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Space-time cooperative diversity scheme using full feedback

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The Journal of china Universities of Posts and Telecommunications 2009年第3期16卷 8-13页

作者： SUN De-chun,YI Ke-chu,LI xiao-hui state Key laboratory of integrated Service {3.s,xidian university,xi’an 710071,china [a]state Key laboratory of integrated Service {3.s xidian university xi'an 710071 china

This article proposes a new space-time cooperative diversity scheme called full feedback-based cooperative diversity scheme （FFBCD）. In contrast to the conventional adaptive space-time cooperative diversity schemes that utilize the feedback from only the destination node, the new scheme utilizes the feedback from both the destination node and the cooperation node. With the feedback from the destination node, the occasional successful reception of the destination node in the information distribution stage can be detected, thus avoiding unnecessary retransmissions in the information delivery stage. The feedback from the cooperation node indicates the receiving state of the cooperation node in the information distribution stage, and the source node and the cooperation node will not perform cooperative retransmission during the information delivery stage unless the cooperation node is received successfully in the information distribution stage. In this way the new scheme can reduce the number of transmission attempt and improve the channel utilization. The expressions of the average number of transmission attempt are given. Numerical approximations and simulation results both show that the new scheme performs better than the non-cooperative scheme and the conventional adaptive space-time cooperative diversity scheme.

关键词： space-time cooperative diversity simple feedback adaptive cooperative diversity transmission attempt

Price-based interference avoidance game in the Gaussian interference channel

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Science china(Information Sciences) 2012年第2期55卷 301-311页

作者： JING ZhenHai1,BAI BaoMing1 & MA xiao2 1state Key laboratory of integrated {3. networks,xidian university,xi'an 710071,china 2Department of Electronics and Communication Engineering,Sun Yat-sen university,Guangzhou 510275,china 1. state Key laboratory of integrated {3. networks Xidian University Xi’an 710071 China2. Department of Electronics and Communication Engineering Sun Yat-sen University Guangzhou 510275 China

This paper considers a distributed interference avoidance problem employing frequency assignment in the Gaussian interference channel(IC).We divide the common channel into several sub-channels and each user chooses one sub-channel for transmission in such a way that the total interference in the IC is *** mechanism named interference avoidance in this paper can be modeled as a competitive game *** a completely autonomous distributed iterative algorithm called distributed interference avoidance algorithm(DIA)is adopted to achieve the Nash equilibrium(NE)of the *** to the self-optimum,the DIA is a sub-optimal ***,through introducing an optimal compensation(or price)into the competitive game model,we successfully develop a compensation-based game model to approximate the optimal interference avoidance ***,an optimal algorithm called iterative optimal interference avoidance algorithm(IOIA)is proposed to reach the optimality of the interference avoidance *** analyze the implementation complexity of the proposed algorithm which is only O(N),with N standing for the number of users in the *** also give the proof on the convergence of the proposed *** performance upper bound and lower bound are derived for the IOIA *** simulation results show that the IOIA does reach the optimality under the condition of interference avoidance mechanism.

关键词： interference channel interference avoidance game theory

Approximating maximum likelihood performance reduced dimension VBLAST detection algorithm

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Science china(Information Sciences) 2010年第7期53卷 1439-1445页

作者： CHENG WenChi & ZHANG HaiLin state Key Lab of ISN, xidian university, xi’an 710071, {3. 1. state Key Lab of ISN Xidian University Xi’an 710071 China

SM (spatial multiplexing) can effectively increase the information rate in multiple input multiple output system. BLAST is the typical representation of SM, especially VBLAST, which has some simple de- tection algorithms such as ML, ZF-DFE and ML-DFE, etc. However, the existing algorithms cannot approach ML performance. This paper discusses the effect for detection performance by the correlation of channel ma- trix, proposes a new algorithm-HPML detection algorithm, which can approach ML performance with low complexity. In the new algorithm, we travel the first d layers, and use the DFE procedure for the remaining layers, then perform ML detection for all obtained signals. Simulation results show that HPML can approach ML performance when the traveling numbers are not less than half of the number of transmitting antennas, and the algorithm complexity is smaller than ML.

