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Radio Receivers and Associated Systems, 1995., Sixth International Conference on

Date 26-27 Sep 1995

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Displaying Results 1 - 25 of 45
  • Loran-C skywave detection using rational modelling techniques

    Publication Year: 1995, Page(s):100 - 104
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (376 KB)

    The autoregressive moving average (ARMA) spectral analysis technique is applied to the problem of estimating the delay of skywaves in Loran-C radionavigation receivers. This establishes a basis on which to design a receiver capable of adjusting its sampling points adaptively to the optimal values in a constantly-changing skywave environment. Such receivers offer the prospect of significantly impro... View full abstract»

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  • A modular testbed for automatic channel selection, link establishment and maintenance

    Publication Year: 1995, Page(s):105 - 108
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (328 KB)

    The paper describes the development of a testbed radio system for automatic channel selection (ACS), automatic link establishment (ALE) and automatic link maintenance (ALM) techniques. As HF radio systems become more automated, the concept of ALE has evolved to describe the start-up phase of communications. ALE involves the co-ordination of channel encoding and decoding, encryption and decryption,... View full abstract»

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  • Mean time to lose lock for a coherent extended tracking range delay-locked loop

    Publication Year: 1995, Page(s):176 - 180
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    The delay-locked loop (DLL) is an appropriate device to guarantee fine synchronization for direct-sequence spread spectrum systems. The mean time to lose lock (MTLL) is a good performance criteria for the DLL operating at low signal to noise ratios. In the paper, the influence of the extended tracking range on the MTLL for a coherent DLL is investigated. A second order loop with passive loop filte... View full abstract»

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  • RF transformers considered as transmission line devices

    Publication Year: 1995, Page(s):109 - 113
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (352 KB)

    The lumped element circuit model for broad-band transformers has been in use for at least 50 years. It was developed for audio frequency transformers. Unfortunately, it ceases to give accurate results when the length of the windings becomes significant with respect to the signal wavelength. This is the case in RF broad-band transformers. For these, a model based on transmission lines is proposed. ... View full abstract»

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  • A low-rate voice/video personal communicator scheme

    Publication Year: 1995, Page(s):11 - 16
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (500 KB)

    A personal communication system (PCS) transceiver is proposed and investigated. A 4.8 kbit/s transformed binary pulse excited (TBPE) linear predictive speech codec, source sensitivity matched Bose-Chaudhuri-Hocquenghem (BCH) block error correction codecs, non-coherent differentially coded non-coherent 16-level quadrature amplitude modulation (16-QAM) modem and packet reservation multiple access (P... View full abstract»

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  • A high performance CDMA cellular radio system based on low-rate convolutional coding

    Publication Year: 1995, Page(s):17 - 21
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (400 KB)

    The field of spread spectrum multiple access is currently receiving considerable attention as a contender for the next generation mobile telephone system. In comparison to advanced time-division multiple access (TDMA) techniques, direct-sequence code-division multiple-access (DS-CDMA) spread-spectrum systems offer increased flexibility in the frequency management of the cellular network, the prosp... View full abstract»

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  • Using method of slowly changing amplitudes for analysing oscillations in phase-locked loops

    Publication Year: 1995, Page(s):181 - 184
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (256 KB)

    The phase-locked loop has been found to be a very useful element in many types of communication systems. It is used in two fundamentally different ways [Gardner (1981), Encinas (1993)]: (1) For demodulation, where it is used to follow phase or frequency modulation of the input signal. (2) For tracking a carrier or synchronizing signal which may vary in frequency with time. The authors discuss stab... View full abstract»

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  • In-band channel sounding in operative cells for mobile and wireless communications

    Publication Year: 1995, Page(s):31 - 35
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (300 KB)

    This paper presents an analysis of the swept time delay crosscorrelator, as used in wideband, RF, channel sounding systems, with a view to examining its use in already occupied channels. It is shown that the probe signal can be selectively filtered at the transmitter and receiver to minimise interference to users within the band. This filtering degrades the dynamic range of the sounder and hence t... View full abstract»

