# Tenth International Conference on Antennas and Propagation (Conf. Publ. No. 436)

## Filter Results

Displaying Results 1 - 25 of 93
• ### Tropospheric scintillation measurements and modelling in Finland

Publication Year: 1997, Page(s):141 - 144 vol.2
Cited by:  Papers (3)  |  Patents (1)
| |PDF (368 KB)

Due to turbulent irregularities in temperature, humidity and pressure, the atmosphere exhibits small-scale variations in refractive index, which cause various refractive effects on electromagnetic waves, that can be observed as random fading and enhancement in the received signal amplitude and phase. This effect is known as scintillation'. Generally, the impact of rain attenuation on satellite li... View full abstract»

• ### EXPRESS: experimentation of propagation in the EHF-band from the satellite STENTOR

Publication Year: 1997, Page(s):136 - 140 vol.2
Cited by:  Papers (1)
| |PDF (412 KB)

The paper gives preliminary information about the propagation experiments which will be carried out in the EHF-band with the satellite STENTOR. The problems linked with using such high frequencies are reviewed and the objectives of the propagation program are clarified. Then, the STENTOR EHF propagation payload is described. This propagation payload consists of two beacons operating at 20.7 GHz an... View full abstract»

• ### Optimal mobile radio channel assignment using energy minimising and geometrical constraints

Publication Year: 1997, Page(s):132 - 135 vol.2
Cited by:  Papers (1)
| |PDF (316 KB)

The growth in the number of mobile users is stimulating interest in the optimum design of mobile communication networks. In particular, network operators are required to satisfy a prescribed traffic demand with a limited spectrum allocation. This implies the allocation of channels to base stations subject to a frequency re-use regime which minimises co-channel and adjacent channel interference. Th... View full abstract»

• ### Modelling of land mobile satellite channels based on measurements at 13° and 29° elevation angle

Publication Year: 1997, Page(s):54 - 58 vol.2
Cited by:  Papers (2)
| |PDF (396 KB)

This paper presents results from land mobile propagation measurements conducted by Inmarsat at 13° and 29° elevation angles in the UK. A number of simultaneous recordings have been made at L-band, using both directive and omnidirectional antennas. The measurements took place in the suburbs of London in a variety of propagation environments ranging from open to shadowed areas. Furthermore, ... View full abstract»

• ### Macrocellular angle-of-arrival and delay propagation characteristics and their impact on smart antenna design and performance

Publication Year: 1997, Page(s):128 - 131 vol.2
Cited by:  Papers (2)
| |PDF (432 KB)

Data relating to the angular and temporal distribution of the propagation channel in the mobile cellular frequency bands is critically important to the process of determining optimum smart antenna base station designs. A programme of work has been undertaken by Nortel Technology to develop a high performance multipath angle-of-arrival (AoA) measurement facility, the Aperture Analyser. The purpose ... View full abstract»

• ### Wideband limitations of ray-optical techniques in radiowave propagation prediction

Publication Year: 1997, Page(s):79 - 82 vol.2
| |PDF (468 KB)

Further growth of mobile communication systems and the provision of mobile multimedia services can only be achieved in the future through the use of sophisticated access schemes, some of which require wideband radio channel information for their planning (e.g. wideband DS-CDMA). The planning and deployment of spectrally efficient wideband wireless personal communication systems in turn requires a ... View full abstract»

• ### Simulation of 20 GHz narrow band mobile propagation data using N-states Markov channel modelling approach

Publication Year: 1997, Page(s):48 - 53 vol.2
Cited by:  Papers (7)
| |PDF (368 KB)

Increasing interest in the use of the 20/30 GHz band for land mobile satellite (LMS) systems has created a need for accurate models of channel variations in these frequency bands. Some measurements have been taken using Italsat. These measurements were carried out in the Netherlands, France, Germany and Austria. A Markov modelling approach is adopted for LMS channel modelling. The data is analysed... View full abstract»

• ### Transionospheric propagation at the boundary of radio transparency range: results of Russian space experiments and plans for low orbiting pilot space station

Publication Year: 1997, Page(s):31 - 34 vol.2
| |PDF (336 KB)

To ensure good design, as well as reliable and stable operation of radio systems using radio communication channels, it is essential to determine the ionospheric spatial structure. Installation of the ionosonde on-board the satellite provided the optimum possibility for determining the ionosphere spatial structure. The ionosonde emits radio waves that propagate throughout the ionosphere and allows... View full abstract»

