Elimination of narrow-band interference using adaptive sampling rate notch filters

Two adaptive sampling algorithms are proposed to eliminate narrowband interference in broadband signals: adaptive sample rate filtering and adaptive decimation filtering. The filters used are fixed-coefficient IIR or FIR digital band-pass filters with center frequency located at some percentage of the sampling frequency (e.g. π/2). The adaptive algorithm adjusts the sample rate or decimation value until the output of the filter is minimized. Relatively complex bandpass filters may be adapted. Preliminary performance evaluations show that both techniques effectively filter narrowband interference from binary phase-shift keying (BPSK) signals