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Multimode Transmission in Network MIMO Downlink with Incomplete CSI

EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2011年第unknown期2011卷 743916-1-743916-13页

作者： Seifi, Nima Viberg, Mats Heath, Robert W., Jr. Zhang, Jun Coldrey, Mikael Chalmers Univ Technol Dept Signals & Syst S-41296 Gothenburg Sweden Univ Texas Austin Dept Elect & Comp Engn Wireless Networking & Commun Grp WNCG Austin TX 78712 USA Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Kowloon Hong Kong Peoples R China Ericsson AB Ericsson Res S-41756 Gothenburg Sweden

We consider a cooperative multicell MIMO (a.k.a network MIMO) downlink system with multiantenna base stations (BSs), which are connected to a central unit and communicate with multiantenna users. In such a network, obtaining perfect channel state information (CSI) of all users at the central unit to exploit opportunistic scheduling requires a substantial amount of feedback and backhaul signaling. We propose a scheduling algorithm based only on the knowledge of the average SNR at each user from all the cooperating BSs, denoted as incomplete CSI. Multimode transmission is applied that is able to adaptively adjust the number of data streams transmitted to each user. Utilizing the results of random matrix theory, an analytical framework is proposed to approximate the ergodic rate of each user with different number of data streams. Using these ergodic rates, a joint user and mode selection algorithm is proposed, where only the scheduled users need to feed back instantaneous CSI. Simulation results demonstrate that the developed analytical framework provides a good approximation for a practical number of antennas. While substantially reducing the feedback overhead, it is shown that the proposed scheduling algorithm performs closely to the opportunistic scheduling algorithm that requires instantaneous CSI feedback from all users.

关键词： Downlink Feedback data flow average SNR matrix theory multimode transmission selection algorithm Network multiple input multiple output systems

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A Comparison of Scheduling Strategies for MIMO Broadcast Channel with Limited Feedback on OFDM Systems

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EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2010年第unknown期2010卷 968703-968703页

作者： Conte, Ermanna Tomasin, Stefano Benvenuto, Nevio Univ Padua Dept Informat Engn I-35131 Padua Italy

We consider a multiuser downlink transmission from a base station with multiple antennas (MIMO) to mobile terminals (users) with a single antenna, using orthogonal frequency division multiplexing (OFDM). Channel conditions are reported by a feedback from users with limited rate, and the base station schedules transmissions and beamforms signals to users. We show that an important set of schedulers using a general utility function can be reduced to a scheduler maximizing the weighted sum rate of the system. For this case we then focus on scheduling methods with many users and OFDM subcarriers. Various scheduling strategies are compared in terms of achieved throughput and computational complexity and a good tradeoff is identified in greedy and semiorthogonal user selection algorithms. In the greedy selection algorithm, users are selected one by one as long as the throughput increases, while in the semiorthogonal approach users are selected based on the channel correlation. An extension of these approaches from a flat-fading channel to OFDM is considered and simplifications that may be useful for a large number of subcarriers are presented. Results are reported for a typical cellular transmission of the long-term evolution (LTE) of 3GPP.

关键词： Orthogonal frequency division multiplexing BASE STATION Subcarriers Feedback multiple input multiple output systems scheduler program general utility function COMMUNITY RATING SYSTEM broadcast channels scheduling policy selection algorithm greedy method flat fading channel

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Comparison of Battery Architecture Dependability

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BATTERIES-BASEL 2018年第3期4卷 31-31页

作者： Savard, Christophe Venet, Pascal Niel, Eric Pietrac, Laurent Sari, Ali Univ Claude Bernard Lyon 1 Univ Lyon Ecole Cent Lyon INSA LyonCNRS F-69622 Villeurbanne France

This paper presents various solutions for organizing an accumulator battery. It examines three different architectures: series-parallel, parallel-series and C3C architecture, which spread the cell output current flux to three other cells. Alternatively, to improve a several cell system reliability, it is possible to insert more cells than necessary and soliciting them less. Classical RAMS (Reliability, Availability, Maintainability, Safety) solutions can be deployed by adding redundant cells or by tolerating some cell failures. With more cells than necessary, it is also possible to choose active cells by a selection algorithm and place the others at rest. Each variant is simulated for the three architectures in order to determine the impact on battery-operative dependability, that is to say the duration of how long the battery complies specifications. To justify that the conventional RAMS solutions are not deployed to date, this article examines the influence on operative dependability. If the conventional variants allow to extend the moment before the battery stops to be operational, using an algorithm with a suitable optimization criterion further extend the battery mission time.

