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Unequal error protection for data partitioned H.264/AVC video broadcasting

MULTIMEDIA TOOLS AND APPLICATIONS 2015年第15期74卷 5787-5809页

作者： Nazir, Sajid Vukobratovic, Dejan Stankovic, Vladimir Andonovic, Ivan Nybom, Kristian Gronroos, Stefan Univ Strathclyde Dept EEE Glasgow Lanark Scotland Univ Novi Sad Dept Power Elect & Commun Engn Novi Sad 21000 Serbia Abo Akad Univ Turku Finland

Application Layer Forward Error Correction (AL-FEC) is becoming a popular addition to protocols for real-time video delivery over IP-based wireless networks. In particular, rateless codes are identified as suitable solution for AL-FEC due to their flexibility and capacity-approaching performance. Since each part of video data is not equally important for video reconstruction, it is beneficial to group it based on its importance, and then provide different degree of protection using Unequal Error Protection (UEP). Data partitioning (DP) is one such low-cost feature in H.264/AVC enabling partitioning of video data based on its importance. We propose schemes for the DP H.264/AVC video transmission using Raptor and Random Linear Codes (RLC) and investigate their performance as AL-FEC solutions in Digital Video Broadcasting. We provide comparisons between optimized Non-Overlapping Window RLC and Expanding Window (EW) RLC, which are two effective UEP RLC strategies. The results using realistic channel traces show viability of the EW RLC as a promising solution for multimedia broadcast applications.

关键词： Video compression Rateless coding Digital Video Broadcasting joint source-channel coding

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New Hybrid Digital/Analog Schemes for Transmission of a Gaussian source Over a Gaussian channel

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IEEE TRANSACTIONS ON INFORMATION THEORY 2010年第12期56卷 6014-6019页

作者： Gao, Yang Tuncel, Ertem Univ Calif Riverside Dept Elect Engn Riverside CA 92521 USA

Two new schemes are proposed for transmitting a Gaussian source over a Gaussian channel. These schemes directly generalize previous results of Bross et al. and Puri et al. A scaled version of either the source itself or the quantization error is superimposed on the digital information, and thus serves as effective channel state information (CSI) unknown to the receiver. It is shown that for any power allocation between the coded and uncoded components of transmission, optimal distortion can be achieved by a continuum of auxiliary random variables (rather than only Costa's) if the decoded auxiliary codeword is properly used. This observation provides a new degree of freedom in point-to-point transmission. This freedom, in turn, can be utilized in multiterminal scenarios, as is demonstrated with an example.

关键词： AWGN channels hybrid digital/analog coding joint source-channel coding uncoded transmission writing on dirty paper

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Policy Allocation for Transmission of Embedded Bit Streams over Noisy channels with Feedback

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IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第11期57卷 3177-3182页

作者： Qiu, Jinshi Banihashemi, Amir H. Carleton Univ BCWS Ctr Dept Syst & Comp Engn Ottawa ON K1S 5B6 Canada

An efficient policy allocation algorithm for the transmission of embedded bit streams over noisy channels with feedback is proposed. The transmission is based on the typeII hybrid ARQ/FEC protocol and uses a nested sequence C of channel codes to protect the packets. There are also constraints on the total bit budget and on the allowed number of retransmissions per packet. The allocation algorithm assigns different protection policies, each policy being a subset of C, to different packets to maximize the average number of correctly received source bits. We study the performance and the complexity of the proposed scheme through the transmission of images encoded by JPEG2000 over mobile channels with correlated Rayleigh fading. We demonstrate by simulations that the proposed multiple-policy scheme provides significant improvements over a purely FEC scheme with no feedback and also the existing fixed-policy schemes. Our results show that feedback is particularly helpful for poor channel conditions and that the proposed scheme is very robust against changes in the channel signal-to-noise ratio (SNR) and the mobile speed.

关键词： joint source-channel coding unequal error protection feedback channels noisy channels policy allocation rate allocation hybrid ARQ/FEC protocols rate-compatible codes image transmission JPEG2000 fading channels

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On the Optimal Performance in Asymmetric Gaussian Wireless Sensor Networks With Fading

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2010年第4期58卷 2436-2441页

作者： Behroozi, Hamid Alajaji, Fady Linder, Tamas Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

