# IEEE Transactions on Information Theory

## Filter Results

Displaying Results 1 - 25 of 53

Publication Year: 2011, Page(s):C1 - C4
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• ### IEEE Transactions on Information Theory publication information

Publication Year: 2011, Page(s): C2
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• ### MMSE Dimension

Publication Year: 2011, Page(s):4857 - 4879
Cited by:  Papers (35)
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If N is standard Gaussian, the minimum mean square error (MMSE) of estimating a random variable X based on √(snr)X+Nvanishes at least as fast as 1/snrassnr→ ∞. We define the MMSE dimension of X as the limit assnr→ ∞ of the product of snr and the MMSE. MMSE dimension is also shown to be the asymptotic ratio of nonlinear MMSE to linear MMSE. For discrete, ab... View full abstract»

• ### Minimum Energy to Send$k$Bits Through the Gaussian Channel With and Without Feedback

Publication Year: 2011, Page(s):4880 - 4902
Cited by:  Papers (26)  |  Patents (1)
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The minimum achievable energy per bit over memoryless Gaussian channels has been previously addressed in the limit when the number of information bits goes to infinity, in which case it is known that the availability of noiseless feedback does not lower the minimum energy per bit, which is -1.59 dB below the noise level. This paper analyzes the behavior of the minimum energy per bit for memoryless... View full abstract»

• ### Feedback in the Non-Asymptotic Regime

Publication Year: 2011, Page(s):4903 - 4925
Cited by:  Papers (74)
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Without feedback, the backoff from capacity due to non-asymptotic blocklength can be quite substantial for blocklengths and error probabilities of interest in many practical applications. In this paper, novel achievability bounds are used to demonstrate that in the non-asymptotic regime, the maximal achievable rate improves dramatically thanks to variable-length coding and feedback. For example, f... View full abstract»

• ### Data Processing Theorems and the Second Law of Thermodynamics

Publication Year: 2011, Page(s):4926 - 4939
Cited by:  Papers (6)
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We draw relationships between the generalized data processing theorems of Zakai and Ziv (1973 and 1975) and the dynamical version of the second law of thermodynamics, a.k.a. the Boltzmann H-Theorem, which asserts that the Shannon entropy, <i>H</i>(<i>Xt</i>), pertaining to a finite-state Markov process {<i>Xt</i>}, is monotonically nondecreasing as a function of... View full abstract»

• ### The Entropy Per Coordinate of a Random Vector is Highly Constrained Under Convexity Conditions

Publication Year: 2011, Page(s):4940 - 4954
Cited by:  Papers (25)
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The entropy per coordinate in a log-concave random vector of any dimension with given density at the mode is shown to have a range of just 1. Uniform distributions on convex bodies are at the lower end of this range, the distribution with i.i.d. exponentially distributed coordinates is at the upper end, and the normal is exactly in the middle. Thus, in terms of the amount of randomness as measured... View full abstract»

• ### Capacity of a Class of Diamond Channels

Publication Year: 2011, Page(s):4955 - 4960
Cited by:  Papers (13)
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We study a special class of diamond channels which was introduced by Schein in 2001. In this special class, each diamond channel consists of a transmitter, a noisy relay, a noiseless relay and a receiver. We prove the capacity of this class of diamond channels by providing an achievability scheme and a converse. The capacity we show is strictly smaller than the cut-set bound. We note that there ex... View full abstract»

• ### The Secrecy Capacity of the MIMO Wiretap Channel

Publication Year: 2011, Page(s):4961 - 4972
Cited by:  Papers (437)
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We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an eavesdropper. Perfect secrecy is achieved when the transmitter and the legitimate receiver can communicate at some positive rate, while insuring that the eavesdropper gets zero bits of information. In... View full abstract»

• ### MIMO Detection for High-Order QAM Based on a Gaussian Tree Approximation

Publication Year: 2011, Page(s):4973 - 4982
Cited by:  Papers (37)  |  Patents (1)
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This paper proposes a new detection algorithm for MIMO communication systems employing high-order QAM constellations. The factor graph that corresponds to this problem is very loopy; in fact, it is a complete graph. Hence, a straightforward application of the Belief Propagation (BP) algorithm yields very poor results. Our algorithm is based on an optimal tree approximation of the Gaussian density ... View full abstract»

