# IEEE Transactions on Information Theory

## Filter Results

Displaying Results 1 - 25 of 32
• ### Recent results in the Shannon theory

Publication Year: 1974, Page(s):2 - 10
Cited by:  Papers (342)  |  Patents (9)
| | PDF (1589 KB)

The first part of this paper consists of short summaries of recent work in five rather traditional areas of the Shannon theory, namely: 1) source and channel coding theorems for new situations; 2) calculation of source rate and channel capacity; 3) channel coding with feedback; 4) source coding; 5) universal coding. The second part of thc paper consists of a relatively detailed discussion of some ... View full abstract»

• ### Information-theoretic computation complexity

Publication Year: 1974, Page(s):10 - 15
Cited by:  Papers (79)  |  Patents (1)
| | PDF (1160 KB)

This paper attempts to describe, in nontechnical language, some of the concepts and methods of one school of thought regarding computational complexity. It applies the viewpoint of information theory to computers. This will first lead us to a definition of the degree of randomness of individual binary strings, and then to an information-theoretic version of Gödel's theorem on the limitations of th... View full abstract»

• ### Noncommuting observables in quantum detection and estimation theory

Publication Year: 1974, Page(s):16 - 24
Cited by:  Papers (40)
| | PDF (1377 KB)

Basing decisions and estimates on simultaneous approximate measurements of noncommuting observables in a quantum receiver is shown to be equivalent to measuring commuting projection operators on a larger Hilbert space than that of the receiver itself. The quantum-mechanical Cramér-Rao inequalities derived from right logarithmic derivatives and symmetrized logarithmic derivatives of the density ope... View full abstract»

• ### Stable fixed-lag smoothing of continuous time processes

Publication Year: 1974, Page(s):25 - 36
Cited by:  Papers (7)
| | PDF (1654 KB)

Attempts to realize optimal fixed-lag smoothers for continuous-time processes have encountered two major difficulties: the presence of delay lines in the smoother, and the instability of most smoothers. This paper considers suboptimal smoothers which still outperform filters and have performance very close to the optimum. Design procedures are exhibited for smoothers that are both finite-dimension... View full abstract»

• ### Error probabilities in binary angle modulation

Publication Year: 1974, Page(s):36 - 42
Cited by:  Papers (12)
| | PDF (1093 KB)

It is shown that many signal-detection problems involving binary phase and frequency modulation can be solved by considering the problem as the convolution of two independent phase distributions. When the two distributions are similar and each represents the probability density function of the phase of a sinusoid in noise, the probability of error is described in terms of modified Bessel functions... View full abstract»

• ### Signal detection in the presence of multiple-access noise

Publication Year: 1974, Page(s):42 - 49
Cited by:  Papers (3)
| | PDF (922 KB)

In this paper we address the mutual interference problems that arise as a result of many independent terminals simultaneously accessing a common channel. "Random code" bounds are used to show the existence of large signal sets for which any one signal can be reliably detected by matched filters despite the mutual interference. Two types of signal sets are considered: sets with a unique signature f... View full abstract»

• ### Phase tracking and demodulation with delay

Publication Year: 1974, Page(s):50 - 58
Cited by:  Papers (23)
| | PDF (1334 KB)

Algorithms are described for estimating carrier phase by a maximum-likelihood procedure similar to the Viterbi algorithm for decoding a digital sequence. These algorithms avoid the constraint of physical realizability imposed by a phase-locked loop and allow a processing lag in estimation. An approximate analysis suggests that threshold extension can be achieved thereby. Computer simulations demon... View full abstract»

• ### A deterministic approach to variable-step delta modulation

Publication Year: 1974, Page(s):58 - 64
| | PDF (927 KB)

A study is described of delta modulators where the quantizing parameter<tex>\Delta</tex>is a function of a finite number of previously emitted bits. Sufficient conditions are obtained for bounding the steady-state quantization error by the current value of<tex>\Delta</tex>under the assumption that input signals are limited both in amplitude and frequency. The nonlinear prob... View full abstract»