• ### An evaluation of frequency diversity performance in microwave frequency mobile radio communication systems

Publication Year: 1997, Page(s):123 - 127 vol.2
| |PDF (400 KB)

The present UK cellular radio system currently uses a frequency spectrum which limits both the number of users for speech communication and the range of services that may be offered. The introduction of millimetric frequencies will offer a larger amount of bandwidth and allows higher capacity services. One drawback of using short wavelength is the increase in the number of fades in a multipath env... View full abstract»

• ### An extended propagation software package for indoor communication systems

Publication Year: 1997, Page(s):298 - 301 vol.2
Cited by:  Papers (3)
| |PDF (224 KB)

At the K.U. Leuven a software package (EPICS) that uses deterministic models to calculate the fields of antenna arrays has been developed. The software also allows one to compute important parameters of communication system like the power delay profile (PDP) and direction of arrival (DOA). Originally, it was designed to evaluate outdoor communication systems, but the emphasis has been moved toward... View full abstract»

• ### The effects of antennas on HF propagation level

Publication Year: 1997, Page(s):75 - 78 vol.2
| |PDF (444 KB)

The transmitting antenna for HF communication links is generally simple with a vertical or horizontal polarization. The receiving antenna provides signals corresponding to different paths or modes( O and X). To interpret HF communication attenuation, fading is computed using a statistical method and the classical antenna field pattern. Such a radiation pattern is inadequate in the case of HF propa... View full abstract»

• ### Effects of integration time on rain rate statistics for Singapore

Publication Year: 1997, Page(s):273 - 276 vol.2
Cited by:  Papers (3)
| |PDF (324 KB)

Four years data from a network of four tipping bucket rain gauges in Singapore have been analysed to obtain the rainfall rate statistics computed using different integration times of 0.5, 1, 5, 10, 30 and 60 minutes (Zhang 1995). Our studies show that both Segal's (1986) and Burgueno et al.'s (1988) methods are applicable for the conversion of rain rate statistics from different integration times ... View full abstract»

• ### A physical-statistical model for land mobile satellite propagation in built-up areas

Publication Year: 1997, Page(s):44 - 47 vol.2
Cited by:  Papers (12)  |  Patents (1)
| |PDF (344 KB)

A physical-statistical model of land-mobile satellite propagation in built-up areas is derived from geometrical considerations and simple diffraction theory. The model has two components. The first predicts the probability with which a line-of-sight path exists between the mobile and the satellite. Some models predict the statistical fading characteristics of the received signal with the shadowing... View full abstract»

• ### Neural networks in ionospheric prediction and short-term forecasting

Publication Year: 1997, Page(s):27 - 30 vol.2
Cited by:  Papers (2)
| |PDF (368 KB)

This paper discusses appropriateness of the neural network approach for ionospheric prediction and short-term forecasting. The idea of using the neural network technique to predict the future behaviour of a time series of the vertical-incidence ionospheric data has been presented and endorsed in the framework of the COST 251 project. It is based on the well-known fact that in recent years attentio... View full abstract»

• ### Capacity increase in cellular radio networks using intelligent underlay overlay

Publication Year: 1997, Page(s):119 - 122 vol.2
Cited by:  Papers (2)
| |PDF (380 KB)

Intelligent underlay overlay, a network feature which enables significant capacity increases in digital cellular TDMA radio networks, is described. The capacity increase is obtained from existing macro'-base station (BTS) sites since intelligent underlay overlay enables a more efficient utilisation of radio channels than currently possible. Theoretical principals and differences in functionality ... View full abstract»

• ### A method to speed up iterative solutions of terrain scattering problems

Publication Year: 1997, Page(s):294 - 297 vol.2
Cited by:  Papers (2)
| |PDF (364 KB)

A method for speeding up integral calculations occurring in iterative solutions of electromagnetic wave scattering problems is described. Present methods suffer from having to perform time consuming integral calculations at many points. The method involves enumerating the full integral only at certain points and approximating the integral at neighbouring points by making localised phase and amplit... View full abstract»

• ### Influence of the vegetation on a VHF radio link over an irregular terrain

Publication Year: 1997, Page(s):15 - 18 vol.2
| |PDF (548 KB)