关键词： BLAST correlation of channel matrix ML detecting algorithm HPML detecting algorithm

A novel method for the improvement of power efficiency in high peak-to-average-power ratio communication systems

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Science china(Information Sciences) 2010年第8期53卷 1697-1702页

作者： REN ZhiYuan 1 , ZHANG HaiLin 1 & GUO Kai 2 1 state Key laboratory of integrated {3. network, xidian university, xi’an 710071, china 2 Aerospace Long March Launch Vehicle Technology Co. Ltd., Beijing 100076, china 1. state Key laboratory of integrated {3. network Xidian University Xi’an 710071 China2. Aerospace Long March Launch Vehicle Technology Co. Ltd. Beijing 100076 China

To solve the problem of low power efficiency of power amplifiers (PA) in the high peak-to-averagepower ratio (PAPR) communication system, a novel signal decomposed amplifier structure has been proposed in order to decrease the energy consumption and increase the power efficiency of PA. The high PAPR signal can be decomposed into several low PAPR branch signals, linearized and amplified in parallel. This structure can reduce the PAPR of branch signals and improve the power efficiency of PA. The simulation results indicate that the power efficiency will be remarkably increased.

关键词： Green Radio power amplifier signal decomposed

SAR image despeckling based on edge detection and nonsubsampled second generation bandelets

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Journal of Systems Engineering and Electronics 2009年第3期20卷 519-526页

作者： Zhang Wenge~(1,2),Liu Fang~(1,2),Jiao Licheng~(2,3.& Gao xinbo~(2,3. 1.School of Computer Science and Technology,xidian Univ.,xi’an 710071,P.R.china 2.Key Lab.of Intelligent Perception and Image Understanding of Ministry of Education of china,xi’an 710071,P.R.china 3.Inst,of Intelligent Information Processing,xidian Univ.,xi’an 710071,P.R.china School of Computer Science and Technology Xidian Univ. Xi'an 710071 P. R. China Key Lab. of Intelligent Perception and Image Understanding of Ministry of Education of china Xi'an 710071 P. R. China Key Lab. of Intelligent Perception and Image Understanding of Ministry of Education of china Xi'an 710071 P. R. China Inst. of Intelligent Information Processing Xidian Univ. Xi'an 710071 P. R. China

To preserve the sharp features and details of the synthetic aperture radar （SAR） image effectively when despeckling, a despeckling algorithm with edge detection in nonsubsampled second generation bandelet transform （NSBT） domain is proposed. First, the Canny operator is utilized to detect and remove edges from the SAR image. Then the NSBT which has an optimal approximation to the edges of images and a hard thresholding rule are used to approximate the details while despeckling the edge-removed image. Finally, the removed edges are added to the reconstructed image. As the edges axe detected and protected, and the NSBT is used, the proposed algorithm reaches the state-of-the-art effect which realizes both despeckling and preserving edges and details simultaneously. Experimental results show that both the subjective visual effect and the mainly objective performance indexes of the proposed algorithm outperform that of both Bayesian wavelet shrinkage with edge detection and Bayesian least square-Gaussian scale mixture （BLS-GSM）.

关键词： computer image processing synthetic aperture radar speckle edge detection nonsubsampled second generation bandelet transform Canny operator threshold shrinkage.

Multiary turbo code fitting for unitary space-time modulation and its MAP decoding algorithm

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Science china(Information Sciences) 2010年第12期53卷 2610-2619页

作者： ZHANG DaPeng 1,2,3.LU Ju 1,XU HongJi 1 & ZHANG xingYu 1 1 School of Information Science and Engineering,Shandong university,Jinan 250100,china 2 state Key {3. of integrated services networks,xidian university,xi'an 710077,china 3.Department of Avionics Engineering,First Aeronautical College of the Air Force,xinyang 464000,china 1. School of Information Science and Engineering Shandong University Jinan 250100 China2. State Key Laboratory of Integrated Services Networks Xidian University Xi’an 710077 China3. Department of Avionics Engineering First Aeronautical College of the Air Force Xinyang 464000 China

Unitary space-time modulation(USTM) fits for rapid Rayleigh flat fading channels as it can realize wireless communication when neither the transmitter nor the receiver knows the channel state information(CSI).However,an intrinsic problem is that only when the signal-to-noise ratio(SNR) is high can it give an ideal bit error rate(BER) *** existing bit-wise processing scheme of the combination of turbo code and USTM improves the BER performance and results in an unacceptable calculation complexity,storage and time delay *** this paper,we propose a multiary processing scheme and its corresponding multiary MAP decoding *** results verify that our scheme can reduce the system complexity while keep a good BER ***,we present the first analysis of the reason for the BER performance deterioration of the combination scheme at low SNR with the help of the definition of USTM.