• ### Tree encoding for symmetric sources with a distortion measure

Publication Year: 1974, Page(s):65 - 76
Cited by:  Papers (23)
| | PDF (1785 KB)

A simple algorithm is developed for mapping the outputs of a source into the set of code sequences generated by a tree code. The algorithm is analyzed for a special case in which the source produces discrete independent equiprobable letters, and the distortion measure satisfies a symmetry condition. Letting<tex>R</tex>be the code rate and<tex>D^{\ast}</tex>be the minimum av... View full abstract»

• ### Coding for a delay-dependent fidelity criterion

Publication Year: 1974, Page(s):77 - 85
Cited by:  Papers (5)
| | PDF (1273 KB)

Coding for fidelity criteria, dependent upon the time delay of coding and transmission, is studied from an information-theoretic viewpoint. The results presented here, unlike the conventional Shannon theory, show that the optimum code frequently has finite block length. By extending some rate-distortion theory results, coding theorems and converses are proven. These suggest a procedure for boundin... View full abstract»

• ### A new theorem about the Mattson-Solomon polynomial, and some applications

Publication Year: 1974, Page(s):85 - 89
Cited by:  Papers (6)
| | PDF (584 KB)

Let<tex>F = GF(2)</tex>, and<tex>FG = F[x]/(x^n + 1). FG</tex>is the residue class ring of polynomials mod<tex>x^n + 1</tex>. An element of<tex>FG</tex>is represented by a polynomial of degree at most<tex>n - 1</tex>$$c(x) = c_0 + c_1 x + \cdots + c_{n-1} x^{n-1}$$ with coefficients in<tex>F</tex>. ... View full abstract»

• ### Families of sequences with optimal Hamming-correlation properties

Publication Year: 1974, Page(s):90 - 94
Cited by:  Papers (158)  |  Patents (2)
| | PDF (647 KB)

The unnormalized Hamming correlation between two sequences of equal length is the number of positions in which these sequences have identical symbols. In this paper, lower bounds on the out-of-phase autocorrelation and on the cross correlation of sequences of given length and alphabet size are derived. A method of constructing families of sequences that uniformly realize these hounds is presented. View full abstract»

• ### Configuration matrices of group codes

Publication Year: 1974, Page(s):95 - 100
Cited by:  Papers (7)
| | PDF (812 KB)

Properties of configuration matrices of group codes for the Gaussian channel are considered. It is shown that the configuration matrix of a code generated by a real-irreducible representation is a scalar multiple of an idempotent matrix. A spectral resolution of the configuration matrix of a code generated by an arbitrary real representation is given, and all of its eigenvalues are determined. A r... View full abstract»

• ### A note on perfect predictability and analytic processes (Corresp.)

Publication Year: 1974, Page(s):101 - 102
Cited by:  Papers (2)
| | PDF (325 KB)

It is well known that perfect reconstruction of an analytic random process can be accomplished given any finite length continuous sample. A proof is given here that sampling infinitely often over any finite interval also leads to perfect reconstruction. Applications of the result to problems in detection theory, particularly concerning optimum array processing, are discussed. View full abstract»

• ### Maximum likelihood estimation of parameters in multivariate Gaussian stochastic processes (Corresp.)

Publication Year: 1974, Page(s):102 - 104
Cited by:  Papers (44)
| | PDF (500 KB)

We outline a proof of the strong consistency of the maximum likelihood estimate of the parameters of Gaussian random processes possessing linear autoregressive moving average or state space representations. View full abstract»

• ### Coarse frequency estimation using the discrete Fourier transform (Corresp.)

Publication Year: 1974, Page(s):104 - 109
Cited by:  Papers (72)
| | PDF (896 KB)

The discrete Fourier transform (DFT) is applied as a coarse estimator of the frequency of a sine wave in Gaussian noise. Probability of anomaly and the variance of the estimation error are determined by computer simulation for several DFT block sizes as a function of signal energy-to-noise density ratio<tex>\mathcal{E}/N_0</tex>. Several data windows are considered, but uniform weighti... View full abstract»

• ### Asymptotic statistics of periodogram-type spectral estimates for the output of nonlinear devices (Corresp.)