We study the estimation of a Gaussian source by a Gaussian wireless sensor network (WSN) where distributed sensors transmit noisy observations of the source through a fading Gaussian multiple access channel to a fusion center. In a recent work Gastpar, ["Uncoded transmission is exactly optimal for a Simple Gaussian Sensor Network," IEEE Trans. Inf. Theory, vol. 54, no. 11, pp. 5247-5251, Nov. 2008] showed that for a symmetric Gaussian WSN with no fading, uncoded (analog) transmission achieves the optimal performance theoretically attainable (OPTA). In this correspondence, we consider an asymmetric fading WSN in which the sensors have differing noise and transmission powers. We first present lower and upper bounds on the system's OPTA under random fading. We next focus on asymmetric networks with deterministic fading. By comparing the obtained lower and upper OPTA bounds under deterministic fading, we provide a sufficient condition for the optimality of the uncoded transmission scheme for a given power tuple P = (P-1, P-2, ... , P-L). Then, allowing the sensor powers to vary under a weighted sum constraint (this includes the sum-power constraint as a special case), we obtain a sufficient condition for the optimality of uncoded transmission and provide the system's corresponding OPTA.

关键词： Gaussian multiple access channel with fading joint source-channel coding power-distortion tradeoff remote source coding sensor networks uncoded transmission

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Progressive image transmission over differentially space-time coded OFDM systems

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WIRELESS COMMUNICATIONS & MOBILE COMPUTING 2006年第8期6卷 1057-1075页

作者： Sun, Yong Xiong, Zixiang Wang, Xiaodong Texas A&M Univ Dept Elect Engn College Stn TX 77843 USA Columbia Univ Dept Elect Engn New York NY 10027 USA

In this paper, we consider progressive image transmission over differentially space-time coded orthogonal frequency-division multiplexing (OFDM) systems and treat the problem as one of optimal joint source-channel coding (JSCC) in the form of unequal error protection (UEP), as necessitated by embedded source coding (e.g., SPIHT and JPEG 2000). We adopt a product channel code structure that is proven to provide powerful error protection and employ low-complexity decision-feedback decoding for differentially space-time coded OFDM without assuming channel state information. For a given SNR, the BER performance of the differentially spacetime coded OFDM system is treated as the channel condition in the JSCC/UEP design via a fast product code optimization algorithm so that the end-to-end quality of reconstructed images is optimized in the average minimum MSE sense. Extensive image transmission experiments show that SNR/BER improvements can be translated into quality gains in reconstructed images. Moreover, compared to another non-coherent detection algorithm, i.e., the iterative receiver based on expectation-maximization algorithm for the space-time coded OFDM systems, differentially space-time coded OFDM systems suffer some quality loss in reconstructed images. With the efficiency and simplicity of decision-feedback differential decoding, differentially space-time coded OFDM is thus a feasible modulation scheme for applications such as wireless image over mobile devices (e.g., cell phones). Copyright (C) 2006 John Wiley & Sons, Ltd.

关键词： progressive image transmission differentially space-time coding OFDM joint source-channel coding SPIHT JPEG 2000

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Information and Energy Transmission With Experimentally Sampled Harvesting Functions

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IEEE TRANSACTIONS ON COMMUNICATIONS 2019年第6期67卷 4479-4490页

作者： Seo, Daewon Varshney, Lav R. Univ Illinois Coordinated Sci Lab Urbana IL 61801 USA Univ Illinois Dept Elect & Comp Engn Urbana IL 61801 USA

This paper considers the problem of simultaneous information and energy transmission, where the energy harvesting function is only known experimentally at sample points, e.g., due to nonlinearities and parameter uncertainties in harvesting circuits. We investigate the performance loss due to this partial knowledge of the harvesting function in terms of transmitted energy and information. In particular, we assume that the harvesting function is a subclass of the Sobolev space and consider two cases, where the experimental samples are either taken noiselessly or in the presence of noise. Using constructive function approximation and regression methods for noiseless and noisy samples, respectively, we show that the worst loss in energy transmission vanishes asymptotically as the number of samples increase. Similarly, the loss in information rate vanishes in the interior of the energy domain;however, it does not always vanish at maximal energy. We further show that the same principle applies in multicast settings, such as medium access in the Wi-Fi protocol. We also consider the end-to-end source-channel communication problem under source distortion constraint and channel energy requirement, where both distortion and harvesting functions are known only at samples.

