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A type-aware coding approach for unequal message protection

PHYSICAL COMMUNICATION 2022年 53卷

作者： Yao, Xinyuanmeng Wan, Hai Ma, Xiao Sun Yat Sen Univ Sch Comp Sci & Engn Guangzhou 510006 Guangdong Peoples R China Guangdong Key Lab Informat Secur Technol Guangzhou 510006 Guangdong Peoples R China

In this paper, to achieve an unequal message protection (UMP), we propose a type-aware coding approach. The proposed approach can be used to construct a UMP code with multiple classes of messages, and can also be employed as a finite-length joint source-channel coding (JSCC) where the source statistics is not required at the transmitter. At the transmitter, an information bit sequence is first encoded using a fixed-to-fixed-length type-aware description and then encoded by a given linear block code along with a "free-ride "approach. At the receiver, a type-search decoding algorithm is employed. Numerical results show that, 1) As a UMP coding, the type-aware coding can provide more protection for biased binary sequences;2) As a finite-length JSCC, the type-aware coding can improve the average error performance for biased sources over the distribution-aware decoding. (c) 2022 Elsevier B.V. All rights reserved.

关键词： Fixed-to-fixed-length type-aware description Free-ride approach joint source-channel coding Type-aware coding approach Unequal message protection

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Robust transmission of progressive image bitstreams based on DCT over broadband wireless channels

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Journal of Harbin Institute of Technology(New Series) 2006年第2期13卷 219-225页

作者：王东华周源华马曾栋 Institute of Image Communication & Information Processing Shanghai Jiaotong University Shanghai 200030 China Research Institute of Communication Technology Harbin Institute of Technology Harbin 150001 China

A robust progressive image transmission scheme over broadband wireless fading channels is developed for 4th generation wireless communication systems （4G） in this paper. The proposed scheme is based on space-time block coded orthogonal frequency-division multiplexing （OFDM） with 4 transmit antennas and 2 receive antennas and uses a simplified minimum mean square error （MMSE） detector instead of maximum likelihood （ML） detectors. Considering DCT is simpler and more widely applied in the industry than wavelet transforms, a progressive image compression method based on DCT called mean-subtract embedded DCT （MSEDCT） is developed, with a simple mean-subtract method for the redundancy of reorganized DC blocks in addition to a structure similar to the embedded zerotree wavelet coding （EZW） method. Then after analyzing and testing bit importance of the progressive MSEDCT bitstreams, the layered unequal error protection method of joint source-channels coding based on Reed-Solomon （RS） codes is used to protect different parts of bitstreams, providing different QoS assurances and good flexibility. Simulation experiments show our proposed scheme can effectively degrade fading effects and obtain better image transmission effects with 10 -20 dB average peak-sig- nal-noise-ratio （PSNR） gains at the median Eb/No than those schemes without space-time coded OFDM or equal error protections with space-time coded OFDM.

关键词： broadband communication embedded source coding image transmission joint source-channel coding

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Comments on "Optimal Erasure Protection for Scalably Compressed Video Streams With Limited Retransmission"

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2009年第1期18卷 214-216页

作者： Dumitrescu, Sorina McMaster Univ Dept Elect & Comp Engn Hamilton ON L8S 4K1 Canada

In order to prove a key result for their development (Lemma 2), Taubman and Thic need the assumption that the upper boundary of the convex hull of the channel coding probability-redundancy characteristic is sufficiently dense. Since a floor value for the density level for which the claim to hold is not specified, it is not clear whether their lemma applies to practical situations. In this correspondence, we show that the constraint of sufficient density can be removed, and, thus, we validate the conclusion of the lemma for any scenario encountered in practice.

关键词： joint source-channel coding unequal erasure protection

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The Error Probability of Generalized Perfect Codes via the Meta-Converse

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IEEE TRANSACTIONS ON INFORMATION THEORY 2019年第9期65卷 5705-5717页

作者： Vazquez-Vilar, Gonzalo Guillen i Fabregas, Albert Verdu, Sergio Univ Carlos III Madrid Signal Theory & Commun Dept Leganes 28911 Spain Gregorio Maranon Hlth Res Inst Madrid 28007 Spain Univ Pompeu Fabra Dept Informat & Commun Technol Barcelona 08018 Spain Inst Catalana Recerca & Estudis Avancats Barcelona 08010 Spain Univ Cambridge Dept Engn Cambridge CB2 1PZ England Natl Acad Engn Washington DC 20418 USA Natl Acad Sci 2101 Constitut Ave Nw Washington DC 20418 USA Australian Natl Univ Canberra ACT Australia Technion Israel Inst Technol Haifa Israel Univ Tokyo Tokyo Japan Univ Calif Berkeley Berkeley CA 94720 USA Math Sci Res Inst 1000 Centennial Dr Berkeley CA 94720 USA MIT Cambridge MA 02139 USA

