Design of fractional delay filter using discrete Fourier transform interpolation method

  • Authors:
  • Chien-Cheng Tseng;Su-Ling Lee

  • Affiliations:
  • Department of Computer and Communication Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan;Department of Computer Science and Information Engineering, Chung Jung Christian University, Tainan, Taiwan

  • Venue:
  • Signal Processing
  • Year:
  • 2010

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Abstract

In this paper, the design of fractional delay FIR filter is investigated. First, the interpolation formula of a discrete-time sequence is derived by using discrete Fourier transform (DFT). Then, the DFT-based interpolation formula is applied to design fractional delay FIR filter by using suitable index mapping. The filter coefficients are easily computed because a closed-form design is obtained. Next, design examples are demonstrated to show that the proposed DFT method has a smaller design error than those of the conventional Lagrange and window fractional delay FIR filters when using the same design parameters. Finally, the designed DFT-based fractional delay FIR filter is applied to design a digital differentiator and half-band filter.