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China Communications 2018年第8期15卷 92-107页

作者： Lianxin Yang Dan Wu Hongkui Shi Yanshan Long Yueming Cai institute of Communications engineering Army Engineering University of PLA College of telecommunications and Information engineering Nanjing University of Posts and Telecommunications

Joint mode selection and link allocation are crucial to achieve the advantage of Device-to-Device(D2 D) communications in improving spectral efficiency. In practice, cellular users tend to not be totally altruistic or absolutely selfish. How to stimulate them to devote their links and how to allocate their links to D2 D pair candidates efficiently are two main challenges. In this paper, we encourage cellular users through the variable payment with regard to the social tie strength between cellular users and D2 D pair candidates. In particular, the social tie strength is inferred through a graph inference model and its impact on the payment is quantified as a negative exponential function. Then, we propose a resource scheduling optimization model based on the non-transferable utility coalition formation game, and a distributed coalition formation algorithm based on the Pareto preference and merge-and-split rule. From them, the final coalition structure is obtained, which reflects the strategy of mode selection and link allocation. Numerical results are presented to verify the effectiveness of our proposed scheme.

关键词： D2D communication mode selection link allocation social ties coalition formation game

Performance Analysis of Mixed Amplify-and-Forward and Decode-and-Forward Protocol in Underlay Cognitive Networks

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China Communications 2016年第3期13卷 115-126页

作者： Tran Trung Duy Hyung Yun Kong Department of telecommunications Posts and Telecommunications Institute of Technology Department of Electrical engineering University of Ulsan

In this paper, we propose and evaluate outage performance of a mixed amplify-and-forward(AF) and decode-and-forward(DF) relaying protocol in underlay cognitive radio. Different from the conventional AF and DF protocols, in the proposed protocol, a secondary source attempts to transmit its signal to a secondary destination with help of two secondary relays. One secondary relay always operates in AF mode, while the remaining one always operates in DF mode. Moreover, we also propose a relay selection method, which relies on the decoding status at the DF relay. For performance evaluation and comparison, we derive the exact and approximate closedform expressions of the outage probability for the proposed protocol over Rayleigh fading channel. Finally, we run Monte Carlo simulations to verify the derivations. Results presented that the proposed protocol obtains a diversity order of three and the outage performance of our scheme is between that of the conventional underlay DF protocol and that of the conventional underlay AF protocol.

关键词： underlay cognitive network cooperative communication outage probability mixed AF and DF protocols Rayleigh fading channel

Design of a modified circular-cut multiband fractal antenna

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The Journal of China Universities of Posts and telecommunications 2016年第6期23卷 68-75页

作者： Hu Zhangfang Xin Wei Luo Yuan Hu Yinping Zhou Yongxin institute of Photoelectronic engineering Chongqing University of Posts and Telecommunications

This paper presents a modified circular-cut multiband fractal antenna with good radiation patterns designed for digital cellular system（DCS）, personal communication system（PCS）, 2.4/5.2/5.8 GHz wireless local area networks（WLAN） and 2.5/3.5/5.5 GHz worldwide interoperability for microwave access（WiMAX） applications simultaneously. Originally, the modified circular monopole antenna is designed to resonate at around 2.1 GHz and 3.6 GHz. After subtracting the circular iterative tree fractal structure, it can produce three other resonances at around 5.6 GHz, 6.47 GHz and 7.89 GHz. Besides, as the number of iterations increases, not only do the new frequency bands appear（it demonstrates the good self-similarity property of the proposed antenna）, but also the operating bands shift from high frequency to low frequency（it shows the well space filling property）. Furthermore, the proposed antenna owns a compact structure, which can achieve the 5.28 dBi of relative high gain. And the measured results are basically accordant to simulated results, which proves the effectiveness of the proposed antenna.

关键词： multiband fractal monopole self-similarity space filling

A Novel Serially Concatenated GMSK System for Satellite Communications

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Chinese Journal of Electronics 2021年第2期30卷 390-396页

作者： HUANG Yun LIU Gang YANG Yinan DING Xingwen CHANG Hongyu School of telecommunications engineering Xidian University Beijing Research institute of Telemetry

A novel serially concatenated GMSK system is proposed for satellite communications subject to low SNR, limited power and spectrum resources. First, we design a Nonrecursive continuous-phase encoder(NRCPE)based GMSK based on the Rimoldi’s decomposition. Then,a corresponding pilot-aided quasi-coherent demodulation algorithm is developed, whose basic principle is that a modified BCJR-based detection performs on the received signals with initial and ending trellisstates being determined using the very limited pilot overhead. Finally,we choose proper modulation parameters for the NRCPE based Gaussian minimum shift keying GMSK signaling according to the trade-offs between the power and spectral efficiency. The simulation results show that the LDPC coded GMSK system using the proposed algorithm can achieve excellent performance and can also work well in the presence of the large Doppler shifts and some burst errors.

关键词： Doppler shift Nonrecursive continuous-phase encoder channel estimation satellite communication modified BCJR-based detection performs corresponding pilot-aided quasicoherent demodulation algorithm concatenated codes novel serially concatenated GMSK system parity check codes minimum shift keying NRCPE satellite communications demodulation

Effective Capacity in Cognitive Radio Networks with Relay and Primary User Emulator

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China Communications 2019年第11期16卷 130-145页

作者： Luyong Zhang Yijie Yang Xuan Li Jinhua Chen Yunbing Chi institute of Information and Communication engineering Beijing University of Posts and Telecommunications

In this paper,the transmission performances are studied in cognitive radio networks with primary user emulator and relay *** the proposed network,the users include primary users,secondary users and primary user *** decreasing access priority of the users are primary users,primary user emulators and secondary *** user access to the network results in different transmission *** impose interference power constraints on the secondary users to protect the primary users from being *** also adopt the transmission mechanism that transits among more than one secondary transmitters,secondary receivers and *** transition models of the transmission states are proposed to describe the transmission *** investigate the transmission performances,the theory of effective capacity is *** transmission performances in terms of effective capacity are expressed and demonstrated under different transmission *** overall effective capacity,as the overall data traffic in the cognitive radio network,is ***,the overall effective capacity is demonstrated under different transmission *** results show the greedy transmission strategy outperforms the rest of the transmission 8 policies in the overall effective *** a larger number of the users,the effective capacity converges to a certain value.

