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Systematics lossy source/channel coding

IEEE TRANSACTIONS ON INFORMATION THEORY 1998年第2期44卷 564-579页

作者： Shamai, S Verdu, S Zamir, R Technion Israel Inst Technol Dept Elect Engn IL-32000 Haifa Israel Princeton Univ Dept Elect Engn Princeton NJ 08544 USA Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel

The fundamental limits of "systematic" communication are analyzed. In systematic transmission, the decoder has access to a noisy version of the uncoded raw data (analog or digital), The coded version of the data is used to reduce the average reproduced distortion D below that provided hy the uncoded systematic link and/or increase the rate of information transmission, Unlike the case of arbitrarily reliable error correction (D --> 0) for symmetric sources/channels, where systematic codes are known to do as well as nonsystematic codes, we demonstrate that the systematic structure may degrade the performance for nonvanishing D. We characterize the achievable average distortion and we find necessary and sufficient conditions under which systematic communication does not incur loss of optimality. The Wyner-Ziv rate distortion theorem plays a fundamental role in our setting, The general result is applied to several scenarios. For a Gaussian bandlimited source and a Gaussian channel, the invariance of the bandwidth-signal-to-noise ratio (SNR, in decibels) product is established, and the optimality of systematic transmission is demonstrated, Bernoulli sources transmitted over binary-symmetric channels and over certain Gaussian channels are also analyzed. It is shown that if nonnegligible bit-error rate is tolerated, systematic encoding is strictly suboptimal.

关键词： Gaussian channels and sources rate-distortion theory source/channel coding systematic transmission uncoded side information Wyner-Ziv rate distortion

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Energy Management Policies for Energy-Neutral source-channel coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2012年第9期60卷 2668-2678页

作者： Castiglione, P. Simeone, O. Erkip, E. Zemen, T. FTW Signal & Informat Proc Dept A-1220 Vienna Austria NJIT CWCSPR Newark NJ 07102 USA NYU Dept Elect & Comp Engn ECE Polytech Inst Brooklyn NY 11201 USA

In cyber-physical systems where sensors measure the temporal evolution of a given phenomenon of interest and radio communication takes place over short distances, the energy spent for source acquisition and compression may be comparable with that used for transmission. Additionally, in order to avoid limited lifetime issues, sensors may be powered via energy harvesting and thus collect all the energy they need from the environment. This work addresses the problem of energy allocation over source acquisition/compression and transmission for energy-harvesting sensors. At first, focusing on a single-sensor, energy management policies are identified that guarantee a minimum average distortion while at the same time ensuring the stability of the queue connecting source and channel encoders. It is shown that the identified class of policies is optimal in the sense that it stabilizes the queue whenever this is feasible by any other technique that satisfies the same average distortion constraint. Moreover, this class of policies performs an independent resource optimization for the source and channel encoders. Suboptimal strategies that do not use the energy buffer (battery) or use it only for adapting either source or channel encoder energy allocation are also studied for performance comparison. The problem of optimizing the desired trade-off between average distortion and backlog size is then formulated and solved via dynamic programming tools. Finally, a system with multiple sensors is considered and time-division scheduling strategies are derived that are able to maintain the stability of all data queues and to meet the average distortion constraints at all sensors whenever it is feasible.

关键词： Wireless sensor networks energy harvesting source/channel coding power control

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Bit-Erasure channel Decoding for GMM-based Multiple Description coding

Bit-Erasure Channel Decoding for GMM-based Multiple Descript...

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Interspeech Conference 2007

作者： Agiomyrgiannakis, Yannis Stylianou, Yannis Univ Crete Dept Comp Sci Iraklion Greece

ISBN: (纸本)9781605603162

Multiple Description coding (MDC) is a plausible way to use the diversity of packet networks to increase the robustness of the transmission to packet losses. The redundancy that is introduced via MDC can also be used to increase the robustness of the transmission to bit-errors. This paper presents a novel decoding method for GMM (Gaussian Mixture Model)-based MDC in the presence of detected bit-errors. Particularly for speech transmission over bit-erasure channels, is is shown that the proposed method considerably improves the quality of the received speech spectral envelopes when one side-description is damaged. In highly correlated descriptions, for example, single and double bit-errors can almost be corrected.

关键词： Multiple Description coding source/channel coding bit-erasure channel decoding Speech coding Voice-over-IP

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Error resilient image communication using content-based multiple description coding

Error resilient image communication using content-based mult...

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3rd International Conference on Information Technology: coding and Computing (ITCC 2002)

作者： Shirani, S McMaster Univ Dept Elect & Comp Engn Hamilton ON Canada

ISBN: (纸本)076951507X

Multiple description coding has been studied as an approach for transmission of images over error Prone environments. The multiple description coding method proposed here takes into account the content of the image and provides the least amount of degradation, caused by loss of descriptors, for those areas of the image which are of greater interest. This is achieved by employing a non-linear geometrical transform to odd redundancy mainly to the area of interest followed by a partitioning of the nonlinearly transformed image into sub-images which are coded and transmitted over separate channels, Simulations show that this approach yields exceptional performance even when only one descriptor is received. Moreover, the method proposed here can be implemented through pre- and post-processing of the image data, without modification to the source codecs (e.g., JPEG).

