Ultra wide band system based on cognitive radio

The spectrum of UWB signals is adjusted by pulse shaping in Impulse Radio. This paper analyzes the problem of tuning radiated UWB signals to meet spectral restriction taking orthogonal Hermite pulses for instance. A simple work model of cognitive UWB system presented in this paper may adapt its spectrum to environment need automatically. The simulation results indicate that shaping the spectrum by modifying the pulse waveform is effective. The UWB systems coexist with other wireless systems with lower interference each other according to the work model.