the various service-quality improvement of wireless sensor networks. In order to improve the coverage of the target area, this paper presents a distributed algorithm of coverage control. Assume that nodes initially deployed on the surface of the water and can only move in vertical direction in 3-D space, the algorithm is first to control the nodes in-depth and relocate the nodes at different depths, then the nodes continue to adjust their depths until there is no augment for improving their coverage, and to achieve efficient coverage of the three-dimensional sensor networks ultimately. Experimental results show that compared with traditional random deployment method, the proposed coverage control algorithm can improve coverage of network effectively.

关键词： Quality control

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：