Abstract:

Ultrawideband (UWB) systems must coexist with narrow band systems and implement adaptive use of available bandwidth for cognitive UWB radio. To deal with these challenges, a cognitive UWB adaptive pulse design method based on the eigenvectors of Hermite matrix and bipolar Gaussian combined signal is presented for narrow band interference (NBI) suppression. Simulations show that the proposed adaptive UWB pulses met with the federal communications commission indoor and outdoor spectral mask and produced arbitrary spectral notches with flexible cognitive avoid ability. Furthermore, through the MonteCarlo simulation of pulse position modulationtime hopping and pulse amplitude modulationtime hopping systems, the proposed adaptive UWB pulses are proved to have stronger multiuser interference and NBI suppression abilities than Scholtz pulse.

Key words: ultrawideband, cognitive radio, Hermite matrix, bipolar Gaussian pulse, interference suppression