By Topic

IEEE Transactions on Communications

Issue 7 • July 1977

Filter Results

Displaying Results 1 - 21 of 21
  • [Front cover and table of contents]

    Publication Year: 1977, Page(s): 0
    Request permission for commercial reuse | PDF file iconPDF (171 KB)
    Freely Available from IEEE
  • Comments on "Design of Space Diversity Receiving and Transmitting Systems for Line-of-Sight Microwave Links"

    Publication Year: 1977, Page(s): 744
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (91 KB)

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • [Back cover]

    Publication Year: 1977, Page(s): 0
    Request permission for commercial reuse | PDF file iconPDF (179 KB)
    Freely Available from IEEE
  • Sampling Rate Conversion for NTSC Color Television

    Publication Year: 1977, Page(s):707 - 712
    Cited by:  Papers (5)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    Techniques are investigated for conversion between different sampling rates for NTSC color television signals. It is concluded that sampling rate conversion between 3 times color subcarrier frequency and 4 times color subcarrier frequency using all digital processing is quite feasible, and that hardware requirements are not unreasonable. Also, accumulation of error due to cascaded sampling rate co... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Statistical Model for Urban Radio Propogation

    Publication Year: 1977, Page(s):673 - 680
    Cited by:  Papers (631)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    A statistical model, based on extensive experimental data, was established to characterize the urban radio propagation medium in various urban environments. Describing the medium by a linear filter, the peaks of the multipath response were analyzed statistically concerning the distribution of the path strength and the path arrival time. The statistical properties of these quantities depend on the ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Combination Sequences for Spread Spectrum Communications

    Publication Year: 1977, Page(s):691 - 696
    Cited by:  Papers (7)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (552 KB)

    Certain communication systems which employ spread spectrum techniques as a means of supporting multiple users need very long codes to guard against the threat of intentional jamming, but cannot tolerate the lengthy acquisition time which long codes usually require. As a possible solution to this problem, the use of combination sequences has been suggested, and this paper presents some new results,... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quantization for Sequential Signal Detection

    Publication Year: 1977, Page(s):696 - 703
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (600 KB)

    The quantization of the observed data for sequential signal detection is studied. The criteria used are the minimizations of the average sample number under the hypothesis, the average sample number under the alternative, and the maximum average sample number. Numerical results show that the performance is not very sensitive to different criteria. Using a sequential probability ratio test (SPRT), ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Optimal Short Desired Impulse Response for Maximum Likelihood Sequence Estimation

    Publication Year: 1977, Page(s):735 - 738
    Cited by:  Papers (4)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    In Maximum Likelihood Sequence Estimation, the number of operations per symbol depends critically on the length of the Desired Impulse Response (DIR). In this paper it is shown that a short but complex DIR of length 2 may be sufficient to cope with most severe distortion impairments found in quadrature modulation systems, thus permitting MLSE data decoding at still manageable complexity. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The Effect of Carrier Phase Error on the Performance of a Duobinary Shaped QPSK Signal

    Publication Year: 1977, Page(s):738 - 744
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    An analysis is presented showing the effect of carrier phase error on the error-rate of a duobinary shaped, quaternary, phaseshift keying digital radio system. A simple upper bound on the probability of error as a function of phase error is derived and the results are compared to those obtained by computer simulation. The conclusion is reached that such a system exhibits approximately 1.0 dB degra... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Passband Data-Driven Echo Canceller for Full-Duplex Transmission on Two-Wire Circuits

    Publication Year: 1977, Page(s):654 - 666
    Cited by:  Papers (55)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (2104 KB)

    A digitally-implemented echo canceller operating at a rate greater than twice the highest passband frequency is proposed for fullduplex data transmission on a two-wire circuit. Located at each end of the communication circuit, the cancellers operate independently of the local receivers and do not require synchronization of the two data stations. Economies in storage and A/D conversion, in comparis... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Results on Discrete-Time, Decision-Directed Integrated Detection, Estimation, and Identification

    Publication Year: 1977, Page(s):715 - 723
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    New results are presented for symbol-by-symbol detection with decision-directed tracking of colored channel disturbances. Recursive sampled-data algorithms are shown for Maximum A Posteriori Probability of detection under colored additive and multiplicative Gaussian noises along with white Gaussian noise. Preliminary evaluation of the algorithms via Monte Carlo simulation shows good performance co... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Systems Analysis and Design of a Fiber Optic VSB-FDM System for Video Trunking

    Publication Year: 1977, Page(s):680 - 686
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (600 KB)