关键词： battery operative dependability selection algorithm

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Validation of an algorithm to Identify Epidermal Necrolysis on a Medico-Administrative Database

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JOURNAL OF INVESTIGATIVE DERMATOLOGY 2024年第3期144卷 708-710.e7页

作者： Bettuzzi, Thomas Hoisnard, Lea Beytout, Quentin Ingen-Housz-Oro, Saskia Sbidian, Emilie Henri Mondor Hosp AP HP Dept Dermatol Creteil France Paris Est Creteil Univ UPEC Epidemiol Dermatol & Evaluat Therapeut EpiDermE Creteil France Henri Mondor Hosp AP HP Tox Bullous Dermatoses & Severe Drug React Referen TOXIBUL Creteil France Henri Mondor Hosp AP HP Univ Hosp Federat FHU TRUE InnovaT theRapy immUne Creteil France Henri Mondor Hosp INSERM Clin Invest Ctr 1430 Creteil France

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CARER: Efficient Dynamic Sensing for Continuous Activity Monitoring

CARER: Efficient Dynamic Sensing for Continuous Activity Mon...

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Annual International Conference of the IEEE Engineering in Medicine and Biology Society

作者： Lawrence K. Au Alex A. T. Bui Maxim A. Batalin Xiaoyu Xu William J. Kaiser Electrical Engineering Department University of California Department of Radiological Sciences University of California

ISBN: (纸本)9781424441211

Advancement in wireless health sensor systems has triggered rapidly expanding research in continuous activity monitoring for chronic disease management or promotion and assessment of physical rehabilitation. Wireless motion sensing is increasingly important in treatments where remote collection of sensor measurements can provide an in-field objective evaluation of physical activity patterns. The well-known challenge of limited operating lifetime of energy-constrained wireless health sensor systems continues to present a primary limitation for these applications. This paper introduces CARER, a software system that supports a novel algorithm that exploits knowledge of context and dynamically schedules sensor measurement episodes within an energy consumption budget while ensuring classification accuracy. The sensor selection algorithm in the CARER system is based on Partially Observable Markov Decision Process (POMDP). The parameters for the POMDP algorithm can be obtained through standard maximum likelihood estimation. Sensor data are also collected from multiple locations of the subjects body, providing estimation of an individual's daily activity patterns.

关键词： Activity patterns selection algorithm Sensor systems Software systems wireless disease management Operating life Sensors energy consumption

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Topology Aware Convention Emergence 14

Topology Aware Convention Emergence

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International Conference on Autonomous Agents and Multiagent Systems

作者： Mohammad Rashedul Hasan Sherief Abdallah Anita Raja University of North Carolina at Charlotte The British University in Dubai

ISBN: (纸本)9781634391313

Single convention convergence across different types of networks is a challenging multi-agent task. Our central hypothesis in this paper is that no simple distributed mechanism (such as the state-of-the-art Generalized Simple Majority (GSM) rule) can achieve this. We augment the agents with "network thinking" capability to solve this single convention convergence problem. Topological features such as node degree is used to design the accumulated coupling strength (ACS) convention selection algorithm. However, ACS does not perform as well in random networks as GSM does. Hence we propose a topology aware convention selection (TACS) algorithm that enables the agents to predict their local neigh-borhood topology and then to select a suitable convention selection algorithm. We have performed an extensive simulation study on random and SF networks showing that the majority of the agents correctly recognize their topology and use the appropriate convention mechanism leading to the convergence into a single convention.

关键词： algorithms Design Experimentation Multi-agent systems Scale-free network Random network Convention selection algorithm Network Thinking Random Network complex networks Convention Multi-agent systems experimentation algorithms topology Agents Global mobile communication-systems wireless phone Converge selection algorithm

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Sensor Scheduling for Energy Constrained Estimation in Multi-Hop Wireless Sensor Networks

Sensor Scheduling for Energy Constrained Estimation in Multi...

