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TCP performance dynamics and link-layer adaptation based optimization methods for wireless networks

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2007年第5期6卷 1864-1879页

作者： Singh, Jatinder Pal Li, Yan Bambos, Nicholas Bahai, Ahmad Xu, Bangnan Zimmermann, Gerd Deutsch Telekom Labs D-10179 Berlin Germany Qualcomm Inc Campbell CA 94304 USA Stanford Univ Dept Elect Engn Stanford CA 94305 USA Univ Calif Berkeley Berkeley CA 94720 USA Deutsch Telekom T Syst D-64295 Darmstadt Germany

Almost a decade long research on the performance of TCP in wireless networks has resulted in many proposals and solutions [1]-[9] to the problem of TCP throughput degradation. Several of these measures, however, have their share of drawbacks. With the continuing emergence of wireless technologies ever since the work on TCP performance over wireless began, smart link-layer mechanisms like adaptive modulation and coding, power control, and incremental redundancy have been designed and deployed. In this work, we outline a cross-layer optimization framework based on the congestion control dynamics of a bulk-transfer TCP flow and demonstrate its application to networks which offer link-layer adaptive measures. We begin by observing that the TCP's congestion window dynamics are comprised of certain recurring patterns which we term as cycles. We then overlay a TCP throughput optimization methodology that selects link-layer transmission modes (e.g. modulation scheme, coding rate, transmission power, or a combination thereof) in accordance with TCP dynamics and wireless channel conditions. We provide insights into the working of the optimization procedure which protects TCP segments against losses on the wireless channel when the TCP congestion window size (in bytes) is below the bandwidth-delay product of the network. The protection against wireless channel losses is rendered by the link-layer by employing robust modulation and coding schemes, high transmission power, etc. We show that TCP dynamics aware link adaptation measures lead to substantial enhancement of TCP throughput in EGPRS and IEEE 802.11a networks.

关键词： adaptive coding adaptive modulation dynamic programming land mobile radio cellular systems power control transport protocols wireless LAN

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Multiplexing/Beamforming switching for coded MIMO in spatially correlated channels based on closed-form BER approximations

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2007年第5期56卷 2555-2567页

作者： Mckay, Matthew R. Collings, Iain B. Forenza, Antonio Heath, Robert W., Jr. Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Kowloon Peoples R China Informat & Commun Technol Ctr Commonwealth Sci & Ind Org Marsfield NSW 2122 Australia LLC San Francisco CA 94107 USA Univ Texas Dept Elect Engn & Comp Engn Wireless Networking & Commun Grp Austin TX 78712 USA

This paper considers low-complexity coded multiple-input-multiple-output transmission in Rayleigh channels with correlation between antennas at both the transmitter and receiver. We consider statistical beamforming (SB) and spatial multiplexing (SM) with a zero-forcing receiver. We calculate the link-level capacity of both schemes with bit-interleaved coded modulation and derive accurate closed-form approximations to the bit error rate. We then show how the resulting expressions can. be used in an adaptive algorithm to select the best combination of code rate, modulation format, and transmission scheme (SB or SM) in order to maximize throughput. Unlike other mode-switching schemes that require empirical lookup tables, this approach applies to any correlation scenario. Numerical studies are used to demonstrate the performance as a function of signal-to-noise ratio and correlation parameters.

关键词： adaptive coding modulation multiple-input-multiple-output (MIMO) communications spatially correlated channels

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adaptive signaling based on statistical characterizations of outdated feedback in wireless communications

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PROCEEDINGS OF THE IEEE 2007年第12期95卷 2337-2353页

作者： Zhang, Honglei Wei, Shuangqing Ananthaswamy, Ganesh Goeckel, Dennis L. Univ Massachusetts Dept Elect & Comp Engn Amherst MA 01003 USA Louisiana State Univ Dept Elect & Comp Engn Baton Rouge LA 70803 USA Analog Devices Inc Wilmington MA 01887 USA

