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1993 Fourth European Conference on Radio Relay Systems

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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)
| | PDF (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»

• Implications of draft new ITU-T Recommendation G.826 on digital radio-relay systems

Publication Year: 1993, Page(s):21 - 28
Cited by:  Papers (1)  |  Patents (2)
| | PDF (228 KB)

Draft new ITU-T Recommendation G.826 specifies error performance parameters and objectives for international digital paths at or above the primary rate. These paths may be based on a PDH, SDH or some other transport network. Future radio-relay systems, which will form part of these paths have to comply with this recommendation. The present paper analyzes the new concepts introduced in G.826 and ap... View full abstract»

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

Publication Year: 1993, Page(s):73 - 78
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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»

Publication Year: 1993, Page(s):221 - 226
Cited by:  Papers (1)
| | PDF (356 KB)

The operational surveillance of radio relay equipment carrying normal traffic has become common within many administrations. The parity check feature of the radio frame is exploited to derive an estimate of the bit error rate (BER) and subsequently the number of events (seconds) when a certain BER is exceeded is cumulated. Thus one may estimate whether the performance of a particular transceiver/r... View full abstract»

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

Publication Year: 1993, Page(s):29 - 32
| | PDF (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»

• Wireless access based on CT-2 radio system

Publication Year: 1993, Page(s):79 - 83
Cited by:  Papers (1)
| | PDF (344 KB)

Several potential technologies have been evaluated for wireless access, including CT-2, DECT and a number of proprietary systems. In most cases it is clear that the system architecture can be independent of the radio technology. To meet the objective of low costs, the proposed system has been based upon a standard radio interface thus allowing volume of scale cost reductions to be achieved. The pr... View full abstract»

• Access radio systems in SDH and mobile networks

Publication Year: 1993, Page(s):108 - 114
Cited by:  Papers (1)
| | PDF (316 KB)

A new access radio family is described, pointing out basic concepts, innovative technologies and overall performance. The radio application in access links appears as a most promising one to be adopted in modern, rapidly evolving telecommunication networks. Examples of application in SDH and in mobile networks are examined in particular, showing the main technical features and a number of operatin... View full abstract»

• Improving SDH radio quality performance: the WEST combiner concept and benefits for space diversity receivers

Publication Year: 1993, Page(s):273 - 278
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Discusses a new and effective approach to describe QAM system performance in high capacity SDH radio as a function of properly weighted power level and spectrum distortion. An efficient combiner for space diversity receivers, based on these concepts-the WESt (Weighted Evaluation Strategy) combiner-is also described, and simulation and laboratory measurements on prototypes are shown View full abstract»

• A single chip adaptive QAM processor for data rates up to 500 Mbit/s

Publication Year: 1993, Page(s):227 - 233
Cited by:  Papers (3)  |  Patents (3)
| | PDF (428 KB)

The miniaturization of CMOS structures allows the realization of a complex-valued adaptive time domain equalizer at a symbol rate of 30 MHz on one VLSI chip by using the application specific' gate array technique (ASICs). By making use of a full custom design and CMOS technology it was possible to integrate on one chip not only an entire complex-valued baseband transversal equalizer but also all ... View full abstract»

• Multicarrier modulation technique for wireless local area networks

Publication Year: 1993, Page(s):33 - 38
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The paper proposes the multicarrier modulation/differential detection technique for wireless local area networks. One computationally efficient closed form expression for the bit error rate in a frequency- and time-selective Rayleigh fading channel is derived, and numerical results to show the BER performance in a practical indoor wireless channel are demonstrated View full abstract»

• A new acquisition technique for carrier recovery with QAM signals

Publication Year: 1993, Page(s):316 - 321
Cited by:  Patents (1)
| | PDF (360 KB)

Describes a frequency error detector (FED) for all modulation systems using quadratic modulation schemes, such as 16-QAM, 64-QAM, 256-QAM and so on. Its main advantage is the very high resistance to all kinds of signal faults such as distortions, level errors or noise. Simultaneously, it permits a high acquisition range to be achieved (more than Δf/fs=5% in noise-free envir... View full abstract»

