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International Conference on wireless communications and Signal Processing, WCSP 2015

作者： Wei, Ji Haixi, Cao Zhen, Yang College of Telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing210003 China

ISBN: (纸本)9781467376860

Cooperative spectrum sensing (CSS) is a key technology to improve the sensing performance. Fully distributed CSS has been applied in cognitive radio ad hoc networks with good detection performance. However, when the number of secondary users (SUs) is large and the range of cognitive radio network is wide, sensing overheads (e.g., time and energy consumption) will increase correspondingly. Meanwhile, the reliability of SUs will potentially influence the detection performance. In this paper, a fully decentralized cooperative spectrum sensing scheme based on consensus theory among reliable SUs is proposed. Firstly, belief vector is used for distinguishing the reliable SUs from the unreliables. Secondly, the sub network with most reliable SUs is chose as reliable region, in which sensing information of reliable SUs can be exchanged among their one-hop neighbors with finite iterations based on consensus theory. Lastly, SUs in consensus network will get a consensus sensing outcome which will be shared with SUs outside of consensus network. The proposed scheme does not need the prior knowledge of primary user in the entire process. Simulation results show that the proposed scheme has better detection performance than traditional methods. © 2015 IEEE.

关键词： Energy utilization

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

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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

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Secrecy outage analysis of integrated satellite-terrestrial relay networks 24

Secrecy outage analysis of integrated satellite-terrestrial ...

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24th Asia-Pacific Conference on communications, APCC 2018

作者： Tao, Xiangshuai Huang, Qingquan Yin, Chunyan Cheng, Guoqiang Ouyang, Jian Liu, Xin College of Communications Engineering Army Engineering University of PLA Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China Nanjing Institute of Telecommunication Technology Nanjing China

ISBN: (纸本)9781538669280

This paper addresses the secure transmission problem of an integrated satellite-terrestrial relay networks (ISTRN), where multiple malicious eavesdroppers attempt to overhear the confidential signals from the satellite to a terrestrial user. Here, the relay is employed with multiple antenna and the decode-and-forward protocol is used. By supposing that the perfect instantaneous channel state information (CSI) of satellite-relay link and the statistical CSI of relay-user and relay-eavesdropper links are available at the relay, an optimization problem is first formulated to maximize the secrecy rate of the ISTRN. Then, the secure transmission scheme is designed to solve the optimization problem and obtain the closed-form beamforming weight vector. To further insight the secrecy performance of the proposed scheme, we derive the analytical expressions of the secrecy outage probability (SOP) of the considered ISTRN, where the satellite-relay link undergoes the shadowed-Rician fading, and the links of relay to user as well as eavesdroppers undergo the correlated Rayleigh fading. Finally, numerical results are given to confirm the superiority of the proposed scheme and the validity of the SOP analysis. © 2018 IEEE.

关键词： Beamforming

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Measurement-device-independent quantum key distribution with hyper-encoding

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Science China(Physics,Mechanics & Astronomy) 2019年第11期62卷 47-56页

作者： Zheng-Xia Cui Wei Zhong Lan Zhou Yu-Bo Sheng Schoool of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Postsand TelecommunicationsNanjing 210003China Institute for Quantum Computing University of Waterloo200 University Ave WWaterloo ON N2L3G1Canada Institute of Quantum Information and Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China

Measurement device-independent quantum key distribution(MDI-QKD) protocols are immune to all possible attacks on the photon detectors during quantum communication, but their key generation rates are low compared with those of other QKD *** each individual photon’s channel capacity is an efficient way to increase the key generation rate, and high-dimensional(HD) encoding is a powerful tool for increasing the channel capacity of photons. In this paper, we propose an HD MDI-QKD protocol with qudits hyper-encoded in spatial mode and polarization degrees of freedom(DOFs). In the proposed protocol, keys can be generated using the spatial mode and polarization DOFs simultaneously. The proposed protocol is unconditionally secure,even for weak coherent pulses with decoy states. The proposed MDI-QKD protocol may be useful for future quantum secure communication applications.

关键词： quantum communication measurement device-independent quantum key distribution high-dimensional hyper encoding

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Price and customer satisfaction based access control scheme

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Journal of Computational Information Systems 2014年第5期10卷 1893-1902页

作者： Zhang, Dengyin Wang, Xuemei Li, Dacheng Key Lab. of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing 210003 China

To solve the fairness problem in user access of mobile communication systems, we proposed an access control scheme based on price and customer satisfaction (PSAC) in this paper. In the scheme, we borrow Cobb-Douglas ordinal utility model to designate a price function which changes with the current system load and service transmission rate, and evaluate customer satisfaction according to waiting time and allocated bandwidth. The system accepts requests in the descending order of these requests' access probability, the calculation of which depends on price and customer satisfaction. Simulation results show that the PSAC algorithm we proposed can achieve high resource utilization, enhance the overall revenue, and ensure the fairness of the user access. © 2014 Binary Information Press.

