IEEE Transactions on Communications

Issue 7  Part 2 • July 1982

This issue contains several parts.Go to:  Part 1

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Displaying Results 1 - 25 of 28

Publication Year: 1982, Page(s): 0
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• Study of Acknowledgment Schemes in a Star Multiaccess Network

Publication Year: 1982, Page(s):1657 - 1667
Cited by:  Papers (11)
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In distributed random access communication, collision occurs when two or more transmissions overlap in time. After a transmission a user should know whether his attempt was successful so that he can decide his next action. Acknowledgments are commonly used to indicate whether a transmission is successful. The authors study the effect of acknowledgments on the performance of a star broadcast networ... View full abstract»

• Line Code Design for High-Capacity Baseband Digital Transmission Systems

Publication Year: 1982, Page(s):1668 - 1678
Cited by:  Papers (4)
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A simple model for the intersymbol interference due to a low-frequency cutoff channel is presented. The model is used to develop a computationally efficient and accurate method for computing symbol error probability for alphabetically line-encoded sequences transmitted over this channel. The model is also used to design alphabetic line codes that minimize the symbol error probability. A method is ... View full abstract»

• Picture Quality Prediction Based on a Visual Model

Publication Year: 1982, Page(s):1679 - 1692
Cited by:  Papers (79)  |  Patents (2)
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Distortion measures are developed for the purpose of predicting the subjective quality of moving monochrome television pictures. The need for such measures is particularly recognized in the area of digital picture coding. Subjectively relevant distortion measures that mirror viewers' assessments of picture quality would make the task of designing and optimizing coding schemes considerably easier. ... View full abstract»

• A Comparison of Calculated and Observed Performance of Digital Radio in the Presence of Interference

Publication Year: 1982, Page(s):1693 - 1700
Cited by:  Papers (19)
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A statistical model of multipath fading and detailed radio characterization measurements made in the laboratory provide the basis for a calculation of the time, during a heavy fading month, that a given digital radio system will be unavailable because of high bit error rates induced by multipath fading, thermal noise, and interference. The author shows that a simple algebraic expression for outage... View full abstract»

• A Hybrid ARQ Scheme with Parity Retransmission for Error Control of Satellite Channels

Publication Year: 1982, Page(s):1701 - 1719
Cited by:  Papers (233)  |  Patents (19)
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Presents a new type of hybrid ARQ scheme for error control in data communication systems. The new scheme is based on the concept that the parity-check digits for error correction are sent to the receiver only when they are needed. Normally, data blocks with some parity-check bits for error detection are transmitted. When a data block D is detected in errors, the retransmissions are not simp... View full abstract»

• An Anomaly of O'Dell's Formula

Publication Year: 1982, Page(s):1720 - 1721
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In telephone traffic theory O'Dell's formula gives the traffic capacity of a group of lines with limited availability at a prescribed loss probability. In some cases an anomaly is observed: a decrease of traffic when the availability is increased. The practical significance of this anomaly is too small to preclude the use of O'Dell's formula for this reason. View full abstract»

• Minimum Euclidean distance and power spectrum for a class of smoothed phase modulation codes with constant envelope

Publication Year: 1982, Page(s):1721 - 1729
Cited by:  Papers (19)
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A class of smoothed phase modulation codes is analyzed in terms of power spectral density and error probability for large signal-to-noise ratios. The signals have constant envelope and the information-carrying phase function is of multi-h partial response continuous phase type. A cyclic variation of modulation index from symbol time interval to symbol time interval is introduced. Coherent t... View full abstract»

• Error Probability Bounds for Unbalanced QAM Over the Gaussian Phase-Jittered, Dispersive Channel

Publication Year: 1982, Page(s):1729 - 1735
Cited by:  Papers (3)
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Presents an analysis concerned with a hybrid QAM system capable of simultaneously handling digital as well as analog data. Upper bounds are computed for the error probability in two- and four-level digital data streams as a function of the noise power, linear distortion, and phase jitter of the channel and of the relative power of the analog and digital signals. The author shows that the digital e... View full abstract»

• Effect of Data Asymmetry on Unbalanced QPSK Signals with Noisy Phase Reference

Publication Year: 1982, Page(s):1735 - 1746
Cited by:  Papers (1)
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The combined effects of data asymmetry and a noisy carrier phase reference on the bit error rate performance of an unbalanced QPSK system are examined. The results are presented in terms of the SNR loss for a nominal error rate of 10-5, parameterized by the mean and variance of the reference phase error φ at the receiver. The effect of asymmetry on the carrier tracking loop (henc... View full abstract»

• Skinner's Method for Computing Bounds on Distributions and the Numerical Solution of Continuous-Time Queueing Problems

Publication Year: 1982, Page(s):1746 - 1749
Cited by:  Papers (5)
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Skinner's method provides a means of computing, numerically, upper and lower bounds on a cumulative distribution function resulting from the convolution of probability density functions. The method thus provides approximate numerical results whose accuracy is known precisely. The authors provide an exposition of Skinner's method. It shows how the method can be applied to the computation of numeric... View full abstract»

• Capacity Allocation in a DAMA Satellite System

Publication Year: 1982, Page(s):1750 - 1757
Cited by:  Papers (16)
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Some analysis and design results for a circuit-switched multiaccess satellite system are presented. The use of a demand assignment multiple access (DAMA) circuit-switched service in satellite communications gives rise to many problems, recently emphasized in the literature. They recall those of an open network of queues with population size constraints. The main results are the extension of comput... View full abstract»

