IEEE Transactions on Information Theory

Volume 33 Issue 2 • March 1987

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Displaying Results 1 - 18 of 18
  • New trellis codes based on lattices and cosets

    Publication Year: 1987, Page(s):177 - 195
    Cited by:  Papers (172)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1933 KB)

    A new technique is proposed for constructing trellis codes. which provides an alternative to Ungerboeck's method of "set partitioning." The new codes use a signal constellation consisting of points from an<tex>n</tex>-dimensional lattice<tex>\Lambda</tex>, with an equal number of points from each coset of a sublattice<tex>\Lambda '</tex>. One part of the input s... View full abstract»

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  • On the performance evaluation of trellis codes

    Publication Year: 1987, Page(s):196 - 202
    Cited by:  Papers (158)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1023 KB)

    Generating function techniques for analyzing the error event and the bit-error probabilities for trellis codes are considered. The conventional state diagram approach for linear codes where the number of states is equal to the number of trellis states cannot be applied directly to arbitrary trellis codes, and instead, a state diagram where the number of states is equal to the square of the number ... View full abstract»

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  • Cycle slipping in an optical communication system employing subcarrier angle modulation

    Publication Year: 1987, Page(s):203 - 209
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1011 KB)

    The output of an ideal photodetector that is modeled as a doubly stochastic Poisson process is used to excite a phase-locked loop. The rate of this Poisson process contains an angle-modulated subcarrier process that is modeled as a Gauss-Markov process. A measure transformation involving a martingale translation is applied to the suboptimal filter used to estimate the phase. Cycle slipping is then... View full abstract»

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  • New results on the real-time transmission problem

    Publication Year: 1987, Page(s):210 - 218
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1121 KB)

    A new concept is presented for the treatment of real-time transmission problems. It basically consists of a modification of the flow of information. The resulting quantity, which we call the forward flow of information, is smaller than the flow of information according to the usual definition except for special cases. We derive various negative coding theorems in which the forward flow of informat... View full abstract»

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  • Ultimate instability of exponential back-off protocol for acknowledgment-based transmission control of random access communication channels

    Publication Year: 1987, Page(s):219 - 223
    Cited by:  Papers (80)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (655 KB)

    When several users simultaneously transmit over a shared communication channel, the messages are lost and must be retransmitted later. Various protocols specifying when to retransmit have been proposed and studied in recent years. One protocol is "binary exponential back-off," used in the local area network Ethernet. A mathematical model with several idealizations (discrete time slots, infinite us... View full abstract»

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  • The forwarding index of communication networks

    Publication Year: 1987, Page(s):224 - 232
    Cited by:  Papers (64)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1378 KB)

    A network is defined as an undirected graph and a routing which consists of a collection of simple paths connecting every pair of vertices in the graph. The forwarding index of a network is the maximum number of paths passing through any vertex in the graph. Thus it corresponds to the maximum amount of forwarding done by any node in a communication network with a fixed routing. For a given number ... View full abstract»

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  • A 0.487 throughput limited sensing algorithm

    Publication Year: 1987, Page(s):233 - 237
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (662 KB)

    We consider Poisson packet traffic accessing a single-slotted channel. We assume the existence of a ternary feedback per channel slot. We also adopt the limited feedback sensing model where each user senses the feedback only while he has a packet to transmit. For this model we develop a collision resolution algorithm with last come-first served characteristics. The algorithm attains the same throu... View full abstract»

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  • Robust transmission of unbounded strings using Fibonacci representations

    Publication Year: 1987, Page(s):238 - 245
    Cited by:  Papers (52)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1195 KB)

    Families of Fibonacci codes and Fibonacci representations are defined. Their main attributes are robustness, manifesting itself by the local containment of errors; and simple encoding and decoding. The main application explored is the transmission of binary strings in which the length is in an unknown range, using robust Fibonacci representations instead of the conventional error-sensitive logarit... View full abstract»

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  • Variable to fixed-length codes for Markov sources

    Publication Year: 1987, Page(s):246 - 257
    Cited by:  Papers (28)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1482 KB)

    Petry's efficient and optimal variable to fixed-length source code for discrete memoryless sources was described by Schalkwijk. By extending this coding technique we are able to give an algorithm for Markov sources that is easy to implement. We can bound the loss of efficiency as a function of the code complexity and the mismatch between the source and the code. Rates arbitrarily close to the sour... View full abstract»

