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Near-Capacity Irregular Variable Length coding and Irregular Unity Rate coding

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2009年第11期8卷 5500-5507页

作者： Maunder, R. G. Hanzo, L. Univ Southampton Dept Elect & Comp Sci Sch ECS Southampton SO9 5NH Hants England

In this contribution we introduce an EXtrinsic Information Transfer (EXIT) chart matching technique for the design of two serially concatenated irregular codecs, each constituted by a variety of component codes. This approach facilitates a higher degree of design freedom than matching the EXIT function of an irregular codec to that of a regular codec, comprising only a single component code. As a result, a narrower EXIT chart tunnel can be created, facilitating operation at E-b/N-o values that are closer to the channel's capacity bound. This is demonstrated for a serial concatenation of iteratively decoded Irregular Variable Length coding (IrVLC) and Irregular Unity Rate coding (IrURC), which is favourably compared with an IrVLC and regular Unity Rate coding (URC) based benchmarker. Finally, we show that the iterative decoding complexity of our IrVLC-IrURC scheme can be reduced by about 25% upon employing a method of jointly performing EXIT chart matching, while seeking a reduced iterative decoding complexity.

关键词： Variable length codes joint source and channel coding trellis codes information rates

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joint coding Rate Control for Audio Streaming in Short Range Wireless Networks

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2009年第2期55卷 486-491页

作者： Kovacevic, Jelena Samardzija, Dragan Temerinac, Miodrag Univ Novi Sad Dept Comp Engn & Commun Fac Tech Sci Novi Sad 21000 Serbia Bell Labs Alcatel Lucent Murray Hill NJ 07974 USA

Streaming high quality audio/video (AV) from home media sources to TV sets and audio speakers over a wireless local area network (WLAN) is a challenging problem because of the fluctuating bandwidth caused by interference and fading. Retransmission and data buffering. as common techniques in data transfer over error-prone channels, are not adequate for delay sensitive applications such as high quality audio streaming. Our approach is to adjust the audio data rate dynamically in order to improve the perceptual quality of audio according to wireless channel quality. It? this paper we specifically focus on robust audio streaming over short range wireless channels. The major strength of the proposed algorithm is in its ability to match the source and channel coding parameters to the given channel conditions, thus providing better quality and lower latency Of audio in home networking.

关键词： audio wireless streaming joint source and channel coding

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Parallel concatenated codes with unequal error protection

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IEEE TRANSACTIONS ON COMMUNICATIONS 1998年第5期46卷 565-567页

作者： Caire, G Biglieri, E Politecn Torino Dipartimento Elettr I-10129 Turin Italy

In this letter we show how parallel concatenated codes (PCC's, also known as "turbo codes") can be endowed with unequal error protection (UEP). Given the two component encoders of the PCC encoder and the desired interleaver size, UEP is achieved by: 1) suitably positioning the different importance classes of information symbols into the encoder input frame) 2) puncturing the PCC redundancy symbols with a nonuniform pattern;and 3) choosing the interleaver of the PCC encoder in a class of interleavers that guarantees isolation of the importance classes. By controlling the amount of redundancy assigned to each importance class and the class positioning in the input frame, a whole family of UEP PCC's with different UEP levels can be obtained from the same component encoders and interleaver size. From a practical viewpoint, a family of UEP PCC's can he decoded by the same "turbo" iterative decoder, provided that the decoder hardware implementation allows for programmable puncturing and interleaving.

关键词： joint source and channel coding turbo codes unequal error protection

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Ensuring quality of service for image transmission: Hybrid loss protection

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2004年第6期13卷 751-757页

作者： Grangetto, M Magli, E Olmo, G Politecn Torino Dipartimento Elettron Ctr Multimedia Radio Commun CERCOM I-10129 Turin Italy

We present hybrid loss protection as a new channel coding and packetization scheme for image transmission over nonprioritized lossy packet networks. The scheme employs an interleaver-based structure, and attempts to maximize the expected peak signal-to-noise ratio (PSNR) at the receiver given the constraint that the probability of failure, i.e., the probability that the PSNR of the decoded image is below a given threshold, is upper-bounded by a user-defined value. A new code-allocation algorithm is proposed, which employs Gilbert-Elliot modeling of the network statistics. Experimental results are provided in the case of transmission of images encoded by SPIHT and JPEG 2000 over a wireline, as well as a wireless UNITS-based Internet connection.

