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A source-channel Separation Theorem With Application to the source Broadcast Problem

IEEE TRANSACTIONS ON INFORMATION THEORY 2016年第4期62卷 1764-1781页

作者： Khezeli, Kia Chen, Jun McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada Cornell Univ Sch Elect & Comp Engn Ithaca NY 14853 USA

A converse method is developed for the source broadcast problem. Specifically, it is shown that the separation architecture is optimal for a variant of the source broadcast problem, and the associated source-channel separation theorem can be leveraged, via a reduction argument, to establish a necessary condition for the original problem, which unifies several existing results in the literature. Somewhat surprisingly, this method, albeit based on the source-channel separation theorem, can be used to prove the optimality of non-separation-based schemes and determine the performance limits in certain scenarios where the separation architecture is suboptimal.

关键词： Bandwidth mismatch broadcast channel capacity region joint source-channel coding separation theorem side information

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Robust Predictive Quantization: Analysis and Design Via Convex Optimization

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IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING 2007年第4期1卷 618-632页

作者： Fletcher, Alyson K. Rangan, Sundeep Goyal, Vivek K. Ramchandran, Kannan Univ Calif Berkeley Berkeley CA 94720 USA Qualcomm Flar Technol Bedminster NJ 07921 USA MIT Cambridge MA 02139 USA

Predictive quantization is a simple and effective method for encoding slowly-varying signals that is widely used in speech and audio coding. It has been known qualitatively that leaving correlation in the encoded samples can lead to improved estimation at the decoder when encoded samples are subject to erasure. However, performance estimation in this case has required Monte Carlo simulation. Provided here is a novel method for efficiently computing the mean-squared error performance of a predictive quantization system with erasures via a convex optimization with linear matrix inequality constraints. The method is based on jump linear system modeling and applies to any autoregressive moving average (ARMA) signal source and any erasure channel described by an aperiodic and irreducible Markov chain. In addition to this quantification for a given encoder filter, a method is presented to design the encoder filter to minimize the reconstruction error. Optimization of the encoder filter is a nonconvex problem, but we are able to parameterize with a single scalar a set of encoder filters that yield low MSE. The design method reduces the prediction gain in the filter, leaving the redundancy in the signal for robustness. This illuminates the basic tradeoff between compression and robustness.

关键词： Differential pulse code modulation erasure channels joint source-channel coding linear matrix inequalities

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joint source-channel Polarization With Side Information

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IEEE ACCESS 2018年 6卷 7340-7349页

作者： Jin, Liqiang Yang, Hongwen Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Beijing 100876 Peoples R China

As an extension of source polarization and channel polarization, this paper considers joint source-channel polarization, which results in a joint source-channel coding (JSCC) scheme using a quasi uniform systematic polar code (SPC). In this JSCC scheme, the source with side information is encoded as a systematic polar codeword and only parity bits are transmitted through the channel. The indices of systematic bits are quasi-uniform, which enable the source and the channel to be jointly polarized to either a high entropy part or a low entropy part. The analysis reveals that the quasi-uniform SPC cannot be constructed via original polar coding. To solve this problem, additional bit-swap coding is introduced to modify original polar coding and construct this kind of SPCs. The proposed JSCC scheme can asymptotically approach the information-theoretical limit. For the noiseless channel, the proposed scheme is degraded into classic Slepain-Wolf coding or lossless source coding based on parity approach.

关键词： joint source-channel polarization joint source-channel coding side information systematic polar codes

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THE source-channel SEPARATION THEOREM REVISITED

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IEEE TRANSACTIONS ON INFORMATION THEORY 1995年第1期41卷 44-54页

作者： VEMBU, S VERDU, S STEINBERG, Y PRINCETON UNIV DEPT ELECT ENGN PRINCETON NJ 08544 USA

The single-user separation theorem of joint source-channel coding has been proved previously for wide classes of sources and channels. We find an information-stable source/channel pair which does not satisfy the separation theorem. New necessary and sufficient conditions for the transmissibility of a source through a channel are found, and we characterize the class of channels for which the separation theorem holds regardless of the source statistics.

