On Fri, Mar 20, 2009 at 9:34 AM, kaleem ahmad <kaleem_...@yahoo.com> wrote: > > Thanks Ed, > > ADC sampling rate = 64MHz > it gives resulution time = 1/64MHz = 156 ns > if we choose N=512 for FFT then total observation time for one scan(one > complete FFT) is = 156ns x 512 = 8 micro sec > if the maximum possible (expected) cycle time is 200ms then: > it needs 200ms/8microsec = 2500 continues FFT scans to cover the range of > frequencies that correspond to 200ms cycle time. > > Is above calculation correct? > > The other possibility to increase the observation time is to increase the > FFT size, but to cover entire 200ms would need 200ms/1/64MHz = 12800000 = > FFT size (Which is not possible! Is it ???) > > Now please comment if my above calculations are correct or not and secondaly > if my calculations are correct then how can I process (using GNURadio) 2500 > cosective FFT's (with surety that no FFT in between these 2500 FFT's is > missing due to slow processing or thread switching) to find two peaks in a > single array (availability of two peaks will give me the oppertunity to > calculate the time distance between them).
It sounds like you're trying to do autobaud for an unknown FSK system - but using the frequency domain to do this instead of the time domain phases. I'd recommend thinking of an algorithm in the time domain that would suit your needs. Brian _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
