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joint source-channel decoding for variable-length encoded data by exact and approximate MAP sequence estimation

IEEE TRANSACTIONS ON COMMUNICATIONS 2000年第1期48卷 1-6页

作者： Park, M Miller, DJ Penn State Univ Dept Elect Engn University Pk PA 16802 USA

joint source-channel decoding based on residual source redundancy is an effective paradigm for error-resilient data compression. While previous work only considered fixed-rate systems, the extension of these techniques for variable-length encoded data was recently independently proposed by the authors and by Demir and Sayood. In this letter, we describe and compare the performance of a computationally complex exact maximum a posteriori (MAP) decoder, its efficient approximation, an alternative approximate decoder, and an improved version of this decoder suggested here. Moreover, we evaluate several source and channel coding configurations. The results show that our approximate MAP technique outperforms other approximate methods and provides substantial error protection to variable-length encoded data.

关键词： hidden Markov models joint source-channel decoding MAP estimation residual redundancy variable length codes

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joint source-channel decoding of variable-length codes with soft information: A survey

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EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2005年第6期2005卷 906-927页

作者： Guillemot, C Siohan, P IRISA INRIA F-35042 Rennes France France Telecom R&D Div F-35512 Rennes France

Multimedia transmission over time-varying wireless channels presents a number of challenges beyond existing capabilities conceived so far for third-generation networks. Efficient quality-of-service (QoS) provisioning for multimedia on these channels may in particular require a loosening and a rethinking of the layer separation principle. In that context, joint source-channel decoding (JSCD) strategies have gained attention as viable alternatives to separate decoding of source and channel codes. A statistical framework based on hidden Markov models (HMMs) capturing dependencies between the source and channel coding components sets the foundation for optimal design of techniques of joint decoding of source and channel codes. The problem has been largely addressed in the research community, by considering both fixed-length codes (FLC) and variable-length source codes (VLC) widely used in compression standards. joint source-channel decoding of VLC raises specific difficulties due to the fact that the segmentation of the received bitstream into source symbols is random. This paper makes a survey of recent theoretical and practical advances in the area of JSCD with soft information of VLC-encoded sources. It first describes the main paths followed for designing efficient estimators for VLC-encoded sources, the key component of the JSCD iterative structure. It then presents the main issues involved in the application of the turbo principle to JSCD of VLC-encoded sources as well as the main approaches to source-controlled channel decoding. This survey terminates by performance illustrations with real image and video decoding systems.

关键词： joint source-channel decoding source-controlled decoding turbo principle variable-length codes

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joint source-channel decoding Scheme for Image Transmission over Wireless channel

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Wuhan University Journal of Natural Sciences 2002年第3期7卷 307-312页

作者： Xiao Dong-liang Sun Hong School of Electronic Information Wuhan University Wuhan Hubei China

We improve the iterative decoding algorithm by utilizing the “leaked” residual redundancy at the output of the source encoder without changing the encoder structure for the noisy channel. The experimental results show that using the residual redundancy of the compressed source in channel decoding is an effective method to improve the error correction performance.

关键词： turbo code joint source-channel decoding residual redundancy arithmetic coding

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joint source-channel decoding of Variable-Length Encoded Markov Multiple sources

Joint Source-Channel Decoding of Variable-Length Encoded Mar...

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International Conference on Networks Security, Wireless Communications and Trusted Computing

作者： Xiang, Weiwei Zou, Yan Lu, Peizhong Informat Sci & Technol Inst Dept Commun Engn Zhengzhou Peoples R China Southwest Inst Electron & Telecom Techn Shanghai Peoples R China

ISBN: (纸本)9780769536101

joint source-channel decoding (JSCD) has been shown to be effective for multimedia transmission over time-varying channels. In this paper, we present a method for joint source-channel soft decision decoding of variable-length encoded multiple sources. Compared with the single source decoding scheme addressed by Marion Jeanne, the proposed technique is more practical in wideband wireless communications. Simulation results show our new method obtains substantial improvements with a minor increasing of complexity. For two sources, the gain in SNR is around 1.5dB when symbol-error rate (SER) reaches 10(-2) and around 1.3dB when SER=10(-3).

关键词： joint source-channel decoding variable-length codes Viterbi decoding multiple sources

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joint source-channel decoding of JPEG2000 images with unequal loss protection

Joint source-channel decoding of JPEG2000 images with unequa...

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33rd IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Bahmani, Sohail Bajic, Ivan V. HajShirMohammadi, Atousa Simon Fraser Univ Sch Engn Sci Burnaby BC V5A 1S6 Canada

ISBN: (纸本)9781424414833

This paper presents a method for joint decoding of JPEG2000 bitstreams and Reed-Solomon codes in the context of unequal loss protection. When the Reed-Solomon decoder is unable to retrieve the erased source symbols, the proposed joint decoder searches through the set of possible erased source symbols, making use of error resilience features of JPEG2000 to retrieve correct symbols. The joint decoder can be used as an add-on module to some of the existing schemes for unequal loss protection, and can improve the PSNR of decoded images by over 10 dB in some cases.

