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88
Cooperative diversity in wireless networks: efficient protocols and outage behavior
 IEEE Trans. Inform. Theory
, 2004
"... Abstract—We develop and analyze lowcomplexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals’ relaying signals for one another. We outline several str ..."
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Cited by 1056 (25 self)
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Abstract—We develop and analyze lowcomplexity cooperative diversity protocols that combat fading induced by multipath propagation in wireless networks. The underlying techniques exploit space diversity available through cooperating terminals’ relaying signals for one another. We outline several strategies employed by the cooperating radios, including fixed relaying schemes such as amplifyandforward and decodeandforward, selection relaying schemes that adapt based upon channel measurements between the cooperating terminals, and incremental relaying schemes that adapt based upon limited feedback from the destination terminal. We develop performance characterizations in terms of outage events and associated outage probabilities, which measure robustness of the transmissions to fading, focusing on the high signaltonoise ratio (SNR) regime. Except for fixed decodeandforward, all of our cooperative diversity protocols are efficient in the sense that they achieve full diversity (i.e., secondorder diversity in the case of two terminals), and, moreover, are close to optimum (within 1.5 dB) in certain regimes. Thus, using distributed antennas, we can provide the powerful benefits of space diversity without need for physical arrays, though at a loss of spectral efficiency due to halfduplex operation and possibly at the cost of additional receive hardware. Applicable to any wireless setting, including cellular or ad hoc networks—wherever space constraints preclude the use of physical arrays—the performance characterizations reveal that large power or energy savings result from the use of these protocols. Index Terms—Diversity techniques, fading channels, outage probability, relay channel, user cooperation, wireless networks. I.
Distributed Source Coding Using Syndromes (DISCUS): Design and Construction
 IEEE TRANS. INFORM. THEORY
, 1999
"... We address the problem of distributed source coding, i.e. compression of correlated sources that are not colocated and/or cannot communicate with each other to minimize their joint description cost. In this work we tackle the related problem of compressing a source that is correlated with anothe ..."
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Cited by 320 (7 self)
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We address the problem of distributed source coding, i.e. compression of correlated sources that are not colocated and/or cannot communicate with each other to minimize their joint description cost. In this work we tackle the related problem of compressing a source that is correlated with another source which is however available only at the decoder. In contrast to prior informationtheoretic approaches, we introduce a new constructive and practical framework for tackling the problem based on the judicious incorporation of channel coding principles into this source coding problem. We dub our approach as DIstributed Source Coding Using Syndromes (DISCUS). We focus in this paper on trellisstructured consructions of the framework to illustrate its utility. Simulation results confirm the power of DISCUS, opening up a new and exciting constructive playingground for the distributed source coding problem. For the distributed coding of correlated i.i.d. Gaussian sources that are ...
Distributed video coding
 PROC. OF THE IEEE 93 (2005) 71–83
, 2005
"... Distributed coding is a new paradigm for video compression, ..."
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Cited by 219 (11 self)
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Distributed coding is a new paradigm for video compression,
Filter Bank Frame Expansions with Erasures
, 2002
"... We study frames for robust transmission over the Internet. In our previous work, we used quantized finitedimensional frames to achieve resilience to packet losses; here, we allow the input to be a sequence in ` 2 (Z) and focus on a filterbank implementation of the system. We present results in par ..."
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Cited by 49 (4 self)
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We study frames for robust transmission over the Internet. In our previous work, we used quantized finitedimensional frames to achieve resilience to packet losses; here, we allow the input to be a sequence in ` 2 (Z) and focus on a filterbank implementation of the system. We present results in parallel, R N or C N versus ` 2 (Z), and show that uniform tight frames, as well as newly introduced strongly uniform tight frames, provide the best performance.
Side information aware coding strategies for sensor networks
 IEEE J. Selected Areas Commun
"... Abstract—We develop coding strategies for estimation under communication constraints in treestructured sensor networks. The strategies have a modular and decentralized architecture. This promotes the flexibility, robustness, and scalability that wireless sensor networks need to operate in uncertain ..."
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Cited by 27 (0 self)
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Abstract—We develop coding strategies for estimation under communication constraints in treestructured sensor networks. The strategies have a modular and decentralized architecture. This promotes the flexibility, robustness, and scalability that wireless sensor networks need to operate in uncertain, changing, and resourceconstrained environments. The strategies are based on a generalization of Wyner–Ziv source coding with decoder side information. We develop solutions for general trees, and illustrate our results in serial (pipeline) and parallel (hubandspoke) networks. Additionally, the strategies can be applied to other network information theory problems. They have a successive coding structure that gives an inherently less complex way to attain a number of prior results, as well as some novel results, for the Chief Executive Officer problem, multiterminal source coding, and certain classes of relay channels. Index Terms—Chief Executive Officer (CEO) problems, data fusion, distributed detection, distributed estimation, multiterminal source coding, rate distortion theory, relay channels, sensor networks, side information, Wyner–Ziv coding. I.
Lattices for distributed source coding: Jointly Gaussian sources and reconstruction of a linear function
 IEEE TRANSACTIONS ON INFORMATION THEORY, SUBMITTED
, 2007
"... Consider a pair of correlated Gaussian sources (X1, X2). Two separate encoders observe the two components and communicate compressed versions of their observations to a common decoder. The decoder is interested in reconstructing a linear combination of X1 and X2 to within a meansquare distortion of ..."
