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IEEE Transactions on Information Theory

Issue 2 • Date Feb. 2005

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Displaying Results 1 - 25 of 33
  • Table of contents

    Publication Year: 2005, Page(s):c1 - c4
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    Freely Available from IEEE
  • IEEE Transactions on Information Theory publication information

    Publication Year: 2005, Page(s): c2
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  • On the asymptotic capacity of stationary Gaussian fading channels

    Publication Year: 2005, Page(s):437 - 446
    Cited by:  Papers (82)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (263 KB) | HTML iconHTML

    We consider a peak-power-limited single-antenna flat complex-Gaussian fading channel where the receiver and transmitter, while fully cognizant of the distribution of the fading process, have no knowledge of its realization. Upper and lower bounds on channel capacity are derived, with special emphasis on tightness in the high signal-to-noise ratio (SNR) regime. Necessary and sufficient conditions (... View full abstract»

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  • Zero-rate reliability of the exponential-server timing channel

    Publication Year: 2005, Page(s):447 - 465
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (496 KB) | HTML iconHTML

    We determine the reliability function of the exponential-server timing channel (ESTC) in the limit as the data rate approaches zero. The limit shows that at low rates, the ESTC is strictly more reliable than the Poisson channel without dark current, answering a question Arikan posed in these Transactions. The proof employs a distance metric over inputs to timing channels that parallels Euclidean a... View full abstract»

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  • Entropy and the law of small numbers

    Publication Year: 2005, Page(s):466 - 472
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (240 KB) | HTML iconHTML

    Two new information-theoretic methods are introduced for establishing Poisson approximation inequalities. First, using only elementary information-theoretic techniques it is shown that, when Sni=1nXi is the sum of the (possibly dependent) binary random variables X1,X2,...,Xn, with E(Xi)=pi an... View full abstract»

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  • Crame´r-Rao and moment-entropy inequalities for Renyi entropy and generalized Fisher information

    Publication Year: 2005, Page(s):473 - 478
    Cited by:  Papers (43)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (178 KB) | HTML iconHTML

    The moment-entropy inequality shows that a continuous random variable with given second moment and maximal Shannon entropy must be Gaussian. Stam's inequality shows that a continuous random variable with given Fisher information and minimal Shannon entropy must also be Gaussian. The Crame´r-Rao inequality is a direct consequence of these two inequalities. In this paper, the inequalities abov... View full abstract»

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  • Spectral efficiency of multicarrier CDMA

    Publication Year: 2005, Page(s):479 - 505
    Cited by:  Papers (42)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (688 KB) | HTML iconHTML

    We analyze the spectral efficiency (sum-rate per subcarrier) of randomly spread synchronous multicarrier code-division multiple access (MC-CDMA) subject to frequency-selective fading in the asymptotic regime of number of users and bandwidth going to infinity with a constant ratio. Both uplink and downlink are considered, either conditioned on the subcarrier fading coefficients (for nonergodic chan... View full abstract»

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  • On the capacity of MIMO broadcast channels with partial side information

    Publication Year: 2005, Page(s):506 - 522
    Cited by:  Papers (849)  |  Patents (64)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB) | HTML iconHTML

    In multiple-antenna broadcast channels, unlike point-to-point multiple-antenna channels, the multiuser capacity depends heavily on whether the transmitter knows the channel coefficients to each user. For instance, in a Gaussian broadcast channel with M transmit antennas and n single-antenna users, the sum rate capacity scales like Mloglogn for large n if perfect channel state information (CSI) is ... View full abstract»

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  • Degrees of freedom in multiple-antenna channels: a signal space approach

    Publication Year: 2005, Page(s):523 - 536
    Cited by:  Papers (130)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB) | HTML iconHTML

    Multiple-antenna systems that are limited by the area and geometry of antenna arrays, are considered. Given these physical constraints, the limit on the available number of spatial degrees of freedom is derived. The commonly used statistical multiple-input multiple-output (MIMO) model is inadequate. Antenna theory is applied to take into account the area and geometry constraints, and to define the... View full abstract»