This paper deals with the study of radio wave propagation over irregular and woody terrain. We characterize the received signal (power and spatial fluctuations) before, into and outside the forest. We describe first the experimental study and give some results about spatial fluctuations of the received signal. We give the experimental procedure to get a reliable value of the received power with a ... View full abstract»

• ### Some super-resolution DF measurements within the HF band

Publication Year: 1997, Page(s):71 - 74 vol.2
| |PDF (384 KB)

The unknown propagation mode content of signals monitored in some earlier super-resolution HF-DF experiments was a significant limitation in the interpretation of the measurements and inferences concerning the mode content had to be made from the processed data. In order to overcome this limitation, further experiments have been undertaken in which the propagation mode content of the signals was d... View full abstract»

• ### ITALSAT propagation experiment at the Yebes radiotelescope

Publication Year: 1997, Page(s):106 - 108 vol.2
Cited by:  Papers (2)
| |PDF (264 KB)

Spain is taking part in the ITALSAT propagation measurements using the radiotelescope from the Yebes Astronomy Centre, as a receiver. The main objective of this experiment is to investigate the effects of atmospheric phenomena on the 50 GHz received signal, performing both radiometric and beacon measurements. Though beacon and radiometer measurements are performed sequentially, if weather conditio... View full abstract»

• ### Advanced LOS path loss model in microwave mobile communications

Publication Year: 1997, Page(s):170 - 173 vol.2
Cited by:  Papers (3)
| |PDF (384 KB)

An advanced LOS (line-of-sight) path loss model with the characteristics of a real urban environment is proposed. Good results are obtained by using a two-path model together with shadowing caused by obstacles that would appear in an actual urban environment and rising reflection points caused by vehicular traffic. By applying the model in the urban environment, microcellular path loss can be pred... View full abstract»

• ### Remote sensing of radio refractivity by lidar

Publication Year: 1997, Page(s):325 - 328 vol.2
| |PDF (348 KB)

Deterministic modelling of tropospheric radio propagation and exploitation of variations of microwave radar propagation require high quality, high resolution refractivity profiles in the first 1-2 km above the Earth's surface. Currently, routine measurements of refractivity are based on radiosonde measurements (via in-situ measurement of temperature and water vapour). Unfortunately, radiosondes ha... View full abstract»

• ### First order propagation in moving chiral media

Publication Year: 1997, Page(s):269 - 272 vol.2
| |PDF (320 KB)

The first-order propagation of electromagnetic waves in moving isotropic chiral media is studied. The present analysis is based on Maxwell's equations, Bohren decomposition and Minkowski's relations taken to the first order in the velocity. Accordingly, the effect of acceleration on the electromagnetic fields is neglected, thus yielding a new model for solving problems involving moving chiral medi... View full abstract»

• ### Performance characterisation of millimetre wave mobile radio systems in forests

Publication Year: 1997, Page(s):391 - 396 vol.2
Cited by:  Papers (1)
| |PDF (356 KB)

The frequencies in the oxygen absorption band in the region of 60 GHz have been suggested for urban microcellular communications. This is due to the extra attenuation exhibited by the atmosphere in this frequency region, thus allowing for greater frequency re-use to be employed. Multipath in a microcellular forest environment due to reflections and scatter off foliage, with line-of-sight (LOS) pre... View full abstract»

• ### Propagation over a tiled pitched roof in urban environment

Publication Year: 1997, Page(s):90 - 93 vol.2
| |PDF (224 KB)

Many urban radiowave propagation models are primarily concerned with propagation over multiple rows of buildings. However, pitched building roofs are structures which permit substantial radiowave transmission through them. The roofs are made, for most of the buildings, of tiles with a thickness smaller than the wavelength at radiowave frequencies. Therefore, in general, a roof can be modelled by a... View full abstract»

• ### Wideband characterisation and modelling of the mobile satellite propagation channel at L- and S-bands

Publication Year: 1997, Page(s):39 - 43 vol.2
Cited by:  Papers (2)
| |PDF (412 KB)

The effects of the wideband propagation channel are critical in the design of mobile satellite systems (MSS), providing world-wide voice and data communications requiring higher data rates and quality of service. The variational effects of the narrowband propagation channel with respect to the elevation angle have been widely reported and modelled. However, there is very little data on the effects... View full abstract»