IEEE Transactions on Communications

Issue 7 • July 1981

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Displaying Results 1 - 25 of 26
  • [Front cover and table of contents]

    Publication Year: 1981, Page(s): 0
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    Freely Available from IEEE
  • Design of Economic PCM Arrays with a Prescribed Grade of Service

    Publication Year: 1981, Page(s):925 - 935
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (967 KB)

    This paper deals with the design of economically structured PCM switching arrays for traffic distribution. The presented switching arrays are symmetrically structured, and have one up to six stages and use different combinations of time stagesTand space stagesS, respectively. It is shown how such arrays can be designed for a required grade of service having a prescribed numbe... View full abstract»

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  • Design Choices for Selective-Repeat Retransmission Protocols

    Publication Year: 1981, Page(s):944 - 953
    Cited by:  Papers (10)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1099 KB)

    The design of selective-repeat retransmission protocols to provide reliable transfer of large data files is discussed. The transmission system is assumed capable of losing, distorting, or reordering the transmitted data frames and acknowledgment frames. The principle design considerations center on methods for managing the finite sequence number space and methods for managing the finite-sized rece... View full abstract»

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  • A Statistical Analysis of ARQ Protocols Operating in a Nonindependent Error Environment

    Publication Year: 1981, Page(s):971 - 981
    Cited by:  Papers (46)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (866 KB)

    In this paper the behavior of the Stop and Wait and Go Back-Nerror detection and retransmission (ARQ) protocols in an environment characterized by nonrandom errors are studied. Analytic models are developed for the case that the error process is modeled as a Markovian process. These models may be used to predict performance measures such as expected queue length and expected delay for t... View full abstract»

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  • An Orthogonally Multiplexed QAM System Using the Discrete Fourier Transform

    Publication Year: 1981, Page(s):982 - 989
    Cited by:  Papers (246)  |  Patents (110)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (690 KB)

    An orthogonally multiplexed QAM (O-QAM) system is a multichannel system with a baud rate spacing between adjacent carrier frequencies; this property is desirable to digitally implement the system using the discrete Fourier transformation (DFT). This paper provides a novel digital signal processing method based on anN/2-point DFT processing in the O-QAM system. A complexity comparison be... View full abstract»

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  • Design of DPCM Quantizers for Video Signals Using Subjective Tests

    Publication Year: 1981, Page(s):990 - 1000
    Cited by:  Papers (34)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1463 KB)

    The application of differential pulse code modulation (DPCM) for broadcast color television signals requires a design which produces no visible impairments under normal viewing conditions. This paper describes a quantizer design which is based on measured visibility thresholds of the various kinds of DPCM impairments such as granular noise, edge busyness, and slope overload. The visibility thresho... View full abstract»

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  • A General Multibeam Satellite Switching Algorithm

    Publication Year: 1981, Page(s):1025 - 1036
    Cited by:  Papers (45)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (958 KB)

    In this paper we consider an SS/TDMA system withMuplink beams,Ndownlink beams, andKconnection points. We first assume that the downlink is α times faster than the uplink, and a simple time multiplexing scheme is employed. An optimal time slot assignment algorithm for anyM, N,alpha, andK,1 leq K leq min (M, alphaN), and for any ... View full abstract»

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  • The Performance Characteristics of Two Extensions of the Sign Detector

    Publication Year: 1981, Page(s):1038 - 1044
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (699 KB)

    Two related techniques have been proposed in the past for improving the performance of the sign detector through higherorder data quantization. The fixed-thresholdm-interval detector and the generalized sign detector using a conditional test are both nonparametric detectors which are fairly simple to implement. In this paper we compare the asymptotic and finite-sample, finite-signal per... View full abstract»

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  • Tolerable Q-Factor Variations in PCM Lines

    Publication Year: 1981, Page(s):1066 - 1070
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (446 KB)

    This paper makes a theoretical assessment of the performance impairments that may be caused on PCM lines by the use of different timing extraction bandwidths in tandem. Two basic situations are examined: 1) random transmitted pattern, and 2) transition between two repetitive patterns. In both cases, the analysis of jitter propagation and acceptance indicates that there is a limited degree of bandw... View full abstract»

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  • Phasing Multitone Signals to Minimize Peak Factors

    Publication Year: 1981, Page(s):1072 - 1074
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (296 KB)

    To maximize the average power of a multitone bandpass signal under a peak power constraint, the tones must be phased so as to minimize the RF peak factor. Results are given here forM= 3, 5, 7, and 9 where theMtones are of equal power and uniformly spaced in frequency. The two methods of phasing studied lead to similar minimized peak factors of roughly 6 dB. Optimum parameter ... View full abstract»

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  • Correction to "A New Teletext Channel"

    Publication Year: 1981, Page(s): 1074
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (108 KB)

    First Page of the Article
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  • On the Accuracy of the Shimbo Approach to Intermodulation and Crosstalk Calculations

    Publication Year: 1981, Page(s):1076 - 1082
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    To simplify the mathematics involved and to facilitate derivations of intermodulation and crosstalk formulas, the Shimbo approach uses a double Fourier transformation and represents the characteristics of a memoryless nonlinear device by a Bessel function series. Such an approach seems to be a very brave approximation as the approximated characteristics vary wildly with respect to the number of Be... View full abstract»

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  • [Back cover]

    Publication Year: 1981, Page(s): 0
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    Freely Available from IEEE
  • Approximate FM Demodulation Using Zero Crossings

    Publication Year: 1981, Page(s):1061 - 1065
    Cited by:  Papers (7)  |  Patents (103)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    This paper deals with approximate methods for demodulating FM signals using their zero crossings. A first-order (linear) interpolation method is devised and analyzed. Computer programs were then prepared to compare this first-order interpolator to the more usual zero-order interpolator. Higher order interpolation is briefly discussed, and the results of using a second-order interpolator are compar... View full abstract»

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  • Optimum Allocation of Servers to Two Types of Competing Customers

    Publication Year: 1981, Page(s):1051 - 1055
    Cited by:  Papers (39)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    We consider the problem of optimal dynamic allocation of a limited number of processors to service the demands from different types of users. The types are differentiated by the rates at which they enter requests for service and the mean length of time they occupy a single processor. The decision to accept or reject a request for service may be based on the number of processors occupied by each ty... View full abstract»

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  • Do All MSK-Type Signaling Waveforms Have Wider Spectra Than Those for PSK?

