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Communications, IEEE Transactions on

Issue 12 • Date Dec. 1991

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Displaying Results 1 - 23 of 23
  • 1991 Technical reviewers

    Publication Year: 1991 , Page(s): 1900 - 1904
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    Freely Available from IEEE
  • Author index

    Publication Year: 1991 , Page(s): I1 - I7
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    Freely Available from IEEE
  • Subject index

    Publication Year: 1991 , Page(s): I7 - I21
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  • A multipoint communication service for interactive applications

    Publication Year: 1991 , Page(s): 1875 - 1885
    Cited by:  Papers (7)  |  Patents (12)
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    The multipoint communication layer (MCL) is a generic multipoint communication service designed to support highly interactive multimedia conferencing applications. It supports full-duplex multipoint communication between an arbitrary number of connected locations over a variety of networks. MCL design was driven by the demanding real-time multipoint communication requirements of MICA (multimedia interactive conferencing application). The authors establish the context for MCL by considering MICA's communication requirements and reviewing related work in the area of multipoint communication. They present the overall design of the MCL service and describe its communication primitives, protocol message structures, and implementation. Comparison is made with alternative strategies and the use of MCL services for other applications is examined View full abstract»

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  • A general class of rearrangeable interconnection networks

    Publication Year: 1991 , Page(s): 1737 - 1739
    Cited by:  Papers (2)
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    A class of rearrangeable interconnection networks which includes the Benes network as a special case is identified. An instance of this class consists of a set of parallel planes each consisting of a Delta network with a suitable number of additional stages. A formal definition is given and a rearrangeability condition is proven which gives a tradeoff between the number of planes and additional stages necessary View full abstract»

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  • Image sequence coding by split and merge

    Publication Year: 1991 , Page(s): 1845 - 1855
    Cited by:  Papers (24)  |  Patents (1)
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    A method is described for reducing the information contained in an image sequence, while retaining the information necessary for the interpretation of the sequence by a human observer. The method consists of first locating the redundant information, reducing the degree of redundancy, and coding the result. The sequence is treated as a single 3D data volume, the voxels of which are grouped into several regions, obtained by a 3D split and merge algorithm. The information is coded by representing the borders of the regions using a pyramidal structure in the x, y, t space. The coefficients of the approximating polynomials are coded in a straightforward manner. For 256×256 pixel, 25 frame/s image sequences, compressions allowing transmission rates near 64 kbit/s are obtained View full abstract»

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  • Optimal probability-of-error thresholds and performance for two versions of the sign detector

    Publication Year: 1991 , Page(s): 1726 - 1728
    Cited by:  Papers (4)
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    Expressions are obtained for specifying the optimal error probability (minimum Pe) thresholds λ01 and λ02 for the traditional and modified sign detectors, respectively. These thresholds are shown to depend on the parameters p, P1, and M where: M is the number of observations zi used in the test statistic; P1=P(H1 ) is the prior probability for hypothesis H1 that signal s1 is present and 1-P1 =P(H0) corresponds to the hypothesis H0 that signal s0 is present; and p=Pr{zi⩾0|H1} with s0=0 for the traditional sign detector and p=Pr{zi⩾λ|H1 }=Pr{zi<λ|H0} with λ =(s0+s1)/2 for the modified sign detector. The expressions for λ01 and λ02, are given explicitly, and shown to be independent of P1 for sufficiently large M. Optimal Pe versus M performance curves, corresponding to both versions of the sign detector, are obtained for a representative range of values for p and P1 View full abstract»

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  • Closed solution of Berlekamp's algorithm for fast decoding of BCH codes

    Publication Year: 1991 , Page(s): 1721 - 1725
    Cited by:  Papers (1)  |  Patents (1)
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    A decision tree solution is presented for the most complicated step in decoding binary BCH codes, namely, the computation of an error location polynomial over GF(2m) from the syndrome vector of received data. The author runs S. Lin's (1970) iterative version of the Berlekamp-Massey algorithm symbolically, keeping the results at each level in the form of branches of a binary decision tree. A decoder can then be constructed that uses the derived formulas to evaluate a decision variable at each level. Complete traversal of the tree using the decision variables leads to the correct polynomial coefficients for the received vector. The decoder can be implemented in a very straightforward way with a simple processor or program that performs extension field arithmetic, or it can be realized entirely in hardware using lookup tables for multiplications, inverses, and exponents, and exclusive OR operations for addition View full abstract»