关键词： multiple-input multiple-output unitary space-time modulation turbo code MAP decoding diversity

Optimal regulation of flexible loads in rural residential buildings considering mobile batteries:A case study in Shaanxi Province

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Building Simulation 2024年第7期17卷 1065-1083页

作者： xi Luo WenceShi School of Building services Science and Engineering Xian University of Architecture and Technology(XAUAT)Xi'an 710055China state Key laboratory of Green Building Xi'an 710055China

While the grid-connected capacity of rural household photovoltaics is increasing rapidly,achieving dynamic supply-demand matching despite fluctuations in solar energy is *** the rapid development of rural electrification,battery-powered technologies,such as electric vehicles and electric agricultural machinery,are becoming increasingly popular in rural *** this context,utilizing idle mobile batteries to assist in energy storage for rural residential buildings offers a new way to solve the problem of dynamic supply-demand *** this study,a field survey was conducted on several typical fruit-growing villages in the Central Shaanxi Plain in Shaanxi Province of *** rural households were selected to calculate the electricity loads of the residential buildings,with due consideration to the intervention of mobile *** the premise of installing 3.kW household photovoltaic systems in rural households,an economical efficiency-oriented model was built for the optimal regulation of flexible *** results were compared in the context of two patterns of electricity consumption,i.e.,unidirectional charging of mobile batteries from buildings and bidirectional charging and discharging between mobile batteries and *** bidirectional pattern significantly increased the photovoltaic consumption of typical rural households on various typical ***,during both scenarios of not implementing time-of-use and implementing time-of-use,the typical day of the winter slack farming season exhibited the best photovoltaic consumption effect among all types of typical ***,the bidirectional pattern also result in a significant increase in the annual electricity sales revenues for typical rural households.

关键词： demand-side response flexible load mobile battery household photovoltaics

A NEW EFFICIENT ID-BASED PROXY BLIND SIGNATURE SCHEME

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Journal of Electronics(china) 2008年第2期25卷 226-231页

作者： Ming Yang Wang Yumin state Key Lab of integrated Service network Xidian University Xi＇an 710071 China

In a proxy blind signature scheme,the proxy signer is allowed to generate a blind signature on behalf of the original signer. The proxy blind signature scheme is useful in several applications such as e-voting,e-payment,etc. Recently,Zheng,et al. presented an IDentity(ID) -based proxy blind sig-nature. In this paper,a new efficient ID-based proxy blind signature scheme from bilinear pairings is proposed,which can satisfy the security properties of both the proxy signatures and the blind signature schemes. Analysis of the scheme efficiency shows that the new scheme is more efficient than Zheng,et al.'s scheme. The proposed scheme is more practical in the real world.

关键词： Blind signature Proxy signature Bilinear pairing

Quantum Authentication Based on the Lengthened String Scheme

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The Journal of china Universities of Posts and Telecommunications 2004年第z1期11卷 14-17,25页

作者： GUO Fen-zhuo~(1,2), WEN Qiao-yan~1, ZHU Fu-chen~3.1.School of Science, Beijing university of Posts and Telecommunications, Beijing 100876, P.R. china 2.state Key {3. of integrated services network, xidian university, xi’an 710071, P.R. china 3.National {3. for Secure Communication, Chengdu 610041, P.R. china School of Science Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

Assuming there is a shared string between the users, we present a novel scheme, the lengthened string scheme (LSS), where the shared string is lengthened firstly by a specially designed algorithm, then some special treatments are applied on the lengthened one before it is used to authenticate. Based on the lengthened string scheme (LSS) we propose a quantum authentication protocol using entanglements. And the robustness of our protocol is discussed. In fact all the quantum key distribution protocols can do identification simultaneously based on the LSS.

关键词： quantum cryptography quantum authentication quantum key distribution LSS