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Information Theory, 2000. Proceedings. IEEE International Symposium on

Date 25-30 June 2000

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  • 2000 IEEE International Symposium on Information Theory (Cat. No.00CH37060)

    Publication Year: 2000
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    Freely Available from IEEE
  • On the accuracy of estimating tail probabilities in queues

    Publication Year: 2000 , Page(s): 83
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  • Delay analysis for prioritized service of variable rate regenerative traffic sources

    Publication Year: 2000 , Page(s): 106
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  • Contradicting a myth: good turbo codes with large memory order

    Publication Year: 2000
    Cited by:  Papers (6)
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    The purpose of this paper is to contradict a common myth about turbo codes. We are specifically addressing R=1/3 parallel-concatenated codes using systematic, recursive constituent codes. Myth: Turbo codes consisting of constituent codes with large memory order (i.e., a large number of trellis states) are not as effective as the original Berrou-Glavieux-Thitimajshima turbo code (1993) in the waterfall region of small signal-to-noise ratios (SNRs). This myth is contradicted by a turbo code whose recursive constituent codes have 256 states. Decoding this turbo code with the BCJR APP decoder gives bit-error-rate (BER) and frame-error-rate (FER) performance better than the original (Berrou) turbocode at all SNRs. View full abstract»

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  • A construction of ternary constant-composition codes with weight three and minimum distance four

    Publication Year: 2000
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    We consider the problem of finding the maximal size A/sub 3/(d,w/sub 0/,w/sub 1/,w/sub 2/) of a ternary constant-composition code. We describe a construction of ternary constant-composition codes that proves A/sub 3/(4,4m+1,2,1)=(m+1)(4m+2) and A/sub 3/(4, 4m-1,2,1)=m(4m+2). View full abstract»

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  • Performance of TETRA under Quasi-synchronous transmission over rayleigh fading channels with equalization

    Publication Year: 2000 , Page(s): 162
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  • Duadic Z4-codes

    Publication Year: 2000 , Page(s): 167
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  • Iterative decoding of non-systematic turbo-codes

    Publication Year: 2000
    Cited by:  Papers (4)  |  Patents (20)
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    Parallel concatenated convolutional codes (PCCCs) are usually constructed using systematic recursive convolutional codes (SRCCs) as constituent codes. In this paper, we introduce a new version of parallel concatenation that uses nonsystematic recursive convolutional codes (NSRCCs) as constituent codes. A systematic constituent code then becomes a particular case of this general scheme. The use of this larger class of constituent codes enhances the number of possible codes in the search space, thus allowing the possibility of finding better codes. We also introduce a modified iterative decoding method for this more general form of parallel concatenation. The decoding technique is no more complex than the standard iterative decoding algorithm. View full abstract»

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  • Bandwidth efficient hybrid ARQ schemes using turbo codes

    Publication Year: 2000
    Cited by:  Papers (3)  |  Patents (2)
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    New bandwidth efficient Type-I and Type-II hybrid-ARQ (HARQ) schemes using turbo trellis coded modulation (TTCM) are proposed. These schemes combine the power-efficiency of turbo codes with the bandwidth efficiency of trellis coded modulation (TCM) to give efficient FEC/ARQ system designs. View full abstract»

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  • Construction and performance of q-ary turbo codes for use with M-ary modulation techniques

    Publication Year: 2000
    Cited by:  Papers (2)
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    This paper describes a construction technique for q-ary turbo codes that computes good recursive systematic convolutional q-ary constituent codes with constraint length v/spl les/5 for q=2/sup m/, m=2, 3, and 4. The construction technique, based on the algorithm of Benedetto, Garello and Montorsi (see IEEE Trans. Commun., vol.46, p.1101-1105, 1998), determines the codes with maximum d/sub i/ for i=2, 3, and 4 and minimum codeword multiplicity, where d/sub i/ is the minimum weight of all code sequences with input weight i. Due to the large number of encoder states involved, standard weight distribution calculations are difficult. The construction algorithm employed is a computer search that generates all possible terminating sequences of weight 2, 3, and 4 to use as inputs to the set of allowable encoders. View full abstract»

