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13th Canadian Workshop on Information Theory (CWIT)

作者： Ho, James Meng, Jin Yang, En-hui Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

ISBN: (纸本)9781479906345

This paper investigates the validity of Shannon's separation theorem in the finite block length regime. Under optimal tradeoffs between source rate and channel block error probability obtained from finite block length analysis, noisy channel quantizers based on joint source-channel coding principles are shown to outperform the separate quantizer designed via Lloyd-Max in terms of end-to-end distortion. Numerical results for the scalar case under the binary symmetric channel and discrete-input memoryless channel demonstrate that the separation of source and channel coding no longer holds in the finite block length regime, but the advantages of joint designs may be large or small depending on the system configuration.

关键词： joint source-channel coding finite block length regime lossy source coding end-to-end distortion

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Minimum Distortion Network Code Design for source coding Over Noisy channels

Minimum Distortion Network Code Design for Source Coding Ove...

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19th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

作者： Park, Moonseo Kim, Seong-Lyun Yonsei Univ Sch Elect & Elect Engn Radio Resource Management & Optimizat Lab Seoul 120749 South Korea

ISBN: (纸本)9781424426430

The XOR network code is widely used in the conventional network coding. However, when the channel is noisy, the XOR code is suboptimal in terms of minimizing distortion in the source signal. We propose to use a new network code for the two-way relay channel, designed to minimize signal distortion due to the channel noise. We assume the source signal X is encoded by a source encoder and the sequence of symbols is transmitted over the two-way relay channel with noise. The received sequence of symbols may be corrupted by the channel noise, and X, the estimation of X, may be different from X. We design a new network code which minimizes the distortion between X and X. To provide an algorithm to obtain a network code with minimum distortion, we define the expected distortion associated with a network code. Starting with the XOR network code, we iteratively optimize the network code to obtain smaller expected distortion, while maintaining the Latin square constraint of the network code. New network code achieves substantial performance gain over the XOR network code.

关键词： Index assignment joint source-channel coding Latin square network coding

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joint source and space-time block coding for MIMO video communications

Joint source and space-time block coding for MIMO video comm...

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60th IEEE Vehicular Technology Conference

作者： Lin, S Stefanov, A Wang, Y Polytech Univ Dept Elect & Comp Engn Brooklyn NY 11201 USA

ISBN: (纸本)0780385217

The problem of efficient video communications over MIMO wireless systems is of great significance, due to the high capacity of the multiple antenna system. The high data rates provided by the MIMO system can be traded off with diversity gain by using different, channel coding schemes. Also, by using different video source coding methods, high compression gain can be traded off with the. error resilience gain. One should jointly consider source coding and channel coding when designing a MIMO wireless video system. However, little is known so far about what. combinations of channel coding and source coding methods have the best overall performance in a MIMO system. In this paper, by comparing the performances of several different,. typical combinations through both theoretical and simulation studies, we show that, no single combination is the best for the entire range of channel conditions, rather different combinations may be best for a sub-range.

关键词： space-time coding MIMO video coding joint source-channel coding

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Distortion Behavior of Amplify-and-Forward Cooperative System with Layered Broadcast coding

Distortion Behavior of Amplify-and-Forward Cooperative Syste...

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2010 IEEE 71st Vehicular Technology Conference

作者： Sethakaset, Ubolthip Quek, Tony Q. S. Sun, Sumei Tarasak, Poramate ASTAR Inst Infocomm Res Singapore 138632 Singapore

ISBN: (纸本)9781424425198

Cooperative system has been receiving considerable attention recently as an effective approach to improve transmission reliability in slow fading wireless channels. In this paper, we exploit cooperative diversity in multiple relay networks to improve the performance of Gaussian source transmission with layered broadcast coding. Specifically, we study the distortion performance of two amplify-and-forward (AF) schemes, namely, distributed beamforming and selection AF. First, we analyze their asymptotic performance in terms of the distortion exponent and the expected distortion. We then show that, under stringent delay constraint, there exist SNR thresholds below which the AF systems achieve lower distortion than the direct transmission system.

关键词： Amplify-and-forward cooperative transmission distortion behavior joint source-channel coding

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channel IMPULSIVE NOISE MITIGATION FOR LINEAR VIDEO coding SCHEMES 44

CHANNEL IMPULSIVE NOISE MITIGATION FOR LINEAR VIDEO CODING S...