关键词： unequal loss protection JPEG2000 Reed-Solomon codes joint source-channel decoding

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Design and analysis of LDPC codes for joint source-channel decoding of two correlated sensors

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IET COMMUNICATIONS 2018年第8期12卷 1003-1010页

作者： Khas, Mohamad Saeedi, Hamid Asvadi, Reza Tarbiat Modares Univ Dept Elect & Comp Engn Tehran Iran Shahid Beheshti Univ Fac Elect Engn Tehran Iran

This study is concerned with the design of ensembles of systematic low-density parity-check (LDPC) codes to increase the lifetime of wireless sensors by taking advantage of the inherent correlation between the transmitted data of the sensors. The authors consider two correlated sensors where the data is encoded independently at each sensor through a systematic LDPC encoder and sent over two independent channels. At the receiver, a joint source-channel decoder consisting of two component LDPC decoders is considered where the encoded bits at the output of each component decoder are used as the a priori information at the other decoder. The authors first perform asymptotic performance analysis using the concept of extrinsic information transfer (EXIT) charts. Then, the developed modified EXIT charts are used to design ensembles for different values of correlation. Our results show that as the average check node degree of the designed ensembles grow, the decoding thresholds corresponding to the designed ensembles approach the theoretical limit. Finite block-length performance evaluation indicates that for larger values of correlation, deploying the designed ensembles through the joint decoder can almost double the sensor's lifetime without increasing the complexity of the encoder.

关键词： parity check codes decoding combined source-channel coding joint source-channel decoding correlated sensors low-density parity-check codes wireless sensors inherent correlation independent channels component LDPC decoders asymptotic performance analysis extrinsic information transfer charts point-to-point communications decoding thresholds

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Fast joint source-channel decoding of Convolutional Coded Markov Sequences with Monge Property

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第1期58卷 128-135页

作者： Dumitrescu, Sorina McMaster Univ ECE Dept Hamilton ON L8S 4L8 Canada

This work addresses the problem of joint source-channel decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy memoryless channel. It is shown that for Markov sources satisfying the so-called Monge property, both the maximum a posteriori probability (MAP) sequence decoding, as well as the soft output Max-Log-MAP decoding can be accelerated by a factor of K without compromising the optimality, where K is the size of the Markov source alphabet. The key to achieve a higher decoding speed is a convenient organization of computations at the decoder combined with a fast matrix search technique enabled by the Monge property. The same decrease in complexity follows, as a by-product of the development, for the soft output Max-Log-MAP joint source channel decoding in the case when the convolutional coder is absent, result which was not known previously.

关键词： joint source-channel decoding maximum a posteriori probability sequence estimation Max-Log-MAP algorithm Markov sequence Monge property

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Iterative joint source-channel decoding of H.264 compressed video

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2010年第2期25卷 75-87页

作者： Levine, David Lynch, William E. Le-Ngoc, Tho Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 2A7 Canada

This paper proposes an Iterative joint source-channel decoding (IJSCD) scheme for error resilient transmission of H.264 compressed video over noisy channels by using the available H.264 compression, e.g., Context-based Adaptive Binary Arithmetic Coding (CABAC), and channel coding, i.e., rate-1/2 Recursive Systematic Convolutional (RSC) code, in transmission. At the receiver, the turbo decoding concept is explored to develop a joint source-channel decoding structure using a soft-in soft-out channel decoder ill conjunction with the source decoding functions, e.g., CABAC-based H.264 semantic verification, in an iterative Manner. Illustrative designs of the proposed IJSCD scheme for an Additive White Gaussian Noise (AWGN) channel, including the derivations of key parameters for soft information are discussed. The performance of the proposed IJSCD scheme is shown for several video sequences. In the examples, for the same desired Peak Signal-to-Noise Ratio (PSNR), the proposed IJSCD scheme offers a savings Of Lip to 2.1 dB in required channel Signal-to-Noise Ratio (SNR) as compared to a system using the same RSC code alone. The complexity of the proposed scheme is also evaluated. As the number of iterations is controllable, a tradeoff call be made between performance improvement and the overall complexity. (C) 2009 Elsevier B.V. All rights reserved.

关键词： Error resilience joint source-channel decoding Likelihood decoding Compressed video H.264

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On the complexity of joint source-channel decoding of Markov sequences over memoryless channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 2008年第6期56卷 877-885页

作者： Dumitrescu, Sorina Wu, Xiaolin McMaster Univ Hamilton ON Canada

We investigate the complexity of joint source-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy memoryless channel. As established previously the MAP decoding can be performed by a Viterbi-like algorithm on a trellis whose states are triples of the states of the Markov source, source coder and convolutional coder. The large size of the product space (in the order of K-2 N, where K is the number of source symbols and N is the number of states of the convolutional coder) appears to prohibit such a scheme. We show that for finite impulse response convolutional codes, the state space size of joint source-channel decoding can be reduced to O(K-2+N log N), hence the decoding time becomes O(TK2 + TN log N), where T is the length in bits of the decoded bitstream. We further prove that an additional complexity reduction can be achieved when K > N, if the logarithm of the source transition probabilities satisfy the so-called Monge property. This decrease becomes more significant as the tree structure of the source code is more unbalanced. The reduction factor ranges between O(KIN) (for a fixed-length source code) and O(K/log N) (for Golomb-Rice code).

关键词： joint source-channel decoding maximum a posteriori sequence estimation finite-state machine complexity

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Repeated joint source-channel decoding with reduced new bit errors

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SIGNAL PROCESSING 2006年第1期86卷 1-7页

作者： Xu, W Siemens AG Dept Mobile Phone Dev D-81359 Munich Germany

In this study, we describe a repeated joint source-channel decoding scheme in which not only a priori information about the bit to be decoded but also its decoding reliability information are used to adaptively control the decoding process. The channel decoding reliability information obtained for instance from a previous decoding attempt is used to properly weight the a priori information so that the new bit errors caused by wrong "natural" a priori information are reduced. In order to efficiently estimate the a priori residual redundancy, an iterative approach based on the Kalman filter theory is employed. As a result, decoding gains can be obtained with almost no new bit errors introduced. The proposed scheme is successfully applied to the GSM full rate system to achieve a more reliable transmission of speech signals in both noisy and less noisy environments. (c) 2005 Elsevier B.V. All rights reserved.

关键词： joint source-channel decoding soft output Viterbi algorithm Kalman filter GSM

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