Tamás Krébesz

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Both the peak power and the average power of emission are limited in UWB systems in order to keep the interference caused in an already existing narrowband radio system low enough. It is frequently overlooked that these power limits have to be checked not over the transmitted UWB signal but at the output of a bandpass filter specified in the FCC(More)
In UWB systems three factors have to be considered to design a radio link: (i) peakand (ii) average power limits defined by FCC Regulations and (iii) low supply voltage available in handheld cheap devices. An exact mathematical model for the interpretation of FCC Regulations is derived. The radio coverage of UWB networking devices is determined and a(More)
For lack of empty radio bands, ultrawideband (UWB) radio system allowing reuse of already occupied frequency bands is the only solution to accommodate new wireless data communication services. Two types of UWB carriers are considered here, the frequency-shifted Gaussian pulse and chaotic signal with FM-DCSK modulation. A generalized model of transmitted(More)
A systematic approach for the derivation of UWB detectors cannot be found in the literature. The detectors published up to now have been developed by inspection, using a heuristic approach. However, that solution prevents the optimization of UWB detector performance. A new approach is proposed here for the derivation of optimum waveform detectors that is(More)
Chaotic signals are ultra-wideband signals that can be generated with simple circuits in any frequency bands at arbitrary power level. The ultra-wideband property of chaotic carriers is beneficial in indoor and mobile applications where multipath propagation limits the attainable bit error rate. Another possible application is the ultra-wideband (UWB)(More)
In an Ultra-WideBand (UWB) Low-Rate (LR) Wireless Personal Area Network (WPAN) application low-cost, low-power and low-complexity systems are expected to meet the requirements of the typical applications. These demands can only be satisfied by simple modulation schemes and easy to implement noncoherent receiver configurations. However performed field tests(More)
To satisfy the huge demand for unlicensed handheld wireless networking devices, the Federal Communications Commission (FCC, USA) made the application of ultra-wideband (UWB) technology possible in 2002. Since then an IEEE standard has already been approved for the physical layer of the UWB impulse radio networking devices. Because of the ultra-wideband(More)