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A family of efficient and channel error resilient wavelet/subband image coders

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1999年第1期9卷 95-108页

作者： Man, H Kossentini, F Smith, MJT Georgia Inst Technol Sch Elect & Comp Engn Atlanta GA 30332 USA Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

We present a new wavelet/subband framework that allows the efficient and effective quantization/coding of subband coefficients in both noiseless and noisy channel environments, Two different models, one based on a zero-tree structure and another based on a quadtree and context-based modeling structure, are introduced for coding the locations of significant subband coefficients. Then, several multistage residual lattice vector quantizers are proposed for the quantization of such coefficients. The proposed framework features relatively simple modeling and quantization/coding structures that produce a bit stream containing two distinct bit sequences, which can then be protected differently according to their importance and channel noise sensitivity levels. The resulting wavelet/subband image coding algorithms provide good tradeoffs between compression performance and resilience to channel errors. In fact, experimental results indicate that for both noiseless and noisy channels, the resulting coders outperform most of the source-channel coders reported in the literature. More importantly, our coders are substantially more robust than all previously reported source-channel coders with respect to varying channel error conditions, This is a desired feature in low-bandwidth wireless applications.

关键词： error resilience image compression joint source-channel coding lattice VQ quadtrees zero trees

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A Truncated Prediction Framework for Streaming Over Erasure channels

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IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第11期63卷 7322-7351页

作者： Etezadi, Farrokh Khisti, Ashish Chen, Jun Univ Toronto Toronto ON M5S 3G4 Canada Univ Toronto Elect & Comp Engn Dept Toronto ON M5S 3G4 Canada Samsung Elect Modem R&D San Diego CA 92122 USA McMaster Univ Hamilton ON L8S 4K1 Canada

We propose a new coding technique for sequential transmission of a stream of Gauss-Markov sources over erasure channels under a zero decoding delay constraint. Our proposed scheme is a combination (hybrid) of predictive coding with truncated memory, and quantization-and-binning. We study the optimality of our proposed scheme using an information theoretic model. In our setup, the encoder observes a stream of source vectors that are spatially independent and identically distributed (i.i.d.) and temporally sampled from a first-order stationary Gauss-Markov process. The channel introduces an erasure burst of a certain maximum length B, starting at an arbitrary time, not known to the transmitter. The reconstruction of each source vector at the destination must be with zero delay and satisfy a quadratic distortion constraint with an average distortion of D. The decoder is not required to reconstruct those source vectors that belong to the period spanning the erasure burst and a recovery window of length W following it. We study the minimum compression rate R(B, W, D) in this setup. As our main result, we establish upper and lower hounds on the compression rate. The upper bound (achievability) is based on our hybrid scheme. It achieves significant gains over baseline schemes such as (leaky) predictive coding, memoryless binning, a separation-based scheme, and a group of pictures based scheme. The lower hound is established by observing connection to a network source coding problem. The bounds simplify in the high resolution regime, where we provide explicit expressions whenever possible, and identify conditions when the proposed scheme is close to optimal. We finally discuss the interplay between the parameters of our burst erasure channel and the statistical channel models and explain how the hounds in the former model can be used to derive insights into the simulation results involving the latter. In particular, our proposed scheme outperforms the baseline schemes over

关键词： Rate distortion theory sequential source coding burst erasure channels multi-terminal source coding joint source-channel coding

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On successive refinement with causal side information at the decoders

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IEEE TRANSACTIONS ON INFORMATION THEORY 2008年第1期54卷 332-343页

作者： Maor, Alina Merhav, Neri Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel

Consider a process, {X-i, Y-i, Z(i)}(i=1)(infinity) producing independent copies of a triplet of jointly distributed random variables (RVs). The {X-i} I part of the process-the source-is observed at the encoder, and is supposed to be reproduced at two decoders, decoder 1 and decoder 2, where the {Z(i)} and the {Y-i} parts of the process are observed, respectively, in a causal manner. The communication between the encoder and the decoders is carried out across two memoryless channels in two successive communication stages. In the first stage, the compressed transmission is available to both decoders, but only decoder 1 reconstructs the source (according to the received data stream and its causal side information (SI){Z(i)}). In the second stage, the second decoder reconstructs the source according to {Y-i} and the transmissions of the encoder at both stages. It is desired to find necessary and sufficient conditions such that the distortions incurred (in each stage) will not exceed given thresholds. First, a single-letter characterization of achievable rates is derived for a pure source-coding problem with successive refinement and causal SI at the decoders. Then, for a joint source-channel coding setting, a separation theorem is proved, asserting that in the limit of long blocks, no optimality is lost by first applying lossy successive-refinement source coding, regardless of the channels, and then applying good channel codes to each one of the resulting bit streams, regardless of the source. Next, conditions for a source to be successively refinable in two different senses are established, and finally, it is shown that the binary-symmetric source is successively refinable.

