IEEE Transactions on Communications

Issue 5 • May 1985

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Displaying Results 1 - 19 of 19
  • [Front cover and table of contents]

    Publication Year: 1985, Page(s): 0
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    Freely Available from IEEE
  • Code Combining - A Maximum-Likelihood Decoding Approach for Combining an Arbitrary Number of Noisy Packets

    Publication Year: 1985, Page(s):385 - 393
    Cited by:  Papers (607)  |  Patents (123)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (871 KB)

    It is well known that if the data rate is chosen below the available channel capacity, error-free communication is possible. Furthermore, numerous practical error-correction coding techniques exist which can be chosen to meet the user's reliability constraints. However, a basic problem in designing a reliable digital communication system is still the choice of the actual code rate. While the popul... View full abstract»

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  • Error Performance Analysis for Narrow-Band Duobinary FM with Discriminator Detection

    Publication Year: 1985, Page(s):399 - 408
    Cited by:  Papers (26)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (918 KB)

    Of the more band-efficient constant envelope digital modulations, duobinary FM is attractive in terms of its potential error performance, as indicated by the minimum distance of the signal structure. In this paper, the error performance of narrow-band duobinary FM, with discriminator detection in an additive Gaussian noise background, is evaluated for a range of system bandwidthsBTand f... View full abstract»

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  • Fiber Optic Analog - Digital Hybrid Signal Transmission Employing Frequency Modulation

    Publication Year: 1985, Page(s):433 - 441
    Cited by:  Papers (8)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (655 KB)

    Investigations are carried out on the SNR performance in fiber optic FM transmission systems which use multimode fibers and 1.3 μm laser diodes. Both laser diode noise and modal noise are quantitatively evaluated in systems with and without employing a superimposed pulse modulation scheme. Based on these investigations, parameters for analog-digital hybrid signal transmission systems employin... View full abstract»

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  • Comparison of High-Level Modulation Schemes for High-Capacity Digital Radio Systems

    Publication Year: 1985, Page(s):442 - 449
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (564 KB)

    This paper presents a comparative study of four 2n-state quadrature amplitude modulation techniques, namely, 16, 32, 64, and 128 QAM, in a digital radio system environment. The effects of filtering, interference, amplifier nonlinearities, and selective fading are investigated using computational and simulation methods. Increase of the carrier-to-noise ratio (CNR) at a fixed symbol error... View full abstract»

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  • Vector Quantization of Differential Luminance and Chrominance Signals

    Publication Year: 1985, Page(s):457 - 464
    Cited by:  Papers (8)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1225 KB)

    A demand for color picture transmission is growing rapidly for various integrated services. For transmission, color pictures must be encoded, but it is widely understood that this can be most conveniently done in the form of luminance and chrominance signals, since the properties of the human visual system can be exploited to achieve considerable redundancy reduction. For encoding these component ... View full abstract»

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  • The Autocorrelation Function for Multi-h Coded Signals

    Publication Year: 1985, Page(s):481 - 484
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (391 KB)

    The autocorrelation function of a binary multi-hcoded signal is determined analytically. This is done by considering the probability density of the "phase change variable" and then deriving the characteristic function. From the autocorrelation, the power spectrum can be found by an analytical or numerical Fourier transformation. Two examples are given. View full abstract»

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  • On Variable Length Codes Under Hardware Constraints

    Publication Year: 1985, Page(s):491 - 494
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    A method for finding a variable length code set under the constraint of maximal clock rate is presented. Given a probability vector and requiring that the length of codewords would be an integer multiple of someK (K> 2)reduces the maximal clock rate needed in implementing the compression system. On the other hand, given a maximal clock rate, the method enables us to use a quantizer w... View full abstract»

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  • [Back cover]

    Publication Year: 1985, Page(s): 0
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    Freely Available from IEEE
  • Fast Error Rate Evaluation in the Presence of Intersymbol Interference

    Publication Year: 1985, Page(s):479 - 481
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    In this paper, we present a general framework which describes a class of fast methods of error rate evaluation in the presence of additive noise and intersymbol interference. An analysis of this framework led us to propose a new method based on a Fourier series expansion which does not make use of the moments of the intersymbol interference. Its computing cost is low and it handles various kinds o... View full abstract»

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  • Performance of First-Order Digital Phase-Locked Loops in Mobile Radio Channels

    Publication Year: 1985, Page(s):450 - 456
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (512 KB)