Wireless links form a critical component of communication systems that aim to provide ubiquitous access to information. However, the time-varying characteristics (or "state") of wireless channels caused by the mobility of transmitters, receivers, and objects in the environment make it difficult to achieve reliable communication. adaptive signaling exploits any channel state information (CSI) available at the transmitter to provide the potential to significantly increase the throughput of wireless links and/or greatly reduce the receiver complexity. As such, adaptive signaling has attracted significant research interest in the last decade and has found application in numerous commercial wireless systems, ranging from cellular data systems to wireless local area networks (WLANS). However, one of the great challenges of wireless communications is that it is difficult to obtain perfect CSI due to the inherently noisy and outdated nature of CSI available at the transmitter. Over the last decade, we have championed the idea of choosing the appropriate transmitted signal based on statistical models for the current channel state conditioned on the channel measurements. In this semi-tutorial paper, we first review how this class of methods has been developed for single-antenna systems, and then present novel recent designs for multiple-antenna systems. Key to the development in each case is the development of the error characterization given the outdated estimates and the use of such to allocate data rate and power over time and possibly space. in general, the focus is on rate allocation, while power allocation is done through a pruning method. Numerical results will demonstrate in both the single-antenna and multiple-antenna cases that such an approach provides a robust method for improving system data rate versus the standard practice of employing link margin to compensate for such uncertainties.

关键词： adaptive coding adaptive modulation beam-forming multiple-input multiple-output (MIMO) spatial multiplexing

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Performance of adaptive coding by selection of space-time block code matrix

Performance of adaptive coding by selection of space-time bl...

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60th IEEE Vehicular Technology Conference

作者： Niida, SL Inoue, T Takeuchi, Y KDDI Corp Mobile Commun Lab Chiyoda Ku Tokyo 1028460 Japan

ISBN: (纸本)0780385217

The 3rd generation mobile communication systems are currently spreading throughout the world and high speed data services on mobile systems such as streaming video, streaming audio and video phone are being widely utilized by the public at large. As higher speed rate services are infiltrated, the provision of wider band wireless systems is expected. MIMO (Multiple Input, Multiple Output) systems, which equip several antennas with both a transmitter and receiver, have recently been attracting much attention. Space-Time coding is a technique that exploits transmission diversity and achieves high performance under a fading environment. The Space-time Block Code is attracting particular attention for its high performance and decoding simplicity. We propose an adaptive coding scheme method using the Space-Time Block Code. It changes the Space-Time Block coding pattern and the modulation symbol according to the receiving condition. In this paper, we discuss this scheme and evaluate its throughput and transmission power performances based on simulation results using on ideal propagation environments and measured data in the experiment.

关键词： space-time block code adaptive coding adaptive modulation real tranmission environment

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Prediction and adaptive coding of sources with large or infinite alphabet.

Prediction and adaptive coding of sources with large or infi...

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IEEE International Symposium on Information Theory

作者： Ryabko, B Astola, J Siberian State Univ Novosibirsk 630102 Russia

ISBN: (纸本)0780382803

This paper suggests a scheme of adaptive coding and prediction for a case where a source generates letters from an alphabet with unknown (and even infinite) size. This scheme can be applied along with any predictor; here we use the Laplace predictor as the main example. We consider a case of prediction for i.i.d. sources, but all results can be easily extended to Markov sources. The suggested scheme is described using the tree notation.

关键词： adaptive codes prediction theory source coding Markov processes probability adaptive coding prediction scheme Laplace predictor Markov source tree notation

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A new approach to adaptive encoding data using self-organizing data structures

A new approach to adaptive encoding data using self-organizi...

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22nd International Symposium on Computer and Information Sciences

作者： Rueda, Luis Oommen, B. John Univ Concepcion Dept Comp Sci Edmundo Larenas 215 Concepcion 4030000 Chile Carleton Univ Sch Comp Sci Ottawa ON K1S 5B6 Canada Agder Univ Coll Dept Informat & Commun Technol Grimstad Norway

ISBN: (纸本)9781424413638

This paper demonstrates how techniques applicable for defining and maintaining a special case of binary search trees (BSTs) can be incorporated into "traditional" compression techniques to yield enhanced superior schemes. We, specifically, demonstrate that the newly introduced data structure, the Fano Binary Search Tree (FBST) can be maintained adaptively and in a self-organizing manner. The correctness and properties of the encoding and decoding procedures that update the FBST are included. We also include the theoretical and empirical analysis, which shows that the number of shift operators is large for small files, and it tends to decrease (asymptotically towards zero) for large files.