关键词： multiple description coding error resilience coding source/channel coding image communication content-based image processing

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Two-dimensional coded classification schemes in wireless sensor networks

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2008年第5期7卷 1450-1455页

作者： Pai, Hung-Ta Han, Yunghsiang S. Sung, Jing-Tian Natl Taipei Univ Grad Inst Commun Engn Taipei Taiwan Natl Taiwan Univ Sci & Technology Dept Elect Engn Taipei Taiwan

This work proposes a novel fault-tolerant classification system based on distributed detection and two-dimensional channel coding. A rule is then derived to reduce the search space such that the optimal code matrix can be found. Simulation results reveal that the proposed scheme has higher classification reliability and better capability of fault tolerance than previous methods. Moreover, a code matrix using repetition codes is presented. The proposed scheme with the repetition code has a lower memory requirement at each sensor and higher detection flexibility than that with the optimal code matrix while only having a slightly lower performance. Finally, an asymptotic performance analysis is provided for the proposed scheme.

关键词： sensor networks networks and systems detection and estimation source/channel coding transmission technology

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Error Rate Analysis of GF(q) Network Coded Detect-and-Forward Wireless Relay Networks Using Equivalent Relay channel Models

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2013年第8期12卷 3908-3919页

作者： Safak, Ilgin Aktas, Emre Yilmaz, Ali Ozgur Hacettepe Univ Dept Elect & Elect Engn TR-06800 Ankara Turkey Middle E Tech Univ Dept Elect & Elect Engn TR-06531 Ankara Turkey

This paper investigates simple means of analyzing the error rate performance of a general q-ary Galois Field network coded detect-and-forward cooperative relay network with known relay error statistics at the destination. Equivalent relay channels are used in obtaining an approximate error rate of the relay network, from which the diversity order is found. Error rate analyses using equivalent relay channel models are shown to be closely matched with simulation results. Using the equivalent relay channels, low complexity receivers are developed whose performances are close to that of the optimal maximum likelihood receiver.

关键词： Cooperative diversity detection and estimation source/channel coding

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Power optimization of wireless media systems with space-time block codes

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IEEE TRANSACTIONS ON IMAGE PROCESSING 2004年第7期13卷 873-884页

作者： Yousefi'zadeh, H Jafarkhani, H Moshfeghi, M Univ Calif Irvine Dept Elect Engn & Comp Sci Irvine CA 92697 USA

We present analytical and numerical solutions to the problem of power control in wireless media systems with multiple antennas. We formulate a set of optimization problems aimed at minimizing total power consumption of wireless media systems subject to a given level of QoS and an available bit rate. Our formulation takes in to consideration the power consumption related to source coding, channel coding, and transmission of multiple-transmit antennas. In our study, we consider Gauss-Markov and video source models, Rayleigh fading channels along with the Bernoulli/Gilbert-Elliott loss models, and space-time block codes.

关键词： Bernoulli and Gilbert-Elliott loss models multiple antenna systems power optimization QoS source/channel coding space-time block codes wireless media systems

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Adaptive Optimization of an Iterative Multiuser Detector for Turbo-Coded CDMA

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2008年第11期7卷 4284-4293页

作者： Shepherd, David P. Brannstrom, Fredrik Schreckenbach, Frank Shi, Zhenning Reed, Mark C. Natl ICT Australia Sydney NSW Australia Australian Natl Univ Canberra ACT 0200 Australia Chalmers Univ Technol Dept Signals & Syst Commun Syst Grp S-41296 Gothenburg Sweden Tech Univ Munich D-8000 Munich Germany

Extrinsic information transfer (EXIT) charts are utilized to optimize the iterative multiuser detector receiver in a multiuser turbo-coded CDMA system. The (receive) power levels are optimized for the system load using a constrained nonlinear optimization approach. The optimal decoding schedule is derived dynamically using the power optimized EXIT chart and a Viterbi search algorithm. Dynamic scheduling is shown to be a more flexible approach which results in a more stable QoS for a typical system configuration than one-shot scheduling, and large complexity savings over a receiver without scheduling. We verify through simulations that complexity savings of over 50% and power savings of over 8dB can be achieved. We show that the optimized power levels combined with adaptive scheduling allows for efficient utilization of receiver resources for heavily loaded systems.

关键词： Multiuser detection transmission technology CDMA wireless access source/channel coding transmission technology

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coding for Cooperative Communications

Coding for Cooperative Communications

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作者： Uppal, Momin Ayub Texas A&M University

The area of cooperative communications has received tremendous research interest in recent years. This interest is not unwarranted, since cooperative communications promises the ever-so-sought after diversity and multiplexing gains typically associated with multiple-input multiple-output (MIMO) communications, without actually employing multiple antennas. In this dissertation, we consider several cooperative communication channels, and for each one of them, we develop information theoretic coding schemes and derive their corresponding performance limits. We next develop and design practical coding strategies which perform very close to the information theoretic limits. The cooperative communication channels we consider are: (a) The Gaussian relay channel, (b) the quasi-static fading relay channel, (c) cooperative multiple-access channel (MAC), and (d) the cognitive radio channel (CRC). For the Gaussian relay channel, we propose a compress-forward (CF) coding strategy based on Wyner-Ziv coding, and derive the achievable rates specifically with BPSK modulation. The CF strategy is implemented with low-density parity-check (LDPC) and irregular repeataccumulate codes and is found to operate within 0.34 dB of the theoretical limit. For the quasi-static fading relay channel, we assume that no channel state information (CSI) is available at the transmitters and propose a rateless coded protocol which uses rateless coded versions of the CF and the decode-forward (DF) strategy. We implement the protocol with carefully designed Raptor codes and show that the implementation suffers a loss of less than 10 percent from the information theoretical limit. For the MAC, we assume quasi-static fading, and consider cooperation in the low-power regime with the assumption that no CSI is available at the transmitters. We develop cooperation methods based on multiplexed coding in conjunction with rateless codes and find the achievable rates and in particular the minimum energy per bit to a

关键词： Cooperative communications source/channel coding Relay channel Dirty-paper coding Rateless coding Slepian-Wolf coding Low density parity-check codes Raptor codes Trellis coded quantization Thesis

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