    Publication Year: 1981, Page(s):1071 - 1072
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (192 KB)

    For all MSK-type signals proposed until now, the main lobes of their power spectral densities were observed to be always wider than those for conventional PSK. Although it is intuitively believed that this observation can be extended to cover all other MSK-type signals not yet found, no formal proof has been reported yet. The present paper attempts to give such a proof. View full abstract»

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  • Anti-Intercept Margins of Relay-Augmented Data Links

    Publication Year: 1981, Page(s):936 - 943
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (744 KB)

    A quantitative measure of the anti-intercept improvement (or margin) of a relay data net is described. It is assumed that the link relays are located to obtain the maximum anti-jam advantage against a line-of-sight jammer. The anti-intercept margin is defined as the ratio of the respective spatial power densities available to the intercept receiver when no relay and relays are used, and can be as ... View full abstract»

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  • Speckle Noise Reduction in Fiber Optic Analog Video Transmission Using Semiconductor Laser Diodes

    Publication Year: 1981, Page(s):1017 - 1024
    Cited by:  Papers (39)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (744 KB)

    This paper investigates the effects of speckle noise on analog video transmission systems using semiconductor laser diodes. The system linearity degradation due to speckle noise is examined using different fiber types. Then this paper proposes a new modulation technique employing a superimposed pulse scheme to reduce speckle noise. It is experimentally confirmed that the proposed modulation method... View full abstract»

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  • An Incremental Adaptive Quantizer: A Novel Quantization Scheme

    Publication Year: 1981, Page(s):1056 - 1061
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    Adaptive quantizers for PCM and DPCM coding of speech have been of great interest, and several excellent quantization strategies have evolved [1], [2]. In this paper we propose another algorithm for the step-size change in a quantizer. In the present strategy the quantizer is always a linear one except for the fact that the step size can be changed by a fixed amount at each sampling instant. This ... View full abstract»

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  • GMSK Modulation for Digital Mobile Radio Telephony

    Publication Year: 1981, Page(s):1044 - 1050
    Cited by:  Papers (452)  |  Patents (57)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (800 KB)

    This paper is concerned with digital modulation for future mobile radio telephone services. First, the specific requirements on the digital modulation for mobile radio use are described. Then, premodulation Gaussian filtered minimum shift keying (GMSK) with coherent detection is proposed as an effective digital modulation for the present purpose, and its fundamental properties are clarified with t... View full abstract»

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  • Erlang and Normal Distribution in Telex Traffic

    Publication Year: 1981, Page(s):1036 - 1038
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    ESS exchanges provide the means of exact accurate measurements of telecommunication traffic. The results of these measurements prove the validity of certain theoretical propositions. Therefore, it is possible to base the short- and long-range planning of network growth, adjusted for time and place, on the conclusions obtained. View full abstract»

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  • Bottleneck Flow Control

    Publication Year: 1981, Page(s):954 - 962
    Cited by:  Papers (239)  |  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1000 KB)

    The problem of optimally choosing message rates for users of a store-and-forward network is analyzed. Multiple users sharing the links of the network each attempt to adjust their message rates to achieve an ideal network operating point or an "ideal tradeoff point between high throughput and low delay." Each user has a fixed path or virtual circuit. In this environment, a basic definition of "idea... View full abstract»

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  • A Quick-Look Decoder with Isolated Error Correction and Node Synchronization

    Publication Year: 1981, Page(s):1074 - 1076
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    In a low-noise environment, a simple inversion circuit can be used for quick-look decoding of a convolutional code. The bit error performance of the raw inversion circuit is improved by a simple pattern-recognition technique operating on the syndrome stream, which is also used to acquire node sync. View full abstract»

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  • Digital Optical Receiver Sensitivity Degradation Caused by Crosstalk in Bidirectional Fiber Optic Systems

    Publication Year: 1981, Page(s):1012 - 1016
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (448 KB)

    Receiver sensitivity degradation caused by Rayleigh backscattering and coupler reflections is investigated for bidirectional digital transmission systems. Experimental values for APD receiver sensitivity degradation in a system operating at a bit rate of 10 Mbits/s and at a wavelength of 830 nm were found to be within 2 to 3 dB (optical) of the values predicted by a simple theoretical model. View full abstract»

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  • On the Dynamic Control of the Urn Scheme for Multiple Access Broadcast Communication Systems

    Publication Year: 1981, Page(s):962 - 970
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (752 KB)

    The Urn scheme is known to perform better than optimal ALOHA and TDMA for all ranges of traffic rates. In this paper we discuss the dynamic behavior of the Urn scheme to show that it possesses bistable behavior in a manner similar to ALOHA schemes and that dynamic control procedures can be applied to improve the system performance effectively. In particular, an input control procedure (ICP) is pre... View full abstract»

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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.

 

 

Full Aims & Scope

Meet Our Editors

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