Summary
International Symposium on Antennas and Propagation
2010
Session Number:2WD2
Session:
Number:2WD2-1
Pulse Shaping for Impulse Radio UWB
Robert Urban, Pavel Pechac,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
There are many ways how to increase quality of service (QOS) or the number of wireless users in the shared spectrum of modern wireless communication. It is possible to use better modulation schemes or multiplexes, but all of these techniques do not constitute a dynamic solution. A more intelligent solution of the spectrum access gives us the potential to solve these spectrum problems. Cognitive systems recognize other services and they are able to change their radio parameters in order to communicate with other cognitive nodes. This idea was well described in [1]. Ultra Wideband (UWB) technology serves as a powerful technology for the physical layer of wireless communication systems. The large bandwidth (7.5 GHz [2]) of UWB could also be used as the physical layer for the most common services. Wimedia Alliance has developed MB-OFDM UWB [3] (Multi Band Orthogonal frequency Multiplex) systems for Wireless USB and other hispeed applications such as video streaming. This technology uses several bands with a width of 528 MHz within the FCC spectral mask [2]. The cognitive technology principles have already been presented for the MB-OFDM UWB by channel cancelation. In this paper, we focus on pulse UWB where the basic modulations such as OOK and basic amplitude detection are supposed. The biggest disadvantage of the pulse system is the fact that it is not possible to use classic narrowband detection (super heterodyne receiver) because it is very difficult to use down conversion in pulse systems. These systems use different techniques to access the physical layer which are corresponding to optics principles or radar techniques. The power spreads into the wide bandwidth of the pulse where data are modulated directly, and the pulse is processed as a carrierless signal in the baseband. There are several shaping techniques presented in [4]. In this paper another principle of shaping technique is presented. The basic Gaussian pulse is directly shaped in the time domain so that the frequency spectrum of this pulse is shifted to an appropriate frequency. Measured data from the simplified system model are presented in chapter 3. This paper is organized as follows. Following this introduction, the frequency spectral mask shaping and the system model are explained. Measurements are then presented in part four, followed by the conclusion at the end.