• A Responsive Distributed Routing Algorithm for Computer Networks

Publication Year: 1982, Page(s):1758 - 1762
Cited by:  Papers (85)  |  Patents (6)
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A new distributed algorithm is presented for dynamically determining weighted shortest paths used for message routing in computer networks. The major features of the algorithm are that the paths defined do not form transient loops when weights change and the number of steps required to find new shortest paths when network links fail is less than for previous algorithms. Specifically, the worst cas... View full abstract»

• Using Automated Validation Techniques to Detect Lockups in Packet-Switched Networks

Publication Year: 1982, Page(s):1762 - 1767
Cited by:  Papers (4)
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The existence of a program for automatically examining the syntax of a protocol for the absence of various undesired properties-such as deadlock-raises the question whether the classical lockups' described in the early packet-switched data network literature could be detected by such a program. The authors answer this question in the affirmative. View full abstract»

• A Capacity Allocation Problem in Voice-Data Networks

Publication Year: 1982, Page(s):1767 - 1772
Cited by:  Papers (3)  |  Patents (1)
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The problem addressed is that of capacity allocation for networks carrying both voice and data. It is assumed that transmission in each of the links of the network is digital, with flow divided into fixed length frames. The frame is allocated between voice and data. The problem is to find the optimum division of capacity for each of the links so as to minimize the probability of blocking of a voic... View full abstract»

• A Class of Companded Unity Bit Coders

Publication Year: 1982, Page(s):1772 - 1775
Cited by:  Papers (2)
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Speech encoding using unity bit coders in the form of delta modulators (DM) has become very popular. Many different designs have been proposed and implemented in monolithic form. The strategy used in all of these coders is to adapt the step size' of the coder to suit the input signal power. The author examines a class of unity bit coders where a basic linear coder is used while the input to this ... View full abstract»

Publication Year: 1982, Page(s):1775 - 1785
Cited by:  Papers (12)  |  Patents (2)
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A comparison of adaptive differential pulse code modulation (ADPCM) speech compression systems is made using different recursive adaptive linear prediction algorithms. The particular algorithms considered are 1) a fixed predictor, 2) the adaptive least mean square (LMS) transversal predictor, 3) the LMS (gradient) lattice predictor, 4) the leas squares (LS) lattice predictor, and 5) an LS lattice ... View full abstract»

• The Effect of Station-Keeping Error on the Distribution of Carrier-to-Interference Ratio

Publication Year: 1982, Page(s):1786 - 1791
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Studies the statistical distribution of carrier-to-interference ratios when mutually interfering geostationary satellites are considered to be randomly positioned within their station-keeping tolerance bands. Results are obtained by approximate analysis and by Monte Carlo methods, from which one can ascertain `outage' probabilities as a function of the relevant parameters. For certain such probabi... View full abstract»

• Assessment of Methods for Evaluating the Immunity of PCM Regenerators to Near End Crosstalk

Publication Year: 1982, Page(s):1791 - 1797
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Compares two performance measures used to assess the immunity of PCM regenerators to near end crosstalk, viz. the NEXT noise figure and the input signal-to-NEXT noise ratio. The NEXT noise figure is shown to be the superior performance measure, and three methods of measuring this parameter are compared on the basis of their sensitivity to implementation imperfections. It is shown that although a s... View full abstract»

• A Reduced Complexity Moment Algorithm for Correlated Digital Signals

Publication Year: 1982, Page(s):1798 - 1799
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The Cariolaro-Pupolin algorithm for computing the moments of correlated digital signals has a complexity proportional to the cube of the number of states of the finite state coding device. By rearranging the Cariolaro-Pupolin procedure, the author obtains an algorithm whose complexity is proportional to the square of the number of states and yields a vector recursion in place of the original matri... View full abstract»

• Comments on "Digital PCM Bit Synchronizer and Detector"

Publication Year: 1982, Page(s):1799 - 1800
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Previously (see ibid., vol.COM-28, p.1197-1204, 1980) the linearized mean-square phase error resulting from a digital PLI has been related to the ratio of the power of the spectral line in the input at the VCO frequency and the value of the noise spectrum at the same frequency. The author shows that this is fundamentally incorrect. View full abstract»

Publication Year: 1982, Page(s): 1800
Cited by:  Papers (1)
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First Page of the Article
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• Authors' reply to "Comments on ́A Study of Userś Buffer Variations in Random Access Satellite Channelś"

Publication Year: 1982, Page(s): 1801
Cited by:  Papers (1)
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For original paper see ibid., vol. COM-27, p.857 (June 1979) and for comments see ibid., vol.COM-29, p.919 (June 1981). View full abstract»

• Final comment by author

Publication Year: 1982, Page(s): 1802
Cited by:  Papers (1)
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First Page of the Article
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Publication Year: 1982, Page(s): 1802
Cited by:  Papers (1)
| |PDF (135 KB)

First Page of the Article
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Aims & Scope

IEEE Transactions on Communications focuses on all telecommunications including telephone, telegraphy, facsimile, and point-to-point television by electromagnetic propagation.

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Meet Our Editors

Editor-in-Chief
Naofal Al-Dhahir
University of Texas at Dallas