On 07/01/2010 11:31 AM, Tom Rondeau wrote: >> Actually, my frequency-domain coefficient generator is based loosely on >> some earlier Swinburne >> code, and then I use the Gnu Radio FFT filter block, after turning the >> frequency-domain >> coefficients into time-domain ones (for some bizarre reason, the Gnu >> Radio FFT filter takes >> its coefficients in time-domain, rather than frequency domain). >> > (I should probably change the subject, but this is just a quick > interlude and hopefully won't spawn a long conversation.) > > Do you really think that's bizarre? I always think of filter taps > being naturally expressed in the time domain. But maybe that's just a > limitation of my background. In the constructor of the fft filter > block we do the FFT to convert them. Since all of our algorithms > return the taps in the time domain, it makes sense to me to handle > both filters the same. > > > Tom > > > Oh, I agree that it's in the tradition of Gnu Radio filters. It's just that after you've finished reading paper after paper about FFT filters for de-dispersion, with everything being expressed in the frequency domain, it's a bit jolting to find that the FFT filter takes "taps" in the time-domain.
Perhaps "bizarre" was too stong a term :-) -- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
