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Tunstall adaptive coding and miscoding

IEEE TRANSACTIONS ON INFORMATION THEORY 1996年第6期42卷 2167-2180页

作者： Fabris, F Sgarro, A Pauletti, R UNIV TRIESTE DIPARTIMENTO SCI MATEMAT TRIESTE ITALY PAULETTI PROFESS PONTE NELLE ALPI BELLUNO ITALY

In the first part of this paper, we tackle the case where a variable length-to-block Tunstall code is used to encode the wrong source (miscoding). It turns out that, exactly as it happens in the case with Huffman coding, the asymptotic excess rate is given by the informational divergence between the probability distribution ruling the source and the probability distribution for which the Tunstall code had been devised. We also prove asymptotic equality between the individual rate of a codeword and the corresponding self-information. This allows us to bound the maximal and the minimal length in a Tunstall tree. In the second part of the paper we study the case where the probability distribution of the source changes in time. If this happens, it is necessary to frequently update the current code, to ensure that the optimality conditions concerning its rate are met. This coding procedure is known as adaptive coding, We propose some schemes for adaptive Tunstall coding, based on the structure of the coding tree, on the ''ordering property,'' analogous to Gallager's sibling property of the Huffman code, and on the ''Tunstall regions,'' analogous to the attraction regions due to Longo and Galasso.

关键词： source coding variable length-to-block coding Tunstall codes adaptive coding informational divergence self-information

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EXIT chart-aided adaptive coding for MMSE turbo equalization with multilevel BICM

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IEEE COMMUNICATIONS LETTERS 2006年第6期10卷 486-488页

作者： Ibi, Shinsuke Matsumoto, Tad Sampei, Seiichi Morinaga, Norihiko Osaka Univ Grad Sch Engn Suita Osaka 5650871 Japan Univ Oulu Ctr Wireless Commun FIN-90570 Oulu Finland Hiroshima Int Univ Dept Informat Technol Hiroshima 7370112 Japan

This letter proposes adaptive coding (AC) for multilevel bit interleaved coded modulation (ML-BICM) with MMSE turbo equalization, of which aim is to minimize the information rate loss due to the mismatch between the channel realization and channel coding. With the aid of the knowledge about extrinsic information transfer (EXIT) characteristics at the receiver, the code parameters such as code rates and/or generator polynomials are adaptively selected independently in each the ML-BICM layer. Numerical results show that throughput efficiency can be significantly improved with the proposed AC technique over the automatic repeat request (ARQ) technique with fixed code rate.

关键词： turbo equalization soft interference cancellation frequency domain MMSE equalization EXIT analysis adaptive coding

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LUMINANCE adaptive coding OF CHROMINANCE SIGNALS

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IEEE TRANSACTIONS ON COMMUNICATIONS 1979年第4期27卷 703-710页

作者： NETRAVALI, AN RUBINSTEIN, CB Bell Laboratories Holmdel NJ USA

We describe two techniques for digital coding of the chrominance components of a color television signal. Both techniques make use of an observation that in color pictures most of the locations of large spatial changes in the chrominance are coincident with large spatial changes in the luminance. This allows us to predict the chrominance samples more efficiently using the previously transmitted chrominance and luminance samples, and the present luminance sample. In general, we determine which of the previous luminance samples best represents the present luminance sample and use the corresponding previous chrominance sample to represent the present chrominance sample. We present results of computer simulations of two such coding schemes. The first scheme, in which the chrominance components are coded by a DPCM coder, uses adaptive prediction of the chrominance components based on the luminance. In the second scheme, the chrominance signal is adaptively extrapolated from its past using the luminance signal for adaptation. Only those chrominance samples where the extrapolation error is more than a threshold are transmitted to the receiver. The addresses of such samples are derived from the luminance signal and therefore need not be transmitted. Our computer simulations on videotelephone type of pictures, indicate that, for the predictive coding, the entropy of the coded chrominance signals can he reduced by about 15 to 20 percent by adaptation. This results in a bit rate of 0.55 bits/ luminance pel, for transmission of chrominance information. Using adaptive extrapolation, only about 20 percent of the chrominance samples need to be transmitted which results in a bit rate of approximately 0.58 bits/luminance pel.

