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Efficiency-aware and fairness-aware joint-layer optimization for downlink data scheduling in OFDM

Science in China(Series F) 2008年第2期51卷 171-182页

作者： GUO KunQi SUN LiXin WANG Ping JIA ShiLou Shanghai Research Center for Wireless Communications Shanghai Institute of Microsystem and Infor- mation Technology Chinese Academy of Sciences Shanghai 200050 China School of Measurement & Control Technology and Communication Engineering Harbin University of Science and Technology Harbin 150080 China Communication Research Center Harbin Institute of Technology Harbin 150001 China

Efficiency and fairness are two crucial issues to be considered for resource alloca- tion in multi-user wireless networks. Based on the joint optimization of physical layer and data link layer, an optimization model is derived to achieve efficient and fair downlink data scheduling in multi-user OFDM wireless networks by maximizing the total utility function with respect to the average waiting time of user queue. A dynamic sub-carrier allocation algorithm （DSAA） based on the optimization model is proposed in order to obtain the maximization of the total scheduling utility. Effi- ciency is improved by combining DSAA with time scale interference predictor （TSIP） which at large time scales predict ON/OFF period of user data with temporal corre- lation structure across multiple time scales in multi-user interference environment. Simulation results verify the efficiency and fairness of the scheme.

关键词： OFDM efficiency and fairness joint-layer scheduling utility function

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New blind equalization schemes based on constant cross algorithm

New blind equalization schemes based on constant cross algor...

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2008 11th IEEE International Conference on communication technology, ICCT 2008

作者： Shun-Lan, Liu Jian-Hong, Hu Ming-Zeng, Dai School of Communication Engineering Hangzhou Dianzi University Hangzhou 310018 China National Laboratory of Information Control Technology for Communication System Jiaxing 314033 China

ISBN: (纸本)9781424422517

In this work, we present two new blind equalization schemes suitable for transmitting cross cross-QAM signals. Based on the framework of constant cross algorithm (CXA), a modified CXA (MCXA) is obtained by adding a constellation-matched error (CME) term to the cost function of the CXA. For the MCXA, the CXA term provides global convergence and the CME term helps to decrease the residual error and accelerate convergence. Furthermore, we propose a decision-directed version of the MCXA, called DD-MCXA, which can improves the performance of the MCXA. Preserving the good initial convergence characteristics of the CXA, the DD-MCXA automatically decreases the effect of the CXA errors when the equalizer is near convergence. Both simulation and analysis demonstrate the good performance of the proposed schemes. © 2008 IEEE.

关键词： Blind equalization

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A fast motion estimation algorithm based on diamond and line/triangle search patterns

A fast motion estimation algorithm based on diamond and line...

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2008 3rd International Conference on Pervasive Computing and Applications, ICPCA08

作者： Yun, Cheng Min, Wu School of Information Science and Engineering Central South University Changsha China Department of Communication and Control Engineering Hunan Institute of Humanities Science and Technology Loudi China

ISBN: (纸本)9781424420209

Based on the directional characteristic of SAD(Sum of Absolute Difference) distribution and the center-biased characteristic of motion vectors, a fast BMA(blockmatching motion estimation algorithm), DLTS(Diamond Line/Triangle Search), is proposed in this paper. DLTS employs line search pattern(LP) or triangle search pattern(TP) adaptively according to the distance between the MBD(Minimum Block Distortion) and SMBD(Second MBD) points to locate the best matching block with large motion vector, and diamond search pattern(DP) to refine the motion vector. Although the proposed DLTS can also be trapped in local minima, the experimental results show that it is faster than DTS(Diamond Triangle Search) and its encoding efficiency is almost the same as that of DTS. © 2008 IEEE.