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  • The evaluation of error probabilities for intersymbol and cochannel interference

    Publication Year: 1991 , Page(s): 1740 - 1749
    Cited by:  Papers (99)
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    An efficient series that can be used to calculate the probability of error in a binary symmetric channel with intersymbol interference and additive noise is derived. The series is derived by representing the noise complementary probability distribution function by an exact or approximate Fourier series. Bounds on the accuracy of the estimate are derived for Gaussian noise. Examples show that only a small numerical effort may be required to compute error probabilities of interest using the series. Applications to both finite and infinite intersymbol interference systems are discussed. A similar technique is used to derive series representations for the probability of error of additive noise channels with cochannel interference or with combined intersymbol and cochannel interferences. The accuracy of the results is bounded for Gaussian noise View full abstract»

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  • Analysis of automatic network management controls

    Publication Year: 1991 , Page(s): 1776 - 1786
    Cited by:  Papers (3)
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    The performance response of circuit-switched networks with stored program control exchanges is analyzed under nonstationary traffic conditions. Models of real time traffic measurements and dynamic flows in such networks are developed. A framework for analysis and design of state-dependent routing and flow control algorithms is provided based on concepts of various traffic measurements and different patterns of traffic nonhomogeneity. It is indicated that global performance objectives can be obtained by means of the state-dependent shortest route algorithms. Issues relevant to an implementation of different traffic control techniques are discussed. An example routing scheme is introduced and compared with known procedures View full abstract»

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  • Signal-to-interference calculations for corner-excited cellular communications systems

    Publication Year: 1991 , Page(s): 1886 - 1896
    Cited by:  Papers (9)
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    Signal-to-inference ratio calculations for corner-excited cellular communications systems are presented. Specifically, the ratio of median signal power to the sum of median interference powers is considered. The interference model includes cochannel interference, and immediately adjacent as well as nonimmediately adjacent channel interference. Related system parameters are cluster size, receiver, and transmitter filter characteristics, propagation exponent, tier coverage, and directional antenna front-to-back ratio. Both mobile-to-baseand base-to-mobile communications are considered. The method and model used for calculation are more complete than any previously reported in the technical literature. The calculated results show that the effect of adjacent channel interference compared to cochannel interference cannot be ignored in general. In mobile-to-base communications, the effect of immediately adjacent channel interference introduced by an interfering mobile which is very close to the receiving base antenna is serious View full abstract»

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  • On the minimum number of interrupts in time-slot assignments for time-division multiple-access systems

    Publication Year: 1991 , Page(s): 1729 - 1732
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    The authors study the minimum number of interrupts in an optimal time-slot assignment of a time-division multiple-access (TDMA) system. If the number of channels c in the TDMA systems equals 2, then there always exists an optimal assignment with, at most, one interrupt. If c⩾3, then there exist TDMA systems for which each optimal assignment requires at least (c-1)(c-2) interrupts View full abstract»

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  • Resource allocation in a dynamically partitionable bus network using a graph coloring algorithm

    Publication Year: 1991 , Page(s): 1794 - 1801
    Cited by:  Papers (5)
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    An efficient dynamic graph traversal algorithm is used to identify nonconflicting requests and to allocate network resources in a dynamically partitionable bus network (DPBN). In centralized network control a special processor receives from the control computer of a partitionable bus network an adjacency matrix which indicates conflicts among requests. It applies the dynamic graph traversal algorithm and returns the identified nonconflicting requests to the control computer. The control computer then physically partitions the network into a number of subnetworks for processing the nonconflicting requests in parallel. In distributed control, each station determines conflicts and sets the switches. The results of performance evaluation show a 40% decrease of network delay as compared with a fully utilized, but unpartitioned local area network View full abstract»