We introduce a definition of perfect and quasi-perfect codes for discrete symmetric channels based on the packing and covering properties of generalized spheres whose shape is tilted using an auxiliary probability measure. This notion generalizes previous definitions of perfect and quasi-perfect codes and encompasses maximum distance separable codes. The error probability of these codes, whenever they exist, is shown to coincide with the estimate provided by the meta-converse lower bound. We illustrate how the proposed definition naturally extends to cover almost-lossless source-channel coding and lossy compression.

关键词： Shannon theory perfect codes quasi-perfect codes maximum likelihood decoding finite blocklength analysis meta-converse hypothesis testing channel coding joint source-channel coding rate distortion theory

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source-optimized channel coding for digital transmission channels

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IEEE TRANSACTIONS ON COMMUNICATIONS 2005年第4期53卷 592-600页

作者： Heinen, S Vary, P Infineon Technol AG Dev Ctr Dusseldorf D-40489 Dusseldorf Germany Rhein Westfal TH Aachen Univ Inst Commun Syst & Data Proc D-52056 Aachen Germany

We present a new class of nonlinear block codes called source-optimized channel codes (SOCCs), which are particularly designed for parametric source encoding of speech, audio, and video. In contrast to conventional channel codes, the new codes are not optimized for minimizing residual bit-error rate, but maximizing the signal-to-noise ratio of transmitted source codec parameters. The decoding of SOCCs is not based on bit-error correction, but on parameter estimation. We compare SOCCs with other approaches to joint source/channel coding such as channel-optimized vector quantization, channel-constrained vector quantization, unequal error protection, and source-controlled channel decoding. In terms of performance, SOCCs show better robustness if under channel mismatch conditions. For real-world applications, SOCCs are attractive, since the separation of source and channel codec is preserved.

关键词： joint source-channel coding nonlinear block codes parameter estimation

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Empirical Coordination with channel Feedback and Strictly Causal or Causal Encoding

Empirical Coordination with Channel Feedback and Strictly Ca...

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IEEE International Symposium on Information Theory (ISIT)

作者： Le Treust, Mael Univ Cergy Pontoise CNRS ENSEA ETISUMR 8051 6 Ave Ponceau F-95014 Cergy Pontoise France

ISBN: (纸本)9781467377041

In multi-terminal networks, feedback increases the capacity region and helps communication devices to coordinate. In this article, we deepen the relationship between coordination and feedback by considering a point-to-point scenario with an information source and a noisy channel. Empirical coordination is achievable if the encoder and the decoder can implement sequences of symbols that are jointly typical for a target probability distribution. We investigate the impact of feedback when the encoder has strictly causal or causal observation of the source symbols. For both cases, we characterize the optimal information constraints and we show that feedback improves coordination possibilities. Surprisingly, feedback also reduces the number of auxiliary random variables and simplifies the information constraints. For empirical coordination with strictly causal encoding and feedback, the information constraint does not involve auxiliary random variable anymore.

关键词： Shannon Theory Feedback Empirical Coordination joint source-channel coding Empirical Distribution of Symbols Strictly Causal and Causal Encoding

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joint source-channel Rate-Distortion Optimization for Wireless Video Transmission 54

Joint Source-Channel Rate-Distortion Optimization for Wirele...

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54th Asilomar Conference on Signals, Systems, and Computers

作者： Hegazy, Rana D. Song, Qing Vosoughi, Arash Milstein, Laurence B. Cosman, Pamela C. Univ Calif San Diego Dept Elect & Comp Engn La Jolla CA 92093 USA Dolby Labs San Francisco CA USA LG Elect Mobile Res Lab San Jose CA USA

ISBN: (纸本)9780738131269

This paper proposes a joint source-channel rate-distortion (RD) optimization for real-time video transmission. The video compression and forward error correction (FEC) options are optimized by looking for the best trade-off between the estimated end-to-end distortion of a video packet and the sum of the number of source bits and FEC bits used to encode that packet. Video coding options include coding mode and quantization parameter, which are selected for each macroblock. channel coding options consist of different FEC code rates that provide different levels of protection against the lossy channel. The proposed RD technique adjusts the bit rate to meet a target using a Lagrange multiplier approach. The encoder also uses the instantaneous channel state information to improve performance for a varying channel. Conventional RD optimization approaches optimize over the video coding modes, and our approach which considers the channel and FEC bits as well has better performance over both AWGN and Rayleigh fading channels. We also consider an approach to reduce the computational complexity of the proposed RD scheme.

