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IEEE Information Theory Workshop, 2005.

Date Aug. 29 2005-Sept. 1 2005

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  • Proceedings of the IEEE ITSOC Information Theory Workshop 2005 on Coding and Complexity

    Publication Year: 2005, Page(s): 0_1
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  • Copyright

    Publication Year: 2005, Page(s): 0_2
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  • Welcome from the co-chairs

    Publication Year: 2005, Page(s): 0_3
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  • Committee members

    Publication Year: 2005, Page(s): 0_4
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  • Finite-length scaling of irregular LDPC code ensembles

    Publication Year: 2005
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (447 KB) | HTML iconHTML

    We investigate the finite-length scaling methodology for irregular LDPC code ensembles when transmission takes place over the binary erasure channel (BEC). We first show how the necessary computations, namely the covariance evolution and the computation of the finite-length shift, can be accomplished in the irregular case. We then investigate how the obtained approximation can be used to predict t... View full abstract»

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  • Table of contents

    Publication Year: 2005, Page(s):0_5 - 0_8
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  • BEAST decoding - asymptotic complexity

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB) | HTML iconHTML

    BEAST is a bidirectional efficient algorithm for searching trees that performs soft-decision maximum-likelihood (ML) decoding of block codes. The decoding complexity of BEAST is significantly reduced compared to the Viterbi algorithm. An analysis of the asymptotic BEAST decoding complexity verifies BEAST's high efficiency compared to other algorithms. The best of the obtained asymptotic upper boun... View full abstract»

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  • Author list

    Publication Year: 2005, Page(s): 0_9
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  • Symbol-by-symbol detection of space-time coded continuous phase modulated signals over fast Rayleigh fading channels

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (403 KB) | HTML iconHTML

    We investigate the detection of space time coded (STC) signals modulated using continuous phase modulation (CPM) in fast Rayleigh fading channels. A symbol-by-symbol iterative detector with an optimum front-end is derived, and its practical implementation using the concept of principal component analysis (PCA) is considered. To assess the performance, numerical examples for different STC-CPM schem... View full abstract»

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  • Rate-compatible path-pruned convolutional codes and their applications on channels with insertion, deletion and substitution errors

    Publication Year: 2005
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB) | HTML iconHTML

    A concatenated system is presented to achieve unequal error protection (UEP) on a channel with insertion/deletion/substitution (IDS) errors. By using a feedback-mapping encoder scheme, the path-pruning of a convolutional code is achieved to periodically generate a specific block code, which can be exploited to correct insertion or deletion errors. This paper presents a general means to obtain a pa... View full abstract»

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  • Duality between packings and coverings of the Hamming space

    Publication Year: 2005
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (362 KB) | HTML iconHTML

    We investigate the packing and covering densities of linear and nonlinear binary codes, and establish a number of duality relationships between the packing and covering problems. Specifically, we prove that if almost all codes are good packings, then only a vanishing fraction of codes are good coverings, and vice versa: if almost all codes are good coverings, then at most a vanishing fraction of c... View full abstract»

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  • Interference management via capacity-achieving codes for the deterministic broadcast channel

    Publication Year: 2005
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB) | HTML iconHTML

    We motivate the consideration of deterministic broadcast channel coding as an interference management technique in wireless scenarios. We address practical coding strategies for such channels and discuss two approaches. The first relies upon enumerative source coding and can be applied for any deterministic broadcast channel problem as the first step in pipelined encoding for vertex rates. The sec... View full abstract»

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  • Fisher information matrix and hyperbolic geometry

    Publication Year: 2005
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (287 KB) | HTML iconHTML

    The Fisher information matrix induces a metric on parametric spaces of families of probability density functions. We analyse here the family of normal distributions showing how hyperbolic geometry arises naturally from the Fisher information metric. View full abstract»

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  • Periodic Oppermann sequences for spread spectrum systems

    Publication Year: 2005
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (333 KB) | HTML iconHTML

    In this paper we introduce periodic Oppermann sequences, which constitute a special class of polyphase sequences. The properties of these sequences are presented, and indicate that periodic Oppermann sequences are suitable for combination to generate families of longer sequences. Numerical examples show that periodic Oppermann sequences can be designed for ranging or synchronisation applications o... View full abstract»

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  • Steepest descent as message passing

    Publication Year: 2005
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (347 KB) | HTML iconHTML

    It is shown how steepest descent (or steepest ascent) may be viewed as a message passing algorithm with "local" message update rules. For example, the well-known backpropagation algorithm for the training of feedforward neural networks may be viewed as message passing on a factor graph. The factor graph approach with its emphasis on "local" computations makes it easy to combine steepest descent wi... View full abstract»

