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Resource allocation for the cluster-based cooperative multicast in OFDM-based cognitive radio systems

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The Journal of China Universities of Posts and Telecommunications 2013年第4期20卷 1-7,33页

作者： ZHANG Shuang-lu XU Wen-jun LI Sheng-yu LIN Jia-ru school of information and communication engineering Beijing University of Posts and Telecommunications

This paper investigates the resource allocation problem for the cluster-based cooperative multicast in orthogonal frequency division multiplexing （OFDM）-based cognitive radio （CR） systems. Aiming at maximizing the system sum rate, an efficient clustering scheme is proposed. It begins with the clustering phase where secondary users （SUs） with good channel conditions are selected as cluster heads, while others decide to which cluster they belong. When the clusters are organized, it turns to a two-stage data transmission phase： in stage 1, the secondary＇ base station （BS） transmits data to the cluster heads; in stage 2, the cluster heads forward the received data to their cluster members. Based on this scheme, a joint subcarrier and power allocation algorithm is proposed. Simulation results show that the proposed scheme significantly outperforms the conventional multicast （CM） as well as the multiple description coding multicast 0VIDCM） in terms of the system sum rate.

关键词： cooperative multicast cognitive radio OFDM cluster

Design and evaluation of V2X communication system for vehicle and pedestrian safety

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The Journal of China Universities of Posts and Telecommunications 2015年第6期22卷 18-26页

作者： Liu Zhenyu Pu Lin Zhu Konglin Zhang Lin school of information and communication engineering Beijing University of Posts and Telecommunications

As the vehicles gain the extensive popularity and increasing demand, traffic accident is one of the most serious problems faced by modem transportation system. Hereinto, crashes between cars and pedestrians cause plenty of injuries and even death. Diverting attention from walking to smartphones is one of the main reasons for pedestrians getting injured by vehicles. However, the traditional measures protecting pedestrians from the vehicles heavily rely on the sound warning method, which do not capable for pedestrians focusing on the smartphones. As the smartphones become ubiquitous and intelligent, they have the capacity to provide alert for the pedestrians with the help of vehicle-to-pedestrian （V2P） communication. In this paper, an efficient vehicle-to-X （V2X） communication system is designed for the vehicle and pedestrian communication to guarantee the safety of people. It achieves the IEEE 802.11p and the WiFi protocols meanwhile on the on-board unit （OBU） designed for vehicles. Extensive evaluation shows that the OBU can provide the reliable communication for vehicle-to-vehicle （V2V） and V2P in terms of packet delivery rate and average delay. Furthermore, two safety applications have been developed to protect the safety of vehicles and pedestrians based on the data transferred from the OBU. The first application is designed to show the driving information and provide the collision forewaming alert on the tablet within the vehicle. The second application is developed for the smartphone to provide forewarning alert information to the smartphone-distracted vulnerable pedestrians. Smartphone states are appreciable to provide the adaptive alert modes. Experimental results show that these applications are capable of alerting the intersection accidents, and the pedestrians can get the adaptive alerts according to smartphone usage contexts.

关键词： V2X communication system pedestrian safety vehicle safety on board unit smartphone collision forewarning +

A New RFID Anti-collision Algorithm Based on the Q-Ary Search Scheme

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Chinese Journal of Electronics 2015年第4期24卷 679-683页

作者： SU Jian WEN Guangjun HONG Danfeng school of communication and information engineering University of Electronic Science and Technology of China College of information engineering Qingdao University

Deterministic tree-based algorithms are mostly used to guarantee that all the tags in the reader field are successfully identified, and to achieve the best performance. Through an analysis of the deficiencies of existing tree-based algorithms, a Q-ary search algorithm was proposed. The Q-ary search(QAS) algorithm introduced a bit encoding mechanism of tag ID by which the multibit collision arbitration was implemented. According to the encoding mechanism, the collision cycle was reduced. The theoretical analysis and simulation results showed that the proposed MS algorithm overcame the shortcoming of existing tree-based algorithms and exhibited good performance during identification.

关键词： Radio frequency identification(RFID) Anti-collision Encoding Energy efficiency

Background knowledge based privacy metric model for online social networks

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 75-82页

作者： CHENG Cheng ZHANG Chun-hong JI Yang school of information and communication engineering Beijing University of Posts and Telecommunications

The data of online social network （OSN） is collected currently by the third party for various purposes. One of the problems in such practices is how to measure the privacy breach to assure users. The recent work on OSN privacy is mainly focus on privacy-preserving data publishing. However, the work on privacy metric is not systematic but mainly focus on the traditional datasets. Compared with the traditional datasets, the attribute types in OSN are more diverse and the tuple is relevant to each other. The retweet and comment make the graph character of OSN notably. Furthermore, the open application programming interfaces （APIs） and lower register barrier make OSN open environment, in which the background knowledge is more easily achieved by adversaries. This paper analyzes the background knowledge in OSN and discusses its characteristics in detail. Then a privacy metric model faces OSN background knowledge based on kernel regression is proposed. In particular, this model takes the joint attributes and link knowledge into consideration. The effect of different data distributions is discussed. The real world data set from *** has been adopted. It is demonstrated that the privacy metric algorithm in this article is effective in OSN privacy evaluation. The prediction error is 30% lower than that of the work mentioned above

