Historically, the Gaussian assumption for noise and interferences has dominated signal processing. The justification for this assumption is usually given by the well known central limit theorem which allows an elegant, manageable, and meaningful mathematical description of noise. Nevertheless, some communication scenarios are characterized by impulsive properties on behalf of Gaussian noise, so they are non-Gaussian distributed. Channels which are corrupted with impulsive noise can be found in several domains like for example powerline communications, ethernet traffic, underwater signal processing, or as proven in this project also the multiuser interferences of ultra wideband (UWB) communication systems. After describing and discussing impulsive noise models in detail, a comparison of their distributions has been carried out showing the suitability of the different models for solving selected problems. For example, it is well known that the channel capacity with additive impulsive noise channels is always greater than the one of additive white Gaussian noise (AWGN) channels supposed that the signal to noise ratio (SNR) remains unchanged. In this project the capacity of channels corrupted by impulsive noise has been investigated. An example shows the negative effect of the widely used hard limiter (for impulsive noise clipping) and suggests the use of an alternative one called soft limiter allowing no loss of information. Furthermore, UWB systems have been investigated regarding multiuser interferences. It is proven that the multiuser interferences of impulse radio systems are impulsive. Their probability density function is determined analytically and confirmed by simulation results. Taking this result into account a new receiver structure has been developed allowing the suppression of impulsive noise without use of a limiter. The performance of this receiver is proven by simulation.
| Identifer | oai:union.ndltd.org:DUETT/oai:DUETT:duett-07262005-124350 |
| Date | 03 August 2005 |
| Creators | Dhibi, Youssef |
| Contributors | Prof. Dr.-Ing. Ludwig Kittel, Priv.-Doz. Dr.-Ing. Thomas Kaiser |
| Publisher | Gerhard-Mercator-Universitaet Duisburg |
| Source Sets | Dissertations and other Documents of the Gerhard-Mercator-University Duisburg |
| Language | German |
| Detected Language | English |
| Type | text |
| Format | application/octet-stream, application/pdf, text/html |
| Source | http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-07262005-124350/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. Hiermit erteile ich der Universitaet Duisburg das nicht-ausschliessliche Recht unter den unten angegebenen Bedingungen, meine Dissertation, Staatsexamens- oder Diplomarbeit, meinen Forschungs- oder Projektbericht zu veroeffentlichen und zu archivieren. Ich behalte das Urheberrecht und das Recht das Dokument zu veroeffentlichen und in anderen Arbeiten weiterzuverwenden. |
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