Re: [Discuss-gnuradio] designing filters: remez?

[Martin Braun]

On Thursday, 10. January 2008 20:01, Patrick Strasser wrote:
> method functions. Is there something bad about designing filters with
> the Remez method? I thought it would be clever to constraint the filter
> to a number of coefficients, as this parameter is most important for
> processing speed.

I haven't had a look at the code, but in general the Remez method is always 
superior. In fact, the last course I had on filter design taught me the 
window method is only really used in quick-and-dirty filter design and in 
teaching, because it's so simple to explain (plus, it's easier to code).

> Moreover, what would bring faster results, a designer using the window
> method or one with the remez method?

I doubt the window method can be beaten in terms of speed, as it's only an FFT 
and a multiplication, but I don't know how much faster it is.
However, usually the filter design is not in the time critical part of an 
application, whereas the number of taps has direct influence on performance.
Given the choice, I'd say use remez when possible.

martin

-- 
Martin Braun
Institut fuer Nachrichtentechnik
Universitaet Karlsruhe

http://www.int.uni-karlsruhe.de