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34
Cooperative strategies and capacity theorems for relay networks
 IEEE Trans. Inform. Theory
, 2005
"... Abstract—Coding strategies that exploit node cooperation are developed for relay networks. Two basic schemes are studied: the relays decodeandforward the source message to the destination, or they compressandforward their channel outputs to the destination. The decodeandforward scheme is a va ..."
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Cited by 547 (14 self)
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Abstract—Coding strategies that exploit node cooperation are developed for relay networks. Two basic schemes are studied: the relays decodeandforward the source message to the destination, or they compressandforward their channel outputs to the destination. The decodeandforward scheme is a variant of multihopping, but in addition to having the relays successively decode the message, the transmitters cooperate and each receiver uses several or all of its past channel output blocks to decode. For the compressandforward scheme, the relays take advantage of the statistical dependence between their channel outputs and the destination’s channel output. The strategies are applied to wireless channels, and it is shown that decodeandforward achieves the ergodic capacity with phase fading if phase information is available only locally, and if the relays are near the source node. The ergodic capacity coincides with the rate of a distributed antenna array with full cooperation even though the transmitting antennas are not colocated. The capacity results generalize broadly, including to multiantenna transmission with Rayleigh fading, singlebounce fading, certain quasistatic fading problems, cases where partial channel knowledge is available at the transmitters, and cases where local user cooperation is permitted. The results further extend to multisource and multidestination networks such as multiaccess and broadcast relay channels. Index Terms—Antenna arrays, capacity, coding, multiuser channels, relay channels. I.
The Distributed KarhunenLoève Transform
 IEEE Trans. Inform. Theory
, 2003
"... The KarhunenLoeve transform (KLT) is a key element of many signal processing tasks, including approximation, compression, and classification. Many recent applications involve distributed signal processing where it is not generally possible to apply the KLT to the signal; rather, the KLT must be ..."
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Cited by 83 (15 self)
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The KarhunenLoeve transform (KLT) is a key element of many signal processing tasks, including approximation, compression, and classification. Many recent applications involve distributed signal processing where it is not generally possible to apply the KLT to the signal; rather, the KLT must be approximated in a distributed fashion.
Rate region of the quadratic Gaussian twoencoder sourcecoding problem
 IEEE Trans. Inf. Theory
, 2008
"... We determine the rate region of the quadratic Gaussian twoencoder sourcecoding problem. This rate region is achieved by a simple architecture that separates the analog and digital aspects of the compression. Furthermore, this architecture requires higher rates to send a Gaussian source than it doe ..."
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Cited by 41 (2 self)
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We determine the rate region of the quadratic Gaussian twoencoder sourcecoding problem. This rate region is achieved by a simple architecture that separates the analog and digital aspects of the compression. Furthermore, this architecture requires higher rates to send a Gaussian source than it does to send any other source with the same covariance. Our techniques can also be used to determine the sum rate of some generalizations of this classical problem. Our approach involves coupling the problem to a quadratic Gaussian “CEO problem.”
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 32 (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.
The Rate Region of the Quadratic Gaussian TwoTerminal SourceCoding Problem. Submitted for publication. Available from http://www.arxiv.org/abs/cs.IT/0510095
"... We consider a problem in which two encoders each observe one component of a memoryless Gaussian vectorvalued source. The encoders separately communicate with a decoder, which attempts to reproduce the vectorvalued source subject to constraints on the expected squared error of each component. We de ..."
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Cited by 31 (2 self)
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We consider a problem in which two encoders each observe one component of a memoryless Gaussian vectorvalued source. The encoders separately communicate with a decoder, which attempts to reproduce the vectorvalued source subject to constraints on the expected squared error of each component. We determine the minimum sum rate needed to meet a pair of target distortions and thereby complete the determination of the rate region for this problem. The proof involves coupling the problem to a quadratic Gaussian “CEO problem.” 1
An Improved Outer Bound for the Multiterminal SourceCoding Problem
 Proc. of the Intl. Symp. on Info. Theory
, 2005
"... Abstract—We prove a new outer bound on the rate–distortion region for the multiterminal sourcecoding problem. This bound subsumes the best outer bound in the literature and improves upon it strictly in some cases. The improved bound enables us to obtain a new, conclusive result for the binary erasu ..."
