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The Achievable Distortion Region of Sending a Bivariate Gaussian source on the Gaussian Broadcast channel

IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第10期57卷 6419-6427页

作者： Tian, Chao Diggavi, Suhas Shamai, Shlom (Shitz) AT&T Labs Res Florham Pk NJ 07932 USA Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

We provide a complete characterization of the achievable distortion region for the problem of sending a bivariate Gaussian source over bandwidth-matched Gaussian broadcast channels, where each receiver is interested in only one component of the source. This setting naturally generalizes the simple single Gaussian source bandwidth-matched broadcast problem for which the uncoded scheme is known to be optimal. We show that a hybrid scheme can achieve the optimum for the bivariate case, but neither an uncoded scheme alone nor a separation-based scheme alone is sufficient. We further show that in this joint source channel coding setting, the Gaussian scenario is the worst scenario among the sources and channel noises with the same covariances.

关键词： Gaussian source joint source-channel coding squared error distortion measure

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Approximate Characterizations for the Gaussian source Broadcast Distortion Region

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第1期57卷 124-136页

作者： Tian, Chao Diggavi, Suhas Shamai, Shlomo AT&T Labs Res Florham Pk NJ 07932 USA Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

We consider the joint source-channel coding problem of sending a Gaussian source on a K-user Gaussian broadcast channel with bandwidth mismatch. A new outer bound to the achievable distortion region is derived using the technique of introducing more than one additional auxiliary random variable, which was previously used to derive sum-rate lower bound for the symmetric Gaussian multiple description problem. By combining this outer bound with the achievability result based on source-channel separation, we provide approximate characterizations of the achievable distortion region within constant multiplicative factors. Furthermore, we show that the results can be extended to general broadcast channels, and the performance of the source-channel separation based approach is also within the same constant multiplicative factors of the optimum.

关键词： Gaussian source joint source-channel coding squared error distortion

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joint source-channel Optimization over Wireless Relay Networks

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IEEE TRANSACTIONS ON COMMUNICATIONS 2011年第4期59卷 1114-1122页

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

Cooperative communications have received considerable attention for wireless multimedia applications as a technique to improve reliability and service coverage. To apply such cooperation over slow fading channels, we consider exploiting the spatial diversity in multiple relay networks. In this paper, we focus on amplify-and-forward relaying schemes, namely, orthogonal amplify-and-forward, selective relaying, and distributed beamforming, for the cooperative wireless multimedia transmission. Furthermore, the successive refinement source coding is exploited such that the multimedia signal is encoded into multiple layers and the quality of its reconstruction at the receiver is improved when more layers are received correctly. We study two strategies for the layered source transmission, namely, progressive transmission and superposition coding. With our developed framework, we propose suboptimal resource allocation algorithms to efficiently assign rate, power, and channel uses to different layers so as to maximize the quality of the multimedia signal reconstructed at the receiver. The proposed optimization methodology is simple and only requires the knowledge of the channel statistics compared to the existing algorithms. As a result, the receiver only requires to feedback the determined rate, power, and channel uses to the transmitter whenever the channel statistics or the layered source transmission strategy changes.

关键词： Cooperative communications amplify-and-forward joint source-channel coding progressive transmission superposition coding successive refinement

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Spread Spectrum Visual Sensor Network Resource Management Using an End-to-End Cross-Layer Design

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IEEE TRANSACTIONS ON MULTIMEDIA 2011年第1期13卷 125-131页

作者： Bentley, Elizabeth S. Kondi, Lisimachos P. Matyjas, John D. Medley, Michael J. Suter, Bruce W. USAF Res Lab Rome NY 13441 USA Univ Ioannina Dept Comp Sci GR-45110 Ioannina Greece

In this paper, we propose an approach to manage network resources for a direct sequence code division multiple access (DS-CDMA) visual sensor network where nodes monitor scenes with varying levels of motion. It uses cross-layer optimization across the physical layer, the link layer, and the application layer. Our technique simultaneously assigns a source coding rate, a channel coding rate, and a power level to all nodes in the network based on one of two criteria that maximize the quality of video of the entire network as a whole, subject to a constraint on the total chip rate. One criterion results in the minimal average end-to-end distortion amongst all nodes, while the other criterion minimizes the maximum distortion of the network. Our experimental results demonstrate the effectiveness of the cross-layer optimization.

关键词： Code division multiple access (CDMA) convolutional codes cross-layer H.264 joint source-channel coding multimedia communications power control resource allocation spread spectrum visual sensor network

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Iterative Encoder-Controller Design for Feedback Control Over Noisy channels

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IEEE TRANSACTIONS ON AUTOMATIC CONTROL 2011年第2期56卷 265-278页

作者： Bao, Lei Skoglund, Mikael Johansson, Karl Henrik Royal Inst Technol KTH Sch Elect Engn ACCESS Linnaeus Ctr SE-10044 Stockholm Sweden

We study a closed-loop control system with state feedback transmitted over a noisy discrete memoryless channel. With the objective to minimize the expected linear quadratic cost over a finite horizon, we propose a joint design of the sensor measurement quantization, channel error protection, and controller actuation. It is argued that despite that this encoder-controller optimization problem is known to be hard in general, an iterative design procedure can be derived in which the controller is optimized for a fixed encoder, then the encoder is optimized for a fixed controller, etc. Several properties of such a scheme are discussed. For a fixed encoder, we study how to optimize the controller given that full or partial side-information is available at the encoder about the symbols received at the controller. It is shown that the certainty equivalence controller is optimal when the encoder is optimal and has full side-information. For a fixed controller, expressions for the optimal encoder are given and implications are discussed for the special cases when process, sensor, or channel noise is not present. Numerical experiments are carried out to demonstrate the performance obtained by employing the proposed iterative design procedure and to compare it with other relevant schemes.

