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The article presents the methodology for measuring verification of the phenomenon of fades in the DAB+ SFN. The verification is related to comparing the characteristics of the fades determined theoretically with the occurring fades in the real environment of a large city. The conditions favorable for the occurrence of fading are presented and by selecting the appropriate propagation analysis tool,...
Single Frequency Networks (SFN) of transmitters are currently used in television and digital broadcasting to effectively cover large areas using minimal spectral resources and using transmitters with much lower power than if the same area were covered using one transmitter. It is therefore a very ecological solution. In this way, much better reception conditions are obtained in large city areas, as...
This paper shows effective method of linear distortions compensation in zero-IF receivers. With application of frequency domain processing a computation efficient method was developed that allows to correct quadrature mismatch in Zero-IF receiver along with gain and group delay independent of receiving signal type. Method was implemented and tested on hardware platform confirming its effectiveness...
The paper presents a simulation model of the radio frequency MIMO-OFDM system. The simulation model was made in Matlab Simulink environment. It contains the transmitter, the receiver and the telecommunication channel models. The telecommunication channel model consists of models used during development of technical documentation of IEEE 802.11n. Signals generated at the transmitter output are fully...
In this paper we discuss state of the art in the field of shielding materials investigation. Two types of newly manufactured shielding materials (nonwoven and fabric) were measured using improved free-space transmission technique at 2-5 GHz depending on electromagnetic wave (EM) polarization and antenna to specimen distance. Results of shielding effectiveness (SE) evaluation based on measured complex...
The paper presents research results pertaining to transmission parameters of wireless communication systems, based on WiMax and IEEE 802.11x radio interfaces. Research was performed in severe operating conditions of an underground mine - testing various parameters, such as: throughput, delays and maximum range.
High Altitude Platform (HAP) concept and idea is presented in the article. Characteristics, advantages and disadvantages of HAPs are described. There is also the comparison available between HAPs and existing telecommunication infrastructure (terrestrial and satellite). Selected examples of the possible limitation and technological restrictions of HAP based systems are presented in the article.
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