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  • Some models exhibiting non-Gaussian intermittency

    Publication Year: 1987, Page(s):258 - 262
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (502 KB)

    A number of investigations have suggested the relevance of models exhibiting a sporadic or intermittent non-Gaussian character. We mention specifically some of the studies of R. Dwyer concerning the cracking of ocean ice. Here a class of simple models exhibiting such an intermittency are constructed. The second- and fourth-order spectra of the processes constructed are determined. The higher order... View full abstract»

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  • The ergodic and entropy theorems revisited

    Publication Year: 1987, Page(s):263 - 266
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (421 KB)

    A new proof of Birkhoff's ergodic theorem is given using a sample path covering idea, an idea created by Ornstein and Weiss in their extension of the information convergence theorem to random fields. A sketch of the Ornstein-Weiss proof for processes is included in the Appendix. View full abstract»

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  • Gaussian arbitrarily varying channels

    Publication Year: 1987, Page(s):267 - 284
    Cited by:  Papers (50)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (2449 KB)

    The {\em arbitrarily varying channel} (AVC) can be interpreted as a model of a channel jammed by an intelligent and unpredictable adversary. We investigate the asymptotic reliability of optimal random block codes on Gaussian arbitrarily varying channels (GAVC's). A GAVC is a discrete-time memoryless Gaussian channel with input power constraint<tex>P_{T}</tex>and noise power<tex>N... View full abstract»

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  • An approach to Ungerboeck coding for rectangular signal sets (Corresp.)

    Publication Year: 1987, Page(s):285 - 290
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1075 KB)

    A method of finding good Ungerboeck codes for large rectangular [quadrature amplitude modulation (QAM)] signal sets is described. Using the concept of Euclidean weights due to Ungerboeck, we prove that a<tex>2^{n}</tex>point basic constellation may be employed to determine exactly the free distance for an Ungerboeck-coded rectangular<tex>2^{m}</tex>point set, when<tex>... View full abstract»

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  • Euclidean distance for combinations of some Hamming codes and binary CPFSK modulation (Corresp.)

    Publication Year: 1987, Page(s):290 - 293
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (549 KB)

    The integration of channel coding and modulation in a communication system to increase the Euclidean distance between modulated signals is analyzed. Systems using binary continuous-phase frequency-shift keying modulation and some block codes, such as Hamming codes and shortened Hamming codes, are considered. It is shown that the minimum Euclidean distance depends on the configuration of the parity... View full abstract»

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  • On the average codeword length of optimal binary codes for extended sources (Corresp.)

    Publication Year: 1987, Page(s):293 - 296
    Cited by:  Papers (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (685 KB)

    Although optimal binary source coding using symbol blocks of increasing length must eventually yield a code having an average codeword length arbitrarily close to the source entropy, it is known that the sequence of average codeword lengths need not be nonincreasing. The sequence is, however, bounded above by the average codeword length of the source, and certain subsequences must be nondecreasing... View full abstract»

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  • Detection of a known signal in colored Gaussian noise---A new coordinate approach (Corresp.)

    Publication Year: 1987, Page(s):296 - 298
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (461 KB)

    The classical problem of detecting a known signal in additive colored Gaussian noise on a finite interval is considered by using as "coordinates" (observables) the inner products formed between the received waveform and the elements of a simply constructed complete set of functions defined on the observation interval. Results of the Karhunen-Lo√®ve (K-L) approach are thereby obtained without the K-... View full abstract»

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  • Comments on "Characterizing the radar ambiguity functions" by L. Auslander and R. Tolimieri

    Publication Year: 1987, Page(s): 298
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (106 KB)

    We present short proofs and a generalization of the recently published results of Auslander and Tolimieri on ambiguity functions. The main ingredients for obtaining these shortcuts are elementary Hilbert space theory and unitarity of the ambiguity map. View full abstract»

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  • Correction to 'Binary unequal error-protection block codes formed from convolutional codes by generalized tail-biting' (Nov 86 776-786)

    Publication Year: 1987, Page(s): 299
    Request permission for commercial reuse | PDF file iconPDF (39 KB)
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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