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  • Exploiting decentralized channel state information for random access

    Publication Year: 2005, Page(s):537 - 561
    Cited by:  Papers (129)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB) | HTML iconHTML

    We study the use of channel state information (CSI) for random access in fading channels. Traditionally, random access protocols have been designed by assuming simple models for the physical layer where all users are symmetric, and there is no notion of channel state. We introduce a reception model that takes into account the channel states of various users. Under the assumption that each user has... View full abstract»

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  • Cubic Boolean functions with highest resiliency

    Publication Year: 2005, Page(s):562 - 571
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB) | HTML iconHTML

    We classify those cubic m-variable Boolean functions which are (m-4)-resilient. We prove that there are four types of such functions, depending on the structure of the support of their Walsh spectra. We are able to determine, for each type, the Walsh spectrum and, then, the nonlinearity of the corresponding functions. We also give the dimension of their linear space. This dimension equals m-k wher... View full abstract»

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  • Codes on finite geometries

    Publication Year: 2005, Page(s):572 - 596
    Cited by:  Papers (94)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1047 KB) | HTML iconHTML

    New algebraic methods for constructing codes based on hyperplanes of two different dimensions in finite geometries are presented. The new construction methods result in a class of multistep majority-logic decodable codes and three classes of low-density parity-check (LDPC) codes. Decoding methods for the class of majority-logic decodable codes, and a class of codes that perform well with iterative... View full abstract»

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  • Multicluster interleaving on paths and cycles

    Publication Year: 2005, Page(s):597 - 611
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (488 KB) | HTML iconHTML

    Interleaving codewords is an important method not only for combatting burst errors, but also for distributed data retrieval. This paper introduces the concept of multicluster interleaving (MCI), a generalization of traditional interleaving problems. MCI problems for paths and cycles are studied. The following problem is solved: how to interleave integers on a path or cycle such that any m (m≥2)... View full abstract»

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  • Bounds on information combining

    Publication Year: 2005, Page(s):612 - 619
    Cited by:  Papers (49)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB) | HTML iconHTML

    When the same data sequence is transmitted over two independent channels, or when a data sequence is transmitted twice but independently over the same channel, the independent observations can be combined at the receiver side. From an information-theory point of view, the overall mutual information between the data sequence and the received sequences represents a combination of the mutual informat... View full abstract»

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  • Updating the parameters of a threshold scheme by minimal broadcast

    Publication Year: 2005, Page(s):620 - 633
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB) | HTML iconHTML

    Threshold schemes allow secret data to be protected among a set of participants in such a way that only a prespecified threshold of participants can reconstruct the secret from private information (shares) distributed to them on a system setup using secure channels. We consider the general problem of designing unconditionally secure threshold schemes whose defining parameters (the threshold and th... View full abstract»

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  • Optimal lattices for sampling

    Publication Year: 2005, Page(s):634 - 647
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1192 KB) | HTML iconHTML

    The generalization of the sampling theorem to multidimensional signals is considered, with or without bandwidth constraints. The signal is modeled as a stationary random process and sampled on a lattice. Exact expressions for the mean-square error of the best linear interpolator are given in the frequency domain. Moreover, asymptotic expansions are derived for the average mean-square error when th... View full abstract»

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  • On simple oversampled A/D conversion in shift-invariant spaces

    Publication Year: 2005, Page(s):648 - 657
    Cited by:  Papers (21)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (345 KB) | HTML iconHTML

    It has been found that the quantization error e for a conventional oversampled analog-to-digital (A/D) conversion behaves like ||e||2=O(τ2) with respect to the sampling rate τ. Recently, conventional A/D conversion has been extended to A/D conversion based on shift-invariant spaces. As consequences of such extension, it offers rich choices to build a nonideal A/D conv... View full abstract»

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  • Model selection for CART regression trees

    Publication Year: 2005, Page(s):658 - 670
    Cited by:  Papers (26)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB) | HTML iconHTML

