Testing the Gaussianity of UWB TH-PPM MUI with imperfect power control and multipath

We study the statistical nature of the multiuser interference (MUI) from pulse-based ultrawideband (UWB) signals with time-hopping (TH) and pulse position modulation (PPM). We determine the domain of validity for the Gaussian assumption for three different conditions: An ideal propagation channel with perfect and imperfect power control, as well as a multipath channel with rdquoperfect averagerdquo power control. Results for imperfect power control suggest that the Gaussian approximation can be used if we consider a large enough number of active users N_u and/or number of pulses per symbol N_s, e.g., for low data rate systems with large number of users. Results for multipath suggest that in dense multipath environment a low number of N_u and/or N_s is enough to reach Gaussianity.