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Next-generation 5G cellular networks are expected to operate on the millimeter wavelength frequencies (e.g., 28 GHz and 38 GHz) to offer broader bandwidths and higher data rates. In this frequency band, rain is a major impairment to received signal power. This work aims to improve predictions of rain attenuation for 5G wireless networks operating at 28 GHz and 38 GHz in heavy rain regions, by exploiting...
Attenuation time series measured on the satellite-to-ground path in Prague in frequency bands 19 and 39 GHz and simultaneously measured rain intensity are analyzed statistically using one-year dataset. Frequency scaling is described by linear models. Empirical power law models are fitted to the measured data directly and to the obtained annual cumulative distributions. Monthly statistics obtained...
Drop Size Distributions (DSDs) measured with an optical disdrometer in Madrid during 5 years are used to derive the copolar attenuation (CPA) and cross polarization discrimination (XPD) at 19.7 and 39.4 GHz. A full wave Method of Moments (MoM) is utilized to calculate specific attenuation and phase rotation through a realistic scattering raindrop model for large raindrops. The best-fit parameters...
Universidad Politécnica de Madrid (UPM) is participating in the Alphasat propagation experiment by measuring the copolar level of the Q-Band beacon at 39.4 GHz since April 2014. In this paper the results of the first two complete years of measurements (until March 2016) are presented with regards to excess and total attenuation. The reference level is calculated on an event-by-event basis in the first...
Underwater Communication has a wide range of applications. In the case of a short-range communication system, the use of electromagnetic waves has been recently proposed as an alternative to the mostly used acoustic waves. The design of the antennas to be used for underwater communication is strongly influenced by the electromagnetic properties of the water and therefore, after its design but before...
The move towards higher frequency bands like 26GHz or 32GHz for scientific satellite data downlinks calls for the need to better characterise the atmosphere at the sites where ground antennas are located. For this reason ESA is undertaking the deployment of microwave radiometers at its Deep Space station locations. This paper reports the results of the first two years of site characterisation at the...
This paper describes the ongoing site-diversity experiment, consisting of three beacon receiver stations in Slovenia and one station in Austria. All the four stations are identical in configuration and are measuring the 20.2 GHz beacon signal, transmitted from the ASTRA 3B geostationary satellite. The stations were gradually deployed in the years 2014 and 2015. The measured attenuation time series...
The paper gives a description of the satellite propagation measurement site established in Ljubljana. It consists of two beacon receivers, measuring the Alphasat and Astra 3B beacons at Ka-band and at Q-band, and of a co-located rain gauge. Statistical analysis of collected measurements is performed to create complementary cumulative distribution functions of excess attenuation and rain rate. First...
For the last decades satellite communication systems have been moving towards higher and higher frequencies; rain attenuation along the Earth-satellite path can be an important limiting factor for the system availability, especially in tropical regions where rain events can be particularly intense. One of the possible countermeasures is site diversity. In this paper we evaluate the performance of...
For a variety of propagation and remote sensing questions, the knowledge on the length, microwaves propagate through rain media, is relevant. Weather radar measurements allow studying the effect for a given location in various directions and elevation angles, representing both terrestrial and satellite paths. This study uses raw data from an operational weather radar to retrieve statistics on how...
A heuristic algorithm based on two threshold values of a scalar indicator, given by the ratio of the brightness temperatures measured by a ground-based radiometer at 31.4 and 23.8 GHz, is employed to detect the presence, if any, of rain events along the Earth to satellite propagation path in the framework of the Alphasat Aldo Paraboni Propagation Experiment. The promising preliminary results have...
Millimeter-Wave (mmW) communication systems, capable of achieving high data rates thanks to the large bandwidth available in this frequency range, are a promising 5G technology. Studies in this paper investigate the radio propagation channel at 3, 10, 17 and 60 GHz in an Outdoor-to-Indoor (O2I) scenario. Measurements were conducted using a wideband channel sounder to derive channel parameters such...
In satellite communications, the demand for capacity increase is met by the use of higher frequency bands, which however are severely impaired by atmospheric phenomena (rain, cloud and gaseous attenuation, scintillation). In order to study propagation effects for future satellite communication frequencies both in temperate and tropical climates, JOANNEUM RESEARCH carries out two long-term propagation...
Considering the imminent migration of services to the Ka- and Q-bands, a payload dedicated to propagation measurements in these bands has become available from the Alphasat satellite under the coordination of the European Space Agency. This has strongly motivated the formation of many measurement campaigns across Europe in an effort to enhance the scientific databases with new, more reliable propagation...
Reliable estimates of satellite channel characteristics are of great importance for satellite communications, especially with use of even higher frequencies as Ka-band and in near future Q- and V-band. At a given rain rate the shape of rain drop size distributions (DSDs) considerably influences the corresponding specific attenuation. In previous work it was shown, that annual DSD statistics give evidence...
The augmenting need for remote monitoring and treating patients by biophysical sensors interconnected via Body Area Networks (BAN) has recently called researchers' attention. The private and confidential transferred data in such application require high information security. One of the solutions is to use human body as a transmission channel. The body surface-confined transmission restricts the off-body...
The use of window functions to improve the side lobe level of antenna arrays is hindered by high value of excitation currents dynamic range ratio. This paper proposes a fast and iterative window function generation strategy aimed at achieving improved side lobe level starting from a preset current dynamic range ratio. Based on this strategy a new window function is developed for standard set of conditions.
The attenuation due to rain is one of the main impairments in satellite communications. It is well known that rain attenuation is dependent on the elevation angle of the link, being more severe at low elevation angles; this has a definite impact on the design of TLC and data download systems based on low earth orbit (LEO) satellites. As measurements at various elevation angles are seldom available,...
The Alphasat telecommunication satellite was launched in July, 2013 and beside of the main payload it carries four scientific experiments. One of them is the Aldo Paraboni Scientific Experiment, a propagation experiment in the Ka and Q radio bands. The experiment is coordinated by the European Space Agency under the framework of ARTES 8 Telecom program. Hungary, similarly to other European experimenters...
The performance of both a recent rainfall rate model and the inter-annual variability prediction method proposed by the International Telecommunication Union has been assessed taking advantage of the availability of 16 years of rain gauge data. The above rainfall rate model produces as well monthly rainfall rate distributions that have been compared with the experimental monthly distributions achieving...
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