In-band interference of three kinds of UWB signals in GPS L1 band and GSM900 uplink band

This paper studies in-band interference of different kind of ultra wideband (UWB) signals. UWB frequency spectra are produced by using several types of narrow pulse waveforms, all based on the Gaussian pulse. Due to the extremely wide bandwidth, these signals spread over the frequency bands allocated to other radio systems. In-band interference power is calculated over the IF bandwidths of two victim receivers as a function of pulse width. Also, the signal attenuation with distance is presented. The victim systems under the study are GPS (L1-band) and GSM900. Based on the results, the 3^rd derivative of a Gaussian pulse seems to be the best choice, from the interference point of view, among the waveforms included in this study. It causes less interference than the Gaussian pulse or Gaussian doublet if the pulse widths are shorter than 1 ns. The system utilizing the direct sequence concept caused less in-band interference power than the system utilizing time hopping amongst all waveforms studied. The studied UWB systems are based on bi-phase baseband data modulation