Finally, several valuable research directions are put forward, such as seeking a new wireless communications theory adapted to analyze nonsinusoidal UWB impulse radio, etc.

In dense multipath environments, IR-UWB (impulse Radio-Ultra Wideband) signals suffer from severe time dispersion which distorts the impulse wave.

The Hilbert-Huang Transform(HHT) methods is used to extract the weak impulse radio signal from interferential and noisy environment in this paper.