关键词： adaptive coding self-organizing data structures binary search trees

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adaptive coding and modulation for the reverse link of broadband satellite networks

Adaptive coding and modulation for the reverse link of broad...

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IEEE Conference and Exhibition on Global Telecommunications (GLOBECOM)

作者： S. Cioni R. De Gaudenzi R. Rinaldo D.E.I.S.-ARCES University of Bologna Bologna Italy ESTEC TOS-ETC European Space Research and Technology Centre-European Space Agency Noordwijk Netherlands

The effective implementation of adaptive coding and modulation for the reverse (user-to-satellite) link of broadband satellite systems, operating at Ka-band and above, calls for the resolution of a number of problems. The many-to-one reverse link nature and the related distributed interference characteristics make efficient and robust link adaptation challenging, particularly when in the presence of bursty traffic and time varying propagation conditions. In this paper, a channel estimation and adaptation algorithm, suitable for the system under analysis, are devised and their performance investigated in a Ka-band multibeam system study case for different multiple access schemes.

关键词： adaptive coding Modulation coding Satellites Physical layer Time division multiple access Interference Channel estimation Frequency Fading Attenuation

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adaptive coding and prediction of sources with large and infinite alphabets

Adaptive coding and prediction of sources with large and inf...

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Data Compression Conference (DCC)

作者： B. Ryabko J. Astola Siberian State University of Telecommunications and Computer Science Russia Technical University of Tampere Finland

The problem of predicting a sequence generated by a discrete source with unknown statistics is considered. This problem is of great importance for data compression, because of its use to estimate probability distributions for PPM algorithms and other adaptive codes. This paper suggested a scheme of adaptive coding (and prediction) for a case where a source generates letters from an alphabet with unknown or infinite size. This scheme can be applied along with Laplace, Krichevsky and any other predictors. The general case of the prediction, which is based on such a grouping, is considered and the estimates of the redundancy are given.

关键词： adaptive coding Data compression Computer science Statistical distributions Probability distribution

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Throughput Analysis of TDMA System Forward Link Packet Data Transmission with Superposition coding

Throughput Analysis of TDMA System Forward Link Packet Data ...

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IEEE Vehicular Technology Conference

作者： Baojin Li Zhifeng Ruan Guoquan Lu Xin Zhang Dacheng Yang Wireess Theories nd Technoogies Lb (WTT) Beijing Universiy of Poss nd Teecounicions Beijing Chin

ISBN: (纸本)1424402638;9781424402632;1424402646

Superposition coding can be used to improve capacity of communications in a variety of scenarios. This paper is concerned with the application of superposition coding in TDMA system forward link packet data transmission with adaptive modulation and coding (AMC). By taking advantage of the total received SINR disparities on the forward link, the system can transmit to multiple users at the same time and frequency by using superposition coding. The average sector throughput of TDMA system forward link packet data transmission with the proposed superposition coding technique is mathematically analyzed for a multi-cell scenario. From numerical examples, it is shown that superposition coding can significantly increase the average throughput of the system.

关键词： adaptive codes adaptive modulation cellular radio radio links time division multiple access TDMA system forward link packet data transmission multicell scenario superposition coding throughput analysis time division multiple access superposition coding adaptive modulation adaptive coding Radio links forward link

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Context Quantization by Minimum adaptive Code Length

Context Quantization by Minimum Adaptive Code Length

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IEEE International Symposium on Information Theory

作者： Soren Forchhammer Xiaolin Wu COM Department Technical University of Denmark Kongens Lyngby Denmark Department Electrical and Computer Engineering McMaster University Hamilton ONT Canada

ISBN: (纸本)9781424413973;1424414296;1424413974

Context quantization is a technique to deal with the issue of context dilution in high-order conditional entropy coding. We investigate the problem of context quantizer design under the criterion of minimum adaptive code length. A property of such context quantizers is derived for binary symbols. A fast context quantizer design algorithm for conditioning binary symbols is presented and its complexity analyzed. It is conjectured that this algorithm is optimal. The context quantization is performed in what may be perceived as a probability simplex space rather than in the space of context instances.

关键词： Quantization adaptive coding Image coding Context modeling Algorithm design and analysis Costs Entropy coding Statistics Source coding Random sequences

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