Statistical and intuitive nonlinear signal processing designs for multiuser interference mitigation in UWB systems
A theoretical model that fully explains the salient features of the probability density function (PDF) of the multiple access interference (MAI) in time-hopping UWB (TH-UWB) systems is discussed. The proposed model is enabled by considering simplified low-duty cycle rectangular and triangular pulses, but reveals precisely why a Gaussian approximation for the MAI in TH-UWB systems is highly inaccurate even when a large number of interferers are present. This theoretical model predicts correctly impulses, singularities, and heavy tails found in the distribution of the MAI. Results obtained from the model are validated by simulation.