A system to generate ultra-wideband(UWB) signals is established.For the low power efficiency and modulation difficulty,a method to implement modulation of UWB signal based on fiber Bragg grating(FBG) is proposed.The proposed method increases the signal noise ratio as well as provides schemes to generate different pulse modulation signals.UWB monocycle signals with bi-phase modulation,pulse-amplitude modulation and pulse-position modulation are realized.The transmission performance of the generated UWB signals over fiber is analyzed.After transmission of 60 km along a single mode fiber,the eye diagram is clear and achieves error free.Simulation and experiment results show that this method is simple and feasible for application in optical UWB communication systems.