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

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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joint source-channel Bit Allocation Based on Expected End-to-End Distortion Model

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Journal of Donghua University(English Edition) 2010年第4期27卷 458-462页

作者：马汉杰陈耀武 Institute of Advanced Digital Technology and Instrumentation Zhejiang University

An adaptive joint source channel bit allocation method for video communications over error-prone channel is *** protect the bit-streams from the channel bit errors,the rate compatible punctured convolution(RCPC)code is used to produce coding rates varying from 4/5 to 1/2 using the same encoder and the Viterbi *** expected end-to-end distortion model was presented to estimate the distortion introduced in compressed source coding due to quantization and channel bit errors *** on the proposed end-to-end distortion model,an adaptive joint source-channel bit allocation method was proposed under time-varying error-prone channel *** results show that the proposed methods could utilize the available channel capacity more efficiently and achieve better video quality than the other fixed coding-based bit allocation methods when transmitting over error-prone channels.

关键词： joint source-channel coding end-to-end distortion bit allocation rate compatible punctured convolution code

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ENERGY EFFICIENT LOSSY TRANSMISSION OVER SENSOR NETWORKS WITH FEEDBACK

ENERGY EFFICIENT LOSSY TRANSMISSION OVER SENSOR NETWORKS WIT...

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2010 IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Jain, Aman Guenduez, Deniz Kulkarni, Sanjeev R. Poor, H. Vincent Verdu, Sergio Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

ISBN: (纸本)9781424442966

The energy-distortion function (E(D)) for a network is defined as the minimum total energy required to achieve a target distortion D at the receiver without putting any restrictions on the number of channel uses per source sample. E(D) is studied for a sensor network in which multiple sensors transmit their noisy observations of a Gaussian source to the destination over a Gaussian multiple access channel with perfect channel output feedback. While the optimality of separate source and channel coding is proved for the case of a single sensor, this optimality is shown to fail when there are multiple sensors in the network. A network with two sensors is studied in detail. First a lower bound on E(D) is given. Then, two achievability schemes are proposed: a separation based digital scheme and a Schalkwijk-Kailath (SK) type uncoded scheme. The gap between the lower bound and the upper bound based on separation is shown to be a constant even as the total energy requirement goes to infinity in the low distortion regime. On the other hand, as the distortion requirement is relaxed, the SK based scheme is shown to outperform separation in certain cases, proving that the optimality of source-channel separation does not hold in the multi-sensor setting.

关键词： Sensor networks energy efficiency feedback joint source-channel coding information theory

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Compressed Sensing Based Video Multicast

Compressed Sensing Based Video Multicast

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Conference on Visual Communications and Image Processing (VCIP)

作者： Schenkel, Markus B. Luo, Chong Frossard, Pascal Wu, Feng Microsoft Res Asia Beijing Peoples R China Ecole Polytech Fed Lausanne Signal Proc Lab LTS4 Lausanne Switzerland

ISBN: (纸本)9780819482341

We propose a new scheme for wireless video multicast based on compressed sensing. It has the property of graceful degradation and, unlike systems adhering to traditional separate coding, it does not suffer from a cliff effect. Compressed sensing is applied to generate measurements of equal importance from a video such that a receiver with a better channel will naturally have more information at hands to reconstruct the content without penalizing others. We experimentally compare different random matrices at the encoder side in terms of their performance for video transmission. We further investigate how properties of natural images can be exploited to improve the reconstruction performance by transmitting a small amount of side information. And we propose a way of exploiting inter-frame correlation by extending only the decoder. Finally we compare our results with a different scheme targeting the same problem with simulations and find competitive results for some channel configurations.

关键词： Compressed Sensing Video Multicast joint source-channel coding

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SoftCast: One-Size-Fits-All Wireless Video 10

SoftCast: One-Size-Fits-All Wireless Video

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ACM SIGCOMM Conference 2010

作者： Jakubczak, Szymon Katabi, Dina MIT Cambridge MA 02139 USA

ISBN: (纸本)9781450302012

The focus of this demonstration is the performance of streaming video over the mobile wireless channel. We compare two schemes: the standard approach to video which transmits H. 264/AVC-encoded stream over 802.11-like PHY, and SoftCast - a clean-slate design for wireless video where the source transmits one video stream that each receiver decodes to a video quality commensurate with its specific instantaneous channel quality.

关键词： Algorithms Design Performance Theory wireless networks scalable video communications joint source-channel coding

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joint source-channel turbo coding for binary Markov sources

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2006年第5期5卷 1065-1075页

作者： Zhu, Guang-Chong Alajaji, Fady Lawrence Technol Univ Dept Math & Comp Sci Southfield MI 48075 USA Queens Univ Dept Math & Stat Kingston ON Canada Queens Univ Dept Elect & Comp Engn Kingston ON Canada

We investigate the construction of joint source-channel (JSC) Turbo codes for the reliable communication of binary Markov sources over additive white Gaussian noise and Rayleigh fading channels. To exploit the source Markovian redundancy, the first constituent Turbo decoder is designed according to a modified version of Berrou's original decoding algorithm that employs the Gaussian assumption for the extrinsic information. Due to interleaving, the second constituent decoder is unable to adopt the same decoding method;so its extrinsic information is appropriately adjusted via a weighted correction term. The Turbo encoder is also optimized according to the Markovian source statistics and by allowing different or asymmetric constituent encoders. Simulation results demonstrate substantial gains over the original (unoptimized) Turbo codes, hence significantly reducing the performance gap to the Shannon limit. Finally, we show that our JSC coding system considerably outperforms tandem coding schemes for bit error rates smaller than 10(-4), while enjoying a lower system complexity.