关键词： causal rate distortion function channel capacity joint source-channel coding side information (SI) source-channel separation source coding successive refinement

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Universal source Controlled channel Decoding with Nonsystematic Quick-Look-In Turbo Codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第4期57卷 960-971页

作者： Shamir, Gil I. Xie, Kai ADC Telecomm Inc San Jose CA 95134 USA

Utilization of redundancy left in a channel coded sequence can improve channel decoding performance. Stronger improvement can usually be achieved with nonsystematic encoding. However, nonsystematic codes recently proposed for this problem are not robust to the statistical parameters governing a sequence and thus should not be used without prior knowledge of these parameters. In this work, decoders of nonsystematic quick-look-in turbo codes are adapted to extract and exploit redundancy left in coded data to improve channel decoding performance. Methods, based on universal compression and denoising, for extracting the governing statistical parameters for various source models are integrated into the channel decoder by also taking advantage of the code structure. Simulation results demonstrate significant performance gains over standard systematic codes that can be achieved with the new methods for a wide range of statistical models and governing parameters. In many cases, performance almost as good as that with perfect knowledge of the governing parameters is achievable.

关键词： joint source-channel coding quick-look-in turbo codes universal source controlled channel decoding

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Robust transmission of MELP-compressed speech: An illustrative example of joint source-channel decoding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2003年第6期51卷 973-982页

作者： Fazel, T Fuja, T Hughes Network Syst Germantown MD 20876 USA Univ Notre Dame Dept Elect Engn Notre Dame IN 46556 USA

A mixed-excitation linear predictive (MELP) speech coder was selected as the U.S. federal standard for 2400 b/s speech compression. This paper examines the quality of MELP-compressed speech when transmitted over noisy communication channels in conjunction with a variety of error-control schemes. The focus is on channel decoders that exploit the "residual redundancy" inherent in the MELP bitstream. This residual redundancy, which is manifested by the correlation in time and the nonuniform distribution of various MELP parameters, can be quantified by modeling the parameters as one-step Markov chains and computing the entropy rate of the Markov chains based on the relative frequencies of transitions. Moreover, this residual redundancy can be exploited by an appropriately "tuned" channel decoder to provide substantial coding gain when compared with decoders that do not exploit it. channel coding schemes include conventional binary convolutional codes and iteratively-decoded parallel concatenated convolutional (turbo) codes.

关键词： error-correction coding joint source-channel coding speech coding turbo codes

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Quantization of memoryless and Gauss-Markov sources over binary Markov channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 1997年第6期45卷 668-675页

作者： Phamdo, N Alajaji, F Farvardin, N QUEENS UNIV DEPT MATH & STAT KINGSTON ON K7L 3N6 CANADA UNIV MARYLAND DEPT ELECT ENGN COLLEGE PK MD 20742 USA

joint source-channel coding for stationary memoryless and Gauss-Markov sources and binary Markov channels is considered, The channel is an additive-noise channel where the noise process is an Mth-order Markov chain, Two joint source-channel coding schemes are considered. The first is a channel-optimized vector quantizer - optimized for both source and channel, The second scheme consists of a scalar quantizer and a maximum a posteriori detector, In this scheme, it is assumed that the scalar quantizer output has residual redundancy that can be exploited by the maximum a posteriori detector to combat the correlated channel noise, These two schemes are then compared against two schemes which use channel interleaving, Numerical results show that the proposed schemes outperform the interleaving schemes, For very noisy channels with high noise correlation, gains of 4-5 dB in signal-to-noise ratio are possible.

关键词： channels with memory joint source-channel coding MAP detection Markov noise vector quantization

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Secret-Key Generation Using Correlated sources and channels

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IEEE TRANSACTIONS ON INFORMATION THEORY 2012年第2期58卷 652-670页

作者： Khisti, Ashish Diggavi, Suhas N. Wornell, Gregory W. Univ Toronto Dept Elect & Comp Engn Toronto ON M5S 3G4 Canada Univ Calif Los Angeles Dept Elect Engn Los Angeles CA 90095 USA MIT Dept Elect Engn & Comp Sci Cambridge MA 02139 USA

We study the secret-key capacity in a joint source-channel coding setup-the terminals are connected over a discrete memoryless channel and have access to side information, modelled as a pair of discrete memoryless source sequences. As our main result, we establish the upper and lower bounds on the secret-key capacity. In the lower bound expression, the equivocation terms of the source and channel components are functionally additive even though the coding scheme generates a single secret-key by jointly taking into account the source and channel equivocations. Our bounds coincide, thus establishing the capacity, when the underlying wiretap channel can be decomposed into a set of independent, parallel, and reversely degraded channels. For the case of parallel Gaussian channels and jointly Gaussian sources we show that Gaussian codebooks achieve the secret-key capacity. In addition, when the eavesdropper also observes a correlated side information sequence, we establish the secret-key capacity when both the source and channel of the eavesdropper are a degraded version of the legitimate receiver. We finally also treat the case when a public discussion channel is available, propose a separation based coding scheme, and establish its optimality when the channel output symbols of the legitimate receiver and eavesdropper are conditionally independent given the input.

