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Conference on Visual Communications and Image Processing 2008

作者： Farshchian, Masoud Pearlman, William A. Telephonics Farmingdale NY 11735 USA Rensselaer Polytech Inst ECSE Dept Troy NY 12180 USA

ISBN: (纸本)9780819469946

Recently, several methods that divide the original bitstream of an image/video progressive wavelet based source coders into multiple correlated substreams have been proposed. The principle behind transmitting independent multiple substream is to generate multiple descriptions of the source such that the graceful degradation is achieved when transmitted over severe fading channels and lossy packet networks since some of the streams may be recovered. Noting that multiple substream can benefit from multiple independent channel paths, we naturally consider Multi-Input Multi-Output communication systems where we obtain multiple independent fading channels. Depending on several factors including: the number of antennas employed, the transmission energy, the Doppler shift (due to the motion between the transmitter antenna and receiver antennas), the total transmission rate and the distortion-rate (D-R) of the source-there exists an optimal number of balanced substreams and an optimal joint source-channel coding policy such that the expected distortion at the receiver is minimized. In this paper we derive an expected distortion function at the receiver based on all of. these parameters and provide a fast real-time numerical technique to find the optimal or near optimal number of balanced substreams to be transmitted. This expected distortion is based on our derivation of the probabilistic loss patterns of a balanced multiple substream progressive source coder.. The accuracy of the derived expected distortion estimator is confirmed by Monte-Carlo simulation employing Dent's modification of Jakes' model. By accurately estimating the optimal number of balanced substream's to be transmitted, a substantial gain in visual quality at low and intermediate signal-to-noise ratio (SNR) is obtained over severely fading channels.' At hi-h SNR, the single stream source coder's source efficiency makes it slightly better than the multiple substream source coder. Overall, using our analytic

关键词： joint source-channel coding MIMO communications SPIHT coding

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A joint source-channel coding Scheme for Transmission of Correlated Discrete sources over a Gaussian Multiple Access channel

A Joint Source-Channel Coding Scheme for Transmission of Cor...

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International Symposium on Information Theory and Its Applications

作者： Rajesh, R. Sharma, Vinod Indian Inst Sci Dept Elect Commun Engg Bangalore 560012 Karnataka India

ISBN: (纸本)9781424420681

We consider the problem of transmission of correlated discrete alphabet sources over a Gaussian Multiple Access channel (GMAC). A distributed bit-to-Gaussian mapping is proposed which yields jointly Gaussian codewords. This can guarantee lossless transmission or lossy transmission with given distortions, if possible. The technique can be extended to the system with side information at the encoders and decoder.

关键词： Gaussian multiple access channel joint source-channel coding Discrete correlated sources

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Multiple description coding of scalable video stream based on unequal loss protection and optimal rate allocation

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SCIENTIA IRANICA 2012年第3期19卷 782-794页

作者： Ardestani, M. R. Shirazi, A. A. Beheshti Iran Univ Sci & Technol Image Proc Lab Sch Elect Engn Tehran Iran

Forward Error Correction (FEC) codes may be used to protect a video code stream against packet erasures or errors when passing through an error-prone network. To have maximum possible fidelity at the decoder side, an Unequal Loss Protection (ULP) approach should be used to packetize the scalable video code stream, so that the different parts of the scalable video stream are protected according to their importance. Unequal loss-protected packetization leads to segmentation of the scalable code stream, such that the source can be reconstructed with the maximum possible fidelity at the decoder side. In Ardestani et al. (2009) [1] we have found an analytical relation between the optimal sizes of any two consecutive segments. This idea yields an efficient (as efficient as the local search algorithm in Stankovic et al. (2002) [2]) low-complexity progressive solution for the segmentation problem. In this paper, we use a progressive approach for ULP packetization of a scalable video stream generated from a T + 2D encoder. In addition, an optimal rate allocation is used for optimal rate budget division between successive Groups Of Pictures (GOPs) of the video sequence. The experimental results demonstrate that the optimal rate budget allocation outperforms the conventional strategy of equal rate budget distribution up to 0.65 dB. (C) 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.

关键词： Unequal loss-protected packetization Multiple description coding joint source-channel coding Scalable video coding Rate allocation

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A HYBRID SENDER/RECEIVER-DRIVEN ERROR PROTECTION SCHEME FOR RELIABLE P2P SCALABLE VIDEO STREAMING

A HYBRID SENDER/RECEIVER-DRIVEN ERROR PROTECTION SCHEME FOR ...