    The performance of the classification and regression trees (CART) pruning algorithm and the final discrete selection by test sample as a functional estimation procedure are considered. The validation of the pruning procedure applied to Gaussian and bounded regression is of primary interest. On the one hand, the paper shows that the complexity penalty used in the pruning algorithm is valid in both ... View full abstract»

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  • On the rate loss of multiple description source codes

    Publication Year: 2005, Page(s):671 - 683
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (407 KB) | HTML iconHTML

    The rate loss of a multiresolution source code (MRSC) describes the difference between the rate needed to achieve distortion Di in resolution i and the rate-distortion function R(Di). This paper generalizes the rate loss definition to multiple description source codes (MDSCs) and bounds the MDSC rate loss for arbitrary memoryless sources. For a two-description MDSC (2DSC), th... View full abstract»

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  • The average amount of information lost in multiplication

    Publication Year: 2005, Page(s):684 - 687
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (181 KB) | HTML iconHTML

    We show that if X and Y are integers independently and uniformly distributed in the set {1,...,N}, then the information lost in forming their product (which is given by the equivocation H(X,Y|XmiddotY)), is Theta(loglogN). We also prove two extremal results regarding cases in which X and Y are not necessarily independently or uniformly distributed. First, we note that the information lost in multi... View full abstract»

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  • On the asymptotic redundancy of lossless block coding with two codeword lengths

    Publication Year: 2005, Page(s):688 - 692
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB) | HTML iconHTML

    With the additional constraint of requiring only two codeword lengths, lossless codes of blocks of size n generated by stationary memoryless binary sources are studied. For arbitrary δ>0, classical large-deviation inequalities imply the existence of codes attaining an expected redundancy of the order O(n-12+δ/). It is shown that it is not possible to construct lossless codes... View full abstract»

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  • On the optimality of the likelihood-ratio test for local sensor decision rules in the presence of nonideal channels

    Publication Year: 2005, Page(s):693 - 699
    Cited by:  Papers (110)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (614 KB) | HTML iconHTML

    Distributed detection has been intensively studied in the past. In this correspondence, we consider the design of local decision rules in the presence of nonideal transmission channels between the sensors and the fusion center. Under the conditional independence assumption among multiple sensor observations, we show that the optimal local decisions that minimize the error probability at the fusion... View full abstract»

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  • Approximate belief propagation, density evolution, and statistical neurodynamics for CDMA multiuser detection

    Publication Year: 2005, Page(s):700 - 706
    Cited by:  Papers (71)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB) | HTML iconHTML

    We present a theory to analyze the performance of the parallel interference canceller (PIC) for code-division multiple-access (CDMA) multiuser detection, applied to a randomly spread, fully synchronous baseband uncoded CDMA channel model with additive white Gaussian noise under perfect power control in the large-system limit. We reformulate PIC as an approximation to the belief propagation algorit... View full abstract»

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  • Convexity in queues with general inputs

    Publication Year: 2005, Page(s):706 - 714
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB) | HTML iconHTML

    In this correspondence, we develop fundamental convexity properties of unfinished work and packet waiting time in a queue serving general stochastic traffic. The queue input consists of an uncontrollable background process and a rate-controllable input stream. We show that any moment of unfinished work is a convex function of the controllable input rate. The convexity properties are then extended ... View full abstract»

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  • Explicit constructions of algebraic-geometric codes

    Publication Year: 2005, Page(s):714 - 722
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (367 KB) | HTML iconHTML

    We propose a simple construction of algebraic-geometric codes which are subcodes of Goppa codes and which coincide with Goppa codes in many cases. The codes we construct have the advantage that for an explicitly given extension of the rational function field, one can easily obtain explicit bases and therefore an exact formula for the dimension. Furthermore, we show that in many cases good upper an... View full abstract»

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Aims & Scope

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

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Meet Our Editors

Editor-in-Chief
Frank R. Kschischang

Department of Electrical and Computer Engineering