Abstract:

In order to reduce the inter symbol interference (ISI) and multiuser interference (MUI) which exist in the ultra wideband positioning system under the multiuser and weak signal environment, an adaptive iterative algorithm based on minimum mean square error estimation (MMSE) for ultrawideband (UWB) pulse design is proposed. Modified Hermite polynomial (MHP) is selected as the basis function of the designed pulse. By analyzing the timefrequency characteristics of MHP, coefficients of combined pulse are modified by the MMSE criterion. According to the fitting degree of power spectrum density between combined pulse and Federal communications commission (FCC) radiation masking, an adaptive algorithm is designed to realize pulse design. Simulation results show that the proposed scheme can obtain higher power utilization, and also obtain strong applicability in multiuser access and weak signal detection.