Performance analysis of IR-UWB in a multi-user environment

In Impulse Radio Ultra Wide Band (IR-UWB) based systems, we show that the Multi-User Interference (MUI) assuming fixed spreading codes can be well approximated by a Generalized-Gaussian Distribution (GGD). Then, we derive an accurate closed-form expression of the approximation for the Average Error Probability (AEP) in both Direct-Sequence (DS) and time-hopping (TH) multiple access context. From this approximation, we are able to characterize and to select the set of codes minimizing the AEP for both multiple access techniques. The merit of each multiple access technique is then analyzed: we especially prove that the probability to find an optimal pair of codes goes to one when increasing the number of chips per symbol with TH technique whereas this probability goes to zero with DS technique. Numerical illustrations confirm our claims.