Copyright | (c) Matthew Donadio 2003 |
---|---|
License | GPL |
Maintainer | m.p.donadio@ieee.org |
Stability | experimental |
Portability | portable |
Safe Haskell | Safe |
Language | Haskell98 |
Module to sharpen FIR filters
Reference: Hamming, Sect 6.6
H'(z) = 3 * H(z)^2 - s * H(z)^3
= H(z)^2 * (3 - 2 * H(z))
Procedure:
- Filter the signal once with H(z)
- Double this
- Subtract this from 3x
- Filter this twice by H(z) or once by H(z)^2