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Modelling and Simulation in Engineering
Volume 2012, Article ID 702917, 10 pages
http://dx.doi.org/10.1155/2012/702917
Research Article

Wideband and Ultrawideband Channel Models in Working Machine Environment

Centre for Wireless Communications, University of Oulu, 90570 Oulu, Finland

Received 23 April 2012; Revised 17 July 2012; Accepted 30 July 2012

Academic Editor: Matthias Pätzold

Copyright © 2012 Attaphongse Taparugssanagorn et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We present statistical models for wideband and ultrawideband (UWB) radio channels in a working machine cabin environment. Based on a set of measurements, it was found that such a small and confined space causes mostly diffuse multipath scattering rather than specular paths. The amplitude of the channel impulse responses in the wideband case is mostly Rayleigh distributed small-scale fading signal, with only a few paths exhibiting Ricean distributions, whereas the ones in the UWB case tend to be log-normally distributed. For the path amplitude, we suggest an exponential decay profile, which has a constant slope in dB scale, with the corresponding parameters for the UWB case. For the wideband case, a twofold exponential decay profile provides excellent fits to the measured data. It was also noted that the root-mean-square (RMS) delay spread is independent of the line-of-sight/obstructed line-of-sight situations of the channel. The multipath components contributing significant energy play a major role in such a small environment if compared to the direct path. In addition, the radio channel gains are attenuated with the presence of a driver inside the cabin.