关键词： Motion estimation

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A care communication system with space sharing function

A care communication system with space sharing function

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22nd International Conference on Advanced Information Networking and Applications, AINA 2008

作者： Koyama, Akio Takenaka, Yosuke Arai, Junpei Barolli, Leonard Department of Informatics Graduate School of Science and Engineering Yamagata University Japan Department of Information and Control Engineering Yamagata College of Industry and Technology Japan Department of Information and Communication Engineering Fukuoka Institute of Technology Japan

ISBN: (纸本)0769530958

Recently, there are a lot research works for multimedia communication systems. Especially, the space sharing communication is one of research trends for multimedia communication. By using the space sharing technology, the users feel as they are in the same space, even if they are in different locations. This can be done taking each video image of two remote points into one space. In this paper, we propose a care communication system with space sharing function. The implemented care communication system supports the communication and information sharing among in-patients, family members, doctors and helpers. In the proposed system, we have developed not only integration of two video images but also a warmth transmission function. By using this function, two persons in different locations can transmit their feelings as they are in the same space. We verified the proposed system effectiveness by conducting some experiments. © 2008 IEEE.

关键词： Information dissemination

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A fast mode decision algorithm of 44 block intra prediction for H.264/AVC

A fast mode decision algorithm of 44 block intra prediction ...

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Proceedings of 2008 3rd International Conference on Intelligent System and Knowledge engineering, ISKE 2008

作者： Cheng, Yun Wu, Min School of Information Science and Engineering Central South University 410083 Changsha China Department of Communication and Control Engineering Hunan Institute of Humanities Science and Technology 417000 Loudi China

ISBN: (纸本)9781424421978

It is well known that H.264/AVC has great advantage of coding efficiency compared with the successful prior coding standards and it can save about 50% bit-rate under the same reconstructed picture quality. But the complexity of H.264/AVC encoder is also very high and it limits the application of H.264/AVC in the domain of real time video communication. Based on some observations in the experiments, we propose a novel fast mode decision algorithm of 44 block intra prediction for H.264/AVC in this paper. The proposed algorithm utilizes the following facts: (i) the horizontal prediction mode has higher possibility to be the best prediction mode than the other eight modes, (ii) The RD costs between the best prediction mode and its adjacent prediction mode have strong correlation, (iii) some 44 blocks' coefficients of DCT are all zeroes in some cases. Therefore, it can reduce the computational complexity of the H.264/A VC encoder remarkably. Experimental results show that the reduced time of our proposed algorithm is about 45% less than that of H.264/AVC, at the expense of 2%, or so bit-rate increasing. © 2008 IEEE.

关键词： Forecasting

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Analysis of simulation risk and VV and a based on extended FMECA

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Xitong Fangzhen Xuebao / Journal of System Simulation 2008年第15期20卷 3934-3939页

作者： Zheng, Li-Ping Liu, Xiao-Ping School of Computer Science and Information Hefei University of Technology Hefei 230009 China Engineering Research Center of Safety Critical Industry Measure and Control Technology Min. of Edu. Hefei University of Technology Hefei 230009 China

VV and A is risk-driven activity, and FMECA is a widely used risk analysis method. Based on them, a new method, aiming to M and S (Modeling and Simulation) domain and named SimFMECA, was put forward. Firstly, FMECA analysis table and process was extended, then a framework of FMI to general simulation system was discussed, moreover, a risk and criticality ranking measure was proposed, and according to the risk rank, required VV and A effort was identified, including VV and A level and VV and A activities. Finally an experiment was carried out to validate SimFMECA. SimFMECA is a qualitative method, and is characteristic of low cost and easy implementation.

关键词： Credibility FMECA Level Modeling and simulation (M and S) Risk VV and A

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Stochastic gradient algorithm for multi-input systems based on the auxiliary model

Stochastic gradient algorithm for multi-input systems based ...

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International Conference on Computer Science and Software engineering, CSSE 2008

作者： Liao, Yuwu Wang, Xianfang Ding, Rui Feng Dept. of Physics and Electronics Information Technology Xiangfan University Xiangfan 441053 China Dept. of Information Engineering Henan Institute of Science and Technology Xinxiang 453003 China School of Communication and Control Engineering Jiangnan University Wuxi 214122 China

ISBN: (纸本)9780769533360

This paper presents an auxiliary model based stochastic gradient parameter estimation algorithm for multi-input output-error systems by minimizing a quadratic cost function. The basic idea is to replace the unknown variables in the information vector with the outputs of an auxiliary model or estimated outputs and the analysis and simulation results indicate that the parameter estimates converge to their true values for persistent excitation input signals. The algorithm proposed has significant computational advantage over existing least squares identification algorithms. A simulation example is given. © 2008 IEEE.