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44th IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

作者： Zheng, S. Cagnazzo, M. Kieffer, M. Univ Paris Saclay Telecom ParisTech LTCI F-75013 Paris France Univ Paris Saclay Univ Paris Sud Cent Supelec L2SCNRS 3 Rue Joliot Curie F-91192 Gif Sur Yvette France

ISBN: (纸本)9781479981311

This paper considers the problem of impulse noise mitigation for videos encoded using a SoftCast-based Linear Video coding (LVC) scheme and transmitted using an OFDM scheme over a wideband channel prone to impulse noise. In the time domain, the impulse noise is modeled as realizations of iid Bernoulli-Gaussian variables. A Fast Bayesian Matching Pursuit algorithm is employed for impulse noise mitigation. This approach requires the provisioning of some OFDM subchannels to estimate the impulse noise locations and amplitudes. Provisioned subchannels cannot be used to transmit data and lead to a decrease of the nominal decoded video quality at receivers in absence of impulse noise. Using a phenomenological model (PM) of the residual noise variance after impulse correction, an algorithm is proposed to evaluate the optimal number of subchannels to provision for impulse noise mitigation. Simulation results show that the PM can accurately predict the number of subchannels to provision and that impulse noise mitigation can significantly improve the decoded video quality compared to a situation where all subchannels are used for data transmission.

关键词： Video transmission SoftCast OFDM Impulse noise mitigation joint source-channel coding

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The duality between information embedding and source coding with side information and some applications

The duality between information embedding and source coding ...

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IEEE International Symposium on Information Theory

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

Aspects of the duality between the information-embedding problem and the Wyner-Ziv problem of source coding with side information at the decoder are developed and used to establish a spectrum new results on these and related problems, with implications for a number of important applications. The single-letter characterization of the information-embedding problem is developed and related to the corresponding characterization of the Wyner-Ziv problem, both of which correspond to optimization of a common mutual information difference. Dual variables and dual Markov conditions are identified, along with the dual role of noise and distortion in the two problem's. For a Gaussian context with quadratic distortion metric, a geometric interpretation of the duality is, developed. From such insights, we develop a capacity-achieving information-embedding system based on nested lattices. We show the resulting encoder-decoder has precisely the same decoder-encoder structure as the corresponding Wyner-Ziv system based on nested lattices that achieves the rate-distortion limit. For a binary context with Hamming distortion metric, the information-embedding capacity is developed, along with its relationship to the corresponding Wyner-Ziv rate-distortion function. In turn, an information-embedding system for this case based on nested, linear codes is constructed having an encoder-decoder that is identical to the decoder-encoder structure for the corresponding system that achieves the Wyner-Ziv rate-distortion limit. Finally, based on these results, a simple layered joint source-channel coding system is developed with a perfectly symmetric encoder-decoder structure. Its application and performance is discussed in a broadcast setting in which there is a need to control the fidelity experienced by different receivers. Among other results, we show that such systems and their multilayer extensions retain attractive optimality, properties, in the Gaussian-quadratic case, but not in the bina

关键词： coding with side information data hiding digital watermarking hybrid coding and transmission information embedding joint source-channel coding Slepian-Wolf coding Wyner-Ziv coding

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channel State Feedback Over the MIMO-MAC

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第12期57卷 7787-7797页

作者： Kumar, K. Raj Caire, Giuseppe Ecole Polytech Fed Lausanne La Algorithm CH-1015 Lausanne Switzerland Univ So Calif Ming Hsieh Dept Elect Engn Los Angeles CA 90089 USA

In order to exploit the full multiplexing gain of multi-antenna multi-user downlink schemes, accurate channel state information at the transmitter (i.e., at the base station) is required. We consider the design of a closed-loop channel state information feedback scheme, where user terminals feed back their channel state information simultaneously to a multi-antenna base station. The underlying information theoretic problem consists of lossy source-channel coding of multiple independent analog sources (i.e., the users' channel coefficients) over a Gaussian multiple- input multiple-output multi-access channel (MIMO-MAC). Unlike the classical source-channel coding setting, this application requires low latency, otherwise the channel state information would be outdated. Hence, source-channel codewords can span only a single fading state of the uplink (feedback) channel. Furthermore, the transmitters are ignorant of the realization of the uplink channel coefficients. In this scenario, the scaling of the maximum of the estimated downlink channel mean-square errors with the SNR dominates the performance of the multiuser downlink. This scaling is described by the distortion SNR exponent, previously introduced in a single-user MIMO setting. This paper analyzes the max-min distortion SNR exponent of the MIMO-MAC for both separated source-channel coding, and a particular hybrid digital-analog joint source-channel coding scheme. For the case of single-antenna users, we prove that the distortion SNR exponent of separated source-channel coding can be achieved by the concatenation of scalar quantization and uncoded quadrature-amplitude modulation (QAM) transmission, with lattice decoding at the base-station receiver. The resulting scheme has very low encoding latency (only a few symbols of the uplink slot) and generally outperforms currently proposed channel state feedback schemes based on analog unquantized transmission or vector quantization with fixed codebooks.