Publication Year: 2011, Page(s):4983 - 4991
Cited by:  Papers (4)
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The sum-rate capacity of a noncoherent memoryless multiple-access Rician fading channel is investigated under three different categories of power constraints: individual per user peak-power constraints, individual per user average-power constraints, or a global power-sharing average-power constraint. Upper and lower bounds on the sum-rate capacity are derived, and it is shown that at high signal-t... View full abstract»

• ### Fading Cognitive Multiple-Access Channels With Confidential Messages

Publication Year: 2011, Page(s):4992 - 5005
Cited by:  Papers (9)
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The fading cognitive multiple-access channel with confidential messages (CMAC-CM) is investigated, in which two users (users 1 and 2) wish to transmit a common message to a destination and user 1 also has a confidential message intended for the destination. The two users transmit to the destination via a multiple access channel, and user 2 also receives noisy channel outputs. Such channel outputs ... View full abstract»

• ### Lattice Strategies for the Dirty Multiple Access Channel

Publication Year: 2011, Page(s):5006 - 5035
Cited by:  Papers (53)
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In Costa's dirty-paper channel, Gaussian random binning is able to eliminate the effect of interference which is known at the transmitter, and thus achieve capacity. We examine a generalization of the dirty-paper problem to a multiple access channel (MAC) setup, where structured (lattice-based) binning seems to be necessary to achieve capacity. In the dirty-MAC, two additive interference signals a... View full abstract»

• ### On the Benefits of Partial Channel State Information for Repetition Protocols in Block Fading Channels

Publication Year: 2011, Page(s):5036 - 5053
Cited by:  Papers (36)
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This paper studies the throughput performance of hybrid automatic repeat request (HARQ) protocols over block fading Gaussian channels. It proposes new protocols that use the available feedback bit(s) not only to request a retransmission, but also to inform the transmitter about the instantaneous channel quality. An explicit protocol construction is given for any number of retransmissions and any n... View full abstract»

• ### Structural Models for Dual Modality Data With Application to Network Tomography

Publication Year: 2011, Page(s):5054 - 5071
Cited by:  Papers (7)
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We propose models for the joint distribution of two modalities for network flow volumes. While these models are motivated by computer network applications, the underlying structural assumptions are more generally applicable. In the case of computer network flow volumes, this corresponds to joint modeling for packet and byte volumes and enables computer network tomography, whose goal is to estimate... View full abstract»

• ### Peer-to-Peer Streaming Capacity

Publication Year: 2011, Page(s):5072 - 5087
Cited by:  Papers (24)  |  Patents (1)
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Peer-to-peer (P2P) systems provide a scalable way to stream content to multiple receivers over the Internet. The maximum rate achievable by all receivers is the capacity of a P2P streaming session. We provide a taxonomy of sixteen problem formulations, depending on whether there is a single P2P session or there are multiple concurrent sessions, whether the given topology is a full mesh graph or an... View full abstract»

• ### Improved Capacity Scaling in Wireless Networks With Infrastructure

Publication Year: 2011, Page(s):5088 - 5102
Cited by:  Papers (44)
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This paper analyzes the impact and benefits of infrastructure support in improving the throughput scaling in networks of <i>n</i> randomly located wireless nodes. The infrastructure uses multiantenna base stations (BSs), in which the number of BSs and the number of antennas at each BS can scale at arbitrary rates relative to <i>n</i>. Under the model, capacity scaling laws ... View full abstract»

• ### Cognitive Networks Achieve Throughput Scaling of a Homogeneous Network

Publication Year: 2011, Page(s):5103 - 5115
Cited by:  Papers (60)
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Two distinct, but overlapping, networks that operate at the same time, space, and frequency is considered. The first network consists ofnrandomly distributed primary users, which form an ad hoc network. The second network again consists ofmrandomly distributed ad hoc secondary users or cognitive users. The primary users have priority access to the spectrum and do not need to change t... View full abstract»