关键词： image transmission joint source and channel coding JPEG 2000 multiple description coding quality of service SPIHT unequal loss protection

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Spatio-Temporal Iterative source-channel Decoding Aided Video Transmission

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2013年第4期62卷 1597-1609页

作者： Huo, Yongkai Zhu, Chuan Hanzo, Lajos Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

Low-complexity uncompressed video transmission meets the requirements of home networking and quality/delay-sensitive medical applications. Hence, it has attracted research attention in recent years. The redundancy inherent in the uncompressed video signals may be exploited by joint source-channel decoding to improve the attainable error resilience. Hence, in this treatise, we study the application of iterative joint source-channel decoding aided uncompressed video transmission, where correlation inherent in the video signals is modeled by a first-order Markov process. First, we propose a spatiotemporal joint source-channel decoding system using a recursive systematic convolutional codec, where both the horizontal and vertical intraframe correlations, as well as the interframe correlations, are exploited by the receiver, hence relying on 3-D information exchange. This scheme may be combined with arbitrary channel codecs. Then, we analyze the three-stage decoder's convergence behavior using 3-D extrinsic information transfer (EXIT) charts. Finally, we benchmark the attainable system performance against a couple of video communication systems, including our previously proposed 2-D scheme, where only intraframe correlations were exploited without invoking a channel codec. Our simulation results show that substantial E-b/N-0 improvements are attainable by the proposed technique.

关键词： Iterative detection joint source and channel coding spatio-temporal video processing video telephony wireless video communication

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Subspace algorithms for error localization with quantized DFT codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2004年第12期52卷 2115-2124页

作者： Rath, G Guillemot, C INRIA IRISA F-35042 Rennes France

Recently, a class of real-number Bose-Chaudbuiri-Hocquengem codes known as discrete Fourier transform (DFT) codes have been considered as joint source and channel codes for providing robustness to erasures and errors over wireless networks. In this paper, we propose three subspace algorithms for error localization with quantized DFT codes. The algorithms are similar to the MUSIC, the minimum-norm, and the ESPRIT algorithms used in. array signal processing for direction-of-arrival estimation. They provide different but related formulations of the error localizations by first partitioning a vector space into the channel error subspace and its orthogonal complement, the noise subspace. The locations of the errors are determined from either the error subspace eigenvectors or the. noise subspace eigenvectors. We also present a brief performance analysis of the localization error in terms of the perturbation of the error subspace due to quantization. Simulation results show that their localization performances are similar, and they perform better than the coding-theoretic approach over a broad range of channel-error-to-quantization-noise ratios.

关键词： discrete Fourier transform (DFT) codes error correction joint source and channel coding subspace algorithms

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Analog error-correcting codes based on chaotic dynamical systems

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IEEE TRANSACTIONS ON COMMUNICATIONS 1998年第7期46卷 881-890页

作者： Chen, B Wornell, GW MIT Dept Elect Engn & Comp Sci Cambridge MA 02139 USA MIT Elect Res Lab Cambridge MA 02139 USA

The properties of chaotic dynamical systems make them useful for channel coding in a variety of practical communication applications. To illustrate this, a novel analog code based on tent map dynamics and having a fast decoding algorithm is developed for use on unknown, multiple, and time-varying signal-to-noise ratio (SNR) channels. This code is shown to be an attractive alternative to both digital codes and linear modulation in such scenarios, Several properties and interpretations of the codes are developed, along with some methods for their optimization.