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  • Bootstrap sequential decoding at high spectral efficiencies

    Publication Year: 2000
    Cited by:  Papers (1)
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    Sequential decoding of large memory codes has been investigated for 8-PSK, 16-QAM, and larger constellations. The results show that high reliability can be achieved at channel signal-to-noise ratios (SNRs) where the code rate is nearly equal to R/sub 0/, yielding 1-1.5 dB coding gain over Viterbi decoding of small memory codes. Since bootstrap hybrid decoding (BHD) is known to improve the cut-off rate of a sequential decoder for binary modulation, further improvements can be expected using this method applied to TCM. We present a lower bound to the computational cut-off rate for the extension of the BHD scheme to TCM. Our analysis is based on the original derivation for the case of binary modulation proposed by Jelinek and Cocke (1971). Numerical evaluations of the expressions obtained for the cases of hard-decision 8-PSK and 8-level quantized 4AM modulation show significant improvements over the usual cut-off rate, similar to the results obtained by Jelinek et al. for BPSK modulation. These results suggest that performance close to capacity can be achieved with sufficiently powerful TCM systems and bootstrap sequential decoding. View full abstract»

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  • On the redundancy of universal lossless coding for general piecewise stationary sources

    Publication Year: 2000
    Cited by:  Papers (6)
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    A lower bound on the achievable redundancy for universal lossless coding of parametric sources with abruptly changing statistics is derived. Unlike the previously known bound for a problem that assumes a fixed number of changes in the statistics, the new bound is general and can be used even if the number of changes increases with the data length. View full abstract»

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  • Interleavers for unpunctured symmetric turbo codes

    Publication Year: 2000
    Cited by:  Papers (1)
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    The turbo code interleaver design problem is considered for relatively large block sizes, where the effect of trellis termination is less marked. An optimised interleaver design technique based on simulated annealing is proposed. The performance is significantly better than the Berrou-Glavieux interleaver without an increase in delay. View full abstract»

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  • Author index

    Publication Year: 2000 , Page(s): 502 - 508
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    Freely Available from IEEE
  • Multi-value match length functions for data compression

    Publication Year: 2000
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    In this paper, we propose a new match length function (MLF) called multi-value MLF (MVMLF) to be used with the Lempel- Ziv type (LZI) data compression scheme. By restricting the function to five essential constraints, we obtain the most complete and compact dynamic dictionary which is efficiently updated. Based on MVMLF, we present two asymptotically optimal compression schemes View full abstract»

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  • Fault-tolerant dynamic systems

    Publication Year: 2000
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    We use unreliable system replicas and unreliable voters to construct redundant dynamic systems that tolerate transient failures in their state transition and error correcting mechanisms. Using low density parity check (LDPC) codes, we develop a fault-tolerant scheme that efficiently protects linear finite state machines (LFSMs) with identical dynamics but distinct input sequences and states. The scheme achieves a probability of failure that remains below any given bound for any pre-specified (finite) time-interval using a constant amount of hardware (XOR gates and voters) per LFSM View full abstract»

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  • Outage analysis for multiple access channel with Rayleigh fading

    Publication Year: 2000
    Cited by:  Papers (2)
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    We consider the outage probabilities of three multiuser scheduling/power control algorithm: TDMA, the K&H algorithm which achieves maximal Shannon capacity, and TD-KH-a combination of the former two. For flat block fading channel, the outage probability of these algorithms can be asymptotically modeled as a reward renewal process. Employing large deviations analysis, TDMA and TD-KH are shown to be superior over K&H under outage probability criteria View full abstract»

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  • Coding of ordered trees

    Publication Year: 2000
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    We study the asymptotic growth of ordered trees, and give important insights in coding of trees from the information theoretic viewpoint. Specifically, we give the optimal length function in a sense that the Kraft inequality is satisfied with equality. It is revealed that the commonly used pre-order coding for special classes of trees are asymptotically tight, but not always for many trees View full abstract»

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  • On the necessary density for spectrum-blind nonuniform sampling