    The performance of a first-order digital phase-locked loop (DPLL) using nonuniform sampling is studied in the mobile radio environments. The mobile radio channel is characterized by introducing fast Rayleigh fading and random phase variation to the signal envelope and phase, respectively. The nonlinear stochastic difference equation describing the loop operation in fading environments is introduce... View full abstract»

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  • Design and Performance Study of a Microprocessor-Based Two-Wire Full Duplex Baseband Modem

    Publication Year: 1985, Page(s):470 - 478
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (824 KB)

    The design and implementation of a microprocessor-based two-wire full duplex baseband modem is presented. The modem uses the time compression multiplexing technique in implementing a full duplex digital data transmission over a two-wire facility. The line signal used is a baseband bipolar signal. Measurements have been carried out on two prototypes in the lab, and results on the performance of suc... View full abstract»

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  • Efficient Selective Repeat ARQ Strategies for Very Noisy and Fluctuating Channels

    Publication Year: 1985, Page(s):409 - 416
    Cited by:  Papers (20)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (920 KB)

    This paper investigates memory and selective repeat ARQ techniques when channels in both directions are very noisy. It demonstrates that a difficulty arises when memory ARQ is used in these situations, and proposes a remedy-the similarity test. The paper considers a combination of both memory ARQ techniques where an unacknowledged block is retransmitted exactly as before, and modified memory ARQ w... View full abstract»

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  • Robust Frame Synchronization for Noisy PCM Systems

    Publication Year: 1985, Page(s):465 - 469
    Cited by:  Papers (15)  |  Patents (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (520 KB)

    Serial digital transmission requires reliable frame synchronization at the receiver in order to demultiplex and recover the transmitted signals. This paper proposes a faster and more robust method of detecting frame synchronization. A large serial memory is used to store sufficient received history to include all bits of the synchronizing codeword. Equations have been developed which predict the s... View full abstract»

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  • Comparison of DFE and MLSE Receiver Performance on HF Channels

    Publication Year: 1985, Page(s):484 - 486
    Cited by:  Papers (29)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (320 KB)

    Data communication at rates near or above 2 kbits/s on 3 kHz-baadwidth HF radio channels is subject to impairment from severe linear dispersion, rapid channel time variation, and severe fading. In this investigation, recorded 2.4 kbit/s QPSK signals received from HF channels were processed to extract a time-varying estimate of the channel impulse response. From the estimated channel impulse respon... View full abstract»

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  • 256-QAM Modem Performance in Distorted Channels

    Publication Year: 1985, Page(s):487 - 491
    Cited by:  Papers (4)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (544 KB)

    Performance degradations of 256-QAM modems in distorted channels are studied in this correspondence. Illustrative linear, parabolic, and sinusoidal amplitude and group delay channel distortions, caused by filter imperfections and/or by selective radio fades, are investigated. To enable an easy comparison with 64-QAM systems, we present the degradations of these systems in the same figures as those... View full abstract»

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  • On the Performance and Convergence of the Adaptive Canceller of Intersymbol Interference in Data Transmission

    Publication Year: 1985, Page(s):425 - 432
    Cited by:  Papers (17)  |  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    The two-stage equalizer of A. Gersho and T. L. Lim is analyzed, and simulation results of its performance, as well as derivation of the lower bound of the probability of error at the output of the canceller, are presented. They indicate that the overall performance of the canceller critically depends on the performance of the first-stage equalizer. Thus, a decision-feedback equalizer is proposed a... View full abstract»

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  • Double Symbol Error Rates for Differential Detection of Narrow-Band FM

    Publication Year: 1985, Page(s):394 - 398
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (480 KB)

    This paper evaluates the double symbol error rate (average probability of two consecutive symbol errors) in differentially detected narrow-band FM. Numerical results are presented for the special case of MSK with a Gaussian IF receive filter. It is shown that, not unlike similar results previously obtained for the single error probability of such systems, large inaccuracies in predicted performanc... View full abstract»

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  • Fiber Optic Video Transmission Employing Square Wave Frequency Modulation

    Publication Year: 1985, Page(s):417 - 424
    Cited by:  Papers (35)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (792 KB)

    Investigations are carried out on the performance of video transmission systems employing square wave frequency modulation (SWFM). A simple formula for the signal-to-noise ratio (SNR) in the SWFM video transmission systems is derived. The SNR performance is compared to that of frequency modulation (FM) and pulse frequency modulation (PFM). SWFM is shown to display the greatest receiver sensitivity... 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