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Cited by 27 (2 self)
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Consider a pair of correlated Gaussian sources (X1, X2). Two separate encoders observe the two components and communicate compressed versions of their observations to a common decoder. The decoder is interested in reconstructing a linear combination of X1 and X2 to within a meansquare distortion of D. We obtain an inner bound to the optimal ratedistortion region for this problem. A portion of this inner bound is achieved by a scheme that reconstructs the linear function directly rather than reconstructing the individual components X1 and X2 first. This results in a better rate region for certain parameter values. Our coding scheme relies on lattice coding techniques in contrast to more prevalent random coding arguments used to demonstrate achievable rate regions in information theory. We then consider the case of linear reconstruction of K sources and provide an inner bound to the optimal ratedistortion region. Some parts of the inner bound are achieved using the following coding structure: lattice vector quantization followed by “correlated” latticestructured binning.
Systematic Lossy Forward Error Protection for Video Waveforms
 in Proc. IEEE International Conference on Image Processing
, 2003
"... A novel scheme for errorresilient digital video broadcasting, using WynerZiv coding, is presented in this paper. We apply the general framework of systematic lossy sourcechannel coding to generate a supplementary bitstream that can correct transmission errors in the decoded video waveform up to a ..."
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Cited by 23 (5 self)
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A novel scheme for errorresilient digital video broadcasting, using WynerZiv coding, is presented in this paper. We apply the general framework of systematic lossy sourcechannel coding to generate a supplementary bitstream that can correct transmission errors in the decoded video waveform up to a certain residual distortion. The systematic portion consists of a conventional MPEGcoded bitstream, which is transmitted over the errorprone channel without any forward error correction. The supplementary bitstream is a low rate representation of the transmitted video sequence generated using WynerZiv encoding. We use the conventionally decoded errorconcealed MPEG video sequence as side information to decode the WynerZiv bits. The decoder combines the errorprone side information and the WynerZiv description to yield an improved decoded video signal. We show how this scheme can be used to build a system which achieves graceful degradation without the need of a layered representation of the video waveform.
On Joint SourceChannel Coding for the WynerZiv Source and the Gel'fandPinsker Channel
 IEEE Trans. Inform. Theory
, 2002
"... We consider the problem of lossy joint sourcechannel coding in a communication system where the encoder has access to channel state information (CSI) and the decoder has access to side information that is correlated to the source. This configuration combines the WynerZiv model of pure lossy source ..."
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Cited by 22 (3 self)
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We consider the problem of lossy joint sourcechannel coding in a communication system where the encoder has access to channel state information (CSI) and the decoder has access to side information that is correlated to the source. This configuration combines the WynerZiv model of pure lossy source coding with side information at the decoder and the Shannon/Gel'fandPinsker model of pure channel coding with CSI at the encoder. We prove a separation theorem for this communication system, which asserts that there is no loss in asymptotic optimality in applying first, an optimal WynerZiv source code and then, an optimal Gel'fandPinsker channel code. We then derive conditions for the optimality of a symbolbysymbol (scalar) sourcechannel code, and demonstrate situations where these conditions are met. Finally, we discuss a few practical applications, including of overlaid communication where the model under discussion is useful.
Distributed Compression In Dense Sensor Networks
 IEEE Signal Processing Magazine
, 2002
"... this article, we propose a new way of removing this redundancy in a completely distributed manner, i.e., without the sensors needing to talk to one another. Our constructive framework for this problem is dubbed DISCUS (distributed source coding using syndromes) and is inspired by fundamental conc ..."
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Cited by 19 (2 self)
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this article, we propose a new way of removing this redundancy in a completely distributed manner, i.e., without the sensors needing to talk to one another. Our constructive framework for this problem is dubbed DISCUS (distributed source coding using syndromes) and is inspired by fundamental concepts from information theory. In this article, we review the main ideas, provide illustrations, and give the intuition behind the theory that enables this framework
On the Feasibility of LargeScale Wireless Sensor Networks
 In Proc. 40th Allerton Conf. on Communication, Control and Computing
, 2002
"... We consider the problem of rate/distortion with side information available only at the decoder. For the case of jointlyGaussian source X and side information Y, and meansquared error distortion, Wyner proved in 1976 that the rate/distortion function for this problem is identical to the conditional ..."
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Cited by 16 (2 self)
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We consider the problem of rate/distortion with side information available only at the decoder. For the case of jointlyGaussian source X and side information Y, and meansquared error distortion, Wyner proved in 1976 that the rate/distortion function for this problem is identical to the conditional rate/distortion function RXY, assuming the side information Y is available at the encoder. In this paper we construct a structured class of asymptotically optimal quantizers for this problem: under the assumption of high correlation between source X and side information Y, we show there exist quantizers within our class whose performance comes arbitrarily close to Wyner’s bound. As an application illustrating the relevance of the highcorrelation asymptotics, we also explore the use of these quantizers in the context of a problem of data compression for sensor networks, in a setup involving a large number of devices collecting highly correlated measurements within a confined area. An important feature of our formulation is that, although the pernode throughput of the network tends to zero as network size increases, so does the amount of information generated by each transmitter. This is a situation likely to be encountered often in practice, which allows us to cast under new—and more “optimistic”—light some negative results on the transport capacity of largescale wireless networks. Index terms: Rate/distortion, rate/distortion with side information, quantization, vector quantization, lattice quantization, lattice codes, hexagonal lattice, source coding, network information theory, adhoc networks, sensor networks, multihop radio networks, wireless networks, throughput, capacity.