Vojtech Derbek’s research while affiliated with Brno University of Technology and other places

This paper describes a time domain channel sounder based on pseudorandom binary sequences. The channel sounder system consists of several off-the-shelf laboratory instruments connected together and controlled from PC. Frequency band of interest is the unlicensed ultra wide band, 3-11 GHz. The system's parameters are discussed and compared to conventional solution, which uses vector network analyzer (VNA). Crucial feature of the proposed system is fast measurement speed. Example measurements are provided and compared to the measurements performed using the VNA.

This paper provides results of radio channel measurement campaign carried out in the intra vehicle environment for ultra-wide band (UWB) and millimeter wave (MMW) frequency bands, namely 3–11 GHz and 55–65 GHz. In discussed frequency bands, we present and compare channel impulse responses (CIRs) for various antenna locations while considering the effect of passengers presence. On the basis of performed statistical evaluation of time of arrival (TOA) based ranging system deployed in mentioned bands, we discuss feasibility and precision of local positioning systems for intra vehicle ambiance.

The concept presented in this paper if focused on a special type of an energy efficient RFID tag, which is suitable also for non-RFID applications, such as low power intelligent networks, sensor applications, cooperative WSN (Wireless Sensor Network), systems for the intelligent household, etc. The highest attention is put on the antenna system, which uses the technology of an adaptive beam forming. One of the goals of this paper is an evaluation of the suitability of the proposed concept and of the whole approach, considering its practical realization.

This paper describes a software defined radio system for measurements of minimum activation power and backscatter power of UHF RFID tags. We propose a platform for performance testing of tags, which is based on a general purpose universal software radio peripheral (USRP) and optimized for operation in the frequency band from 700 MHz to 1100 MHz at the output power of 2 W ERP. The presented HW and SW stack extends the standard library of USRP with RFID specific functions, an interface to LabVIEW, and by a top level LabVIEW code for automated testing.