Gerd Wölfle

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Currently, for the planning of wireless cellular networks in urban scenarios either empirical (direct ray or over rooftop ray) or ray-optical (ray tracing) propagation models are used. In this paper both approaches are compared to one another and to measurements in different urban city centers. Additionally a new concept which is called Dominant Path Model(More)
Ray-optical propagation models are often utilized for the prediction of the field strength (and delay spread) in mobile radio networks. However, the practical usage of these deterministic models is limited by their high computational demands. A new method for the acceleration of ray-optical models is presented in this paper. It is based on a single(More)
| In the last years different prediction models for indoor environments were developed for the frequency range between 500 MHz and 5 GHz. Each of these models has its own advantages and disadvantages. In this paper four of the most popular models are compared to one another and to measurements in different buildings. The comparison is limited to the(More)
Abstract | A new model for the field strength prediction for mobile communication networks inside buildings is presented in this paper. The model is based on the determination of the dominant paths between the transmitter and the receiver. The field strength is predicted with artificial neural networks, trained with measurements. In contrast to other neural(More)
| Ray-optical propagation models are often used for the prediction of the field strength (and delay spread) in wireless mobile communication networks. But these models suffer from long computation times. For large areas in urban or indoor scenarios the computation times are in the range of hours which is too long for the planning of mobile radio networks. A(More)
Most applications for location based services rely on a precise determination of the location of the mobile terminal. Especially in urban and indoor environments multipath propagation leads to very complicated scenarios without line-of-sight between the mobile terminals and the base stations. In these scenarios a localization technique based on simple delay(More)
| Ray-optical propagation models are often used for the prediction of the field strength (and delay spread) in wireless mobile communication networks. But these models suffer from long computation times. For large areas in urban or indoor scenarios the computation times are in the range of hours which is too long for the planning of mobile radio networks. A(More)
| Deterministic 3-D modelling of wave propagation in urban areas has become a widely discussed technique for the planning of microcells. However, the practical use of these deterministic models has been limited due to their high computational demands. This paper presents a new approach with the aim of combining the accuracy of ray optical models with the(More)