Re: [Discuss-gnuradio] Can threading disturb sensing continuety

[kaleem ahmad]

Thank  Brian,

Can you give some hint, what do mean ??? I mean a little idea what do you
want to say?

Best Regards


Brian Padalino wrote:
> 
> On Fri, Mar 20, 2009 at 9:34 AM, kaleem ahmad <address@hidden>
> 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
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> 
> 

-- 
View this message in context: 
http://www.nabble.com/Can-threading-disturb-sensing-continuety-tp22598748p22621780.html
Sent from the GnuRadio mailing list archive at Nabble.com.