Spectral Properties ofUltra Wideband Signalswith GeneralTime-Hopping Codes

Spectra ofUltraWideband(UWB)signals arere- stricted tofrequency masksdefined byregulation authorities like theFederal Communications Commission (FCC)intheUnited States ortheRegulierungsbehorde furTelekommunikation und Post(RegTP) inGermany.To makeoptimumuseofthese frequency masks, technologies thatsmooththepeaksinthesig- nals' powerspectral density (PSD) should beimplemented. This contribution investigates theinfluences ofvarious modulation schemesaswellasdifferent timehopping codeswithgeneral probability density functions onthePSDsofimpulse radio UWB signals. IndexTerms-UltraWideband, Spectral Masks,Impulse Ra- dio