• ### On Throughput Optimality With Delayed Network-State Information

Publication Year: 2011, Page(s):5116 - 5132
Cited by:  Papers (39)
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The problem of routing/scheduling in a wireless network with partial/delayed network (channel and queue) state information (NSI) is studied in this paper. Two cases are considered: (i) centralized routing/scheduling, where a central controller obtains heterogeneously delayed information from each of the nodes (thus, the controller has NSI with different delays from different nodes), and makes rout... View full abstract»

• ### Geographic Protocol Information and Capacity Deficit in Mobile Wireless Ad Hoc Networks

Publication Year: 2011, Page(s):5133 - 5150
Cited by:  Papers (11)
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Overheads incurred by network protocols diminish the capacity available for relaying useful data in a dynamic communications network. Discovering lower bounds on the amount of protocol overhead incurred is important for the development of efficient network protocols and for characterizing the effective capacity available for network users. This paper presents an information-theoretic framework for... View full abstract»

• ### Cooperative Transmission for Wireless Networks Using Mutual-Information Accumulation

Publication Year: 2011, Page(s):5151 - 5162
Cited by:  Papers (21)
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Cooperation between the nodes of wireless multihop networks can increase communication reliability, reduce energy consumption, and decrease latency. The possible improvements are even greater when nodes perform mutual information accumulation. In this paper, we investigate resource allocation for unicast and multicast transmission in such networks. Given a network, a source, and a destination, our... View full abstract»

• ### Rumors in a Network: Who's the Culprit?

Publication Year: 2011, Page(s):5163 - 5181
Cited by:  Papers (172)  |  Patents (1)
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We provide a systematic study of the problem of finding the source of a rumor in a network. We model rumor spreading in a network with the popular susceptible-infected (SI) model and then construct an estimator for the rumor source. This estimator is based upon a novel topological quantity which we term rumor centrality. We establish that this is a maximum likelihood (ML) estimator for a class of ... View full abstract»

• ### On Universal LDPC Code Ensembles Over Memoryless Symmetric Channels

Publication Year: 2011, Page(s):5182 - 5202
Cited by:  Papers (11)
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A design of robust error-correcting codes that achieve reliable communication over various channels is of great theoretical and practical interest. Such codes are termed universal. This paper considers the universality of low-density parity-check (LDPC) code ensembles over families of memoryless binary-input output-symmetric (MBIOS) channels. Universality is considered both under belief-propagatio... View full abstract»

• ### Signal Codes: Convolutional Lattice Codes

Publication Year: 2011, Page(s):5203 - 5226
Cited by:  Papers (24)  |  Patents (2)
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The coded modulation scheme proposed in this paper has a simple construction: an integer sequence, representing the information, is convolved with a fixed, continuous-valued, finite impulse response (FIR) filter to generate the codeword - a lattice point. Due to power constraints, the code construction includes a shaping mechanism inspired by precoding techniques such as the Tomlinson-Harashima fi... View full abstract»

• ### Optimal Exact-Regenerating Codes for Distributed Storage at the MSR and MBR Points via a Product-Matrix Construction

Publication Year: 2011, Page(s):5227 - 5239
Cited by:  Papers (308)  |  Patents (8)
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Regenerating codes are a class of distributed storage codes that allow for efficient repair of failed nodes, as compared to traditional erasure codes. An [n, k, d] regenerating code permits the data to be recovered by connecting to anykof thennodes in the network, while requiring that a failed node be repaired by connecting to anydnodes. The amount of data downloaded for repai... View full abstract»

## Aims & Scope

IEEE Transactions on Information Theory publishes papers concerned with the transmission, processing, and utilization of information.

Full Aims & Scope

## Meet Our Editors

Editor-in-Chief
Alexander Barg

Department of Electrical and Computer Engineering and the Institute for Systems Research, University of Maryland

email: abarg-ittrans@ece.umd.edu