Fractional Delay Lines using Lagrange Interpolators

Ph. Depalle - S. Tassart
phd@ircam.fr - tassart@ircam.fr

IRCAM, Analysis/Synthesis Department
1 place Igor-Stravinsky, 75004 PARIS, FRANCE

Abstract:

We propose in this paper an original approach to the implementation of the Lagrange Interpolator Filter (LIF) based on the formal power series expansion of the transfer function of the ideal fractional delay digital filter. This approach leads to a different, new, modular and robust algorithm usable for real-time delay-varying applications.

• Introduction
• Lagrange Interpolators
  • Ideal Fractional Delay Filters
  • Lagrange Interpolator Filter
  • Power Series Expansion
  • Iterative Definition
  • Horner's scheme
  • Influence of the Parity Order
  • Choice of the Order
• Delay-Varying Implementation
  • Modular LIF structure
  • Algorithm
  • LIF Order Adaptation
• Conclusion
• References
• About this document ...