• Economics of local loop competition by radio access

Publication Year: 1993, Page(s):9 - 14
Cited by:  Papers (2)
| | PDF (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»

• Analysis and simulation of a distributed rural radiotelephone network

Publication Year: 1993, Page(s):97 - 102
Cited by:  Patents (3)
| | PDF (324 KB)

The paper presents the results of simulations of a self configuring radio system using packet radio techniques to set up duplex circuits, which has many advantages for the provision of telephone services in rural areas of developing countries. It is justifiable to consider blocking on this type of network as being described by the order of the network consisting of the stations not being used at a... View full abstract»

• Technical and economic assessment on radio relay systems in the local and distribution Italian networks

Publication Year: 1993, Page(s):84 - 89
Cited by:  Patents (4)
| | PDF (392 KB)

Presents a technical and economic assessment on digital radio relay systems (DRRSs) for the Italian local and distribution network. The authors summarize the evolution trends for the Italian local and distribution network, outlining the modification of network structure to understand the possible application field of DRRSs. They deal with the role of the DRRSs for the introduction of SDH systems a... View full abstract»

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

Publication Year: 1993, Page(s):115 - 121
Cited by:  Patents (2)
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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»

Publication Year: 1993, Page(s):193 - 197
Cited by:  Patents (1)
| | PDF (256 KB)

The utilization of frequency bands above 20 GHz for short distance digital radio links requires relatively small antennas (diameter less than one meter) adapted to the particular frequency band. Due to the competitive market situation the antennas have to be very cheap in series production. Furthermore, the antennas have to meet the system relevant stringent electrical requirements concerning refl... View full abstract»

• 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)
| | PDF (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»

• Multipoint radio systems: planning tools using terrain data bases derived from satellite remote sensing

Publication Year: 1993, Page(s):204 - 209
| | PDF (404 KB)

Describes how the satellite derived terrain data bases can be used as a planning aid in the development of a multipoint radio system and to analyse the feasibility of such data. The main advantages of satellite derived terrain data are their availability in a relatively short period of time and the spatial resolution (up to 10 m) which is suitable to represent urban areas. The analysis of the radi... View full abstract»

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

Publication Year: 1993, Page(s):255 - 260
Cited by:  Papers (1)  |  Patents (7)
| | PDF (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»

• 58 GHz technology and experimental link

Publication Year: 1993, Page(s):302 - 306
| | PDF (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»

• Fourth European Conference on Radio Relay Systems' (Conf. Publ. No.386)

Publication Year: 1993
| | PDF (12 KB)

The following topics were dealt with: WARC '92 effect, fixed service, competition, performance objective, availability objective, radio LAN, multipoint radio, access network, synchronous digital hierarchy, managed transmission network, radio link design, radio relay system, MM-wave radio relay system View full abstract»

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

Publication Year: 1993, Page(s):279 - 286
Cited by:  Patents (10)
| | PDF (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»

• The benefit of cross-polar co-channel operation in digital radio networks

Publication Year: 1993, Page(s):167 - 174
| | PDF (484 KB)

Digital radio systems with co-channel operation are a powerful and economic transport medium for modern transmission networks. Thereby co-channel operation provides an extremely efficient use of radio frequency resources, offers economical solutions for capacity extensions and re-utilization of existing infrastructure, and gives advantages in densely meshed radio networks. The performance and reli... View full abstract»

• Frame selector [for combining parallel data channels]

Publication Year: 1993, Page(s):234 - 237
| | PDF (196 KB)

Frame selection is a method used to combine parallel data channels in order to achieve lowest possible error rate. This method has significant improvement potential compared to conventional switching techniques and early warning systems. The frame selection technique also improves the residual bit error rate since it works at every error rate View full abstract»

• An evolutionary approach to the management of SDH radio equipments

Publication Year: 1993, Page(s):140 - 147
Cited by:  Papers (1)  |  Patents (1)
| | PDF (396 KB)

A number of radio relay and fibre optic systems are required to be remotely controlled and monitored. Year by year customer's requirements are becoming more and more demanding in order to achieve an effective supervision of the network. With SDH equipment these requirements are becoming even more complex to be satisfied. The paper illustrates Siemens Telecomunicazioni's approach to provide a satis... View full abstract»