关键词： joint source-channel coding turbo codes AWGN and Rayleigh fading channels Shannon limit Markov sources iterative decoding bit error rate

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ENERGY EFFICIENT LOSSY TRANSMISSION OVER SENSOR NETWORKS WITH FEEDBACK

ENERGY EFFICIENT LOSSY TRANSMISSION OVER SENSOR NETWORKS WIT...

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IEEE International Conference on Acoustics, Speech, and Signal Processing

作者： Aman Jain Deniz Gunduz Sanjeev R. Kulkarni H. Vincent Poor Sergio Verdu Dept. of Electrical Engineering Princeton University Princeton NJ 08544

ISBN: (纸本)9781424442959

关键词： Sensor networks energy efficiency feedback joint source-channel coding information theory

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Hybrid Digital-Analog coding with Bandwidth Compression for Gaussian source-channel Pairs

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IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第4期57卷 997-1012页

作者： Wang, Yadong Alajaji, Fady Linder, Tamas Bank Montreal Toronto ON Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

Three hybrid digital-analog (HDA) systems, denoted by HDA-I, HDA* and HDA-II, for the coding of a memoryless discrete-time Gaussian source over a discrete-time additive memoryless Gaussian channel under bandwidth compression are studied. The systems employ simple linear coding in their analog component and superimpose their analog and digital signals before channel transmission. Information-theoretic upper bounds on the asymptotically optimal mean squared error distortion of the systems are obtained under both matched and mismatched channel conditions. Allocation schemes for distributing the channel input power between the analog and the digital signals are also examined. It is shown that systems HDA* and HDA-II can asymptotically achieve the optimal Shannon-limit performance under matched channel conditions. Low-complexity and low-delay versions of systems HDA-I and HDA-II are next designed and implemented without the use of error correcting codes. The parameters of these HDA systems, which employ vector quantization in conjunction with binary phase-shift keying modulation in their digital part, are optimized via an iterative algorithm similar to the design algorithm for channel-optimized vector quantizers. Both systems have low complexity and low delay, and guarantee graceful performance improvements for high CSNRs. For memoryless Gaussian sources the designed HDA-II system is shown to be superior to the HIDA-I designed system. When applied to a Gauss-Markov source under Karhunen-Loeve processing, the HDA-I system is shown to provide considerably better performance.

关键词： Broadcasting hybrid digital-analog coding joint source-channel coding linear analog coding robustness vector quantization

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A Scalable Information Security Technique: joint Authentication-coding Mechanism for Multimedia over Heterogeneous Wireless Networks

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WIRELESS PERSONAL COMMUNICATIONS 2009年第1期51卷 5-16页

作者： Zhou, Liang Zheng, Baoyu Wei, Anne Geller, Benoit Cui, Jingwu Nanjing Univ Posts & Telecommun Inst Signal Proc & Transmiss Nanjing 210003 Peoples R China Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China Conservat Natl Arts & Metiers CEDRIC F-75003 Paris France Ecole Normale Super SATIE F-94230 Cachan France Ecole Natl Super Tech Avancees LEI F-75015 Paris France

There have been increasing concerns about the security issues of wireless transmission of multimedia in recent years. Wireless networks, by their natures, are more vulnerable to external intrusions than wired ones. Therefore, many applications demand authenticating the integrity of multimedia content delivered wirelessly. In this work, we propose a framework for jointly authenticating and coding multimedia to be transmitted over heterogeneous wireless networks. We firstly provide a novel graph-based authentication scheme which can not only construct the authentication graph flexibly but also trade-off well among some practical requirements such as overhead, robustness and delay. And then, a rate-distortion optimized joint source-channel coding (JSCC) approach for error-resilient scalable encoded video is presented, in which the video is encoded into multiple independent streams and each stream is assigned forward error correction (FEC) codes to avoid error propagation. Furthermore, we consider integrating authentication with the specific JSCC scheme to achieve a satisfactory authentication results and end-to-end reconstruction quality by optimally applying the appropriate authentication and coding rate. Simulation results show the effectiveness of the proposed authentication-coding scheme for multimedia over wireless networks.

关键词： Multimedia security Authentication joint source-channel coding Wireless networks

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joint source-channel coding of GGD sources with allpass filtering source reshaping

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JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION 2005年第1期16卷 19-37页

作者： Cai, JF Chen, CW Nanyang Technol Univ Sch Comp Engn Singapore 639798 Singapore Florida Inst Technol Dept Elect & Comp Engn Melbourne FL 32901 USA

An optimal joint source-channel coding (OJSCC) scheme is developed for encoding memoryless generalized Gaussian distribution (GGD) sources and transmission over noisy channels, including memoryless channels and bursty channels. In particular;we are able to incorporate both transition probability and bit error rate of a bursty channel model into an end-to-end rate-distortion (R-D) function. This R-D function results in an optimum tradeoff between source coding accuracy and channel error protection under a fixed transmission rate. Based on the results of OJSCC, we further proposed a robust joint source-channel coding (RJSCC) scheme based on a combination of OJSCC with allpass filtering source reshaping. Experimental results based on a broad class of GGD sources suggest that the RJSCC scheme consistently outperforms the OJSCC scheme when the shape factor, a parameter of GGD, is less than 2.0. The comparison of RJSCC with the state-of-the-art robust quantization (RQ) [IEEE Trans. Image Process. 7 (1998) 406-505] shows that RJSCC is comparable with RQ at low bit rate and significantly better than RQ at high bit rate. In addition, an image transmission system using RJSCC demonstrates that the RJSCC system can be efficiently employed in practical applications. (C) 2004 Elsevier Inc. All rights reserved.

关键词： joint source-channel coding source reshaping bit allocation

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