关键词： Information theoretic security joint source-channel coding public discussion secret-key agreement wiretap channel

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The Capacity Region of the L-User Gaussian Inverse Compute-and-Forward Problem

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IEEE TRANSACTIONS ON INFORMATION THEORY 2016年第12期62卷 6953-6968页

作者： Chen, Yanying Song, Yiwei Devroye, Natasha Univ Illinois Chicago IL 60607 USA Univ Illinois Dept Elect & Comp Engn Chicago IL 60607 USA

We consider an L-user multiple access channel where transmitter m has access to the linear equation u(m) = circle plus(L)(l=1) f(ml) w(l), of independent messages w(l) is an element of F-p(kl) with f(ml) is an element of F-p, and the destination wishes to recover all L messages. This problem may be motivated as the last hop in a network where relay nodes employ the compute-and-forward strategy and decode linear equations of messages;we seek to do the reverse and extract messages from sums over a multiple access channel. In particular, we exploit the particular form of dependencies between the equations at the different relays to improve the reliable communication rates beyond those achievable by simply forwarding all equations to the destination independently. The presented achievable rate region for the discrete memoryless channel model is shown to be capacity for the additive white Gaussian noise channel.

关键词： Terms channel capacity multiple access channel compute-and-forward correlated sources joint source-channel coding multiuser channels

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AirNet: Neural Network Transmission Over the Air

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2024年第9期23卷 12126-12139页

作者： Jankowski, Mikolaj Gunduz, Deniz Mikolajczyk, Krystian Imperial Coll London Dept Elect & Elect Engn London SW7 2AZ England

State-of-the-art performance for many edge applications is achieved by deep neural networks (DNNs). Often, these DNNs are location- and time-sensitive, and must be delivered over a wireless channel rapidly and efficiently. In this paper, we introduce AirNet, a family of novel methods that allow DNNs to be efficiently delivered over wireless channels under stringent transmit power and latency constraints. It is a part of a new class of joint source-channel coding methods that maximize the accuracy of the DNNs transmitted to the receiver, rather than recover the DNNs with high fidelity. In AirNet, we propose to directly map the DNN parameters to the transmitted channel symbols, while training the network under the channel constraints with robustness to channel noise. AirNet achieves higher accuracy compared to the separation-based alternatives. We further improve its performance by pruning the network below the available bandwidth, and using bandwidth expansion for significant network parameters. We also exploit unequal error protection (UEP) by selectively expanding the important layers. Finally, we propose an ensemble training approach where networks for different channel conditions can be obtained simultaneously, resolving the impractical memory requirements of training distinct networks for different channel conditions.

关键词： Wireless communication Training Artificial neural networks Bandwidth Wireless sensor networks Atmospheric modeling Task analysis Neural network compression joint source-channel coding network pruning distributed inference

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An end-to-end embedded approach for multicast/broadcast of scalable video over multiuser CDMA wireless networks

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IEEE TRANSACTIONS ON MULTIMEDIA 2007年第3期9卷 655-667页

作者： Chan, Yee Sin Modestino, James W. Qu, Qi Fan, Xingzhe Univ Miami Dept Elect & Comp Engn Coral Gables FL 33124 USA Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA

We investigate an embedded multicast/broadcast approach for transport of digital video over spread-spectrum code-division multiple access (CDMA) cellular networks. Previous work has shown that the incorporation of a scalable source coding scheme with multiresolution modulation provides a promising design paradigm for the practical realization of the information-theoretic performance predictions originally developed by Cover [1], which demonstrated that optimal multicast/broadcast performance could be achieved by an embedded transmission scheme. Hence, the major technical challenge associated with the design of an end-to-end embedded multicast/broadcast system is how to match an embedded modulation constellation with a scalable source coding scheme. In this work, taking into consideration both the interference-limited and bandwidth-limited characteristics of a CDMA system, we provide a cross-layer approach incorporating adaptive power allocation and channel coding strategies and effectively match a discrete cosine transform based scalable motion-compensated video encoder to an embedded multiresolution modulation scheme to simultaneously deliver a basic quality-of-service (QoS) to less capable receivers while maximizing both the QoS for more capable receivers and the system capacity. We demonstrate the efficacy of this approach using the ITU-T H.263+ video scalable hybrid coder, although the approach is generally extensible to other scalable coding schemes as well.

关键词： adaptive modulation and coding code-division multiple access (CDMA) cross-layer drift control embedded transmission H.263+ joint source-channel coding joint source coding-power control multicast/broadcast turbo codes wireless video

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