Monte Carlo analysis of matched-filter performance after narrowband interference suppression

One technique for suppressing narrowband interference in a pseudonoise (PN) spread-spectrum system prior to matched filtering with the PN sequence is threshold excision (THE), which sets the Fourier amplitudes equal to zero at all fast Fourier Transform (FFT) frequencies at which the spectrum exceeds a given threshold. The threshold dependence of the matched filter signal-to-noise ratio (SNR) obtained after THE, without time-domain weighting of the data and with a raised-cosine window, is analyzed. A Monte Carlo simulation is performed for synthetic data sets consisting of a binary PN signal, white Gaussian background noise, and sinewave interference spread throughout the wide signal band. The results are compared to those obtained from vector space interference excision (VSIE).<>