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  • Performance analysis of cellular networks

    Publication Year: 1991 , Page(s): 1787 - 1793
    Cited by:  Papers (71)  |  Patents (2)
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    Dynamic channel allocation can reduce the probability of blocking in cellular telephone networks. However, more is needed to achieve optimal performance. The author aims at estimating the minimal blocking probability for some simple cellular networks. Some dynamic channel allocation strategies are analyzed, the optimal performance (obtained by dynamic allocation and flow control) of some very simple networks is computed, and simple bounds on optimal performance are presented. These results lead to a better understanding of cellular networks and can be used to evaluate new control algorithms View full abstract»

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  • The performance analysis of a concatenated ARQ scheme using parity retransmissions

    Publication Year: 1991 , Page(s): 1869 - 1874
    Cited by:  Papers (3)
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    The authors analyze an ARQ (automatic repeat request) scheme using parity retransmissions. By dividing each transmission block into subblocks, the combination of a transmission block and its retransmission block has the structure of a concatenated code. They derive formulae for calculating an upper bound on the probability of undetected errors and a lower bound on the throughput for such an ARQ scheme. Numerical results show that even with extremely simple code design, such an ARQ scheme has satisfactory performance View full abstract»

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  • PN code-aided ranging for optical satellite communication systems

    Publication Year: 1991 , Page(s): 1832 - 1844
    Cited by:  Papers (4)
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    A model for the pseudonoise (PN) code-aided estimation of the transmission path delay and ranging for direct-detection on-off-keying (OOK) optical intersatellite channels is suggested in which the intensity of the optical field is modulated by a PN code and random binary data symbols. A closed-loop code-tracking loop model, motivated by the maximum-likelihood (ML) estimation of the phase difference between the received PN code and a locally generated one, is obtained. The maximum-likelihood model is approximated and, consequently, receiver models for the high and low signal-to-noise ratio (SNR) are suggested. The resulting code tracking loop S-curves of the receivers are that of the S-curves of a noncoherent delay-locked loop (NCDLL). The performance of the two receivers under the influence of background noise, signal count and PN code length is obtained View full abstract»

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  • Voice packet loss: destination versus internodal links

    Publication Year: 1991 , Page(s): 1733 - 1736
    Cited by:  Papers (2)
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    Voice packet loss behavior at both the destination and internodal links in a packet-switched network is investigated. The fractional loss and blocking time periods for both are derived using a bivariate Markov model. The numerical results show that blocking due to the delay constraint at the destination can result in long periods of consecutive packet loss, which seriously degrade voice quality. The authors' work indicates that packets with excessive delay should be discarded at the internodal links, instead of blocking them at the destination. The relation between the internodal link buffer size and end-to-end permissible queueing delay is established View full abstract»

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  • A new segmentation algorithm for videophone applications based on stereo image pairs

    Publication Year: 1991 , Page(s): 1856 - 1868
    Cited by:  Papers (8)  |  Patents (8)
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    The stereo image pair of a speaking person in front of a stationary background taken by two CCD-cameras is used as an input scene for a new segmentation algorithm. The algorithm is based on the phase correlation technique which provides a disparity vector field. A brightness adjustment procedure is performed to provide stereo image pairs suited for the segmentation procedure. Then, a coarse segmentation into background and speaking person is made to achieve a reliable segmentation result. Finally, finer segmentation using a coarse-to-fine control strategy is performed only at the object boundaries. An application is demonstrated by applying a lowpass filter selectively to the background of input sequences for low bit rate image coding algorithms View full abstract»

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  • Connection management for the transport layer: service specification and protocol verification