关键词： cognitive radio primary user emulator(PUE) relay communication effective capacity transmission strategy

Improvement of location methods based on RFID

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The Journal of China Universities of Posts and telecommunications 2013年第6期20卷 36-41页

作者： WU Ling HUANG Li-ya institute of Electronic Science and engineering Nanjing University of Posts and Telecommunications

The most common location algorithms based on received signal strength （RSS） are location identification based on dynamic active radio frequency identification （LANDMARC） and virtual reference elimination （VIRE）. However, both the original algorithms suffer from some drawbacks. In this paper, several aspects of the two original algorithms have been modified to reduce the positioning errors. Firstly, Lagrange interpolation has been used instead of linear interpolation. Secondly, adaptive threshold has been introduced in the new algorithm. Thirdly, insert virtual reference tags to improve the location accuracy of the boundary of the sensing area. Finally, combine LANDMARC with VIRE to absorb both advantages. Compared with the original algorithms, on average, simulated results show that the modified algorithms can improve the location performance efficiently and achieve the goal of accurate positioning in indoor environment.

关键词： LANDMARC VIRE received signal strength indicator (RSSI) Lagrange adaptive threshold

A Real-Time Interprocessor Synchronization Algorithm for Communication in Distributed Computer Systems

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Journal of Computer Science & Technology 1987年第4期2卷 292-302页

作者：段平蔡希尧 The Northwest telecommunications engineering institute Xi’an The Northwest telecommunications engineering institute Xi’an

A real-time synchronization algorithm for interprncessor communication ispresented, which is based on the techniques of Reference 2, except that bufferedcommunication is used. The upper and lower bounds of the mean re... 详细信息

关键词： A Real-Time Interprocessor Synchronization Algorithm for Communication in Distributed Computer Systems node

Physical layer authentication in UAV-enabled relay networks based on manifold learning

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Science China(Information Sciences) 2022年第12期65卷 263-283页

作者： Shida XIA Xiaofeng TAO Na LI Shiji WANG Jin XU National engineering Lab for Mobile Network Technologies Beijing University of Posts and Telecommunications Beijing University of Posts and telecommunications Research institute

An unmanned aerial vehicle(UAV) relay network is a promising solution in the next-generation wireless networks due to its high capacity and unlimited geography. However, because of the openness of wireless channels and UAV mobility, it is remarkably challenging to guarantee the secure access of UAV relay. In this paper, we investigate the physical layer authentication(PLA) to verify the identity of the UAV relay for preventing unauthorized access to users’ information or network service. Unlike most existing PLA methods for UAV, the proposed PLA scheme fully considers the time-varying of physical layer attributes caused by UAV mobility, and transforms the authentication problem into recognizing nonlinearly separable physical layer data. Particularly, we propose a manifold learning-based PLA scheme that can authenticate the mobile UAV relay in real time by establishing the local correlation of physical layer attributes. The Markov chain of physical layer data in the time domain is established to evaluate UAV state transition probability through the proposed diffusion map algorithm. The legitimate UAV and spoofing attackers can always be authenticated by the different motion states. Performance analysis offered a comprehensive understanding of the proposed scheme. Extensive simulations confirm that the performance of the proposed scheme improves over 18% in resisting the intelligent spoofing UAV compared with the traditional methods.

关键词： UAV relay physical layer authentication mobility manifold learning diffusion map state transition probability

The robustness of sparse network under limited attack capacity

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Chinese Physics B 2017年第8期26卷 577-586页

作者：王小娟宋梅金磊王珍 Electronic engineering institute Beijing University of Posts and TelecommunicationsBeijing 100876China Electronic engineering institute of PLA Hefei 230000China

The paper studies the robustness of the network in terms of the network structure. We define a strongly dominated relation between nodes and then we use the relation to merge the network. Based on that, we design a dominated clustering algorithm aiming at finding the critical nodes in the network. Furthermore, this merging process is lossless which means the original structure of the network is kept. In order to realize the visulization of the network, we also apply the lossy consolidation to the network based on detection of the community structures. Simulation results show that compared with six existed centrality algorithms, our algorithm performs better when the attack capacity is limited. The simulations also illustrate our algorithm does better in assortative scale-free networks.

关键词： robustness dominated relation merge lossless

Applications of optical duobinary in optical carrier suppression and separation labeling

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Chinese Optics Letters 2010年第7期8卷 642-646页

作者：隆正浩忻向军周锐张子兴徐大雄 institute of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications School of Electronic engineering Beijing University of Posts and Telecommunications

A novel approach is used to implement optical carrier suppression and separation （OCSS） labeling. Then, the performance of 10/40-Gb/s duobinary payload with 2.5-Gb/s amplitude shift keying （ASK） or duobi- nary label by numerical simulations is studied. Influencing factors, such as demultiplexer bandwidth and fiber Bragg grating （FBG） filter bandwidth, are investigated. Simulation result shows that the received sensitivity of ASK label is higher than that of the duobinary label, while the received sensitivity of duobi- nary payload with duobinary label is higher than that with ASK label.

关键词： Computer simulation Fiber Bragg gratings