关键词： channel state feedback joint source-channel coding multiple-antenna multiple-access channel (MIMO-MAC)

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Multiple Description Quantizer Design for Multiple-Antenna Systems with MAP Detection

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IEEE TRANSACTIONS ON COMMUNICATIONS 2010年第1期58卷 136-145页

作者： Zhou, Yugang Chan, Wai-Yip Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada

We study the design of index assignment based multiple description quantizers for multiple-antenna systems with slow Rayleigh fading. A time-interleaver is employed at the transmitter to provide independent channel instances for the multiple descriptions, and a maximum a posteriori (MAP) detector is employed at the receiver to jointly decode the multiple descriptions. The concatenation of index assignment, binary phase-shift keying modulators, space-time orthogonal block coder, multiple-antenna channel, and MAP detector is modeled as a discrete memoryless channel. We optimize multiple description vector quantizers using an upper bound of the channel transition probability achieved by the MAP detector. The proposed scheme of combining multiple description coding and space-time orthogonal block coding is shown to be superior to each individual coding scheme.

关键词： joint source-channel coding multiple descriptions index assignment space-time coding multiple antennas

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Error-resilient video communications over CDMA networks with a bandwidth constraint

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2006年第11期15卷 3241-3252页

作者： Shen, Yushi Cosman, Pamela C. Milstein, Laurence B. Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

We present an adaptive video transmission scheme for use in a code-division multiple-access network, which incorporates efficient bandwidth allocation among source coding, channel coding, and spreading under a fixed total bandwidth constraint. We derive the statistics of the received signal, as well as a theoretical bound on the packet drop rate at the receiver. Based on these results, a bandwidth allocation algorithm is proposed at the packet level, which incorporates the effects of both the changing channel conditions and the dynamics of the source content. Detailed simulations are done to evaluate the performance of the system, and the sensitivity of the system to estimation error is presented.

关键词： bandwidth allocation channel estimation code-division multiple-access (CDMA) joint source-channel coding mode switching multiuser system video communications wireless Internet

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Sending a Laplacian source Using Hybrid Digital-Analog Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第7期62卷 2544-2557页

作者： Abbasi, Fariba Aghagolzadeh, Ali Behroozi, Hamid Univ Tabriz Fac Elect & Comp Engn Tabriz 51664 Iran Babol Univ Technol Fac Elect & Comp Engn Babol Sar *** Iran Sharif Univ Technol Dept Elect Engn Tehran 113659363 Iran

In this paper, we study transmission of a memoryless Laplacian source over three types of channels: additive white Laplacian noise (AWLN), additive white Gaussian noise (AWGN), and slow flat-fading Rayleigh channels under both bandwidth compression and bandwidth expansion. For this purpose, we analyze two well-known hybrid digital-analog (HDA) joint source-channel coding schemes for bandwidth compression and one for bandwidth expansion. Then we obtain achievable (absolute- error) distortion regions of the HDA schemes for the matched signal-to-noise ratio (SNR) case as well as the mismatched SNR scenario. Using numerical examples, it is shown that these schemes can achieve a distortion very close to the provided lower bound (for the AWLNchannel) and to the optimum performance theoretically attainable bound (for AWGN and Rayleigh fading channels) on mean-absolute error distortion under matched SNR conditions. In addition, a non-linear analog coding scheme is analyzed, and its performance is compared to the HDA schemes for bandwidth compression under both matched and mismatched SNR scenarios. The results show that the HDA schemes outperform the non-linear analog coding over the whole CSNR region.

关键词： Additive white Laplacian noise (AWLN) channel bandwidth compression/expansion hybrid digital-analog (HDA) codes joint source-channel coding non-linear analog coding

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