Jan. 23, 1993

Dfir is a digital filter design package which includes several different
design strategies for FIR (finite impulse response) filters.

Equiripple linear phase multi-band filter:
  This is an augmented version of the McClellan-Parks design.
  - Amplitude contraints (Grenez approach)
  - Option for sin(x)/x compensation
  - Monotonic cubic interpolation used to fill in values of the
    amplitude, weights, or constraints between given values.  This
    allows for easy specification of non-constant bands with a
    relatively small number of points.
  - Modularization allow the design algorithm to be called as part of
    an iterative design (actually used by the Nyquist designs).

Linear phase differentiators:
  Based on the McClellan-Parks / Grenez algorithms augmented as above.

Linear phase Hilbert transform filters
  Based on the McClellan-Parks / Grenez algorithms augmented as above.

Minimum-mean square error interpolating filters:
  This is an augmented version of the Oetken-Parks design.
  - Input power spectrum modelled by monotonic cubic interpolation
  - The continuous portion of the power spectrum can be augmented
    with sinusoids at discrete frequencies
  - Allow both even and odd numbers of coefficients

Equiripple Nyquist filters:
  These filters have regular zero crossings (for data communications
  or interpolation applications)
  - The filter is specified in terms of stop-band frequencies and
    weights

Minimum phase factor of an equiripple Nyquist filter
  These filters when cascaded with the matching filter give a Nyquist
  response (regular zero crossings)
  - The filter is specified in terms of stop-band frequencies and
    weights

=============
The code for this package is written in ANSI Fortran 77.  It has been
run on DECstations and Suns.

The routines are covered by copyright, see the file "Copying" for details of
the distribution conditions.

dfir-V2R0.tar.Z
anonymous ftp from:
  aldebaran.EE.McGill.CA  in pub/dfir

=============
Additionally a package to plot filter responses is availble as
pltfilter-V2R0.tar.Z
anonymous ftp from:
  aldebaran.EE.McGill.CA  in pub/pltfilter

=============
Peter Kabal
Department of Electrical Engineering    McGill University
+1 514 398-7130   +1 514 398-4470 Fax
kabal@TSP.EE.McGill.CA