关键词： adaptive coding TV Computer simulation Computer errors Predictive coding Bit rate Entropy Extrapolation Displays Broadcasting

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On asymptotically optimal methods of prediction and adaptive coding for Markov sources

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JOURNAL OF COMPLEXITY 2002年第1期18卷 224-241页

作者： Ryabko, BY Topsoe, F Siberian State Univ Telecommun & Comp Sci Novosibirsk Russia Univ Copenhagen Dept Math Copenhagen Denmark

The problem of predicting a sequence x(1), x(2), ... generated by a discrete source with unknown statistics is considered. Each letter x(t+1) is predicted using information on the word x(1), x(2),...x(t) only. In fact, this problem is a classical problem which has received much attention. Its history can be traced back to Laplace. To estimate the efficiency of a method of prediction, three quantities are considered: the precision as given by the Kullback-Leibler divergence, the memory size of the program needed to implement the method on a computer, and the time required, measured by the number of binary operations needed at each time instant. A method is presented for which the memory size and the average time are close to the minimum. The results can readily be translated to results about adaptive coding. (C) 2001 Elsevier Science (USA).

关键词： prediction adaptive coding universal coding epsilon-capacity epsilon-net imaginary sliding window

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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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Analysis of a State Based Approach for adaptive coding and Modulation in Mobile Satellite Environments

Analysis of a State Based Approach for Adaptive Coding and M...

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77th IEEE Vehicular Technology Conference (VTC)

作者： Tarchi, Daniele Corazza, Giovanni E. Vanelli-Coralli, Alessandro Univ Bologna Dept Elect Elect & Informat Engn I-40136 Bologna Italy

ISBN: (纸本)9781467363372

In the last years the increasing presence of multimedia applications and devices is even requiring higher throughput links with a higher availability. In order to exploit such advanced services, ubiquitous and broadband connections are required. Even if much of populated areas are nowadays covered by terrestrial wireless broadband networks, there is an increasing request of satellite communications able to cover low density populated areas and to fill the coverage gaps. In the last years two novel communication standards specifically suited for mobile satellite communications, i.e., DVB-SH and DVB-RCS NG, have been introduced. Among others, they consider adaptive waveforms techniques for increasing the system reliability and throughput aiming to exploit the variable channel behavior. adaptive coding and modulation (ACM) belongs to this family of algorithms, by adapting the modulation and coding scheme based on the channel behavior. In this paper we focus on a state adaptive algorithm suited for mobile applications by considering the effect of the mobile speed.

关键词： adaptive coding Satellite communication wireless broadband network mobile satellite communication mobile communication satellite Communication standards Mobile Applications labeling scheme Throughput MULTIMEDIA APPLICATION algorithms

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Saliency-driven Omnidirectional Imaging adaptive coding: Modeling and Assessment 19

Saliency-driven Omnidirectional Imaging Adaptive Coding: Mod...

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19th IEEE International Workshop on Multimedia Signal Processing (MMSP)

作者： Luz, Guilherme Ascenso, Joao Brites, Catarina Pereira, Fernando Univ Lisbon Inst Super Tecn Inst Telecomunicacoes Lisbon Portugal

ISBN: (纸本)9781509036493

Omnidirectional imaging, also known as 360 and spherical imaging, records all 3600 of a scene from a specific spatial position, thus offering the user the capability to enjoy three rotational degrees of freedom (3-DoE). To offer a good quality of experience, omnidirectional imaging requires very high bitrates as high spatial resolution are a must and, ideally, also high frame rates. Due to the lack of video coding solutions specifically designed for omnidirectional imaging, this type of content is typically coded with the available image and video coding standards, such as JPEG, H.264/AVC and HEVC, after applying a 2D rectangular projection. In this context, this paper proposes an omnidirectional imaging coding solution allowing to reach improved coding performance by using an adaptive coding solution where the most visually salient image/video regions are coded with higher quality in a process appropriately controlled by the quantization parameter. To determine the saliency of the various omnidirectional imaging regions, a machine-learning based saliency detection model is proposed. The proposed coding solution achieves compression gains as measured by a novel objective quality metric also driven by saliency. This novel objective quality metric is validated by formal subjective testing where very high correlations with the subjective tests scores are achieved.

