By Topic

IEEE Transactions on Communications

Issue 3 • March 1978

Filter Results

Displaying Results 1 - 17 of 17
  • [Front cover and table of contents]

    Publication Year: 1978, Page(s): 0
    Request permission for commercial reuse | PDF file iconPDF (170 KB)
    Freely Available from IEEE
  • [Back cover]

    Publication Year: 1978, Page(s): 0
    Request permission for commercial reuse | PDF file iconPDF (156 KB)
    Freely Available from IEEE
  • Satellite Repeater Capacity for Two Carrier Level SCPC Operation

    Publication Year: 1978, Page(s):404 - 406
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    Many important applications of single channel per carrier (SCPC) operation involve communication links between earth terminals whose G/T values differ substantially. Typical links might connect a small community with the closest commercial center, or an offshore oil rig with a base station. In order to make the best use of the available satellite power, the l... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Autonomous Line Scanning for SPC Telephone Switching Systems

    Publication Year: 1978, Page(s):368 - 373
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (656 KB)

    An Autonomous Line Scanning Unit (ALSU) for completely autonomous detection of call originations in the SPC Telephone Switching System is described. Through its own memories, ALSU maintains an up-to-date record of subscribers' statuses, detects call originations, performs 'hit timing check' and informs the Switching System of the identity of calling subscribers. The ALSU needs minimum interaction ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of the Dedicated Communication Line in a Mine Tunnel for a Shunt-Loaded Trolley Wire

    Publication Year: 1978, Page(s):355 - 361
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (576 KB)

    The theory of transmission in a semicircular tunnel containing two axial conductors is simplified for the case of radio frequencies. It is shown that the effect of ohmic losses in the wall can be represented as series impedances per unit length in the equivalent coupled transmission line circuits. This opens the way for a systematic calculation of the mode conversion phenomena that occur when one ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Basic Dynamic Routing Problem and Diffusion

    Publication Year: 1978, Page(s):320 - 327
    Cited by:  Papers (32)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (848 KB)

    Diffusion theory has sometimes been successful in providing excellent approximate solutions to difficult queueing problems. Here we explore whether such methods can be used to analyze a basic dynamic routing strategy associated with a single idealized node in a data network. We analyze a dynamic routing policy where messages, or packets, that arrive at a certain node are routed to leave the node o... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Multi-User-Class, Blocked-Calls-Cleared, Demand Access Model

    Publication Year: 1978, Page(s):378 - 385
    Cited by:  Papers (83)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    Constraints on capacity allocation are investigated for circuit-switched demand access to a common transmission resource by user communities with differing traffic intensity and capacity requirements. A simple birth-death steady-state traffic model is used together with a geometrical representation of any given set of constraints placed upon user access. State probabilities have a simple product f... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Low-Rate Digital Formant Vocoder

    Publication Year: 1978, Page(s):344 - 355
    Cited by:  Papers (2)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1216 KB)

    A complete algorithm of a 1200-bits/s digital formant vocoder system is described. This vocoder algorithm draws heavily on the results of recent research in linear predictive coding. The transmitting parameters are frequencies and amplitudes of the first three formants, the pitch period, voiced/unvoiced decision, and the gain. Formant bandwidths are estimated at the synthesizer by using the amplit... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Differential Encoding for Multiple Amplitude and Phase Shift Keying Systems

    Publication Year: 1978, Page(s):385 - 391
    Cited by:  Papers (85)  |  Patents (19)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (728 KB)

    Because of the symmetry in most two-dimensional signal constellations, ambiguities exist at the receiver as to the exact phase orientation of the received signal set. In PSK systems, this ambiguity is resolved by the use of differential encoding. This paper presents differential encoding techniques which can be used with a variety of symmetric signal sets to remove their phase ambiguity. While not... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Simple Interleaver for Use with Viterbi Decoding

    Publication Year: 1978, Page(s):406 - 408
    Cited by:  Papers (3)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    An interleaver/de-interleaver can be used to improve the performance of a Viterbi decoder in the presence of bursty noise. This note describes the design and a method for testing block interleavers which can be used to combat the effects of periodic pulsed RFI. Simulations show that satisfactory decoder performance can be obtained over a range of RFI parameters. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of Maximum-Likelihood Receiver in the Nonlinear Satellite Channel

    Publication Year: 1978, Page(s):373 - 378
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (752 KB)

    A computer-simulation algorithm is described for calculating the performance of a maximum-likelihood (ML) receiver in the nonlinear satellite communications channel. It is assumed that performance is dominated by isolated single errors and that the channel can be approximated by one of finite memory, M \leq 10 bits. The algorithm employs the brute force metho... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Buffer Management in a Packet Switch

    Publication Year: 1978, Page(s):328 - 337
    Cited by:  Papers (97)  |  Patents (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (696 KB)

    Consider a single packet switch with a finite number of packet buffers shared between several output queues. An arriving packet is lost if no free buffer is available, as in the CIGALE network. It has been observed by simulation that if load increases too much, congestion may occur, i.e., throughput declines; it appears that the busiest link's queue tends to hog the buffers. Therefore, we will lim... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • VHF and UHF Links Using Mountains as Reflectors

    Publication Year: 1978, Page(s):391 - 400
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (688 KB)

    The use of mountain reflections for establishing VHF and UHF communication links is analyzed. First, the reflection characteristics are analyzed and then a method is established for calculating the signal strength received in any such link. The use of topographical maps for obtaining the necessary path's parameters is explained and finally, theoretical calculations and measured values for one such... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Delay and Throughput Evaluation of Switching Methods in Computer Communication Networks

    Publication Year: 1978, Page(s):337 - 344
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (888 KB)

    Message, packet and line switching in computer communication networks are analyzed by a queueing model. Message transmission delay time and network throughput between a source-destination node pair are obtained as a function of various parameters including message length, traffic arriving at the network, and the number of switching nodes existing between the nodes. A criterion to determine the mos... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Analytic Evaluation of the Performance of the "Send and Wait" Protocol

    Publication Year: 1978, Page(s):313 - 319
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    In this study, we are concerned with a simple error control protocol, the "send and wait" protocol, which uses the classical technique of positive acknowledgment and time-out periods. We first analyze the influence of the time-out on the packet transmission rate. Then we use a queuing analysis to obtain the ergodicity condition and to compute the buffer queue length probability distribution. Final... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Hybrid D-PCM, A Combination of PCM and DPCM

    Publication Year: 1978, Page(s):362 - 368
    Cited by:  Papers (20)  |  Patents (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (872 KB)

    After a short review of the basic principles of PCM and DPCM coding it is shown that combining the two methods in one coding system results in a combination of some favorable properties. The hybrid D-PCM system combines the bit-rate reduction of DPCM with a low error sensitivity. In another approach the hybrid D-PCM system is also derived from a usual DPCM system with a leaking integrator. Two dif... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Selective Frequency Spacing and the Half Step Synthesizer

    Publication Year: 1978, Page(s):400 - 404
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (472 KB)

    The half step synthesizer uses frequency steps that are half integer multiples of the fundamental frequency spacing. The possible separations between adjacent carriers are 1, 1½, 2, 2½, ... times the fundamental frequency spacing. By providing twice as many potential locations for intermodulation spectra, the inband intermodulation power is distributed so that there is less (about one ha... 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