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Your search keyword '"RADIO wave propagation"' showing total 3 results
Start Over Descriptor "RADIO wave propagation" Topic digital radio
3 results on '"RADIO wave propagation"'

1. Medium Wave Digital Radio Mondiale (DRM) Field Strength Time Variation in Different Reception Environments.

Author

Guerra, D., Gil, U., De La Vega, D., Prieto, G., Arrinda, A., Ordiales, J. L., and Angueira, P.

Subjects
*DIGITAL audio broadcasting, *DIGITAL communications, *LOGARITHMIC functions, *TRANSCENDENTAL functions, *LOGNORMAL distribution, *DISTRIBUTION (Probability theory), *RADIO wave propagation, *GSM communications, *MOBILE communication systems
Abstract

This paper examines the temporal variability in fixed reception of the ground-wave propagated DRM (Digital Radio Mondiale) signal. This field strength analysis in the medium wave band has been performed using the first Spanish DRM field trial. Several fixed reception points located along radial routes provided the field strength sample distributions in rural and suburban areas. Additionally a second measurement campaign was carried out in several dense and open areas of downtown Madrid. The maximum likelihood estimations and logarithmic functions were used to analyse the fit of the experimental data with theoretical statistical distributions. A deep analysis of the most important parameters of the distribution has been carried out in order to characterize the field strength behavior in the different reception situations. It has been taken into account the influence of environment, measurement time interval, distance to the transmitter and the presence of critical reception impairments. The most remark- able result of this study has shown that the time variability of the ground-wave medium wave DRM channel is well approximated by a Log Normal and also by a Nakagami process. The Log Normal distribution is preferred as it is the one considered by the analog medium wave broadcasts for the ground-wave propagation case. [ABSTRACT FROM AUTHOR]

Published
2006
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2. Medium Wave DRM Field Test Results in Urban and Rural Environments.

Author

Guerra, David, Prieto, Gorka, Fernández, Igor, Matlas, José M., Angueira, Pablo, and Ordiales, Juan Luis

Subjects
*DIGITAL audio broadcasting, *ELECTROMAGNETIC ground waves, *MOBILE communication systems, *RADIO wave propagation, *CONFIGURATION space, *WAVE functions
Abstract

This paper presents the results of the first Spanish field trial carried out to analyze a DRM (Digital Radio Mondiale) system in the medium-wave band. A 4-kW average power omni directional ground-wave experimental DRM transmission at a frequency of 1359 kHz was surveyed by means of a measurement vehicle for fixed and mobile reception. Several radial routes starting from the transmitter site provided rural and suburban behavior features of the system. Urban reception trials were performed in several dense and open streets of Madrid, within the expected coverage area. Field strength threshold values were determined for the tested transmission configurations and compared with the AM ground-wave ITU model predictions. Reliability versus distance from the transmitter is stated in this paper for different transmission configurations and the causes of dropouts for different reception conditions are explained. This analysis took into account subjective quality features of each configuration, providing practical planning parameter values. [ABSTRACT FROM AUTHOR]

Published
2005
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3. Multiple-site investigation of the properties of an HF radio channel and the ionosphere using Digital Radio Mondiale broadcasting

Author

Piotr Koperski, Andrzej Kulak, and Janusz Mlynarczyk

Subjects
Atmospheric Science, Computer science, Transmitter, Aerospace Engineering, ionosphere, Astronomy and Astrophysics, HF radio channel, Digital radio, Software-defined radio, Radio spectrum, Radio propagation, Geophysics, Digital Radio Mondiale, radio wave propagation, Space and Planetary Science, Electronic engineering, General Earth and Planetary Sciences, Digital broadcasting, Computer Science::Information Theory, Radio wave
Abstract

The Digital Radio Mondiale (DRM), one of the new digital radio broadcasting standards, has been designed to overcome typical short wave radio channel difficulties, such as the multipath propagation and fast temporal changes of the received signal level, both related to the properties of the ionosphere along the path of propagation. In particular, some of the RF carriers used in the applied COFDM transmission technique serve to estimate the current state of the radio channel to enable the proper demodulation of the received signal. We have been detecting such RF carriers on select frequency channels (standard DRM broadcast) using a network of recording stations located in different parts of Poland in order to collect data on the HF radio channel. We have been also evaluating the usefulness of this procedure in providing information on the current state of the ionosphere in the refraction region between the transmitter and receivers. When the DRM system becomes more widespread, this method can supplement data that comes from the ionosondes, since it does not require much financial resources and the receivers can be easily scattered over a large area. This paper presents a set of experimental data and its analysis.

Published
2012

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