关键词： SHANNON THEORY channel CAPACITY, source coding joint source-channel coding SEPARATION THEOREM

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Analysis and Improvement of Error-Floor Performance for JSCC Scheme Based on Double Protograph LDPC Codes

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2020年第12期69卷 14316-14329页

作者： Chen, Qiwang Lau, Francis C. M. Wu, Huihui Chen, Chen Huaqiao Univ Xiamen Key Lab Mobile Multimedia Commun Coll Informat Sci & Engn Xiamen 361021 Peoples R China Hong Kong Polytech Univ Dept Elect & Informat Engn Kowloon Hong Kong Peoples R China McGill Univ Dept Elect & Comp Engn Montreal PQ H3A 0G4 Canada

In a joint source-channel coding (JSCC) system, excessive source compression can cause an error floor. In the original JSCC scheme based on double protograph LDPC (DP-LDPC) codes, only connections exist between check nodes (CNs) of the source protograph and variable nodes (VNs) of the channel protograph, and error floors are observed. In this paper, we investigate the joint protograph that forms the basis of a DP-LDPC code. The joint protograph consists of a source protograph, a channel protograph, and connections between the two protographs. Our main focus is on the complete-source-variable-linking (CSVL) protomatrix of the joint protograph, which determines the error floor of the DP-LDPC code. We propose a generalized source protograph extrinsic information transfer (GSP-EXIT) algorithm for evaluating the source decoding thresholds of the CSVL protomatrix. Based on the proposed algorithm, we analyze CSVL protomatrices with regular or irregular source protographs. We present design criteria for connections between VNs of the source protograph and CNs of the channel protograph. Such design rules will result in a higher source decoding threshold, which implies a lower error floor. We also propose a differential evolution algorithm for optimizing the source protograph. We present/compare analytical results and/with simulation results, and conclude that they are consistent.

关键词： Parity check codes channel coding Decoding source coding Joining processes Complexity theory Complete-source-variable-linking protomatrix double protograph LDPC code error floor GSP-EXIT algorithm joint source-channel coding

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User Grouping for the Uplink of Multiuser Hybrid mmWave MIMO

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IEEE ACCESS 2020年 8卷 55323-55341页

作者： Perez-Adan, Darian Fresnedo, Oscar Gonzalez-Coma, Jose P. Castedo, Luis Univ A Coruna Dept Comp Engn La Coruna 15001 Spain Univ A Coruna CITIC Res Ctr La Coruna 15001 Spain

Hybrid analog/digital schemes for precoding/combining have proved to be a low-complexity and/or low-power strategy to obtain reasonable beamforming gains in multiuser millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems. Hybrid precoding/combining performs jointly baseband processing and analog processing in the radio frequency (RF) domain. In these systems, the number of RF chains limits the maximum number of streams simultaneously handled by the transceivers. In the uplink of a multiuser mmWave MIMO system, the hardware reduction based on hybrid transceivers is limited by the number of data streams that must be simultaneously served by the centralized node. Most works approach hybrid transceiver design by considering more RF chains than data streams, an unrealistic assumption when the number of nodes is large. On the other hand, statistically independent information is conventionally assumed in multiuser mmWave systems. This assumption does not hold in scenarios like wireless sensor networks (WSNs), where the sources produce correlated information. In this paper, by enabling inter-user correlation exploitation, we propose a grouping approach to handle a high number of individual sources with a limited number of RF chains through distributed quantizer linear coding (DQLC) mappings. The allocation of the users per group and the hybrid design of the combiner at the common central node to serve the grouped users is also analyzed. We also propose a hybrid minimum mean square error (MMSE) combining design in order to exploit the spatial correlation between the sources in a conventional uncoded mmWave uplink. Simulation results show the performance advantages of the proposed approaches in various hardware-constrained system settings.

关键词： Millimeter-wave communications multiuser channels joint source-channel coding hybrid combining source correlation

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A Trellis-Coded Quantization Approach to Transmitting Correlated Gaussian sources Over a Fading MAC Without Transmitter-CSI

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IEEE TRANSACTIONS ON COMMUNICATIONS 2021年第5期69卷 2975-2986页

作者： Yahampath, Pradeepa Illangakoon, Chathura Univ Manitoba Dept Elect & Comp Engn Winnipeg MB R3T 5V6 Canada

It is known that source-channel separation is sub-optimal for communicating correlated Gaussian sources over a Gaussian multiple access channel (GMAC). Considering a two-to-one GMAC which undergoes Rayleigh block-fading, we present a novel approach to practical joint source-channel coding for the scenario in which the common receiver has instantaneous CSI but only the CSI distribution is available to the individual transmitters. This approach, referred to as source-channel trellis-coded vector quantization (SC-TCVQ), simply relies on using TCVQs as fixed-rate source-channel encoders. One key issue is the optimization of the TCVQ codebooks to the mean channel signal-to-noise ratio (CSNR), and to this end, we present an analytical method to obtain the rates required for codebook design. Another key issue is the joint estimation of the sources at the receiver, for which we present a detector-estimator based on the Cartesian product of the two encoder-trellises. Simulation results show that the proposed SC-TCVQ codes, in some cases, can even beat the asymptotic performance bound for a separate source-channel code consisting of a distributed vector quantizer and capacity achieving channel codes. SC-TCVQ appears to be the best known practical code design to date for the given communication problem.

