How distant is the ideal filter of being a causal one?

J.M. Almira, Alfonso E. Romero

Research output: Contribution to journalArticlepeer-review


In this paper the characterization as convolution operators of filters sending finite energy signals to bounded signals is used to prove several theoretical results concerning the distance between the ideal filter and the spaces of physically realizable filters. Both the analog and the digital cases are studied and the formulas for the distance and the angle between the filters in each case are also given.
Original languageEnglish
Pages (from-to)45
Number of pages56
JournalAtlantic Electronic Journal of Mathematics
Publication statusPublished - 2008


  • Filters
  • Shift Invariant Operators
  • Applications of Fourier Analysis
  • History of Mathematics.

Cite this