Publication Year: 1974, Page(s):109 - 111
Cited by:  Papers (1)
| | PDF (416 KB)

The high resolution statistics of a periodogram-type spectral estimate for a periodic deterministic signal plus Gaussian noise are well understood. If, however, the signal plus noise is first passed through a nonlinear memoryless device (such as a hard limiter), the situation becomes much more complicated. The main result of this correspondence is the derivation of the high resolution limit of the... View full abstract»

• ### On the convergence interval of the power cepstrum (Corresp.)

Publication Year: 1974, Page(s):111 - 112
Cited by:  Papers (3)
| | PDF (277 KB)

It is shown that in cepstrum analysis of multipath signals the stringent conditions imposed on the strength of the delayed echo a can be relaxed to require at most only that a be different from one. View full abstract»

• ### On estimating signal-to-noise ratio using the sample correlation coefficient (Corresp.)

Publication Year: 1974, Page(s):112 - 113
Cited by:  Papers (29)
| | PDF (227 KB)

Two versions of a Gaussian signal, corrupted by independent Gaussian noises, are available for estimating the signal-to-noise power ratio. This correspondence demonstrates that the sample correlation coefficient can be used to construct an unbiased estimator that is asymptotically efficient. View full abstract»

• ### Fixed-memory recursive filters (Corresp.)

Publication Year: 1974, Page(s):113 - 115
Cited by:  Papers (15)
| | PDF (438 KB)

This correspondence presents three algorithms for computing least-squares estimates based on fixed amounts of data. View full abstract»

• ### On Glave's upper bound to the error probability for correlated digital signals (Corresp.)

Publication Year: 1974, Page(s):115 - 119
Cited by:  Papers (1)
| | PDF (754 KB)

A generalized method is presented for the computation of peak and rms values of intersymbol interference in correlated digital PAM signals. These values can be used to compute a recently proposed upper bound on the error probability for such signals. View full abstract»

• ### Frame-to-frame coding of television pictures using two-dimensional Fourier transforms (Corresp.)

Publication Year: 1974, Page(s):119 - 120
Cited by:  Papers (10)  |  Patents (4)
| | PDF (354 KB)

Two systems are described for reducing the data rate required to transmit TV signals. Basic to the operation of both systems is the fact that if there is an object in the scene moving more or less in linear translation, then the two-dimensional frame-difference signal computed during the present frame will be very similar to the frame-difference signal which was computed during the previous frame ... View full abstract»

• ### Bibliography on digital graphic image compression and quality (Corresp.)

Publication Year: 1974, Page(s):120 - 122
Cited by:  Papers (2)
| | PDF (519 KB)

This bibliography lists published papers that specifically relate to the compression or quality of digitized images of graphics data. By graphics data we mean printed matter, handwriting, line drawings, or any image data that is basically two-level: information on background. The data compression covered here assumes information reduction to images with two levels of signal amplitude followed by r... View full abstract»

• ### On the computation of rate-distortion functions (Corresp.)

Publication Year: 1974, Page(s):122 - 124
Cited by:  Papers (30)
| | PDF (461 KB)

In a recent paper [1], Blahut suggested an efficient algorithm for computing rate-distortion functions. In this correspondence we show that the sequence of distributions used in that algorithm has a limit yielding a point on the<tex>R(d)</tex>curve if the reproducing alphabet is finite, and we obtain a similar but weaker result for countable reproducing alphabets. View full abstract»

• ### A generalization of Huffman coding for messages with frequencies given by upper and lower bounds (Corresp.)

Publication Year: 1974, Page(s):124 - 125
Cited by:  Papers (2)
| | PDF (273 KB)

A generalization of the Huffman coding procedure is given for cases in which the source letter probabilities are known only to fall in certain ranges. 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