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IEEE International Conference on Image Processing

作者： Chi-Wen Lo Chia-Wen Lin Yung-Chang Chen Information and Communications Research Labs Industrial Technology Research Institute Taiwan Department of Electrical Engineering National Tsing Hua University Hsinchu Taiwan

ISBN: (纸本)9781479923427

This paper proposes a hybrid sender/receiver-driven error protection scheme to transmit scalable video packets over packet-lossy peer-to-peer networks. In our scheme, given an estimated system uplink capacity, a joint source-channel coding (JSCC) mechanism based on receiver-driven subscriptions is proposed to minimize the visual distortion received by child-peers by subscribing to appropriate amounts of source and channel coding packets. Because the bandwidth for inter-peer transmissions may fluctuate largely due to peer dynamics, in our method peers estimate the available system uplink capacity based on consensus propagation to avoid the fluctuating allocations of JSCC. To efficiently utilize the uplink bandwidth of peers, parent-peers use sender-driven contribution-guided peer selection to reject the low-contribution subscriptions requested from candidate child-peers. Simulation results demonstrate that our method significantly improves visual quality, compared to other state-of-the-art schemes.

关键词： peer-to-peer video streaming scalable video coding (SVC) forward error correction joint source-channel coding Combined source-channel coding Forward error correction Subscriptions peer to peer file sharing up link Peers Videotapes HYBRID Bandwidth

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joint source-channel Decoding Over MIMO channels Based on Partial Marginalization

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第12期60卷 6734-6739页

作者： Persson, Daniel Larsson, Erik G. Skoglund, Mikael Linkoping Univ Dept Elect Engn SE-58183 Linkoping Sweden Royal Inst Technol Sch Elect Engn SE-10044 Stockholm Sweden

We investigate fast joint source-channel decoding employed for communication over frequency-flat and frequency-selective block-fading multiple-input multiple-output channels. Our setting has applications for communication with short codes under low-latency constraints. The case of no transmitter channel state information is considered. We propose a partial marginalization decoder that allows performance to be traded for computational complexity, by adjusting a user parameter. By tuning this parameter to its maximum value, the minimum mean square error (MMSE) decoder is obtained. In the conducted simulations, the proposed scheme almost achieves the MMSE performance for a wide range of the channel signal-to-noise ratios, with significant reductions in computational complexity.

关键词： Fast decoding joint source-channel coding low latency multiple-input multiple-output (MIMO) short codes

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joint source and channel coding for MIMO systems: Is it better to be robust or quick?

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IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第4期54卷 1393-1405页

作者： Holliday, Tim Goldsmith, Andrea J. Poor, H. Vincent Goldman Sachs New York NY 10004 USA Stanford Univ Dept Elect Engn Stanford CA 94305 USA Princeton Univ Sch Engn & Appl Sci Princeton NJ 08544 USA

A framework is developed for optimizing the tradeoff between diversity, multiplexing, and delay in multiple-input multiple-output (MIMO) systems to minimize end-to-end distortion. The goal is to find the optimal balance between the increased data rate provided by antenna multiplexing, the reduction in transmission errors provided by antenna diversity and automatic repeat request (ARQ), and the delay introduced by ARQ. First, closed-form analytical results are developed to minimize end-to-end distortion of a vector quantizer concatenated with a space-time MIMO channel code in the high SNR regime. The minimizati(in determines the optimal point on the diversity-multiplexing tradeoff curve. For large but finite SNR this optimal point is found via convex optimization, which is illustrated with an example of a practical joint source-channel code design. It is then shown that for MIMO systems with ARQ retransmission, sources without a delay constraint have distortion minimized by maximizing the ARQ window size. This results in a new multiplexing-diversity tradeoff region enhanced by ARQ. However, under a source delay constraint the problem formulation changes to account for delay distortion associated with random message arrival and random ARQ completion times. In this case, the simplifications associated with a high SNR assumption break down, and a dynamic programming formulation is required to capture the channel diversity-multiplexing tradeoff as well as the random arrival and retransmission dynamics. Results based on this formulation show that a delay-sensitive system obtains significant performance gains by adapting its operating point on the diversity-multiplexing-delay region to system dynamics.

关键词： automatic repeat request (ARQ) diversity-multiplexing-delay tradeoff joint source-channel coding multiple-input multiple-output (MIMO) channels

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Optimal and robust communication for a uniform source

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IET COMMUNICATIONS 2012年第6期6卷 577-586页

作者： Nguyen, H. T. Ramstad, T. A. Balasingham, I. Norwegian Univ Sci & Technol NTNU Dept Elect & Telecommun NO-7491 Trondheim Norway NTNU Dept Elect & Telecommun NO-7491 Trondheim Norway Oslo Univ Hosp Intervent Ctr NO-0027 Oslo Norway Univ Oslo Inst Clin Med NO-0317 Oslo Norway

A communication system based on the joint source-channel coding principle is proposed, where a fixed-rate source encoder is used to avoid the error propagation effect as experienced when variable length coding is used and thus gain system robustness. An explicit expression of the mean square error (MSE) distortion of the system for a uniform source is derived. We provide an algorithm to achieve the optimal solution by investigating the Karush-Kuhn-Tucker (KKT) condition. The numerical results show that the overall performance of the proposed system is close to the performance of the entropy coded scalar quantiser (ECSQ) system established by A. Gyorgy and T. Under for almost all rate region. A 0.176-bits-per-sample performance loss is found for the worst case by comparing our considered system and ECSQ system. An observation resembling the finding by V. Goya1 et al. is that in the low rate region, there exist certain regimes in which the proposed system outperforms the ECSQ system. Finally, the proposed system outperforms the equal rate system with a large margin.

