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Efficient algorithms for optimal uneven protection of single and multiple scalable code streams against packet erasures

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IEEE TRANSACTIONS ON MULTIMEDIA 2007年第7期9卷 1466-1474页

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

We study algorithmic approaches for rate-fidelity optimal packetization of a single and multiple scalable source code streams with uneven erasure protection (UEP). A new algorithm is developed to obtain the globally optimal solution for scalable source codes of convex rate-fidelity function and for a wide class of erasure channels, including channels for which the probability of losing n packets is monotonically nonincreasing in n, and independent erasure channels with packet erasure rate smaller than 0.5. This is achieved at linear space complexity and near-linear time complexity in the transmission budget, representing significant improvement over the known globally optimal algorithm. When applied to SPIHT compressed images, the results of the proposed algorithm are virtually the same as the global optima. The above success is also extended to UEP packetization of multiple scalable code streams. We improve the existing algorithms in both speed and performance.

关键词： joint source-channel coding Monge property multimedia streaming rate-distortion optimization uneven erasure protection

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Packet video transmission over wireless channels with adaptive channel rate allocation

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2005年第4-5期16卷 475-498页

作者： Kung, WY Kim, CS Kuo, CCJ Univ So Calif Dept Elect Engn Integrated Media Syst Ctr Los Angeles CA 90089 USA Chinese Univ Hong Kong Dept Informat Engn Shatin Hong Kong Peoples R China

A robust video communication system based on layered coding and unequal error protection is developed in this work. We consider two video communication scenarios. First, for pre-compressed video bitstreams, a channel code rate allocation scheme is proposed to minimize the expected mean square error subject to a constraint on the overall bit budget. Second, for real-time video transmission, we jointly optimize the quantization parameters and the channel coding rates according to channel conditions. To this end, we develop a simple rate-distortion model for general video coders using DCT and motion compensation, so that the rate and the distortion can be estimated without an expensive encoding procedure. Simulation results Show that the proposed algorithms provide acceptable image quality even in high bit error rate environments. (c) 2005 Elsevier Inc. All rights reserved.

关键词： packet video wireless video robust video transmission joint source-channel coding unequal error protection

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Two-Way Semantic Communications Without Feedback

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2024年第6期73卷 9077-9082页

作者： Yu, Kaiwen He, Qi Wu, Gang Univ Elect Sci & Technol China Natl Key Lab Wireless Commun Chengdu 611731 Peoples R China

Semantic communications can significantly improve transmission efficiency, especially in the low signal-to-noise (SNR) regime. However, two-way semantic communications still remain an unexplored topic, which is a critical issue in many machine communication scenarios. Simply extending existing semantic communication systems to the two-way situation requires bidirectional information feedback during the training process, resulting in significant communication overhead. To fill this gap, we investigate a two-way semantic communication (TW-SC) system, where the information feedback can be omitted by exploiting the weight reciprocity in the transceiver. Particularly, the channel simulator and semantic transceiver are implemented on both TW-SC nodes and the channel distribution is modeled by a conditional generative adversarial network. Simulation results demonstrate that the proposed TW-SC system performs closing to the state-of-the-art one-way semantic communication systems but requiring no feedback between the transceiver in training process.

关键词： Semantics Training Transmitters Receivers Wireless communication Generators Artificial neural networks Semantic communications deep learning joint source-channel coding

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Multi-Way Relay Networks: Orthogonal Uplink, source-channel Separation and Code Design

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IEEE TRANSACTIONS ON COMMUNICATIONS 2013年第2期61卷 753-768页

作者： Timo, Roy Lechner, Gottfried Ong, Lawrence Johnson, Sarah Univ S Australia Inst Telecommun Res Adelaide SA 5001 Australia Univ Newcastle Sch Elect Engn & Comp Sci Callaghan NSW 2308 Australia

We consider a multi-way relay network with an orthogonal uplink and correlated sources, and we characterise reliable communication (in the usual Shannon sense) with a single-letter expression. The characterisation is obtained using a joint source-channel random-coding argument, which is based on a combination of Wyner et al.'s Cascaded Slepian-Wolf source coding and Tuncel's Slepian-Wolf coding over Broadcast channels. We prove a separation theorem for the special case of two nodes;that is, we show that a modular code architecture with separate source and channel coding functions is (asymptotically) optimal. Finally, we propose a practical coding scheme based on low-density parity-check codes, and we analyse its performance using multi-edge density evolution.