关键词： Discrete memoryless channel joint encoder-controller design joint source-channel coding limited information control quantized feedback control

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Sensitivity of Quadratic Gaussian Matching to Interference

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IEEE COMMUNICATIONS LETTERS 2011年第9期15卷 922-924页

作者： Varshney, Lav R. Mitter, Sanjoy K. MIT Dept Elect Engn & Comp Sci Cambridge MA 02139 USA MIT Informat & Decis Syst Lab Cambridge MA 02139 USA

It is well known that uncoded transmission of a memoryless Gaussian source over a memoryless additive white Gaussian noise channel results in optimal performance theoretically attainable. When there is additional interference in the channel, uncoded transmission is robust. It achieves the same sensitivity performance as optimal performance, measured using sensitivity results of Pinsker, Prelov, and Verdu.

关键词： Uncoded transmission joint source-channel coding interference sensitivity

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Optimal HDA Codes for Sending a Gaussian source over a Gaussian channel with Bandwidth Compression in the presence of an Interference

Optimal HDA Codes for Sending a Gaussian Source over a Gauss...

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IEEE Information Theory Workshop (ITW)

作者： Varasteh, Morteza Behroozi, Hamid Sharif Univ Technol Dept Elect Engn Tehran Iran

ISBN: (纸本)9781457704376

In this paper, we consider transmission of a Gaussian source over a Gaussian channel under bandwidth compression in the presence of interference known only to the transmitter. We study hybrid digital-analog (HDA) joint source-channel coding schemes and propose two novel coding schemes that achieve the optimal mean-squared error (MSE) distortion. This can be viewed as the extension of results by Wilson et al. [1], originally proposed for sending a Gaussian source over a Gaussian channel in two cases: 1) Matched bandwidth with known interference only at the transmitter, 2) bandwidth compression where there is no interference in the channel. The proposed HDA codes can cancel the interference of the channel and obtain the "optimum performance theoretically attainable" (OPTA) of the AWGN channel with no interference in the case of bandwidth compression. We also provide performance analysis in the presence of signal-to-noise ratio (SNR) mismatch where we expect that HDA schemes perform better than strictly digital schemes.

关键词： AWGN channel hybrid digital-analog coding joint source-channel coding writing on dirty paper coding

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UEP Framework in Multiresolution Modulation for Robust Image Broadcasting

UEP Framework in Multiresolution Modulation for Robust Image...

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22nd IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Datta, Hiten Ilow, Jacek Dalhousie Univ Dept Elect & Comp Engn Halifax NS B3J 1Z1 Canada

ISBN: (纸本)9781457713484

Unequal error protection (UEP) for multimedia communications relies on transmitting more important data through the sub-channels experiencing lower bit error rates (BERs). In radio broadcasting, UEP is implemented by deploying multiresolution (MR) modulations which allow the support for users close to the transmitter with higher perceived recovered image quality, while the users farther away experience the acceptable quality. This paper proposes a new approach to design MR modulations for such an image broadcasting scenario that optimizes the near users quality by exploiting the inherent scalability in image compression and UEP flexibility in 2-D modulation schemes. The proposed new framework for the design of MR modulations effectively integrates constellation distances and priority bits assignments, resulting in two user optimized joint source-channel coding. We present the simulation results for near and far users's image quality in such two-tier optimized radio broadcasting systems.

关键词： 2D modulation scheme Approximation methods Bit error rate Image quality PSNR Quadrature amplitude modulation Receivers bit error rates combined source-channel coding error statistics image coding image compression image resolution joint source-channel coding modulation multimedia communication multimedia communication multiresolution modulation radio broadcasting radio transmitters recovered image quality robust image broadcasting transmitter two-tier optimized radio broadcasting system unequal error protection

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A Cognitive Approach for Effective coding and Transmission of 3D Video

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ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 2011年第1期7卷 23-23页

作者： Milani, Simone Calvagno, Giancarlo Univ Padua Dept Informat Engn I-35131 Padua Italy

Future multimedia applications will rely on the transmission of 3D video contents within heterogeneous fruition scenarios, and as a matter of fact, the reliable delivery of 3D video signals proves to be a crucial issue in such communications. To this purpose, multimedia communication experts have been designing cross-layer strategies to improve the quality of the perceived 3D experience. This article presents a new cross-layer strategy, called Cognitive source coding (CSC), that defines a new 3D video system able to identify the different elements of the 3D scene and choose the most appropriate coding strategy.

关键词： Algorithms Design Measurements Performance Cross-layer optimization source coding joint source-channel coding 3D video cognitive source coding

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On Distortion Bounds for Dependent sources Over Wireless Networks

On Distortion Bounds for Dependent Sources Over Wireless Net...

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IEEE International Symposium on Information Theory (ISIT)

作者： Jalali, Shirin Effros, Michelle CALTECH Ctr Math Informat Pasadena CA 91125 USA CALTECH Dept Elect Engn Pasadena CA 91125 USA

ISBN: (纸本)9781457705953

Characterizing the set of achievable distortions in lossy transmission of dependent sources over multi-user channels is an open problem. Even for a channel such as the multiple access channel, where the capacity is well-understood, the complete characterization of achievable distortions is still unknown. Since separation of source coding and channel coding is sub-optimal for this case, bounds on achievable distortions require tools beyond prior channel capacities and rate-distortion bounds. In this paper we propose a systematic approach for finding lower bounds on the set of distortions achievable through joint source-channel coding.

关键词： channel coding Decoding joints Niobium source coding Systematics channel capacity channel capacity channel coding dependent source distortion joint source-channel coding lossy transmission multi-access systems multiple access channel multiuser channel multiuser channels radio networks rate distortion bound rate distortion theory source coding wireless networks

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