IEEE Transactions on Communications

Issue 9 • September 1977

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Displaying Results 1 - 25 of 28
  • [Front cover and table of contents]

    Publication Year: 1977, Page(s): 0
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    Freely Available from IEEE
  • Optimum Reception in an Impulsive Interference Environment - Part I: Coherent Detection

    Publication Year: 1977, Page(s):910 - 923
    Cited by:  Papers (212)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1347 KB)

    Because communications systems are seldom significantly interfered with by classical white Gaussian noise, it is necessary to consider other, appropriate (and tractable) interference models, if realistic estimates of system performance are to be obtained for the general spectral-use environment. For this purpose, Middleton's recently developed canonical statistical-physical model of "impulsive" in... View full abstract»

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  • Optimum Reception in an Impulsive Interference Environment - Part II: Incoherent Reception

    Publication Year: 1977, Page(s):924 - 934
    Cited by:  Papers (71)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (913 KB)

    In Part I, the relevant statistical properties of the recently developed statistical-physical model of generalized impulsive interference have been briefly reviewed (for sub Class A noise) and then applied specifically to optimum coherent detection. It is shown that by using optimum and (locally optimum) detection algorithms (canonically and explicitly derived), substantial savings in signal power... View full abstract»

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  • PSK-Type Modulation with Overlapping Baseband Pulses

    Publication Year: 1977, Page(s):980 - 990
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (838 KB)

    One of the most interesting challenges in the field of digital radio is to generate and transmit signals which meet the spectral requirements and which have high detection efficiencies. The spectral efficiency of PSK-type modulation with overlapping baseband pulses is known to be better than that with nonoverlapping pulses of the same form; but, to our knowledge, no analysis is presently available... View full abstract»

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  • Incohernet Adaptive Reception of Signal with Unknown Envelope

    Publication Year: 1977, Page(s):1009 - 1016
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (631 KB)

    This paper deals with the design of adaptive algorithms for reception of a narrowband signal with an unknown envelope in a noisy channel (Gaussian noise). We here consider a system (with a "real teacher") which learns from the samples classified by this self-learning system (decision directed adaptive receiver). By using those samples which are accepted as learning samples, the parameters of the u... View full abstract»

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  • An Analysis of Jitter Accumulation in a Chain of PLL Timing Recovery Circuits

    Publication Year: 1977, Page(s):1027 - 1032
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (485 KB)

    This paper analyzes the timing jitter accumulation which is produced in a chain of regenerative repeaters when a second-order phase-locked loop (PLL) is used as a timing filter. In a PLL timing recovery circuit, the growth of timing jitter varies with the value of damping factorzeta. In this paper, therefore, approximate equations of timing jitter accumulation are given with respect to ... View full abstract»

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  • Third Order Intermodulation Interference - Bounds and Interference-Free Channel Assignment

    Publication Year: 1977, Page(s):1041 - 1046
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (605 KB)

    In this paper a relationship between difference triangles and third order intermodulation interference is demonstrated, and two applications of this relationship are developed. In the first application, the relationship allows us to find intermodulation-free channel assignments where such arrangements are possible. The second application concerns cases where this is not possible. In the second app... View full abstract»

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  • On the Degradation of Hard-Limiting Systems by Sampling

    Publication Year: 1977, Page(s):1050 - 1052
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (338 KB)

    Sampling performed in conjunction with hard-limiting of a narrow band signal in band-limited white Gaussian noise increases the loss in output signal-to-noise ratio over that incurred by hardlimiting the original time-continuous signal. The largest increase in noise is by a factor ofpi^{2}/8in both the band-pass and the base-band cases, and occurs when the input signal-to-noise ratio is... View full abstract»

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  • [Back cover]

    Publication Year: 1977, Page(s): 0
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    Freely Available from IEEE
  • Adaptive Detection of Signals in Impulsive Noise Environments