关键词： joint source-channel coding two-way relay network source-channel separation

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Cache-Aided K-User Broadcast channels With State Information at Receivers

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IEEE TRANSACTIONS ON INFORMATION THEORY 2024年第4期70卷 2518-2537页

作者： Reisizadeh, Hadi Maddah-Ali, Mohammad Ali Mohajer, Soheil Univ Minnesota Twin Cities Dept Elect & Comp Engn Minneapolis MN 55455 USA

We study a K-user coded-caching broadcast problem in a joint source-channel coding framework. The transmitter observes a database of files that are being generated at a certain rate per channel use, and each user has a cache, which can store a fixed fraction of the generated symbols. In the delivery phase, the transmitter broadcasts a message so that the users can decode their desired files using the received signal and their cache content. The communication between the transmitter and the receivers happens over a (deterministic) time-varying erasure broadcast channel, and the channel state information is only available to the users. We characterize the maximum achievable source rate for the 2-user and the degraded K -user problems. We provide an upper bound for any caching strategy's achievable source rates. Finally, we present a linear programming formulation to show that the upper bound is not a sharp characterization. Closing the gap between the achievable rate and the optimum rate remains open.

关键词： Coded caching joint source-channel coding broadcast channel wireless networks

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Computation Over Gaussian Networks With Orthogonal Components

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IEEE TRANSACTIONS ON INFORMATION THEORY 2014年第12期60卷 7841-7861页

作者： Jeon, Sang-Woon Wang, Chien-Yi Gastpar, Michael Andong Natl Univ Dept Informat & Commun Engn Andong 760749 South Korea Ecole Polytech Fed Lausanne Sch Comp & Commun Sci CH-1015 Lausanne Switzerland Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA

Function computation over Gaussian networks with orthogonal components is studied for arbitrarily correlated discrete memoryless sources. Two classes of functions are considered: 1) the arithmetic sum function and 2) the type function. The arithmetic sum function in this paper is defined as a set of multiple weighted arithmetic sums, which includes averaging of the sources and estimating each of the sources as special cases. The type or frequency histogram function counts the number of occurrences of each argument, which yields various fundamental statistics, such as mean, variance, maximum, minimum, median, and so on. The proposed computation coding first abstracts Gaussian networks into the corresponding modulo sum multiple-access channels via nested lattice codes and linear network coding and then computes the desired function using linear Slepian-Wolf source coding. For orthogonal Gaussian networks (with no broadcast and multiple-access components), the computation capacity is characterized for a class of networks. For Gaussian networks with multiple-access components (but no broadcast), an approximate computation capacity is characterized for a class of networks.

关键词： Distributed averaging function computation joint source-channel coding lattice codes linear source coding network coding sensor networks

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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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Deep Learning-Constructed joint Transmission-Recognition for Internet of Things

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IEEE ACCESS 2019年 7卷 76547-76561页

作者： Lee, Chia-Han Lin, Jia-Wei Chen, Po-Hao Chang, Yu-Chieh Natl Chiao Tung Univ Inst Commun Engn Hsinchu 30010 Taiwan