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Cited by 17 (2 self)
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Abstract—We prove a new outer bound on the rate–distortion region for the multiterminal sourcecoding problem. This bound subsumes the best outer bound in the literature and improves upon it strictly in some cases. The improved bound enables us to obtain a new, conclusive result for the binary erasure version of the “CEO problem. ” The bound recovers many of the converse results that have been established for special cases of the problem, including the recent one for the Gaussian twoencoder problem. Index Terms—CEO problem, erasure distortion, multiterminal source coding, outer bound, rate region, rate–distortion. Fig. 1. Separate encoding of correlated sources.
Multiple access channels with states causally known at transmitters,” November 2010, submitted to IEEE Transactions on Information Theory, available online at http://arxiv.org/abs/1011.6639
"... Abstract—It has been recently shown by Lapidoth and Steinberg that strictly causal state information can be beneficial in multiple access channels (MACs). Specifically, it was proved that the capacity region of a twouser MAC with independent states, each known strictly causally to one encoder, can ..."
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Cited by 11 (3 self)
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Abstract—It has been recently shown by Lapidoth and Steinberg that strictly causal state information can be beneficial in multiple access channels (MACs). Specifically, it was proved that the capacity region of a twouser MAC with independent states, each known strictly causally to one encoder, can be enlarged by letting the encoders send compressed past state information to the decoder. In this study, a generalization of the said strategy is proposed whereby the encoders compress also the past transmitted codewords along with the past state sequences. The proposed scheme uses a combination of longmessage encoding, compression of the past state sequences and codewords without binning, and joint decoding over all transmission blocks. The proposed strategy has been recently shown by Lapidoth and Steinbergtostrictlyimprove upon the original one. Capacity results are then derived for a class of channels that include twouser moduloadditive statedependent MACs. Moreover, the proposed scheme is extended to statedependent MACs with an arbitrary number of users. Finally, output feedback is introduced and an example is provided to illustrate the interplay between feedback and availability of strictly causal state information in enlarging the capacity region. Index Terms—Longmessage encoding, multiple access channels (MACs), output feedback, quantizeforward, statedependent channels, strictly causal state information. I.
Distributed Compression for MIMO Coordinated Networks with a Backhaul Constraint
"... Abstract—We consider the uplink of a backhaulconstrained, MIMO coordinated network. That is, a singlefrequency network with ..."
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Cited by 10 (1 self)
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Abstract—We consider the uplink of a backhaulconstrained, MIMO coordinated network. That is, a singlefrequency network with
On Uplink Network MIMO under a Constrained Backhaul and Imperfect Channel Knowledge
"... Abstract — It is known that next generation mobile comunications systems will most likely employ multicell signal processingoften referred to as network MIMO in order to improve spectral efficiency and fairness. Many publications exist that predict strong achievable rate improvements, but usually ..."
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Cited by 10 (6 self)
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Abstract — It is known that next generation mobile comunications systems will most likely employ multicell signal processingoften referred to as network MIMO in order to improve spectral efficiency and fairness. Many publications exist that predict strong achievable rate improvements, but usually neglecting various practical issues connected to network MIMO. In this paper, we analyse the impact of a constrained backhaul infrastructure and imperfect channel knowledge on uplink network MIMO from an information theoretical point of view. Especially the latter aspect leads to the fact that the channel conditions for which network MIMO is reasonably beneficial are strongly constrained. We observe different base station cooperation schemes in scenarios of maximal 3 base stations and 3 terminals, provide simulation results, and discuss the practicability of the discussed schemes and the implications of our results. I.
Distributed Joint SourceChannel coding for Functions over a Multiple Access Channel
"... In this paper we provide sufficient conditions for lossy transmission of functions of correlated data over a multiple access channel (MAC). The conditions obtained can be shown as generalized version of Yamamoto’s result [28]. We also obtain efficient joint sourcechannel coding schemes for transmis ..."
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Cited by 8 (8 self)
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In this paper we provide sufficient conditions for lossy transmission of functions of correlated data over a multiple access channel (MAC). The conditions obtained can be shown as generalized version of Yamamoto’s result [28]. We also obtain efficient joint sourcechannel coding schemes for transmission of discrete and continuous alphabet sources to recover the function values.