关键词： privacy metric social network background knowledge kernel regression

Two-party certificateless authenticated key agreement protocol with enhanced security

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The Journal of China Universities of Posts and Telecommunications 2019年第1期26卷 12-20,39页

作者： Wu Tao Jing Xiaojun school of information and communication engineering Beijing University of Posts and Telecommunications

Two-party certificateless authenticated key agreement(CL-AKA) protocol is a hot topic in the field of wireless communication security. An improved two-party CL-AKA protocol with enhanced security is proposed,which is of provable security and unforgeability in the extended Canetti-Krawczyk(eCK) security model based on the hardness assumption of the computational Diffie Hellman(CDH) problem. Compared with other similar protocols, it is more efficient and can satisfy security properties such as free of the centralized management of certificate and key, free of bilinear pairings, two-party authentication, resistant to unknown key-share attack, key compromise impersonation attacks, the man-in-the-middle-attack(MIMA) of key generation center(KGC), etc. These properties make the proposed protocol have better performance and adaptability for military communication.

关键词： certificateless cryptography authenticated key agreement protocol two-party authentication protocol security properties

Effect of cavity dissipation on the emission spectrum of an atom interacting with a field in the dispersive approximation

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Chinese Physics B 2010年第1期19卷 337-342页

作者：王海军高云峰 school of Physcial Science and information engineering Liaocheng University school of Medium and communication Liaocheng University

The emission spectrum of a two-level atom interacting dispersively with a single mode radiation field in the dissipative cavity is investigated. A general expression for the emission spectrum is derived. The numerical results for the initial field in coherent state are calculated. It is found that the spectrum structure is influenced significantly by the cavity damping constant k, and the spectrum structure is dependent on the interaction time r when the cavity dissipation is present. Only one peak located at wa appears in the atomic spectra for larger T.

关键词： emission spectrum cavity dissipation two-level atom

Recovery of correlated row sparse signals using smoothed L_0-norm algorithm

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The Journal of China Universities of Posts and Telecommunications 2012年第6期19卷 123-128页

作者： LIU Yu MA Cong ZHU Xu-qi ZHANG Lin school of information and communication engineering Beijing University of Posts and Telecommunications

Distributed compressed sensing （DCS） is an emerging research field which exploits both intra-signal and inter-signal correlations. This paper focuses on the recovery of the sparse signals which can be modeled as joint sparsity model （JSM） 2 with different nonzero coefficients in the same location set. Smoothed L0 norm algorithm is utilized to convert a non-convex and intractable mixed L2,0 norm optimization problem into a solvable one. Compared with a series of single-measurement-vector problems, the proposed approach can obtain a better reconstruction performance by exploiting the inter-signal correlations. Simulation results show that our algorithm outperforms L1,1 norm optimization for both noiseless and noisy cases and is more robust against thermal noise compared with LI,2 recovery. Besides, with the help of the core concept of modified compressed sensing （CS） that utilizes partial known support as side information, we also extend this algorithm to decode correlated row sparse signals generated following JSM 1.

关键词： DCS JSM row sparse signal smoothed L0-norm partially known support

Nonbinary ldpc-coded probabilistic shaping scheme for MIMO systems based on signal space diversity

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Digital communications and Networks 2023年第3期9卷 779-787页

作者： Weimin Kang school of information and communication engineering North University of ChinaTaiyuan030051China

This paper first describes a binary Low-Density Parity-Check(LDPC)-coded Probabilistic Shaping(PS)scheme for Multiple-Input Multiple-Output(MIMO)systems based on Signal Space Diversity(SSD).Second,a Nonbinary(NB)LDPC-coded PS scheme for MIMO systems based on SSD is *** first scheme can be used to obtain a shaping gain,whereas the second can also realize a coding *** theoretical average mutual information of the optimized rotated quadrature amplitude modulation constellations is analyzed and the simulated error per-formance with 22 and 44 MIMO schemes is *** theoretical average mutual information analysis and simulation results show that the proposed NB LDPC-coded PS scheme for MIMO systems based on SSD is reliable and robust,and is therefore suitable for future wireless communication systems.

关键词： Probabilistic shaping Multiple-input multiple-output Signal space diversity Average mutual information

A Low-Complexity Signal Detection Utilizing AOR Iterative Method for Massive MIMO Systems

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China communications 2017年第11期14卷 269-278页

作者： Zhenyu Zhang Xiaoming Dai Yuanyuan Dong Xiyuan Wang Tong Liu school of Computer & communication engineering University of Science & Technology Beijing Department of information and communication engineering Harbin Engineering University

Massive multiple-input multiple-output(MIMO) system is capable of substantially improving the spectral efficiency as well as the capacity of wireless networks relying on equipping a large number of antenna elements at the base stations. However, the excessively high computational complexity of the signal detection in massive MIMO systems imposes a significant challenge for practical hardware implementations. In this paper, we propose a novel minimum mean square error(MMSE) signal detection using the accelerated overrelaxation(AOR) iterative method without complicated matrix inversion, which is capable of reducing the overall complexity of the classical MMSE algorithm by an order of magnitude. Simulation results show that the proposed AOR-based method can approach the conventional MMSE signal detection with significant complexity reduction.

关键词： massive multiple-input multiple-output(MIMO) accelerated overrelaxation(AOR) iterative method minimum mean square error(MMSE) convergence complexity