1988 Fourth International Conference on HF Radio Systems and Techniques

11-14 April 1988

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  • Fourth International Conference on HF Radio Systems and Techniques (Conf. Publ. No.284)

    Publication Year: 1988
    IEEE is not the copyright holder of this material | PDF file iconPDF (30 KB)
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  • The design and simulation of an adaptive HF data network

    Publication Year: 1988, Page(s):1 - 5
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (457 KB)

    The availability of agile, remotely controllable HF equipment has been exploited in the design of an HF data network which will provide communications between some 80 locations in a full deployment. Each station will be software controlled so that network management, frequency management and link management will be handled automatically without operator intervention. This represents a major improv... View full abstract»

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  • Adaptive data link protocols: design and performance over automated HF skywave links

    Publication Year: 1988, Page(s):6 - 11
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (524 KB)

    HF today offers increased reliability on account of equipment improvements and the application of embedded processing, facilitating network frequency and link management. This has lead to a resurgence of interest in its use for data communications where the emphasis is on achieving high integrity without sacrificing throughput. Powerful techniques are needed to achieve these goals in the hostile H... View full abstract»

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  • Simplified HF communications station using an adaptive processor

    Publication Year: 1988, Page(s):12 - 16
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (383 KB)

    The 1980s has seen a resurgence in interest in the HF spectrum and its potential for reliable data communications. Considerable progress has been made in the use of real-time channel evaluation (RTCE), automated frequency management, and compact ionospheric prediction programs. The availability of powerful, reasonably priced computers and the widespread provision of remote control facilities on co... View full abstract»

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  • Adaptive control and channel encoding in an automatic HF communication system

    Publication Year: 1988, Page(s):17 - 23
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (433 KB)

    The HF region of the radio spectrum is normally regarded as being unsuitable for reliable 24-hour communications due to time and spatial variability which can affect the availability and reliability of channels. The main parameters of concern are the variation in maximum and lowest usable frequencies, maximum data rate achievable, and the fading/interference structure at any time. Traditional appr... View full abstract»

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  • An interactive HF computer link

    Publication Year: 1988, Page(s):24 - 27
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (215 KB)

    Since the beginning of this century ionospheric propagation (HF) has been an important medium of radio communications. It has supported commercial telegraphy, telex traffic and military communications. Although it is a communication channel with high data corruption, the low cost of an HF system compared to the satellite for a small to medium number of users, the lower vulnerability in military ap... View full abstract»

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  • HF data message and facsimile terminal system

    Publication Year: 1988, Page(s):28 - 32
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (476 KB)

    The data terminal (HF-Maxi terminal) is an outcome of the research and development done by CRC. The first generation of the HF message terminal developed by CRC (HF-Mini terminal) used a simple selective ARQ protocol for data transmission reference. Alternate techniques were investigated to improve the ARQ protocol for the second generation of a HF packet radio system by utilizing the soft decisio... View full abstract»

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  • HF data communication for extremely low SNR and high interference level

    Publication Year: 1988, Page(s):33 - 37
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (399 KB)

    By using low data rates and both intelligent signal conception and digital signal processing (DSP) for estimation and detection, it is possible to realize new applications in the field of digital short wave communications (HF). For links with unknown interference level or low transmitter power, unmatched antennas and high path attenuation a special transmission principle was designed and realized.... View full abstract»

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  • A method of real-time channel evaluation in adaptive HF systems

    Publication Year: 1988, Page(s):38 - 42
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (418 KB)

    A simple and cost effective channel evaluation method, suitable for application to an adaptive HF system, is proposed. The method is based on a modification of a well known Gooding's pseudo error monitoring scheme. A theoretical and experimental research was carried on to find the trade-off between the confidence level of channel quality estimation and length of measurement interval. Some results ... View full abstract»

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  • An RTCE-assisted ARO transmission scheme: design & performance

    Publication Year: 1988, Page(s):43 - 50
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (472 KB)

    The authors provide an outline of the theory of the technique followed by a description of experiments to verify the method. Next, the design of an ARQ-based transmission system incorporating zero-crossing RTCE is described and its performance discussed. Finally, the application of higher-order zero-crossing analysis to RTCE and demodulation is considered. The dynamic range of the method is somewh... View full abstract»

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  • Real time HF channel evaluation and 8-ary FSK signaling for adaptive communications

    Publication Year: 1988, Page(s):51 - 55
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (384 KB)

    Modern HF radio communication requires operational simplicity and high reliability. However, continually changing ionospheric conditions make operations difficult, even by an experienced operator. The advent of adaptive technology has allowed systematic and automatic real-time evaluation of HF paths, and automatic link establishment. The Harris RF-7110 autolink adaptive controller is an example of... View full abstract»

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  • An adaptive HF system and its computerized performance evaluation

    Publication Year: 1988, Page(s):56 - 60
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (405 KB)

    Presents the principal requirements from a modern adaptive HF communication system, the basic design concepts of the implemented system which successfully answers these requirements, the accompanying field trial methodology and briefly, some of the field trials results. The basic lesson learned from the implementation and the field trials of the described system is that a modern HF communication s... View full abstract»

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  • Practical real time frequency management for automated HF networks

    Publication Year: 1988, Page(s):61 - 65
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (376 KB)

    A frequency management system for an automatic HF network is described. MUF updates are calculated automatically with 99% reliability without the need for dedicated, specialist equipment. The process also allows disturbances to be identified and utilised if appropriate. Channel selection is achieved in such a way as to minimise interference and maximise reliability. The chosen channel is monitored... View full abstract»

