2000 Eighth International Conference on HF Radio Systems and Techniques

10-13 July 2000

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  • Eighth International Conference on HF Radio Systems and Techniques

    Publication Year: 2000, Page(s):i - xvi
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  • Author Index

    Publication Year: 2000, Page(s):xvii - xviii
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  • TRILION project: transmission of images through the ionosphere

    Publication Year: 2000, Page(s):1 - 5
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (371 KB)

    This article presents a digital communication system operating in the HF band, whose aim is to realise very high rate transmissions through the ionosphere. A filtering technique based on antenna diversity is used and some results are commented. View full abstract»

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  • Image coding and ionospheric link

    Publication Year: 2000, Page(s):7 - 11
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (398 KB)

    This paper concerns a part of a larger project called TRILION: "Transmission d'Images par Liaison Ionospherique", its goal is to realize a videoconference through the HF band. One of the challenges of TRILION is to achieve a wide band transmission of at least 20 kHz, in order to reach a high rate of transmission. An other challenge is to optimize the different techniques of standard coding (JPEG, ... View full abstract»

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  • ATM interface for HF channel

    Publication Year: 2000, Page(s):13 - 17
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (498 KB)

    The possibility is evaluated of using an HF channel as back-up channel for the connection of a far subnetwork to an ATM network. An intelligent interface between the ATM network and the HF radio channel is introduced to ensure minimum ATM services. Simulation results provide an estimation of transmission delays, buffer size and best traffic management. View full abstract»

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  • Reliable vocoder data transmission over fading HF channels

    Publication Year: 2000, Page(s):19 - 22
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (287 KB)

    The quality of shortwave channels may vary considerably due to the time-specific changes of the transmission conditions. So the correct transmission of a continuous data stream, e.g. digitized speech signals output by a vocoder cannot be guaranteed under adverse conditions even by means of complex error correction measures or costly high transmitter power. This results in the loss of vocoder data-... View full abstract»

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  • Some experiences of frequency use in an adaptive HF network

    Publication Year: 2000, Page(s):23 - 27
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (365 KB)

    Communication over paths beyond line-of-sight without intermediate relays can be achieved using HF systems utilising ground wave or ionospheric propagation. In the past decades advances in the development of automatic and adaptive HF systems have made it possible to have these systems working without the cost of experienced operators. These new frequency agile systems call for new ideas on how to ... View full abstract»

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  • Interconnected communication networks

    Publication Year: 2000, Page(s):29 - 32
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (395 KB)

    Traditionally most services have used several independently operating specially developed communications networks to carry their specific message and traffic types. They have been labour intensive requiring operator assistance when transferring messages across different communication systems. Communication systems currently being deployed are fully automated, thus in principle enabling communicati... View full abstract»

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  • Loop antennas in the 3-30 MHz band

    Publication Year: 2000, Page(s):33 - 36
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (338 KB)

    The loop antenna, in common use in the 3-30 MHz band, was reassessed in a previous paper in which it was considered as a folded dipole, with suggested theoretical advantages. This paper demonstrates that the two lowest-order modes which exist in small loop antennas correspond to the true loop, otherwise known as the magnetic dipole (zero-order mode) and the folded dipole (first-order mode), and sh... View full abstract»

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  • Undirectional tuned loop antennas using combined loop and dipole modes

    Publication Year: 2000, Page(s):37 - 41
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (424 KB)

    This paper presents a simple computer simulation model that assumes that both the loop and dipole radiation modes can exist simultaneously. The model computes the antenna pattern and directivity for any chosen combination of the two modes. The patterns obtained by varying the parameters defining how the modes are combined (in relative amplitudes, phase and position) and then matched for best fit w... View full abstract»

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  • An optimised vehicular loop antenna for NVIS applications

    Publication Year: 2000, Page(s):43 - 47
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (395 KB)

    Near vertical incidence skywave (NVIS) antennas intended for vehicle mounting offer limited scope for development given the usually severe size constraints that apply at typical NVIS frequencies (2-10 MHz). We present the results of research aimed at achieving an optimised antenna for this application when mounted on a typical "Land Rover"-sized vehicle, and particularly in producing a design proc... View full abstract»

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  • HF 125 W half-loop antennas in ALE and ECCM for land mobile, navy and helicopter use

    Publication Year: 2000, Page(s):49 - 52
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (384 KB)

    This paper describes a small sized mobile HF half-loop antenna and its integrated agile coupler designed to work with a 125 W transceiver in automatic link establishment (ALE) and/or frequency hopping (FH). This equipment is a 50 /spl Omega/ antenna which comprises a digital tuning circuit for fast switching in transmission-reception (traffic mode), and an active wide-band circuit for continuous r... View full abstract»

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  • COFDM modem for terrestrial radio broadcasting

    Publication Year: 2000, Page(s):53 - 57
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (476 KB)

    This paper presented a complete system proposal for terrestrial audio broadcasting that shows the current state of the art in COFDM modem technology. COFDM was chosen because of its very good compromise between extreme robustness and a high spectral efficiency, and its ability to allow for a very versatile system accommodating various bandwidths, propagation conditions and services, while maintain... View full abstract»

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  • MC-CDM-a promising approach for digital broadcast in the AM-band

    Publication Year: 2000, Page(s):59 - 63
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (422 KB)

