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Radio Relay Systems, 1993., Fourth European Conference on

Date 11-14 Oct 1993

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Displaying Results 1 - 25 of 62
  • Modem for a PMP radio system using trellis coded modulation with burst transmission

    Publication Year: 1993, Page(s):63 - 67
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (260 KB)

    A new family of modems for point-to-multipoint (PMP) systems is described, designed to improve frequency utilisation, power economy and transmission quality. The key technique is the application of the trellis coded modulation (TCM), which gives a coding gain compared to uncoded modulation schemes, thus resulting in higher system gain and/or lower transmit power (RF and DC). However the applicabil... View full abstract»

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  • Hardware realization of an XPIC system/measurement method and results

    Publication Year: 1993, Page(s):255 - 260
    Cited by:  Papers (1)  |  Patents (7)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (364 KB)

    A new generation of 64 QAM radio relay systems developed for the transmission of SDH- and PDH- signals has been presented by Geidel et al. (1991). The most advanced version from the technical point of view as well as with respect to cost effectiveness and frequency economy was a system with quadruple carrier transmission, using both frequency and polarization multiplex techniques with cross polari... View full abstract»

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  • Advanced SDH radio systems for transport of STM-1

    Publication Year: 1993, Page(s):349 - 354
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (268 KB)

    Describes advanced long haul SDH radio systems operating with 30 and 40 MHz channel spacing. To achieve high quality and robust radio systems, newly developed key technologies such as multi-level coded modulation (MLCM) and decision feedback equalization (DFE) are applied. Their main features, performance and measured data are presented View full abstract»

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  • Performance analysis of LMS adaptive filtering for PMP radio system applications

    Publication Year: 1993, Page(s):68 - 72
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (244 KB)

    Point to multipoint (PMP) radio systems normally operate in propagation environments where significant delay spreads may be encountered due to the fact that, in base stations, sectorial or even omnidirectional aerials are employed. In most of the cases there is a line of sight link but, because of lateral/ground reflections and because most of the times neither antenna can be mounted clear of loca... View full abstract»

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  • Error-correction techniques and adaptive linearization in SDH radio

    Publication Year: 1993, Page(s):238 - 243
    Cited by:  Patents (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (348 KB)

    In high capacity digital radio-relay systems (DRRSs) it is necessary to make use of complex modulation schemes (e.g. 32-, 64-, 128-, 256- or even 512-QAM) to achieve desired spectral efficiency. These modulation schemes are particularly sensitive to many types of impairments and their use requires sophisticated techniques to deal with some of them. The article describes two countermeasures used to... View full abstract»

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  • Equivalence relations between angle diversity and other diversity methods. Analytical model and practical results

    Publication Year: 1993, Page(s):261 - 265
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (288 KB)

    Diversity reception is an efficient means to improve signal quality or to reduce outage time in radio-relay systems. Already well known from application in analogue and digital systems are space diversity (SD) and frequency diversity (FD). Also, angle diversity (AD) has found increasing interest for radio-relay due to its main advantages: need of one Rx-antenna only, and no waste of frequency band... View full abstract»

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  • A 60 GHz transmission experiment in the Netherlands

    Publication Year: 1993, Page(s):296 - 301
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (312 KB)

    Describes the results of a 60 GHz transmission experiment conducted in the Netherlands and the radio equipment developed by PTT Research for experimental purposes. The experiment revealed that the higher millimetre wave bands, in particular the 60 GHz band, offer significant potential for local communications. The CCIR model for rain attenuation was found to be useful for modelling this type of tr... View full abstract»

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  • Recent technical and regulatory developments affecting the UK fixed services frequency bands

    Publication Year: 1993, Page(s):4 - 8
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    There have been a number of concurrent technical and regulatory developments affecting UK users of fixed service spectrum. As the body responsible for efficient spectrum management in the UK, the Radiocommunications Agency (RA) has been working closely with equipment manufacturers and network operators to respond effectively to these developments. The paper reviews the key developments affecting d... View full abstract»