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  • Use of oblique-incidence-sounders in HF frequency management

    Publication Year: 1988, Page(s):66 - 70
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (432 KB)

    Examines the current status of OIS schemes for application in the management of frequencies in an HF system or complex of systems. Certain efforts are now underway to assess this approach to HF resource management in general and an understanding as to the direction of these programs is outlined. The authors indicate the NRL efforts in this context. Finally they provide a view as to the future of O... View full abstract»

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  • Real-time frequency selection and HF spectrum monitor

    Publication Year: 1988, Page(s):71 - 75
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (330 KB)

    Early in the 1980s, a real-time frequency selecting system, abbreviated to RTFSS, was developed in China and successfully used in communication. Equipped with a spectrum monitor, the system can select frequency for both directions. This system can automatically establish an HF link in the best channel. Several methods of data processing are improved based upon the CURTS system, therefore the relia... View full abstract»

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  • A modular frequency management facility with application at HF

    Publication Year: 1988, Page(s):76 - 80
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (417 KB)

    Frequency management techniques are playing an increasingly important role in the design and implementation of the new generation of tactical and strategic HF communications systems. The increasing demand for high quality data links and spread spectrum capability has established automated frequency management as a necessity rather than just a convenience. The authors outline the purpose of frequen... View full abstract»

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  • An HF radio link processor with adaptive frequency management

    Publication Year: 1988, Page(s):81 - 85
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (336 KB)

    The reliability of modern HF-communication systems is essentially influenced by the effectiveness of the frequency management. The important functions are: selection of momentary best frequency from a frequency pool with dependence of transmission parameters; control of transmission quality; and change of frequency as a reaction to interference. Functions like these can be handled in a more effect... View full abstract»

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  • ARTAC-an automatic adaptive HF radio system in field tests

    Publication Year: 1988, Page(s):86 - 89
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (168 KB)

    Discusses how in an automatic, adaptive HF system with error correction, RF power output levels around 400W will provide good results. To enhance the reliability and throughput of the link, especially over the shorter distances, the allocated frequencies should include the 'odd' bands (the high bands that were not listed as useable in the traditional predictions). Further studies of sporadic E ref... View full abstract»

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  • Modelling in the HF network design process

    Publication Year: 1988, Page(s):90 - 94
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (316 KB)

    Modelling can play a significant role in the design process by providing the ability to trade off a wide range of parameters in a cost effective and well controlled manner. The author presents an example of how modelling has been used to assist the design specification of an HF radio network and to predict its performance under a wide range of conditions.<<ETX>> View full abstract»

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  • A computer aided design tool for collocated HF links

    Publication Year: 1988, Page(s):95 - 99
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (311 KB)

    There have been many programs and techniques developed to deal with the cosite EMI problem. Previous programs have evolved from semimanual to highly automated techniques. However the EMI problem has grown to such an extent on today's ships that system design and analysis requires computer aided tools. COEDS (communication engineering design system) is one of the tools that has been developed to ai... View full abstract»

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  • Planning and operation of an HF broadcast relay station

    Publication Year: 1988, Page(s):100 - 104
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (342 KB)

    International short wave broadcasting has expanded on a worldwide scale and in order to maintain a UK presence in this field of broadcasting the BBC has expanded and improved its transmission facilities to meet the increased competition that exists in the HF broadcast spectrum. This has been achieved within the UK by a progressive replacement of old 100kW HF transmitters by modern high efficiency ... View full abstract»

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  • BLOSSOM-a technical description of the RAE meteor burst communications system

    Publication Year: 1988, Page(s):105 - 109
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (353 KB)

    Presents a technical description of the BLOSSOM (beyond line of sight signalling over meteors) MBC system as at March 1986. The BLOSSOM system can be split up into three main parts. Firstly, the RF subsystem, built by RAE, comprising all the RF equipment including antennas, RF converters, transmitter, relays, switches and protection circuitry. Secondly, the control subsystem, built by PRRML, compr... View full abstract»

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  • Space diversity reception in meteor burst communications system

    Publication Year: 1988, Page(s):110 - 114
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (318 KB)

    Presents some early results from a dual investigation of the data both in terms of cross-correlation coefficients and in terms of an assessment of the available duty cycle with and without spatial diversity. This study has not yet revealed whether space diversity provides a significant increase in performance and further study is necessary before a definitive statement can be made.<<ETX>&... View full abstract»

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  • Numerical modelling of the ship antennas array

    Publication Year: 1988, Page(s):115 - 119
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (158 KB)

    The author presents a numerical method of ship antenna array analysis. The influence of the ship transmitter antenna on the ship receiver antenna is described. The linear antenna, especially the monopole antenna, is the main type of the ship antenna array. The numerical model is applied using the thin-wire model of the linear antenna array. The theoretical results have been verified by experiments... View full abstract»

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  • Analysis of shipboard HF antennas with PDMPH2 computer code

    Publication Year: 1988, Page(s):120 - 124
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (176 KB)

    The analysis of some shipboard HF antennas is quite complicated. This contribution shows the numerical and experimental results obtained for the rather realistic configuration formed by a twin fan antenna and a monopole centered on the top of a conducting box, both antennas being on an infinite conducting ground plane. Calculations and measurements are in very good agreement. The computer code PDM... View full abstract»

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