A Novel Design Technique for Variable Non-recursive Digital Filter based on FrFT

  • P. Mohindru Punjabi University
  • R. Khanna Thapar University
  • S. S. Bhatia Thapar University


A novel technique is introduced through this paper to tune the frequency characteristics of a low-pass  finite impulse response (FIR) filter. The work is based on fractional Fourier transform (FrFT) which can be used in modifying the magnitude and phase characteristics of a filter with adjustable FrFT angle as tuning parameter. The analysis of desired impulse response of filter in fractional Fourier domain establishes the dependence of its frequency response on the changeable fractional order parameter. The essence of using FrFT in variable digital filter design is that we need not to re-compute impulse response coefficients and redesign a new filter in order to bring changes in the filter characteristics. Thus it is projected in the work that fractional Fourier transform can be used in tuning window-based FIR digital filters. Ill. 4, bibl. 2, tabl. 12 (in English; abstracts in English and Lithuanian).

DOI: http://dx.doi.org/10.5755/j01.eee.121.5.1657