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  • Proceedings of 6th International Conference on Radio Receivers and Associated Systems (Conf. Publ. No.415)

    Publication Year: 1995
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (176 KB)

    The following topics were dealt with: receiver architectures; equipment characterisation; antennas; HF receivers; system issues; receiver subsystems View full abstract»

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  • The acquisition performance of delay-lock loops in noise

    Publication Year: 1995, Page(s):192 - 197
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (528 KB)

    Describes results of a computer simulation of a re-configurable delay-lock loop (DLL) which allows fast acquisition of code synchronisation in very poor input SNR conditions. The DLL is based on an analogue prototype but is implemented digitally and this allows the loop to be switched very easily from a noncoherent configuration during initial acquisition to a coherent loop after code, carrier and... View full abstract»

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  • Comparative study of pilot symbol assisted modem schemes

    Publication Year: 1995, Page(s):36 - 41
    Cited by:  Papers (16)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (464 KB)

    The performance of a range of 1, 2 and 4 bit/symbol pilot symbol assisted modulation (PSAM) arrangements employing first-order linear, low pass, polynomial and optimum higher-order linear interpolation schemes is analysed in contrast to that of the equivalent non-coherent modems. Both the non-coherent modems as well as the coherent PSAM schemes exhibited a residual bit error rate (BER), but the be... View full abstract»

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  • An antenna correlation measuring receiver

    Publication Year: 1995, Page(s):91 - 94
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (304 KB)

    The paper presents a simple antenna correlation measuring receiver that is capable of measuring the complex cross-correlation of the signals produced by two receiving antennas connected to it. To measure complex correlation, information about the amplitude and phase of each signal is required. Synchronous phase measurement dictates that highly phase-stable oscillators and signal generators are use... View full abstract»

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  • An Omega radio-navigation receiver for animal tracking

    Publication Year: 1995, Page(s):163 - 167
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (528 KB)

    By taking a fundamental look at the way animal-tracking systems work, suggestions are made for alternative systems of improved performance. The feasibility of an animal-tracking `tag', based on an Omega radio-navigation receiver is explored, and the design and performance of a prototype receiver described. The paper demonstrates that such an Omega tag is more than competitive with the use of the w... View full abstract»

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  • Evolution of radio systems into the 21st century

    Publication Year: 1995, Page(s):1 - 5
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (444 KB)

    Progress in the development and application of radio communications over the past century, from initial discoveries to mass markets has been both rapid and profound. As we approach the second century of radio this paper explores the possible evolution of radio systems in the coming years. In considering future evolution of radio systems we should recognise the enormous potential of radio systems t... View full abstract»

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  • A new diversity code for high spectrum occupancy applications

    Publication Year: 1995, Page(s):139 - 143
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (472 KB)

    The resurgent use of HF, the increase in VHF/UHF usage and in particular the employment of data transmission has meant that the newer enabling technologies such as digital signal processing (DSP) have found a fertile ground in these mature electronic technologies. The main reason is the ability of DSP to overcome the problems that have dogged earlier users. For example, adaptive modem techniques h... View full abstract»

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  • Channel-adaptive modulation

    Publication Year: 1995, Page(s):144 - 147
    Cited by:  Papers (9)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (328 KB)

    Packet reservation multiple access (PRMA) assisted adaptive modulation using 1, 2 and 4 bit/symbol transmissions is proposed as an alternative to dynamic channel allocation (DCA) in order to maximise the number of users supported in a traffic cell. The cell is divided in three concentric rings and in the central high signal-to-noise ratio (SNR) region 16-level star quadrature amplitude modulation ... View full abstract»

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  • A cooled UHF receiving system for radio astronomy

    Publication Year: 1995, Page(s):168 - 171
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (292 KB)

