Re: [Discuss-gnuradio] bandwidth for USRP

[David Carr]

All this RA talk makes me curious about what a typical RA IF setup looks 
like.

Do RA samplers usually employ quadrature sampling (I and Q) or do they 
sample
a "real" signal at twice the desired bandwidth? 
Also, if the big boys use 1GHz sample rates, what do the little boys 
use? 10s or 100s of MHz?

If you only have one or two bits of dynamic range there must be a pretty 
big AGC in the loop.
-DC

Vincenzo Pellegrini wrote:
> Hi everybody,
> this is probably a silly question, but there's one thing i cannot fully
> understand.
>
> Considering that the 2 ADCs per channel on the USRP allow complex
> samping at 64Msps, and therefore a 64MHz Spectral Bandwidth, and that my
> inexpensive PC just needs 45% of CPU calculation power in order to make
> an 8MHz wide FFT of the 8 complex Msps allowed (as a maximum) by the USB
> 2.0 bus,
>
> doesn't it look like the USB 2.0 is a heavily constraining bottleneck?
>
> And, if I'm not wrong about this, will it be possible in the future to
> have a USRP <--> PC interface which doesn't limit us so much.
>
> thanks
> (...and apologies in case this question doesn't make much sense)
>
> vincenzo pellegrini     
>
>
>
>
> _______________________________________________
> Discuss-gnuradio mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
>