关键词： joint source-channel coding entropy codes error propagation effect Interpolation and function approximation (numerical analysis) entropy coded scalar quantiser combined source-channel coding variable length codes KKT condition fixed-rate source encoder optimal communication ECSQ system mean square error methods MSE distortion mean square error distortion variable length coding robust communication Karush-Kuhn-Tucker condition Codes

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joint source-channel RATE CONTROL FOR PIXEL-DOMAIN DISTRIBUTED VIDEO coding

JOINT SOURCE-CHANNEL RATE CONTROL FOR PIXEL-DOMAIN DISTRIBUT...

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

作者： Chen, Hu Steinbach, Eckehard Chen, Chang Wen Tech Univ Munich Inst Media Technol D-80333 Munich Germany SUNY Buffalo Dept Comp Sci & Engn Buffalo NY 14260 USA

ISBN: (纸本)9781457705397

We study the scenario of pixel-domain distributed video coding for noisy transmission environments and propose a method to allocate the available rate between source coding and channel coding to generate a robust video stream. Having observed in experiments the uncertainty of the source and the channel coding rate, we model them as random variables via offline training, estimate the decoding failure probability and calculate the mean end-to-end distortion. Adaptive quantization is performed for each slice to minimize its mean end-to-end distortion. With this joint source-channel rate allocation, we compare the robustness of two coding prototypes, namely distributed video coding and distributed video coding with forward error correction. According to our experimental results, under same total bit budget, the distributed video coding only scheme proves more robust than the latter one and the gain is up to 1 dB in PSNR.

关键词： Distributed video coding joint source-channel coding error-resilience

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Optimal Phase Transitions in Compressed Sensing

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IEEE TRANSACTIONS ON INFORMATION THEORY 2012年第10期58卷 6241-6263页

作者： Wu, Yihong Verdu, Sergio Univ Penn Wharton Sch Dept Stat Philadelphia PA 19104 USA Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

Compressed sensing deals with efficient recovery of analog signals from linear encodings. This paper presents a statistical study of compressed sensing by modeling the input signal as an i.i.d. process with known distribution. Three classes of encoders are considered, namely optimal nonlinear, optimal linear, and random linear encoders. Focusing on optimal decoders, we investigate the fundamental tradeoff between measurement rate and reconstruction fidelity gauged by error probability and noise sensitivity in the absence and presence of measurement noise, respectively. The optimal phase-transition threshold is determined as a functional of the input distribution and compared to suboptimal thresholds achieved by popular reconstruction algorithms. In particular, we show that Gaussian sensing matrices incur no penalty on the phase-transition threshold with respect to optimal nonlinear encoding. Our results also provide a rigorous justification of previous results based on replica heuristics in the weak-noise regime.

关键词： Compressed sensing joint source-channel coding minimum mean-square error (MMSE) dimension phase transition random matrix Renyi information dimension Shannon theory

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joint Unitary Triangularization for MIMO Networks

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2012年第1期60卷 326-336页

作者： Khina, Anatoly Kochman, Yuval Errez, Uri Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel MIT Signals Informat & Algorithms Lab Cambridge MA 02139 USA

This paper considers communication networks where individual links can be described as those based on multiple-input multiple-output channels. Unlike orthogonal modulation methods (such as the singular-value decomposition), we allow interference between subchannels, which can be removed by the receivers via successive cancellation. The degrees of freedom earned by this relaxation are used for obtaining a basis, and corresponding decomposition, which are simultaneously good for more than one link. Specifically, we derive necessary and sufficient conditions for shaping the ratio vector of subchannel gains of two broadcast-channel receivers. We then apply this decomposition to two scenarios: First, in digital multicasting we present a practical capacity-achieving scheme which uses only scalar codes and linear processing. Then, we consider the joint source-channel problem of transmitting a Gaussian source over a two-user multiple-input multiple-output channel, where we show the existence of non-trivial cases, where the optimal distortion pair (which for high signal-to-noise ratios (SNRs) equals the optimal point-to-point distortions of the individual users) may be achieved by employing a hybrid digital-analog scheme over the induced equivalent channel. These scenarios demonstrate the advantage of choosing a modulation basis based upon multiple links in the network. Thus, we coin the approach "network modulation."

关键词： Broadcast channel GDFE generalized triangular decomposition (GTD) geometric mean decomposition GSVD joint source-channel coding MIMO multicasting multiplicative majorization

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