    Publication Year: 2000
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    It is known that in the absence of distortion, the minimum average sampling density for a multiband signal is given by its spectral occupancy. Furthermore, there exist nonuniform sampling patterns of the same average sampling density such that reconstruction is feasible even if the actual spectral support of the multiband signal is unknown. This is called spectrum-blind nonuniform sampling. However, if the samples are distorted, an increased sampling density may lead to superior reconstruction View full abstract»

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  • New results on binary quasi-cyclic codes

    Publication Year: 2000
    Cited by:  Papers (2)
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    Twelve new binary quasi-cyclic codes, which improve the lower bounds on minimum distances for binary linear codes, are presented, and a Web database on best-known binary quasi-cyclic codes is constructed for public access View full abstract»

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  • Optimum slope convolutional codes

    Publication Year: 2000
    Cited by:  Papers (3)
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    A new family of binary convolutional codes is introduced: the maximum slope (MS) code family. MS codes are defined such, that there exist no other rate R=b/c binary convolutional code with the same free distance df and overall constraint length v, whose lower bounds on the active distance family exhibit a larger slope. Tables for the rate R=1/2 maximum slope code family with memory m=1, 2,…,5 are given. Furthermore, tables for new rate R=(c-1)/c, c=2, 3,…, 5, punctured convolutional codes with optimum free distance codes and MS mother codes are given. Simulation results for woven convolutional codes with MS component codes are presented. It is shown, that the component code choice makes a tradeoff between df and α View full abstract»

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  • Large deviations of probability rank

    Publication Year: 2000
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    Consider a pair of random variables (X,Y) with distribution P. The probability rank function is defined so that G(x|y)=1 for the most probable outcome x conditional on Y=y, G(x|y)=2 for the second most probable outcome, and so on, resolving ties between elements with equal probabilities arbitrarily. The function G was considered in Arikan (1996) in the context of finding the unknown outcome of a random experiment by asking questions of the form `is the outcome equal to x?' sequentially until the actual outcome is determined. The primary focus in Arakan (1996) and Arakan and Merhav (1998) was to find tight bounds on the moments E[G(X|Y)θ]. The present work is closely related to these works but focuses more directly on the large deviations properties of the probability rank function View full abstract»

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  • Minimum conditional entropy context quantization

    Publication Year: 2000
    Cited by:  Papers (10)
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    We consider the problem of finding the quantizer Q that quantizes the K-dimensional causal context Ci=(Xi-t(i),Xi-t(2),...,Xi-t(K) ) of a source symbol Xi into one of M conditioning states such that the conditional entropy H(Xi|Q(Ci)) is minimized. The resulting minimum conditional entropy context quantizer can be used for sequential coding of the sequence X0, X1, X2, View full abstract»

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  • Decoding the 6-error-correcting Z4-linear Calderbank-McGuire code

    Publication Year: 2000
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    Calderbank and McGuire discovered 2 remarkable Z4 -linear codes (see Des. Codes Cryptography, vol.10, no.2, Feb. 1997 and IEEE Trans. Inform. Theory, vol.42, no.1, p.217-26, Jan.1996). The binary Gray images of these codes have respective parameters (64,2 37,12) and (64,232,14) and thus have 2 (resp. 4) times as many codewords as the best known linear codes of the same length and minimum distance. A decoding algorithm for the 5-error-correcting code is given by C. Rong et al. (see IEEE Trans. Inform. Theory, vol.45, no.5, p.1423-34, July 1999). The approach there (following the ideas of the pioneers of Z4-codes) is to split the study into several cases according to the Lee type of the error vector. Then the Galois ring algebra is used to decide, whether the syndromes are compatible with an error vector of the prescribed type. Unfortunately, it seems to be very difficult to apply this method to the case of the six-error-correcting code. A different approach to that of C. Rong et al. is required. Using the ideas presented here it is easy to also develop a list decoding algorithm for the 5-error-correcting code. The author discusses this possibility View full abstract»

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  • A new reverse jacket transform based on Hadamard matrix

    Publication Year: 2000
    Cited by:  Papers (5)
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    This paper presents the reverse jacket transform (RJT) and a simple decomposition of its matrix which is used to develop a fast algorithm for the RJT. The matrix decomposition is of the form of the matrix products of Hadamard matrices and successively lower order coefficient matrices View full abstract»

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