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  • Propagation on 23, 31 and 50 GHz line-of-sight over-water paths

    Publication Year: 1993, Page(s):355 - 360
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (288 KB)

    Propagation investigations have been performed during a period of three years (1988-1990) on the east coast of Sweden. The primary purpose of the measurements was to establish the limitations in availability caused by fading due to rain, snow, multipath propagation, hail and fog. Prediction models (CCIR) for rain and multipath fading have been adapted, monthly and annually, to experimental cumulat... View full abstract»

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  • A N+2 protection switching system for synchronous STM-1 signals and plesiochronous 140 Mbit/s signals by using two carrier technique

    Publication Year: 1993, Page(s):128 - 133
    Cited by:  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (268 KB)

    The availability of a high capacity radio link mainly depends on the reliability of the radio system and the occurrence of fading events. For improving availability and quality of a radio relay link there are protection channels added to the operating channels. In the configuration 1+1 one protection channel is assigned to each operating channel. In the configuration n+2 two protection channels ar... View full abstract»

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  • Proposal for modulation level controlled radio system applied to ATM networks

    Publication Year: 1993, Page(s):322 - 327
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (368 KB)

    Analyzes the cell loss performance of the modulation level controlled radio system applied to ATM networks. This system increases total transmissible capacity by controlling the number of modulation levels, so can effectively absorb traffic fluctuation occurring in ATM networks and reduce cell loss probability. As a result of analysis, it was found that the proposed system can drastically reduce A... View full abstract»

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  • Planar sector-beam antenna for point to multipoint systems around and above 10 GHz

    Publication Year: 1993, Page(s):73 - 78
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (224 KB)

    After justifying the choice of radiation pattern for an antenna dedicated to point to multipoint systems above 10 GHz, the article describes the design of such an antenna working at 23 GHz. Planar printed antennas are discussed View full abstract»

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  • RF modem for high capacity radio system

    Publication Year: 1993, Page(s):244 - 249
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (348 KB)

    Presents a new high-capacity microwave system in the upper 6 GHz band based on microwave modulation and demodulation. This equipment is designed in two versions, organised around a common TX/RX, and differing only in the framing and error code correction modules. The first version transmits the highest level (140 Mbit/s) of plesiochronous digital hierarchy (PDH) and uses 16QAM modulation. The seco... View full abstract»

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  • Blind algorithms for joint clock recovery and baseband combining in digital radio

    Publication Year: 1993, Page(s):279 - 286
    Cited by:  Patents (10)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (412 KB)

    A strategy is illustrated for joint space diversity baseband combining and timing recovery in microwave digital radio, based on a phase-independent criterion. The proposed receiver both provides a steady-state performance close to minimum mean square error receiver and solves the problems related to system synchronization, with an effective synergic action of clock recovery and adaptive baseband c... View full abstract»

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  • Opportunities for Sub STM-1 radio systems in the BT network

    Publication Year: 1993, Page(s):115 - 121
    Cited by:  Patents (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (424 KB)

    The paper outlines applications for Sub STM-1 radio systems within the BT United Kingdom network and provides information for discussion within the ITU and ETSI forums towards standardisation of SDH systems below STM-0 (VC-3). It outlines the benefits of functional integration of SDH radio systems and add drop multiplexers (ADM). It also provides a brief overview of BT's UK synchronous transmissio... View full abstract»

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  • Video transmission using millimetre wave radio systems

    Publication Year: 1993, Page(s):311 - 315
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (244 KB)

    The development of a video distribution system in the 28 GHz band by BT started in 1986 to meet the demand for a radio system that could provide the final link to customers to make available a satellite service where customers could not have direct satellite reception for a number of reasons. Subsequently the system has been adapted to also provide point-to-point closed circuit TV applications. At... View full abstract»

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  • A compact BCM modem implementation for SDH access radio

    Publication Year: 1993, Page(s):267 - 272
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (348 KB)