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  • Bounds on the performance of sphere decoding of linear block codes

    Publication Year: 2005
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (463 KB) | HTML iconHTML

    A sphere decoder searches for the closest lattice point within a certain search radius. The search radius provides a tradeoff between performance and complexity. We derive tight upper bounds on the performance of sphere decoding of linear block codes. The performance of soft-decision sphere decoding on AWGN channels as well as that of hard-decision sphere decoding on binary symmetric channels is a... View full abstract»

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  • Asymptotically optimum detection for large wireless networks with fading

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (363 KB) | HTML iconHTML

    This paper proves that CDMA with beam forming single user detection (SUD-CDMA) is asymptotically optimum, even if it is done on a user by user basis (naive CDMA), for many large wireless networks in the presence of unknown fading. The paper models the transmitters and receivers as uniformly distributed over a grid in a 3-D, 2-D or 1-D universe and allows every transmitter to broadcast to all recei... View full abstract»

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  • The multivariate merit factor of a Boolean function

    Publication Year: 2005
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (409 KB) | HTML iconHTML

    A new metric, the multivariate merit factor (MMF) of a Boolean function, is presented, and various infinite recursive quadratic sequence constructions are given for which both univariate and multivariate merit factors can be computed exactly. In some cases these constructions lead to merit factors with non-vanishing asymptotes. A formula for the average value of 1/MMF is derived and a characterisa... View full abstract»

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  • Bounds on signature coding for fast frequency hopping with asynchronous access

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (367 KB) | HTML iconHTML

    Signature coding for fast frequency hopped channel is studied, where the bandwidth is partitioned into frequency subbands. A frequency hopping pattern is assigned to each user that specifies the sequence of frequency subbands in which the user can transmit a sinus waveform during a time slot. Partial activity is considered where only a small fraction of the potential users may be active simultaneo... View full abstract»

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  • Maximum entropy and the Edgeworth expansion

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (328 KB) | HTML iconHTML

    For sums of i.i.d. random variables the maximum entropy distribution with respect to the first moments fixed is compared with the Edgeworth expansion. It is demonstrated that the Edgeworth expansion can and shall be considered as a linear extrapolation of the maximum entropy distribution. The coefficients in the Edgeworth expansion can be used as a first approximation for numerical calculation of ... View full abstract»

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  • New monomial bent functions over the finite fields of odd characteristic

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (365 KB) | HTML iconHTML

    We consider p-ary bent functions having the form f(x) = Trn (axd). A new class of ternary monomial regular bent function with the Dillon exponent is discovered. The existence of Dillon bent functions in the general case is an open problem of deciding whether a certain Kloosterman sum can take on the value -1. Also described is the general Gold-like form of a bent function tha... View full abstract»

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  • A finite-field transform domain construction of binary low-density parity-check codes

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB) | HTML iconHTML

    A new method of finding binary cyclic codes from the finite-field transform domain is presented. These cyclic codes have sparse parity-check matrix and thus are suitable for iterative decoding. Some interesting properties of the proposed construction method include the knowledge of the minimum distance and the ability to trade the increase in code dimension with a reduction in the parity-check mat... View full abstract»

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  • Correlation analysis of random number sequences based on pseudo random binary sequence generation

    Publication Year: 2005
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (405 KB) | HTML iconHTML

    In this paper, the hardware structural correlation effects associated with digit pick-off positions on a maximal length linear feedback shift register (LFSR) in random number (RN) generation, based on a pseudorandom binary sequence (PRBS), are examined using the RN autocorrelation function (ACF). The ACF of the RN codeword sequence is derived analytically from the known noise-like autocorrelation ... View full abstract»

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  • Capacity of M-ary 2-D RLL constraints for optical recording channels

    Publication Year: 2005
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (323 KB) | HTML iconHTML

    A new class of M-ary two-dimensional (2-D) run-length limited (RLL) constraints is introduced in this paper. In particular, only RLL d constraints on 2D m × n arrays with limited height m are considered. Column vectors of 2-D arrays are used as states in a directed graph. The transfer matrix of the graph is obtained with consideration of non-binary alphabet, and the largest eigenvalue of the... View full abstract»

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  • Iterative list decoding

    Publication Year: 2005
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (314 KB) | HTML iconHTML

    We analyze the relation between iterative decoding and the properties of the extended parity check matrix. By considering a modified version of bit flipping, which produces a list of decoded words, we derive several relations between decodable error patterns and parameters of the code. By developing a tree of codewords at minimal distance form the received vector, we also obtain new information ab... View full abstract»

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