The widely deployed Internet-of-Things (IoT) devices provide intelligent services with its cognition capability. Since the IoT data are usually transmitted to the server for recognition (e.g., image classification) due to low computational capability and limited power supply, achieving recognition accuracy under limited bandwidth and noisy channel of wireless networks is a crucial but challenging task. In this paper, we propose a deep learning-constructed joint transmission-recognition scheme for the IoT devices to effectively transmit data wirelessly to the server for recognition, jointly considering transmission bandwidth, transmission reliability, complexity, and recognition accuracy. Compared with other schemes that may be deployed on the IoT devices, i.e., a scheme based on JPEG compression and two compressed sensing-based schemes, the proposed deep neural network-based scheme has much higher recognition accuracy under various transmission scenarios at all signal-to-noise ratios (SNRs). In particular, the proposed scheme maintains good performance at the very low SNR. Moreover, the complexity of the proposed scheme is low, making it suitable for IoT applications. Finally, a transfer learning-based training method is proposed to effectively mitigate the computing burden and reduce the overhead of online training.

关键词： Internet of things (IoT) recognition transmission joint source-channel coding deep learning deep neural networks transfer learning JPEG compressed sensing

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Fast algorithm for rate-based optimal error protection of embedded codes

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IEEE TRANSACTIONS ON COMMUNICATIONS 2003年第11期51卷 1788-1795页

作者： Stankovic, V Hamzaoui, R Saupe, D Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA Univ Konstanz Dept Comp & Informat Sci D-78457 Constance Germany

Embedded image codes are very sensitive to channel noise because a single bit error can lead to an irreversible loss of synchronization between the encoder and the decoder. Sherwood and Zeger introduced a powerful system that protects an embedded wavelet image code with a concatenation of a cyclic redundancy check coder for error detection and a rate-compatible punctured convolutional coder for error correction. For such systems, Chande and Farvardin proposed an unequal error protection strategy that maximizes the expected number of correctly received source bits subject to a target transmission rate. Noting that an optimal strategy protects successive source blocks with the same channel code, we give an algorithm that accelerates the computation of the optimal strategy of Chande and Farvardin by finding an explicit formula for the number of occurences of the same channel code. Experimental results with two competitive channel coders and a binary symmetric channel showed that the speed-up factor over the approach of Chande and Farvardin ranged from 2.82 to 44.76 for transmission rates between 0.25 and 2 bits per pixel.

关键词： forward error correction (FEC) image coding image communication joint source-channel coding

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Robust transmission of multistage vector quantized sources over noisy communication channels-applications-to MELP speech codec

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2006年第6期55卷 1805-1811页

作者： Lahouti, Farshad Khandani, Amir K. Saleh, Aladdin Univ Tehran Sch Elect & Comp Engn Coll Engn Tehran 14395 Iran Univ Waterloo Dept Elect & Comp Engn Coding & Signal Transmiss Lab Waterloo ON N2L 3G1 Canada Wireless Technol Mississauga ON L4W 5N2 Canada

joint source-channel coding is an effective approach for the design of bandwidth efficient and error resilient communication systems with manageable complexity. An interesting research direction within this framework is the design of source decoders that exploit the residual redundancy for effective signal reconstruction at the receiver. Such source decoders are expected to replace the traditionally heuristic error concealment units that are elements of most multimedia communication systems. In this paper, we consider the reconstruction of signals encoded with a multistage vector quantizer (MSVQ) and transmitted over a noisy communications channel. The MSVQ maintains a moderate complexity and, due to its successive refinement feature, is a suitable choice for the design of layered (progressive) source codes. An approximate minimum mean squared error source decoder for MSVQ is presented, and its application to the reconstruction of the linear predictive coefficient (LPC) parameters in mixed excitation linear prediction (MELP) speech codec is analyzed. MELP is a low-rate standard speech codec suitable for bandwidth-limited communications and wireless applications. Numerical results demonstrate the effectiveness of the proposed schemes.

关键词： error concealment joint source-channel coding linear predictive coding (LPC) line spectral frequencies (LSFs) Markov model MELP minimum mean squared error (MMSE) estimation multistage vector quantization (MSVQ) residual redundancy source decoding

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