Analysis on interference of DS-UWB signal to narrowband systems

The power of ultra-wideband (UWB) signals has an extremely large frequency bandwidth which is a potential interference to narrow band systems. So UWB systems must obey the rules of frequency management of FCC when share frequency resources with traditional narrowband systems. It's presented the analysis of power spectral density (PSD) of direct sequence code UWB (DS-UWB) signals and some key factors of interference power of DS-UWB signals. It's studied that the relationship between envelop of DS-UWB PSD and energy spectral density (ESD) of pulse waveform and that among continuous and disperse components of PSD, modulated sequences and pulse repetition frequency (PRF). It's shown that some pseudo-random codes with suitable properties and parameters can reduce the interference power of DS-UWB signals to narrowband systems. Simulations have been done to prove it in this paper.