    Publication Year: 1977, Page(s):1022 - 1027
    Cited by:  Papers (24)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (544 KB)

    A detector structure and an adaptive algorithm are proposed for the reception of signals in noise backgrounds possessing broad-tailed probability distributions typical of impulsive noise. The adaptive detector combines the best features of linear matched filtering and hard-limiting receiver structures resulting in a small-signal SNR performance which is an improvement over either of these detector... View full abstract»

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  • Applications of Ali-Silvey Distance Measures in the Design Generalized Quantizers for Binary Decision Systems

    Publication Year: 1977, Page(s):893 - 900
    Cited by:  Papers (97)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (768 KB)

    The Ali-Silvey class of distance measures is applied to the problem of designing quantizers for use in binary detection systems. To find optimal solutions the notion of quantization must be generalized slightly, and necessary conditions are established for the selection of quantizer parameters in this context. Local, or small-signal, conditions are also derived and these are seen to agree with asy... View full abstract»

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  • A Maximum-Likelihood Sequence Estimator with Decision-Feedback Equalization

    Publication Year: 1977, Page(s):971 - 979
    Cited by:  Papers (78)  |  Patents (21)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (976 KB)

    A decision-feedback equalizer (DFE) is proposed as a prefilter which limits the complexity of a maximum-likelihood sequence estimator (MLSE) implemented by the Viterbi algorithm (VA) for channels having a long impulse response. By imbedding a DFE into the structure of the MLSE, the overall impulse response of the system is truncated to a short duration. With this practical receiver, a compromise m... View full abstract»

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  • Phase Compensation Receivers for Optical Communication

    Publication Year: 1977, Page(s):900 - 909
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1008 KB)

    Phase compensation receivers are investigated in the context of optical communication, with particular emphasis on low visibility channels. It is shown that phase compensation can be viewed as a reduction of the number of spatial modes in the signal field so that an improvement in communication performance can be realized by a receiver which exploits the spatial coherence of the compressed signal ... View full abstract»

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  • Buffer Sharing in Computer-Communication Network Nodes

    Publication Year: 1977, Page(s):958 - 970
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1048 KB)

    This paper discusses a technique of sharing extra storage buffers among a number of nodes (for example concentrators) or among a number of output lines in a single node (for example, in a message switching center). Buffer sharing can be used to reduce the probability that a message is blocked, while at the same time buffer storage cells can be conserved. In addition, buffer sharing reduces sensiti... View full abstract»

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  • A Fast Computational Algorithm for the Discrete Cosine Transform

    Publication Year: 1977, Page(s):1004 - 1009
    Cited by:  Papers (649)  |  Patents (61)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (448 KB)

    A Fast Discrete Cosine Transform algorithm has been developed which provides a factor of six improvement in computational complexity when compared to conventional Discrete Cosine Transform algorithms using the Fast Fourier Transform. The algorithm is derived in the form of matrices and illustrated by a signal-flow graph, which may be readily translated to hardware or software implementations. View full abstract»

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  • Suboptimal Continuous Shift Keyed (CSK) Demodulation for the Efficient Implementation of Low Crosstalk Data Communication

    Publication Year: 1977, Page(s):1037 - 1041
    Cited by:  Papers (12)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (456 KB)

    A suboptimal receiver of constant envelope, continuousfrequency MSK-type modulations called Continuous Shift Keying (CSK) is proposed that halves demodulator complexity with no more than a 1.6 dB loss in detectability in AWGN. The technique is especially applicable to a frequency division multiple access system composed of many unsynchronized user terminals. View full abstract»

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  • The Use of a High Order Error Measure in Nonlinear Modulation

    Publication Year: 1977, Page(s):1016 - 1022
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (544 KB)

    In this paper a high order error measure is used for the evaluation and design of nonlinear modulation schemes. This high order measure works as a deterrent against threshold effects, and through its use a simple, two-dimensional nonlinear modulation scheme is fully analyzed and efficiently designed. View full abstract»