关键词： Stochastic systems

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A GA-based QoS multicast routing algorithm for large-scale networks

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International Journal of High Performance Computing and Networking 2008年第5-6期5卷 381-387页

作者： Koyama, Akio Nishie, Toshiki Arai, Junpei Barolli, Leonard Department of Informatics Graduate School of Science and Engineering Yamagata University 4-3-16 Jonan Yonezawa 992-8510 Japan Department of Information and Control Engineering Yamagata College of Industry and Technology 2-2-1 Matsuei Yamagata 990-2473 Japan Department of Information and Communication Engineering Fukuoka Institute of Technology 3-30-1 Wajiro-Higashi Higashi-Ku Fukuoka 811-0295 Japan

For multimedia applications, the routing algorithms should consider many Quality of Service (QoS) parameters. However, to find routes with two or more QoS parameters is an NP-hard problem. Therefore, recently many researchers are trying to use heuristic methods such as Genetic Algorithm (GA). In a previous work, a QoS multicast routing based on GA was proposed. However, in this algorithm, the multicast routing falls in the local minimum and cannot satisfy the application requirements. In this paper, we propose a new QoS multicast routing protocol, which has better genetic operations than the conventional algorithm, resulting in a better performance. Copyright © 2008, Inderscience Publishers.

关键词： Quality of service

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Optimal real time DSP implementation of Extended Adaptive Multirate Wide Band (AMR-WB+) Speech Codec

Optimal real time DSP implementation of Extended Adaptive Mu...

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IEEE Region 10 International Conference TENCON

作者： Rachana Nagal Manish Kumar Rahul Jain Department of Electronics and Communication Engineering Amity School of Engineering and Technology New Delhi India Department of Instrumentation and Control Engineering Amity School of Engineering and Technology New Delhi India

Speech transmission are the most used form of communications in the personal communication systems and spectral efficiency is the very important aspect in wireless communication system and so low bit rate speech codecs play an important role in determining the systempsilas spectral efficiency. The AMR-WB+ (Extended Adaptive Multirate Wide Band) speech codec provides unique performance at very low bit rates from below 10 kbps to 24 kbps. The speech codec has high robustness to withstand high-bit error rates and performs well in tandeming conditions, hence leading to efficient bandwidth utilization and increased channel capacity. In this paper, several optimization techniques are presented for efficient implementation of AMR-WB+ on real time digital signal processor TMS320C6713, with an aim to overcome the limitation of computational burden and also scaling this application for enhanced speed to process more number of channels. The work presented here is the optimization of decoder part of AMR-WB+ speech codec and a step to minimize its MIPS (Millions Instruction per second), which includes debugging profiling and optimization with the help of code composer studio (CCS an IDE for TMS320C6713) and finally the implementation of the decoder on DSP Processor TMS320C6713. These techniques are in general implemented in any DSP processor platform.

关键词： Digital signal processing Wideband Speech codecs Bit rate Decoding Wireless communication Robustness Error analysis Bandwidth Channel capacity

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Finite support 2-D FIR QMF PR filter bank design by spectral factorization using Gröbner basis

Finite support 2-D FIR QMF PR filter bank design by spectral...

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Asia-Pacific Conference on communications

作者： A. Thamrongmas C. Charoenlarpnopparut Electronics and Communication Engineering Program School of Communications Instrumentations & Control Sirindhorn International Institute of Technology Thammasat University Thailand

In this paper, the application of spectral factorization by using Grobner basis approach to the problem of 2-D finite support QMF filter bank design is proposed along with illustrative example. Earlier, it has been shown that the Grobner basis can be applied to solve the problem of 2-D factorization and its effectiveness in dealing with polynomial equation system are demonstrated. Despite the fact that there exist many good techniques for designing one dimensional QMF synthesis and analysis filter banks, the two-dimensional counterpart has a major bottleneck due to the generalization of 2-D spectral factorization. The proposed algorithm is the direct generalization of the 1-D QMF filter bank design by spectral factorization. Furthermore, the filter coefficients can be computed in symbolic forms and thus provide a good opportunity for further optimization if additional criteria are given.

关键词： Finite impulse response filter Filter bank OFDM Video coding Resource management Base stations Broadcasting Frequency synchronization Interchannel interference Wireless communication

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