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2010 49th IEEE Conference on Decision and Control

作者： Yilin Mo Emanuele Garone Alessandro Casavola Bruno Sinopoli Carnegie Mellon University Pittsburgh PA USA Universita degli Studi della Calabria Rende (CS) Italy

ISBN: (纸本)9781424477456

Wireless Sensor Networks (WSNs) enable a wealth of new applications where remote estimation is essential. Individual sensors simultaneously sense a dynamic process and transmit measured information over a shared channel to a central fusion center. The fusion center computes an estimate of the process state by means of a Kalman filter. In this paper we assume that the WSN admits a tree topology with fusion center at the root node. At each time step only a subset of sensors can be selected to transmit their observations to the fusion center due to limited energy budget. We propose a stochastic sensor selection algorithm to randomly select a subset of sensors according to certain probability distribution, which is chosen to minimize the expected next step estimation error covariance matrix while maintaining the connectivity of the network. One of the main advantages of the stochastic formulation over the traditional deterministic formulation is that the stochastic formulation provides smaller expected estimation error than the deterministic formulation. Further, we prove that the optimal stochastic sensor selection problem can be relaxed into a convex optimization problem and thus solved efficiently. We also provide a possible implementation of our algorithm which does not introduce any communication overhead. Finally a numerical example is provided to show the effectiveness of the proposed approach.

关键词： Sensors process state Tree Topology Probability distribution wireless multi-hop networks shared channel Stochastic FUSION selection algorithm Kalman filters Energy budget Estimation error Spread spectrum communication

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CoRET: A Network Coding Based Multicast Retransmission Scheme for Mobile Communication Networks

CoRET: A Network Coding Based Multicast Retransmission Schem...

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IEEE International Conference on Communications Workshops

作者： Hao Wu Jun Zheng National Mobile Communications Research Laboratory Southeast University

ISBN: (纸本)9781612842325

This paper proposes a network Coding based RETransmission (CoRET) scheme for supporting multicast service in mobile communication networks. CoRET introduces network coding and employs a Hamming distance based packet selection algorithm to select packets for encoding in order to improve the retransmission performance in terms of efficiency and reliability. Simulation results show that CoRET can achieve better retransmission performance than an existing retransmission scheme, Random Pick. Moreover, a mathematical model is developed to analyze the impact of the number of original packets encoded into a packet for retransmission (i.e., encoding number) on the retransmission performance in order to find an optimal encoding number that can achieve the best performance. Numerical results show that for a reliable transmission channel a smaller encoding number can achieve a better performance while for an unreliable channel a larger encoding number is preferred.

关键词： Multicast Network coding Retransmission Mobile communication network RETRANSMISSION Mobile communications networks Packet Network coding selection algorithm Hamming distance networks(communications) Multicast

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GROWTH OPTIMAL INVESTMENT WITH THRESHOLD REBALANCING PORTFOLIOS UNDER TRANSACTION COSTS

GROWTH OPTIMAL INVESTMENT WITH THRESHOLD REBALANCING PORTFOL...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Sait Tunc Mehmet A. Donmez Suleyman S. Kozat Georgia Institute of Technology Industrial Engineering Department Atlanta USA Koc University Electrical and Electronics Engineering Department Istanbul Turkey Bilkent University Electrical and Electronics Engineering Department Ankara Turkey

ISBN: (纸本)9781479903573

We study how to invest optimally in a stock market having a finite number of assets from a signal processing perspective. In particular, we introduce a portfolio selection algorithm that maximizes the expected cumulative wealth in i.i.d. two-asset discrete-time markets where the market levies proportional transaction costs in buying and selling stocks. This is achieved by using "threshold rebalanced portfolios", where trading occurs only if the portfolio breaches certain thresholds. Under the assumption that the relative price sequences have log-normal distribution from the Black-Scholes model, we evaluate the expected wealth under proportional transaction costs and find the threshold rebalanced portfolio that achieves the maximal expected cumulative wealth over any investment period.

关键词： Portfolio management threshold rebalancing transaction cost discrete-time market continuous distribution CONTINUOUS DISTRIBUTIONS transaction costs Threshold selection algorithm log normal distribution signal processing Stock exchanges buying and selling Proportional

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Adaptive streaming media VOD system under the background of new media

Adaptive streaming media VOD system under the background of ...

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2015 International Conference on Automation,Mechanical Control and Computational Engineering(AMCCE 2015)

作者： Yunxiang Zhang Yunpeng He Shengcan Jin Bin Wang Business College Jiamusi University Radio and Television Bureau of Jiamusi College of Information Science & Electronic Technology Jiamusi University

In this thesis, the main part is the research on the Video-On-Demand. Using an adaptive streaming media transmission program, according to network conditions on the video-on-demand server control pro

ISBN: (纸本)9781510803084

In this thesis, the main part is the research on the Video-On-Demand. Using an adaptive streaming media transmission program, according to network conditions on the video-on-demand server control pro

关键词： VOD Streaming media Adaptive Streaming Video Self tuning Videotapes customers design scheme Clients Network protocols selection algorithm Video on demand

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