关键词： Error resilience rate-distortion optimization forward error correction joint source-channel coding

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ADAPTIVE STATE ESTIMATION OVER LOSSY SENSOR NETWORKS FULLY ACCOUNTING FOR END-TO-END DISTORTION 20

ADAPTIVE STATE ESTIMATION OVER LOSSY SENSOR NETWORKS FULLY A...

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IEEE Statistical Signal Processing Workshop (SSP)

作者： Li, Bohan Nanjundaswamy, Tejaswi Rose, Kenneth Univ Calif Santa Barbara Dept Elect & Comp Engn Santa Barbara CA 93106 USA

ISBN: (纸本)9781538615713

This paper investigates state estimation with wireless sensors communicating over unreliable bandwidth-limited networks. Specifically, we consider so-called smart sensors equipped with simple processing units, which enable predictive coding at the sensor side, to meet the bandwidth constraint. While predictive coding significantly reduces the bit-rate by removing temporal redundancies, it exacerbates the impact of packet loss, due to error propagation through the prediction loop, potentially causing significant degradation of the reconstructed signal. To fully account for and control the conflict between coding efficiency and robustness to packet loss, we propose a coding approach that explicitly optimizes the tradeoff between rate and end-to-end distortion (EED). The proposed method determines optimal switching decisions between available coding modes, offering different compression-robustness operating points, based on EED that is optimally estimated at the encoder (sensor), in order to realize the best rate-distortion tradeoff. Simulation results demonstrate that the proposed approach achieves considerable gains in signal-to-noise ratio for state estimation over lossy sensor networks.

关键词： Kalman filter wireless sensors lossy networks end-to-end distortion joint source-channel coding

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source Broadcasting and Asymmetric Data Transmission With Bandwidth Expansion

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IEEE TRANSACTIONS ON COMMUNICATIONS 2019年第10期67卷 6698-6710页

作者： Bross, Shraga, I Zalach, Hagai Bar Ilan Univ Fac Engn IL-52900 Ramat Gan Israel CEVA DSP IL-4673302 Herzliyya Israel

We consider the broadcasting of a scalar memoryless Gaussian source over a two-user Gaussian broadcast channel with bandwidth expansion. In concurrent with the source description, a message that should be decoded reliably just by the "higher quality" user is sent. Conditioned on the message rate, we derive a necessary condition for the achievability of a mean-squared-error distortion pair at the two receivers, which extends the Reznic-Feder-Zamir bound. This necessary condition and a sufficient condition that we derive establish the set of achievable energy-distortion exponents for this setting.

关键词： Gaussian broadcast channel source broadcasting asymmetric data transmission joint source-channel coding

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Task-Oriented Semantic Communication with Foundation Models

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China Communications 2024年第7期21卷 65-77页

作者： Chen Mingkai Liu Minghao Zhang Zhe Xu Zhiping Wang Lei Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China School of Ocean Information Engineering Jimei UniversityXiamen 361021China Key Laboratory of Underwater Acoustic Communication and Marine Information Technology(Xiamen University) Ministry EducationXiamen 361005China

In the future development direction of the sixth generation(6G)mobile communication,several communication models are proposed to face the growing challenges of the *** rapid development of artificial intelligence(AI)foundation models provides significant support for efficient and intelligent communication *** this paper,we propose an innovative semantic communication paradigm called task-oriented semantic communication system with foundation ***,we segment the image by using task prompts based on the segment anything model(SAM)and contrastive language-image pretraining(CLIP).Meanwhile,we adopt Bezier curve to enhance the mask to improve the segmentation ***,we have differentiated semantic compression and transmission approaches for segmented ***,we fuse different semantic information based on the conditional diffusion model to generate high-quality images that satisfy the users'specific task ***,the experimental results show that the proposed system compresses the semantic information effectively and improves the robustness of semantic communication.

关键词： diffusion model foundation model joint source-channel coding task-oriented semantic communication

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