Splitting the Unit Delay -
These pages give instructions for downloading and using the MATLAB Files
associated with the article:
Tools for Fractional Delay Filter Design
Timo I. Laakso,
and Unto K. Laine,
"Splitting the unit delay - tools for fractional delay filter design,"
IEEE Signal Processing Magazine, vol. 13, no. 1, January 1996.
How to download the Matlab files
Description of the files
The file fdtools.zip has been compressed using pkzip. The Matlab
files have been tested to run correctly on Unix, Macintosh, and Windows
The accompanying set of MATLAB routines can be used to design fractional
delay FIR and allpass filters and to plot their responses. The basic MATLAB
and the MATLAB Signal Processing Toolbox are needed.
The Figures included in the above article can be plotted using the files
FDFIR2.M and FDAP2.M. The former generates the magnitude and phase delay
curves and the impulse responses for FIR fractional delay (FD) filters.
The latter gives the phase delay responses and the impulse responses of
the allpass fractional delay filters. These two functions use the other
files which are the actual filter design functions and their subroutines.
The FIR FD package consists of the following 11 MATLAB routines (m-files):
fdfir2.m (main program)
The allpass FD package consists of the following MATLAB routines (m-files):
fdap2.m (main program)
Comments or suggestions can be sent by e-mail to Timo I. Laakso or to Vesa Välimäki.
This software is being provided to you, the LICENSEE, by Helsinki University
of Technology (HUT) under the following license. By obtaining, using and/or
copying this software, you agree that you have read, understood, and will
comply with these terms and conditions: Permission to use, copy, modify
and distribute, including the right to grant others rights to distribute
at any tier, this software and its documentation for any purpose and without
fee or royalty is hereby granted, provided that you agree to comply with
the following copyright notice and statements, including the disclaimer,
and that the same appear on ALL copies of the software and documentation,
including modifications that you make for internal use or for distribution:
Copyright 1996 by Helsinki University of Technology (HUT) All rights reserved.
The allpass design package is copyrighted by NOKIA, MIT, and GE (1994).
THIS SOFTWARE IS PROVIDED "AS IS", AND Helsinki University of
Technology MAKE NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED. By
way of example, but not limitation, Helsinki University of Technology MAKE
NO REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR
PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE OR DOCUMENTATION WILL NOT
INFRINGE ANY THIRD PARTY PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.
The name of the HUT may NOT be used in advertising or publicity pertaining
to distribution of the software. Title to copyright in this software and
any associated documentation shall at all times remain with the HUT and
USER agrees to preserve same.
Timo Laakso and Vesa Välimäki
London, January 26, 1996
Last update: Feb. 1, 1996
Helsinki University of Technology
Laboratory of Acoustics and Audio Signal Processing