    Publication Year: 1991 , Page(s): 1762 - 1775
    Cited by:  Papers (2)
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    A symmetric connection management service between two service access points is specified, using a state transition system and safety and progress requirements. At each access point. the user can request connection establishment, request connection termination, and signal whether or not they are willing to accept connection requests from the remote user. The protocol can indicate connection establishment, connection termination, and rejection of a connection establishment request. The authors then specify a protocol and verify that it offers the service, given communication channels between the access points that can lose, reorder, and duplicate messages, but which guarantee delivery of a message that is repeatedly sent. The protocol achieves the service using 2-way and 3-way handshakes, and can be directly combined with any existing single-connection data transfer protocols to provide a transport layer protocol that offers both connection management and data transfer services. The protocol and service are compared to TCP and its intended service, and to ISO TP Class 4 and its intended service View full abstract»

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  • The FODA-TDMA satellite access scheme: presentation, study of the system, and results

    Publication Year: 1991 , Page(s): 1823 - 1831
    Cited by:  Papers (15)  |  Patents (2)
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    A description is given of FODA-TDMA (FIFO ordered demand assignment-TDMA), a satellite access scheme designed for mixed traffic (patent N. 9373A/89). The study of the system is presented and the choice of some parameters is justified. A simplified analytic solution is found, describing the steady-state behavior of the system. Some results of the simulation tests for an already existing hardware environment are also presented for channel speeds of 2 and 8 Mb/s, considering both the stationary and the transient cases. The results of experimentation at 2 Mb/s on the EUTELSAT-F2 satellite are also presented and compared with the results of the simulation View full abstract»

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  • Congestion-free communication in high-speed packet networks

    Publication Year: 1991 , Page(s): 1802 - 1812
    Cited by:  Papers (77)  |  Patents (10)
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    The process of packet clustering in a network with well-regulated input traffic is studied and a strategy for congestion-free communication in packet networks is proposed. The strategy provides guaranteed services per connection with no packet loss and an end-to-end delay which is a constant plus a small bounded jitter term. It is composed of an admission policy imposed per connection at the source node, and a particular queuing scheme practiced at the switching nodes, which is called stop-and-go queuing. The admission policy requires the packet stream of each connection to possess a certain smoothness property upon arrival at the network. This is equivalent to a peak bandwidth allocation per connection. The queuing scheme eliminates the process of packet clustering and thereby preserves the smoothness property as packets travel inside the network. Implementation is simple View full abstract»

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  • Error bounds for trellis-coded MPSK on a fading mobile satellite channel

    Publication Year: 1991 , Page(s): 1750 - 1761
    Cited by:  Papers (51)
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    Analytical performance bounds are presented for trellis-coded MPSK, transmitted over a satellite-based land mobile channel. Upper bounds are evaluated using the well-known transfer function bounding technique, and lower bounds are achieved through knowledge of exact pairwise error probabilities. In order to analyze practical trellis-codes (four or more states), the uniform properties displayed by a certain class of trellis-codes are exploited, enabling the encoder transfer function to be obtained from a modified state transition diagram, having no more states than the encoder itself. Monte Carlo simulation results are presented in confirmation of all performance bounds and indicate a general weakness in the transfer function upper bounds. A new asymptotically tight upper bound is derived based on a simple modification to the standard transfer function bound, and results are presented for the four- and eight-state trellis-codes in Rician and Rayleigh fading View full abstract»

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  • Input buffer limiting: behavior analysis of a node throughout the range of blocking probabilities

    Publication Year: 1991 , Page(s): 1813 - 1822
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    A numerical method is suggested for estimating the performance parameters of a node with input buffer limiting, throughout the range of blocking probabilities. Congestion is attributed to the sudden increase in the effective service time when the input rate increases. This sudden increase, resulting in the thrashing of the throughput rate, can be related to changes in the shape of the potential function of the node. The methodology of deriving the potential function of the node from its gradient dynamics and dynamic flow conservation considerations is presented. Using the results from catastrophe theory, it is shown that the abrupt changes in the throughput can be expected due to the existence of a catastrophe point in the parameter space. The behavior of a node in a homogeneous network can be characterized by a fold catastrophe. The simulation results are found to agree with the results obtained by the numerical method 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.

 

 

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Meet Our Editors

Editor-in-Chief
Robert Schober
University of British Columbia