    The effect of repeater nonlinearities and noises on the transmission performance of a fiber optic VSB-FDM system for video trunking is analyzed. General design formulas are then given and used to derive a set of design requirements for fiber optic CATV systems. Finally, design results are presented for standard 5-, 12-, 21-, and 30channel CATV systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Robust Detectors for Signals in Non-Gaussian Noise

    Publication Year: 1977, Page(s):686 - 690
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    The robustness of suboptimal nonlinear detectors for known discrete-time signals in non-Gaussian noise is investigated. The measure of robustness used is the degradation of asymptotic relative efficiency (compared to a linear detector) from that achieved by an optimal nonlinear detector. The first order density of non-Gaussian noise is modeled as a mixture of a small variance Gaussian background n... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Loop-Induced Magnetic Fields with Negligible Side-Lobes

    Publication Year: 1977, Page(s):723 - 727
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    In schools for the hard-of-hearing where adjacent classrooms are equipped with non-carrier induction loop systems, it is necessary to realize a geometric discrimination between the classroomfields. One approach to reaching the required 24 dB per meter rolloff at the boundaries is the orthogonal field principle reported first in 1965 by de Boer, Bosman and Joosten (ref. 2, 3, 4). In this paper a me... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Error Margin Estimating in Repeaters

    Publication Year: 1977, Page(s):727 - 730
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (376 KB)

    In this paper a new method of estimating error margin in T carrier repeaters is proposed. This estimate is based on two sets of data: (a) measurements from a commonly used test wherein bipolar violations are inserted into the line at an audio rate, and (b) the crosstalk environment in which the repeater is operating. An audio component due to violations in the ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Statistical Analyses of Digital Phase-Locked Loops with Time Delay

    Publication Year: 1977, Page(s):731 - 735
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    In this correspondence, first it is pointed out that introducing time delay of one sampling interval in digital phase-locked loop considerably eases restriction on operating times of digital circuits in the loop. Then statistical analyses are performed for first- and secondorder loops with time delay of one sampling interval in order to see the effect of the time delay on their performances. Appro... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Maximum Likelihood Sequence Estimation of Binary Sequences Transmitted Over Bandlimited Nonlinear Channels

    Publication Year: 1977, Page(s):633 - 643
    Cited by:  Papers (45)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (832 KB)

    The problem of designing and evaluating the performance of a maximum likelihood sequence receiver for binary PSK transmission over bandlimited nonlinear channels is considered in this paper. The effects of intersymbol interference followed by AM/AM and AM/PM conversions are taken into account while optimizing the performance in the presence of white Gaussian noise. A new representation for the out... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Architecture and Construction of a Hardware Sequential Encoder for Speech

    Publication Year: 1977, Page(s):703 - 707
    Cited by:  Papers (12)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (592 KB)

    Recent work has shown the usefulness of sequential or "tree" encoding of speech. We report on construction of a TTL hardware multi-path sequential encoder which uses the so-called M algorithm search procedure. The device attains a signal-to-noise ratio of about 20 dB at 16 kbits/s. Hardware peculiar to this type of encoder is discussed, including architecture o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Approximate Analysis of Delay for Fixed and Variable Length Packets in an Unslotted ALOHA Channel

    Publication Year: 1977, Page(s):644 - 654
    Cited by:  Papers (32)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    In this paper we compute the mean delay for an unslotted ALOHA random access channel for both fixed and variable length packets. The analysis is based on the concept of a user cycle and obtains steady state results. When the channel is "stable", the results seem quite accurate. The input parameters to the model are the number of users, the mean think time, and mean retransmission time. The model y... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous Phase Tracking and Detection in Data Transmission Over Noisy Dispersive Channels

    Publication Year: 1977, Page(s):712 - 715
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (408 KB)

    A new technique, related to the Viterbi algorithm for simultaneous phase jitter tracking and data detection of signals transmitted over the dispersive channel with Gaussian noise is proposed. This technique produces a reliable phase estimate and avoids the poor receiver performance which occurs with Viterbi decoding in the presence of phase jitter due to the use of a phase estimate derived from un... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Self-Orthogonalizing Adaptive Equalization Algorithms

    Publication Year: 1977, Page(s):666 - 672
    Cited by:  Papers (76)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    A comparison is made of several self-orthogonalizing adjustment algorithms for linear tapped delay line equalizers. These adaptive algorithms accelerate the rate of convergence of the equalizer tap weights to those which minimize the output mean-squared error of a data transmission system. Accelerated convergence of the estimated gradient algorithm is effected by premultiplying the correction term... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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