    The 250 ft (76 m) Lovell radio telescope at Jodrell Bank has been a familiar feature on the Cheshire landscape for nearly forty years and throughout this time it has been a scientific instrument of tremendous value in radio astronomy research. This includes spectral line observations (allowing scientists to investigate the chemistry of the Universe), mapping of distant objects (up to the edge of t... View full abstract»

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  • Technology Foresight and future trends in radio

    Publication Year: 1995, Page(s):62 - 66
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    The Technology Foresight programme was announced in the 1993 White Paper `Realising Our Potential' on science, engineering and technology. It brings together industrialists and scientists from private enterprise, the Universities, and Government. The objective is to consider how the UK can best take advantage of the markets and technologies likely to emerge during the next 10-20 years, and identif... View full abstract»

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  • Improvements to the analysis-by-synthesis loop in CELP codecs

    Publication Year: 1995, Page(s):114 - 118
    Cited by:  Papers (1)  |  Patents (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (416 KB)

    In this paper extensions to the analysis-by-synthesis (AbS) loop used in code excited linear predictive (CELP) speech codecs are considered. Methods for updating the short-term synthesis filter once the excitation parameters have been determined are examined. We show that significant improvements can be achieved by updating the synthesis filter, similar to those obtained using the well known metho... View full abstract»

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  • A new method for multipath channel characterisation for terrestrial transmitted video

    Publication Year: 1995, Page(s):22 - 25
    Cited by:  Papers (2)  |  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    Under the multipath conditions of terrestrial television transmission, ghost carriers cause additive information to be generated by the VSB filter within the television receiver. By analysis of this a priori effect of the VSB filter under a ghosted condition the inphase and phase quadrature detected video signals are defined. Derived from these results, a new algorithm based upon correlation techn... View full abstract»

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  • Spread spectrum signal detection using a cross correlation receiver

    Publication Year: 1995, Page(s):42 - 46
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (380 KB)

    A technique is presented for the detection of very low power spread spectrum signals with high resolution direction finding, by cross correlating the outputs of two spatially separated receivers and forming the “time domain filtered cross spectral density” (TDFCSD). Detection is achieved by threshold detection within the amplitude of this TDFCSD, while direction finding is achieved by ... View full abstract»

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  • Optical technique for identification and decoding of digitally modulated signals in surveillance receivers

    Publication Year: 1995, Page(s):203 - 207
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (456 KB)

    An acousto-optic technique for identifying and decoding various unknown types of digitally modulated signals is described. The performance of the system, which uses a bicell photodiode detector assembly, is modelled. It is shown that the output of the system, which consists of the sum and difference of the signals from the two bicell elements, is different and easily identifiable for each of the f... View full abstract»

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  • A high-performance 1 GHz surface transverse wave based receiver for hand-held personal communications

    Publication Year: 1995, Page(s):76 - 80
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (468 KB)

    This paper describes a compact, efficient and highly sensitive 1 GHz superheterodyne receiver which can track, receive and detect frequency modulation (FM), and frequency shift keying (FSK) signals with a modulation bandwidth of 200 kHz and a sensitivity threshold of 500 nV. The tracking bandwidth of 500 kHz allows reliable operation over the temperature range of (-30...+60) deg. C. The receiver c... View full abstract»

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  • HF radar receiving system image rejection requirements

    Publication Year: 1995, Page(s):128 - 132
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (776 KB)

    The sensitivity and consequent detection capability of an HF radar employing a superheterodyne receiving system may be compromised by spurious signals arising from inadequate receiver image rejection characteristics. The image rejection phenomenon arises due to the fact that in addition to the intended action of a mixer in translating a wanted signal from its input frequency to an intermediate fre... View full abstract»

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  • Identification of PSK signals

    Publication Year: 1995, Page(s):95 - 99
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (368 KB)

    PSK signals may be identified using decision theoretic techniques. The paper compares the performance of the optimum, the statistical moments, the DFT and the maximum likelihood DFT classifiers. The robustness of each classifier is examined for the effects of symbol imbalance due to a finite signal time frame, error in the SNR estimate, channel filtering and phase error. Simulation results are pre... View full abstract»

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