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GNSS systems are susceptible to radio interference despite then operating in a spread spectrum. The commerce jammers power up to 2 watts that can block the receiver function at a distance of up to 15 kilometers in free space. Two original methods for GNSS receiver testing were developed. The first method is based on the usage of a GNSS simulator for generation of the satellite signals and a vector...
The paper presents telemetry system for stratospheric balloon mission based on the UHF transceivers designed for Internet of Things. The system operates in 869.5 MHz frequency band. The system uses very short packet without channel coding that can be successfully received and decoded under low signal to noise ratio. The modem sensitivity −124 dBm and the transmission power 25 dBm can ensure reliable...
The paper introduces a design of radio spectrography receiver that shall serve as equipment for reception, monitoring, and processing of solar radio bursts. These burst can affect operation of many radio communication and navigation services as is presented on example of GPS satellites signal degradation. The concept and design of the spectrography receiver is presented together with discussion of...
At present, there are relatively more precise pHEMT models available for computer-aided design, and they are frequently compared to each other. However, such comparisons are mostly based on absolute errors of drain-current equations and their derivatives. In the paper, a novel method is suggested based on relative root-mean-square errors of both drain current and its derivatives up to the third order...
We propose the model of radio channel for ADS-B signal reception at the ground area of airport, which is typical by interference caused by multipath propagation. The model is based on a tapped delay line (TDL) model. The source data for model parameters estimation are obtained by measurements at Prague Vaclav Havel airport. We compare simulated results based on proposed model with experimental measurements.
The paper describes approach to processing of the ADS-B extended squitter signals and data provided by targets on the ground area of the airport. These signals are affected by radio channel environment which causes distortion and interference. The paper presents a method for estimation of the channel TDL model based on empirical data processing. This method is applied on measurement and processing...
The topic of the paper is focused on the design and implementation of the radio front-end part for experimental GNSS software receiver developed at the Department of Radio Engineering of the Czech Technical University in Prague. The receiver is designed for the processing of signals of present and future global navigation satellite systems, including GPS, GLONASS and Galileo. For the biggest possible...
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