On 18/10/11 01:38 PM, Mattia Rizzi wrote: > I’m using gnuradio-3.3.0 with GRC. > I’ve builded a graph with a Complex cosine (8Ms/s of sample rate and 1 > MHz of frequency), the fractional interpolator with 12/8 value for > interpolation and a FFT sink with 12MS/s of sample rate. (throttle > block included). > I’m expecting to see a 1MHz cosine with the FFT, but i see a 2.25MHz > cosine. If i put 8/12 (the inverse) i see the (correct) 1MHz cosine. > Why? > If i use the Rational resampler, with interpolation 12 and decimation > 8, i see the correct 1MHz cosine. What’s wrong with fractional > interpolator block? > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > Because the fractional interpolator takes the *inverse* as the desired fraction--think of it as a decimation ratio.
-- Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