关键词： Encoding Transmitters Receivers Rayleigh channels Decoding Correlation Bandwidth Multiple-access channels Rayleigh fading joint source-channel coding rate-distortion theory distributed vector quantization trellis-coded quantization uncoded transmission

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Outer Bounds on the Admissible source Region for Broadcast channels With Correlated sources

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IEEE TRANSACTIONS ON INFORMATION THEORY 2015年第9期61卷 4616-4629页

作者： Khezeli, Kia Chen, Jun McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada Cornell Univ Sch Elect & Comp Engn Ithaca NY 14853 USA

Two outer bounds on the admissible source region for broadcast channels with correlated sources are presented: the first one is strictly tighter than the existing outer bound by Gohari and Anantharam, while the second one provides a complete characterization of the admissible source region in the case where the two sources are conditionally independent given the common part. These outer bounds are deduced from the general necessary conditions established for the lossy source broadcast problem via suitable comparisons between the virtual broadcast channel (induced by the source and the reconstructions) and the physical broadcast channel.

关键词： Bandwidth mismatch broadcast channel capacity region deterministic channel joint source-channel coding

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Remote walkthrough over mobile networks using 3-D image warping and streaming

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IEE PROCEEDINGS-VISION IMAGE AND SIGNAL PROCESSING 2004年第4期151卷 329-336页

作者： Bao, P Gourlay, D Nanyang Technol Univ Sch Comp Engn Singapore 639798 Singapore Chinese Univ Hong Kong Dept Informat Engn Shatin Hong Kong Peoples R China

A mobile walkthrough environment based on 3-D superview warping and view compensation streaming is presented. In this environment, 3-D views are rendered on the remote clients using 3-D oversized reference views and compensated on a view-on-demand basis by the graphically rendered views from the server. The view compensations (hole residuals and the depth map) are coded using a layered joint source-channel coding with unequal error corrections to protect the significant packets on noisy and erasure mobile channels. The new compensated view will then serve as a reference view for the subsequent rendering on the clients. This environment enables numerous mobile virtual applications, such as remote m-gaming, remote m-design, in-learning, m-CAD/CAM, etc., scalable to different network capabilities.

关键词： Reed-Solomon erasure channel codes client-server systems Mobile radio systems mobile communication 3D image warping mobile channels superview warping combined source-channel coding Reed-Solomon codes mobile networks image coding view-on-demand basis 3D image streaming mobile walkthrough scheme error correction codes Image and video coding Video on demand and video servers joint source-channel coding erasure channels telecommunication channels video on demand

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Incremental Refinements and Multiple Descriptions With Feedback

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IEEE TRANSACTIONS ON INFORMATION THEORY 2022年第10期68卷 6915-6940页

作者： Ostergaard, Jan Erez, Uri Zamir, Ram Aalborg Univ Dept Elect Syst DK-9000 Aalborg Denmark Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel

It is well known that independent (separate) encoding of K correlated sources may incur some rate loss compared to joint encoding, even if the decoding is done jointly. This loss is particularly evident in the multiple descriptions problem, where it is the same source that is encoded in each description. We observe that under mild conditions about the source and distortion measure, the sum-rate of K separately encoded individually good descriptions tends to the rate-distortion function of the joint decoder in the limit of vanishing small coding rates of the descriptions. Moreover, we then propose to successively encode the source into K independent descriptions in each round in order to achieve a final distortion D after M rounds. We provide two examples - a Gaussian source with mean-squared error and an exponential source with one-sided error - for which the excess rate vanishes in the limit as the number of rounds M goes to infinity, for any fixed D and K. This result has an interesting interpretation for a multi-round variant of the multiple descriptions problem, where after each round the encoder gets a (block) feedback regarding which of the descriptions arrived: In the limit as the number of rounds M goes to infinity (i.e., many incremental rounds), the total rate of received descriptions approaches the rate-distortion function. We provide theoretical and experimental evidence showing that this phenomenon is in fact more general than in the two examples above.

关键词： Multiple description (MD) coding successive refinement joint source-channel coding source coding with feedback

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