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  • A Look at Crosstalk in Quadrature-Carrier Modulation Systems

    Publication Year: 1977, Page(s):884 - 892
    Cited by:  Papers (26)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (688 KB)

    A method is presented for comparing the performance of different quadrature-carrier modulation techniques. It is based on the calculation of the mean-square crosstalk between adjacent digital communications channels. This method was used to determine the crosstalk of a number of constant envelope modulation schemes, including Staggered Quaternary Phase Shift Keying (SQPSK) and Minimum Shift Keying... View full abstract»

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  • Intermodulation Spectra for Two SCPC Systems

    Publication Year: 1977, Page(s):990 - 994
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (512 KB)

    Carrier-to-intermodulation (C/IM) power ratios are derived for two types of single-channel-per-carrier (SCPC) systems in terms of the single-carrier transfer characteristic of the satellite TWT. The first system is based on a set of equal-amplitude, uniformly spaced carriers and is appropriate whenever complete earth-station interconnectivity is required in a bandwidth-limited environment. The sec... View full abstract»

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  • Improved Demodulation of Sampled FM Signals in High Noise

    Publication Year: 1977, Page(s):1052 - 1054
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (312 KB)

    Simulation results are presented which are very convincing in favor of FM demodulators driven by in-phase and quadraturephase signals. Application of the extended Kalman filtering algorithms to the appropriate signal model directly yields demodulators in which the error covariance equations are uncoupled from the state estimate equations. These demodulators perform a little better than others deri... View full abstract»

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  • A Worst-Case Crosstatk Comparison Among Several Modulation Schemes

    Publication Year: 1977, Page(s):1032 - 1037
    Cited by:  Papers (16)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (600 KB)

    The effects of worst-case crosstalk (from a time-domain point of view) on unsynchronized frequency division multiplexed (FDM) constant envelope modulations are considered assuming coherent hard-decision receivers and no filtering for bandwidth constraint. Continuous-phase frequency shift keying (FSK) is found to be superior to various forms of phase shift keying (PSK). View full abstract»

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  • A Simplified Analysis of Scan Times in an Asymmetrical Newhall Loop with Exhaustive Service

    Publication Year: 1977, Page(s):951 - 957
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (552 KB)

    A Newhall loop with exhaustive service, infinite buffer storage, and non-identical terminals is analyzed. A simple and computationally efficient procedure is demonstrated for determining first and second moments of queue lengths and scan times. View full abstract»

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  • A Gaussian Sum Approach to Phase and Frequency Estimation

    Publication Year: 1977, Page(s):935 - 942
    Cited by:  Papers (17)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (800 KB)

    In this paper, a theory of optimal nonlinear estimation from sampled data signals where the a posteriori probability densities are approximated by Gaussian sums is adapted for application to phase and frequency estimation in high noise. The nonlinear estimators (demodulators) require parallel processing of the received signal. In the limit as the number of parallel processors becomes infinite the ... View full abstract»

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  • An Experimental 560 Mbits/s Repeater with Integrated Circuits

    Publication Year: 1977, Page(s):995 - 1004
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1176 KB)

    The bandwidth penalty of digital systems is very obvious in the case of transmission over coaxial cables because of the exponential increse of cable attenuation with square root of frequency. From capacity point of view, it is only at very high information rates (> 500 Mbit/s typically) that a digital system might be competitive with an analog system, because the disadvantage of noise accumulat... View full abstract»

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  • Binomial Switching Networks for Concentration and Distribution

    Publication Year: 1977, Page(s):873 - 883
    Cited by:  Papers (29)  |  Patents (12)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (1232 KB)

    In this paper a new class of switching networks is presented for concentration and distribution interconnection assignments between disjoint sets of input and output terminals. These networks are called binomial switching networks because of their structural association with the binomial distribution. Binomial networks are uniform in that all connecting paths are of equal length and are such that ... 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