By Topic

IEE Proceedings - Communications

Issue 3 • Jun 1998

Filter Results

Displaying Results 1 - 14 of 14
  • New channel access protocol for a wide area DGPS deformation monitoring network

    Publication Year: 1998, Page(s):203 - 211
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1312 KB)

    A new kind of one-point-to-multipoint random access channel protocol called the acknowledgement-type random access and code division multiple access channel protocol (ACK-ALOHA-CDMA) is presented. It is particularly applicable to the data transmission of differential Global Positioning System (DGPS) deformation or disaster monitoring networks with a large number of monitoring stations distributed ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved fading distribution for mobile radio

    Publication Year: 1998, Page(s):197 - 202
    Cited by:  Papers (35)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (628 KB)

    Probability distribution functions (PDFs) are discussed for characterising narrowband fading processes in mobile radio communications. In particular, the effects of short-term channel variations (fast fading), and longer term channel variations (shadow fading) are discussed in relation to commonly used PDFs. A channel model is proposed to represent the mixture of these processes, and is shown to b... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Priority queue with two-state Markov-modulated arrivals

    Publication Year: 1998, Page(s):152 - 158
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (568 KB)

    The authors consider a single server priority queueing system with two priority classes of customers. The work is motivated for performance analysis of multiplexing video and data in communication networks, where videos at cell level arrive according to a two-state Markov-modulated Poisson process (MMPP) and data arrive according to a Poisson process. With the supplementary variable method, the au... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Finding sufficient inputs to calculate communications channel capacity

    Publication Year: 1998, Page(s):175 - 179
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    A method is suggested for finding only those source inputs that are sufficient for computing the capacity of large communications channels. An efficient algorithm is proposed to implement the method. The suggested approach has application in finding the capacity of large telecommunications channels, such as those with intersymbol interference, which are computationally intensive. A discrete memory... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digital techniques for mobile radio chirp sounders

    Publication Year: 1998, Page(s):191 - 196
    Cited by:  Papers (11)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (472 KB)

    The theory of chirp sounding is reviewed. This is followed by a description of a digital mobile radio chirp sounder which is implemented using direct digital frequency synthesisers (DDFS), field programmable gate arrays and microcontrollers. The gate arrays and the microcontroller provide the user interface via either a keypad or a PC, generate the programming words for the DDFS and two phase-lock... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of knockout concentrators

    Publication Year: 1998, Page(s):145 - 151
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (580 KB)

    The knockout switch architecture has been found attractive for large-scale switch implementations because of its satisfactory cell loss performance, with constant output buffer speed-up independent of switch dimension. The per port hardware complexity of a knockout concentrator, however, does grow linearly with the switch dimension. In the paper, several approaches are investigated to reduce the h... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Extended UK models for high frequency spectral occupancy

    Publication Year: 1998, Page(s):168 - 174
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (640 KB)

    Since 1982, a programme of research has undertaken the measurement, analysis, and mathematical modelling of occupancy across the entire high frequency (HF) spectrum at the times of the solstices, and this work has been published. Since the establishment of an automated, remotely controlled UK measurement system in 1989, occupancy measurements have been made at nominally fortnightly intervals. The ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improving the capacity of CDMA systems using convolutional coding and interference cancellation

    Publication Year: 1998, Page(s):186 - 190
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    The authors compare methods of reducing the co-channel interference on a DS-CDMA downlink signal by employing convolutional coding at the base station and a Viterbi decoder as the initial estimator for a parallel cancellation scheme. The combination of a matched filter and the Viterbi algorithm is shown to afford increased performance compared to equivalent bandwidth systems which do not use forwa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Delay performance of an input queueing packet switch with two priority classes

    Publication Year: 1998, Page(s):141 - 144
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (368 KB)

    The performance of the preemptive priority queueing strategy in an input queueing switch with two priority classes is considered. A new queueing model is proposed which consists of two independent input buffers with separate head of line (HOL) queues. This model takes account of the priority queue structure as well as the influence of the preemptive priority scheme for output contention. By applyi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Systolic decoder for burst error-correcting codes

    Publication Year: 1998, Page(s):126 - 132
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (600 KB)

    The author develops a new systolic architecture for the decoding of single-burst error-correcting cyclic codes (SBECCC). The well known decoding procedure for these codes, based on the error-trapping technique, is expressed by means of uniform recurrence equations to be implemented using systolic arrays. The decoder uses the generator polynomial of the code. For a (n,k) SBECCC, with a burst-error ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evaluation of reservation-arbitrated access schemes for statistical multiplexing of variable-bit-rate video traffic over dual-bus metropolitan area networks

    Publication Year: 1998, Page(s):159 - 167
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (700 KB)

    To address the problem of video communications over 802.6 MANs, a reservation-arbitrated (RA) access protocol is proposed which allows a variable-bit-rate video source to reserve isochronous channels on a bandwidth-on-demand basis. The paper explains the general method of RA access, compares four different schemes of acquiring incremental bandwidth in response to a reservation request, and evaluat... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Smart codec: an adaptive packet data link

    Publication Year: 1998, Page(s):180 - 185
    Cited by:  Papers (1)  |  Patents (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (584 KB)

    An adaptive convolutional code-rate system for packet data is presented which adapts the level of coding to overcome the effect of varying levels of noise. The system utilises the frame structure of packet data to synchronise adaption and uses a parallel decoding technique to ensure a hitless changeover between a number of different coding rates. The issues concerning the design are discussed in d... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fast and accurate estimation of ATM quality-of-service parameters with applications to call admission control

    Publication Year: 1998, Page(s):133 - 140
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (664 KB)

    It is demonstrated how fast and accurate estimates of quality-of-service (QOS) parameters can be obtained for an ATM multiplexer queueing model fed by multiple Markovian traffic sources. This has been achieved by constructing a simple approximation of the buffer overflow probability, which involves computation of two parameters based on the theory of large deviations. Upper bounds on other QOS par... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Coding for coherent optical CDMA networks

    Publication Year: 1998, Page(s):117 - 125
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (708 KB)

    The adoption of incoherent optical signal processing in CDMA LANs faces the limitation of the absence of complementary elements which hinder the design of optical code sequences that are fully orthogonal to each other. Coherent optical processing has been shown to be able to overcome the limitation. The paper looks at the coding aspect of CDMA LANs with coherent optical processing. The architectur... View full abstract»

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