    The SDH access radio network calls today for a modem that is properly implemented. Neither the simplicity of a 4-PSK modem, nor the sophisticated multilevel high capacity modems with their expensive power consumption are suitable. The authors think that the compactness, the low power consumption, the right spectrum efficiency associated with a good receiver sensitivity and consequently a low cost ... View full abstract»

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  • The DECT standard in local loop access applications

    Publication Year: 1993, Page(s):103 - 107
    Cited by:  Patents (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (256 KB)

    The paper discusses the suitability of the Digital European Cordless Telecommunications (DECT) radio interface for use in a wireless local loop (WLL) application. The relevance of this standard for WLL applications is highlighted, particularly with respect to the likely service requirements and attributes of these local access networks. The paper concludes with an example of a potential DECT WLL a... View full abstract»

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  • 58 GHz technology and experimental link

    Publication Year: 1993, Page(s):302 - 306
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (216 KB)

    Trends in military and civilian communication systems lead to the increasing use of millimeter wave frequencies. Among those the 60 GHz band is particularly interesting due to the atmospheric absorption (frequency reuse, discretion). Alcatel Telspace has studied millimeter waves technologies allowing the development of a new millimeter wave products generation. The paper describes the results of t... View full abstract»

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  • Impact of Recommendation G.826 on the system design of radio relay systems

    Publication Year: 1993, Page(s):29 - 32
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (252 KB)

    The paper first discusses the development of the new ITU-TSS (CCITT) error performance Recommendation G.826 and the subsequent development by ITU-RS (CCIR) Study Group 9 of a preliminary draft new Recommendation aligned to G.826. The paper then considers the stringency and impact of the new SG9 Recommendation on the system design of digital radio-relay systems (DRS) and the complexity and cost for... View full abstract»

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  • Economics of local loop competition by radio access

    Publication Year: 1993, Page(s):9 - 14
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (236 KB)

    Describes the economics of radio access in the local loop, compares the attractiveness of competing technologies and concludes that there are no general solutions. Each potential service area must be analysed separately in order to determine the optimum mix of technologies. In general radio based technologies appear best suited to low population density areas with GSM solutions appropriate for wid... View full abstract»

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  • Loss of pointer in SDH digital radio relay systems

    Publication Year: 1993, Page(s):134 - 139
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (308 KB)

    The use of synchronous digital hierarchy (SDH) in digital radio relay systems (DRRS) requires the analysis of the effect of error statistics on the transmission frame. In fact, due to the recent adoption in high capacity SDH DRRSs of transmission techniques such as low redundancy error-correcting codes, trellis coded modulations, Viterbi receivers, etc., the errors produced in the presence of nois... View full abstract»

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  • Spread spectrum wireless links

    Publication Year: 1993, Page(s):39 - 44
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (320 KB)

    The paper explains the basic technology of spread spectrum modulation. An application provides licence-free `instant' wireless links under Part 15 of the FCC Rules in the USA. Western Multiplex has designed a spread spectrum digital microwave radio with a standard Tl/El interface for a private point-to-point service. This radio performs very effectively in the presence of interference, dispersive ... View full abstract»

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  • Performance of a 64 QAM radio using digital filters with small rolloffs

    Publication Year: 1993, Page(s):328 - 333
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (276 KB)

    The increasing demand for transmission capacity of public and private networks and the limited availability of radio frequencies is the major driving force behind the search for microwave radio concepts with high spectral efficiency. In the past this has led to the design of systems with increasingly higher modulation levels, with the bulk of modern high capacity digital microwave radios employing... View full abstract»

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  • Measured improvements using angle and space diversity on a terrestrial microwave radio link

    Publication Year: 1993, Page(s):215 - 220
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (296 KB)

    In order to measure the error performance of angle diversity (AD) and space diversity (SD) systems a field trial is in progress on a 52.9 km hop between Karlstad and Filipstad, situated in the western part of Sweden. The transmission quality of the digital radio system with both space and angle diversity configurations is measured simultaneously and the observed bit error ratios for these configur... View full abstract»

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