Narrowband interference suppression method in Cognitive Ultra-wide Band Radio

This paper investigates a novel narrowband interference (NBI) suppression method in Cognitive Ultra-wide Band (CUWB) Radio system. UWB signals and NBI are separated by Fractional Fourier Transform (FRFT) domain filters, and therefore an estimation of NBI can be obtained by utilizing inverse FRFT. The simulation results show that the UWB pulse waveform designed by Semi-definite Programming (SDP), which is a weighted sum of chirp functions, meets the emission mask established by the Federal Communications Commission (FCC), and the use of chirp function ensures that the FRFT domain duration of UWB pulse waveform is very short. Therefore the NBI parameters (e.g. center frequency, bandwidth, energy) are more convenient to be obtained by the estimated NBI. The UWB signal will not have a detrimental effect on the performance of the narrowband system by suppressing the UWB signal in the NBI band.