关键词： broadcast channels chaotic systems error-correction codes fading channels joint source and channel coding nonlinear dynamics twisted modulation

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Multilayered protection of embedded video bitstreams over binary symmetric and packet erasure channels

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2005年第3期16卷 359-378页

作者： Cho, SD Pearlman, WA Rensselaer Polytech Inst Ctr Image Proc Res Dept Elect Comp & Syst Engn Troy NY 12180 USA

This paper presents a multilayered protection of embedded video bitstreams over bit errors and packet erasure channels using Error Resilient and Error Concealment 3-D SPIHT (ERC-SPIHT) algorithm, which is based on the 3-D SPIHT concepts. A robust source coder is created to give error resilience in source level of the codestream. This robustness is achieved by partitioning the wavelet coefficients into many independent sub-bitstreams while maintaining spatio-temporal tree structures. For higher protection against channel noise, we use a product code. In each packet, the concatenation of a rate compatible punctured convolutional (RCPC) code and an error detecting parity check (CRC) code is used. Across the packets, Reed-Solomon codes are used. These steps provide the robust source coder with additional layers of protection against channel noise. Finally, in the decoder side, an error concealment function is performed for the lost blocks. Simulations show that the multilayered protection of 3-D SPIHT outperforms the methods that use single layer protection in terms of average PSNRs and the PSNR ranges, and provides higher average PSNR's and lower PSNR variances. (C) 2004 Elsevier Inc. All rights reserved.

关键词： video compression video transmission robust source coding error resilient transmission joint source and channel coding 3-D wavelet transform embedded wavelet coding

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Lossy coding of Correlated sources Over a Multiple Access channel: Necessary Conditions and Separation Results

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IEEE TRANSACTIONS ON INFORMATION THEORY 2018年第9期64卷 6081-6097页

作者： Guler, Basak Gunduz, Deniz Yener, Aylin Penn State Univ Dept Elect Engn University Pk PA 16802 USA Univ Southern Calif Dept Elect Engn Los Angeles CA 90089 USA Imperial Coll London Dept Elect & Elect Engn London SW7 2AZ England

Lossy coding of correlated sources over a multiple access channel (MAC) is studied. First, a joint source-channel coding scheme is presented when the decoder has correlated side information. Next, the optimality of separate source and channel coding that emerges from the availability of a common observation at the encoders or side information at the encoders and the decoder is investigated. It is shown that separation is optimal when the encoders have access to a common observation whose lossless recovery is required at the decoder, and the two sources are independent conditioned on this common observation. Optimality of separation is also proved when the encoder and the decoder have access to shared side information conditioned on which the two sources are independent. These separation results obtained in the presence of side information are then utilized to provide a set of necessary conditions for the transmission of correlated sources over a MAC without side information. Finally, by specializing the obtained necessary conditions to the transmission of binary and Gaussian sources over a MAC, it is shown that they can potentially be tighter than the existing results in the literature, providing a novel converse for this fundamental problem.

关键词： Common information conditional independence hybrid coding joint source and channel coding multiple access channel rate-distortion theory separation theorem

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Hermitian Symmetric DFT Codes: A New Class of Complex DFT Codes

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第5期60卷 2396-2407页

作者： Kumar, A. Anil Makur, Anamitra Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore

We introduce a new class of real number codes derived from DFT matrix, Hermitian symmetric DFT (HSDFT) codes. We propose a new decoding algorithm based on coding-theoretic as well as subspace based approach. Decoding of HSDFT codes requires only real arithmetic operations and smaller dimension matrices compared to the decoding of the state-of-art real BCH DFT (RBDFT) class of codes. HSDFT codes will also be shown to have more burst error correction capacity. For a Gauss-Markov source, on a binary symmetric channel at lower to moderate bit error rates (BERs), HSDFT codes show better performance than RBDFT codes, and on a Gilbert-Elliot channel HSDFT codes consistently perform better than RBDFT codes.

关键词： DFT codes joint source and channel coding real number codes subspace algorithms

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