关键词： Customer satisfaction

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A fast covariance matrix reconstruction method for two-dimensional direction-of-arrival estimation

A fast covariance matrix reconstruction method for two-dimen...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Xiaohuan Wu Wei-Ping Zhu Jun Yan Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications China

ISBN: (纸本)9781509041183

In this paper, a new method for two-dimensional (2-D) direction-of-arrival (DOA) estimation is proposed. We first reconstruct the covariance matrix of the coarray with block-Toeplitz structure and then retrieve the DOAs. Our method is computationally efficient as supported by the derived closed-form expression for the estimated covariance matrix. Unlike other methods, which require fully loaded arrays, the proposed method can be applied in the case of common rectangular arrays with arbitrary geometries. The estimated azimuth and elevation angles are automatically paired. Moreover, our method is of high estimation accuracy and immune to the angle ambiguity effect. Numerical simulations are carried out to verify the effectiveness of the proposed method.

关键词： 2-D DOA estimation Toeplitz-block-Toeplitz structure generalized rectangular array (GRA)

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AN IMPROVED EPON UPSTREAM TRANSMISSION SCHEME WITH ZERO INTER-PERIOD IDLE LOSS

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Journal of Electronics(China) 2011年第4期28卷 664-669页

作者： Shen Jianhua Guo Hongmei Mi Zhengkun Key Lab of Broadband Wireless Communication and Sensor Network Technology （ NUPT） Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

Existing Ethernet Passive Optical network(EPON) Dynamic Bandwidth Allocation(DBA) algorithms suffer from the disadvantage of idle time loss,which lower the upstream bandwidth *** letter proposes an improved upstream transmission scheme with idle-time eliminating *** analysis and numerical calculation prove that the improved scheme can ef-fectively eliminate the idle time and enhance the efficiency of upstream link *** results have shown that the bandwidth utilization can be raised up to 15% in heavy-load scenarios while the time delay performance of Assured Forwarding(AF) and Best Effort(BE) services are improved simultaneously.

关键词： Ethernet Passive Optical network(EPON) Dynamic Bandwidth Allocation(DBA) algorithm Channel transmission scheme Idle time eliminating

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Nonorthogonal object identification based on ghost imaging

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Photonics Research 2015年第5期3卷 238-242页

作者： Xiaofan Gu Shengmei Zhao Institute of Signal Processing & Transmission Nanjing University of Posts and Telecommunications (NUPT) Key Lab of Broadband Wireless Communication and Sensor Network Technology NUPT Ministry of Education

Ghost imaging could be used to make a quick identification of orthogonal objects by means of photocurrent correlation measurements. In this paper, we extend the method to identify nonorthogonal objects. In the method, an object is illuminated by one photon from an entangled pair, and the other one is diffracted into a particular direction by a pre-established multiple-exposure hologram in the idler arm. By the correlation measurements, the nonorthogonal object in the signal arm could be discriminated within a very short time. The constraints for the identification of nonorthogonal objects are presented, which show that the nonorthogonal objects can be discriminated when the overlapping portion between any two objects is less than half of all the objects in the set. The numerical simulations further verify the result.

关键词： Nonorthogonal object identification based on ghost imaging

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A dynamic web services selection algorithm based on trust model for grid environment

A dynamic web services selection algorithm based on trust mo...

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6th China Conference of wireless sensor networks, CWSN 2012

作者： Zhang, Lin Liu, Zhengbang Wang, Ruchuan Wang, Haiyan College of Computer Nanjing University of Posts and Telecommunications Jiangsu Province Nanjing 210003 China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks Nanjing University of Posts and Telecommunications Jiangsu Province Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Jiangsu Province Nanjing 210003 China

ISBN: (纸本)9783642362514

In order to find the service nodes, which the users are satisfied with, in a high speed and efficiency in open network environment, a new grid-oriented multi-level service selection model is proposed, which is based on the concept of user-similarity group. On this condition, direct trust calculation based on time decay is given and fine-grained recommendation trust calculation is studied, which can distinguish the ability of honesty. In addition, based on activity level of nodes, dynamic weight-allocation method is proposed, which can make the prediction results be closer to the fact. After job-interaction, the update algorithm about honesty ability of recommendation nodes is researched, which will provide more reasonable and reliable reference for the next prediction. Simulation results show that the service selection model and trust calculation methods are reasonable and accurate. © 2013 Springer-Verlag.

关键词： Grid computing

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Heralded amplification of single-photon entanglement with polarization feature

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Frontiers of physics 2018年第5期13卷 241-249页

作者： Yu-Yu Jin Sheng-Xian Qin Hao Zu Lan Zhou Wei Zhong Yu-Bo Sheng School of Science Nanjing University of Posts and Telecommunications Nanjing 210003 China New Energy Technology Engineering Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

Heralded noiseless amplification is beneficial in overcoming transmission photon loss in a noisy quantum channel. We propose a single-photon-assisted heralded noiseless amplification protocol of the single- photon entanglement （SPE）, where the single-photon qubit has an arbitrary unknown polarization feature. We focus on both the complete and partial photon loss during the transmission process. After the amplification, the parties can recover the pure less-entangled SPE into a maximally entangled SPE and increase its fidelity. Moreover, the polarization feature of the single-photon qubit will be well preserved and not be leaked. Our protocol can be realized under our current experimental condition. Based on the features above, our protocol may be useful in the quantum secure communication schemes that encode information in the polarization degree of freedom of photons.

关键词： quantum communication single-photon entanglement quantum state amplification polarization feature

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