关键词： Energy harvesting information theory multicast joint source-channel coding Sobolev spaces

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Soft and joint source-channel decoding of quasi-arithmetic codes

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EURASIP JOURNAL ON APPLIED SIGNAL PROCESSING 2004年第3期2004卷 393-411页

作者： Guionnet, T Guillemot, C Inst Natl Rech Informat & Automat IRISA Project TEMICS F-35042 Rennes France

The issue of robust and joint source-channel decoding of quasi-arithmetic codes is addressed. Quasi-arithmetic coding is a reduced precision and complexity implementation of arithmetic coding. This amounts to approximating the distribution of the source. The approximation of the source distribution leads to the introduction of redundancy that can be exploited for robust decoding in presence of transmission errors. Hence, this approximation controls both the trade-off between compression efficiency and complexity and at the same time the redundancy (excess rate) introduced by this suboptimality. This paper provides first a state model of a quasi-arithmetic coder and decoder for binary and M-ary sources. The design of an error-resilient soft decoding algorithm follows quite naturally. The compression efficiency of quasi-arithmetic codes allows to add extra redundancy in the form of markers designed specifically to prevent desynchronization. The algorithm is directly amenable for iterative source-channel decoding in the spirit of serial turbo codes. The coding and decoding algorithms have been tested for a wide range of channel signal-to-noise ratios (SNRs). Experimental results reveal improved symbol error rate (SER) and SNR performances against Huffman and optimal arithmetic codes.

关键词： robust arithmetic and quasi-arithmetic coding joint source-channel coding soft decoding estimation MAP

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joint source-channel Vector Quantization for Compressed Sensing

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2014年第14期62卷 3667-3681页

作者： Shirazinia, Amirpasha Chatterjee, Saikat Skoglund, Mikael KTH Royal Inst Technol Sch Elect Engn Commun Theory Dept S-10044 Stockholm Sweden

We study joint source-channel coding (JSCC) of compressed sensing (CS) measurements using vector quantizer (VQ). We develop a framework for realizing optimum JSCC schemes that enable encoding and transmitting CS measurements of a sparse source over discrete memoryless channels, and decoding the sparse source signal. For this purpose, the optimal design of encoder-decoder pair of a VQ is considered, where the optimality is addressed by minimizing end-to-end mean square error (MSE). We derive a theoretical lower bound on the MSE performance and propose a practical encoder-decoder design through an iterative algorithm. The resulting coding scheme is referred to as channel-optimized VQ for CS, coined COVQ-CS. In order to address the encoding complexity issue of the COVQ-CS, we propose to use a structured quantizer, namely low-complexity multistage VQ (MSVQ). We derive new encoding and decoding conditions for the MSVQ and then propose a practical encoder-decoder design algorithm referred to as channel-optimized MSVQ for CS, coined COMSVQ-CS. Through simulation studies, we compare the proposed schemes vis-a-vis relevant quantizers.

关键词： Vector quantization multi-stage vector quantization joint source-channel coding noisy channel compressed sensing sparsity mean square error

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Fast algorithm for distortion-based error protection of embedded image codes

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2005年第10期14卷 1417-1421页

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

We consider a joint source-channel coding system that protects an embedded bitstream using a finite family of channel codes with error detection and error correction capability. The performance of this system may be measured by the expected distortion or by the expected number of correctly decoded source bits. Whereas a rate-based optimal solution can be found in linear time, the computation of a distortion-based optimal solution is prohibitive. Under the assumption of the convexity of the operational distortion-rate function of the source coder, we give a lower bound on the expected distortion of a distortion-based optimal solution that depends only on a rate-based optimal solution. Then, we propose a local search (LS) algorithm that starts from a rate-based optimal solution and converges in linear time to a local minimum of the expected distortion. Experimental results for a binary symmetric channel show that our LS algorithm is near optimal, whereas its complexity is much lower than that of the previous best solution.

关键词： joint source-channel coding image transmission local search unequal error protection

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An Efficient Tree Search Algorithm for the Free Distance of Variable-Length Error-Correcting Codes

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IEEE COMMUNICATIONS LETTERS 2018年第3期22卷 474-477页

作者： Huang, Chun Wu, Ting-Yi Chen, Po-Ning Alajaji, Fady Han, Yunghsiang S. Natl Chiao Tung Univ Inst Commun Engn Hsinchu 300 Taiwan Univ Illinois Dept Elect & Comp Engn Champaign IL 61801 USA Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada Dongguan Univ Technol Sch Elect Engn & Intelligentizat Dongguan 523808 Peoples R China

We propose an efficient tree search algorithm for determining the free distance of variable-length error-correcting codes (VLECs). A main idea behind the algorithm is to structure all pairs of code word-concatenated sequences as a tree, in which we seek the pair of sequences that determine the free distance. In order to speed up the algorithm, we establish constraints that do not compromise optimality in determining the free distance. Experimental results on VLECs algorithmically constructed for the English alphabet show that our algorithm requires a considerably smaller number of bitwise distance computations and covers a much smaller number of tree nodes than Dijkstra's algorithm operating over the pairwise distance graph while being a hundred times faster in terms of execution time.

关键词： joint source-channel coding variable length error-correcting codes free distance Dijkstra's algorithm

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