    For digital AM broadcast we investigate the possibility of using multicarrier-code division multiplex (MC-CDM) that is combined with multilevel codes based on Reed Solomon codes. Both lower bounds and simulation results for a low complexity receiver are given. View full abstract»

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  • Improved channel estimation and demodulation for OFDM on HF ionospheric channels

    Publication Year: 2000, Page(s):65 - 69
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (527 KB)

    In this paper OFDM is analyzed on the HF ionospheric channel. The non-coherent DPSK modulation shows a high error floor and an improvement in performance can be achieved, if channel-estimation is improved. As pilot-based channel estimation would lower the throughput, decision-directed methods are presented and analyzed by simulation. View full abstract»

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  • Circular to linear array mapping using calibration data

    Publication Year: 2000, Page(s):71 - 75
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (439 KB)

    For surveillance and direction finding at HF angular super-resolution techniques can mean significant advantages. Aside from better azimuthal accuracy, elevation resolution and self-calibration are also at hand. Efficient closed form super-resolution algorithms do exist for linear antenna arrays, but unfortunately there are very few for the (needed) circular ones. After giving a short background, ... View full abstract»

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  • The modeling of the HF signal structure in the vicinity of the maximum usable frequency of a randomly-inhomogeneous ionosphere

    Publication Year: 2000, Page(s):77 - 79
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (276 KB)

    Mixed integral representations for a two-point propagator are used in a numerical simulation of the mean intensity, the angular spectrum, and the scintillation index in the neighborhood of the boundary of the shadow zone at oblique ionospheric propagation of HF radio waves. View full abstract»

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  • Use of the SCIPION ionospheric sounder for different kinds of applications

    Publication Year: 2000, Page(s):81 - 85
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (585 KB)

    SCIPION is a new state of the art digital sounder that has been developed by France Telecom-CNET for ionospheric monitoring and research. Extensive data processing using DSP technology has resulted in a low power, low cost and full featured system for both vertical and oblique soundings. In this paper, the system is briefly described and some illustrative examples of its capabilities are shown. View full abstract»

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  • From the Sun to the modem-an integrated approach to HF system performance analysis

    Publication Year: 2000, Page(s):87 - 90
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (500 KB)

    Radio operators, frequency managers and system designers analysing or operating HF systems need to account for the performance of the equipment and the behaviour of the ionosphere. To facilitate this a number of propagation prediction tools have evolved. Their accuracy depends not only upon the models employed but also upon the integrity of the data entered. To improve the latter a number of advan... View full abstract»

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  • Advanced use of LQA data in improving the quality and the speed of ALE link establishment while reducing sounding requirements in HF networks

    Publication Year: 2000, Page(s):91 - 94
    Cited by:  Papers (1)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (317 KB)

    The goal of an automatic link establishment (ALE) system is to assist the user of a HF transceiver to establish a link with an outstation by automatically selecting an appropriate channel. For users that are untrained in HF propagation, this is an extremely critical requirement. However, it was discovered that the first generation of ALE controllers that implemented the FED-STD-1045 standard were ... View full abstract»

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  • Neural network processor based on SAW device for digital modulation recognition

    Publication Year: 2000, Page(s):95 - 99
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (357 KB)

    It is shown that a SAW device can be used as a linear part of the artificial neural network (ANN) processing radio signals. The structure of the SAW ANN processor is proposed and the method of its training is developed based on the use of the in-phase and quadrature envelopes of the radio signals. The network recognising QPSK and BPSK signal is trained and its performance is simulated. View full abstract»

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  • Equalisation of HF channels using the SFAEST algorithm

    Publication Year: 2000, Page(s):101 - 105
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (443 KB)

    Communication over the high frequency (HF) band is characterised and limited by multipath propagation, fading and noise. Equalisation techniques are used to combat distortion introduced by the channel. This paper examines the use of the SFAEST (stabilised fast a posteriori error sequential technique) algorithm to drive the equaliser coefficients. Its performance is compared with commonly used algo... View full abstract»

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  • Performance testing of MIL-STD-188-110B high data rate HF waveforms

    Publication Year: 2000, Page(s):107 - 111
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (478 KB)

    The high frequency (HF) band is used primarily for maritime, military and aeronautical systems and long distance AM broadcasting. It is typically allocated to users in 1.24 kHz and 3 kHz channels. Over the last twenty years, several NATO standards and US military standards have been developed which can provide reliable communications over HF. The highest data rate currently available, with forward... View full abstract»

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  • Performance testing of STANAG 5065 LF waveforms

    Publication Year: 2000, Page(s):113 - 117
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (446 KB)

    STANAG 5065 was developed to provide NATO countries with interoperable shore-to-ship broadcast communications using the low frequency (LF) band (specifically 60 kHz-160 kHz). This paper begins with an overview of STANAG 5065. Following this, the Harris RF-5710A modem implementation is discussed along with performance data. The paper concludes with a summary of the results. View full abstract»

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  • Source separation in the HF band using a compact system of direction finding

    Publication Year: 2000, Page(s):119 - 122
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (312 KB)

    A compact direction finding system has been developed which operates using a set of seven collocated HF active antennas. It is described in Marie et al. (2000). It has been shown that the estimation of the direction of arrival can be efficient as the diversity of their spatial responses replaces the space diversity of a classical array. That technique implies however a particular computation of th... View full abstract»

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