Spectral line suppression in TH-IR ultra wideband systems

The analytical, non-cyclostationary based, derivation of the power spectral density (PSD) of a general time-hopping (TH) impulse radio (IR) ultra wideband (UWB) signal with pulse position modulation (PPM) is introduced. Our analysis suggests that the PPM modulation index influences the overall shape of the signal´s PSD in a way that can be useful for spectral line suppression or for diminishing the PSD maximum peak power. Finally, the results are compared with the PSD obtained from simulation, suggesting that fast Fourier transform (FFT) based spectral estimation methods significantly overestimate the continuous part of the PSD for small and medium signal lengths, which would have implications in assessing interference margins by means of simulation.