关键词： omnidirectional video saliency detection HEVC adaptive coding objective quality metric subjective evaluation

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CARE: Corruption-Aware Retransmission with adaptive coding for the Low-Power Wireless 23

CARE: Corruption-Aware Retransmission with Adaptive Coding f...

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23rd IEEE International Conference on Network Protocols (ICNP)

作者： Dong, Wei Yu, Jie Liu, Xiaojin Zhejiang Univ Coll Comp Sci Hangzhou Zhejiang Peoples R China

ISBN: (纸本)9781467382953

Wireless communications are inherently unreliable, especially for low-power wireless networks like 802.15.4. Packet corruptions typically occur because of interference, fading or noise. In this paper, we investigate the problem of corruption-aware retransmission with adaptive coding in commercial-off-the-shelf (COTS) low-power devices. We propose an accurate corruption detection algorithm for identifying the number of corrupted bytes in a packet based on the RSSI time series during packet reception. Based on the corruption level, we design an adaptive coding scheme based on Reed Solomon (RS) codes. We carefully select the coding parameters so as to optimize the network performance. Finally, we design and implement CARE, a Corruption-Aware REtransmission protocol by incorporating corruption detection and adaptive coding. We conduct extensive experiments based on COTS low-power devices. Results show that CARE significantly improves the performance for weak and highly interfered links while incurring no additional overhead for good links.

关键词： adaptive coding Corruption detection Low-power wireless Retransmission

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An adaptive coding Method for Dual-Polarized Mobile Satellite Communications 6

An Adaptive Coding Method for Dual-Polarized Mobile Satellit...

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6th International Conference on Wireless Communications and Signal Processing (WCSP)

作者： Yang, Yang Xiong, Xin Jiang, Bin Gao, Xiqi Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Jiangsu Peoples R China

ISBN: (纸本)9781479973392

This paper addresses the adaptive coding problem for mobile satellite communication systems with the dualpolarized multi-input multi-output (MIMO) deployment. In general, the satellite communication systems have a long channel delay, and then traditional adaptation schemes suffer from performance degradation. To overcome this drawback, we propose to add statistical channel state information (CSI) into the designing of adaptive coding schemes, where statistical CSI is obtained by averaging instantaneous CSI. Also, because the reciprocity property is utilized, the statistical CSI-aided adaptation scheme does not need to feed back any CSI. Numerical results show that the proposed adaptation scheme outperforms existing ones in term of spectral efficiency, especially when the maximum channel delay is very great.

关键词： adaptive coding Estimation MIMO Mobile communication Satellite antennas Satellite communication Satellites adaptive coding Satellite communication satellite antennas Satellite communication systems mobile communication satellites multiple input multiple output systems mobile satellite communication

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A New Technique for Lossless Compression of Color Images based on Hierarchical Prediction, Inversion and Context adaptive coding

A New Technique for Lossless Compression of Color Images bas...

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Data Compression Conference (DCC)

作者： Koc, Basar Arnavut, Ziya Sarkar, Dilip Kocak, Hilseyin Stetson Univ Deland FL 32723 USA SUNY Coll Fredonia Fredonia NY 14063 USA Univ Miami Coral Gables FL 33124 USA

ISBN: (纸本)9781728106571

This work introduces a new technique for lossless compression of color images. The technique is composed of first transforming an RGB image into luminance and chrominance domain (Y CuCv). Then, the luminance channel Y is compressed with a context-based, adaptive, lossless image coding technique (CALIC). After processing the chrominance channels with a hierarchical prediction technique that was introduced by Kim and Cho, Burrows-Wheeler Inversion Coder (BWIC) or JPEG 2000 is used to compress of the chrominance channels Cu and Cv. It is demonstrated that, on a wide variety of images, particularly on medical images, the technique achieves substantial compression gains over other well-known compression schemes such as CALIC, JPEG 2000, LOCO-I, BPG(HEVC), and the previously proposed hierarchical prediction and context adaptive coding technique LCIC.

关键词： Image coding Transform coding Biomedical imaging Color adaptive coding Prediction algorithms

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