Re: calculate SNR and watch a binary file

[Markus Feldmann]

Rob Mahurin schrieb:
> On Mar 26, 2009, at 3:24 PM, Markus Feldmann wrote:
> > I upload binary files. The first is with a sin signal:
> > http://rapidshare.com/files/213866747/ 
> > usrp_output_64bit_complex_only_sin_signal.dat.html
> >
> > and another one without any test signal, but only noise:
> > http://rapidshare.com/files/213867606/ 
> > usrp_output_64bit_complex_only_noise.dat.html
>
>
> These files came from some analog-to-digital converter?  If you look  
> at them with hexdump, there is stuff that looks like data only in the  
> first 200 bytes or so.  The rest of the file looks likes zeros and  
> the occasional 0x80bf.  I wouldn't expect the data read from these  
> files to have a meaningful Fourier transform.
>
> Cheers,
> Rob
I also noticed that the beginning looks different to
the rest.

Maybe i have to collect 32bit to one float count ?
As i wrote, 1 sample consists of 32 bit, and because
this comes from an IQ signal, this should be 2 samples ???!

If i only plot the vector containnig the float samples:
c=read_complex_binary('usrp_output_64bit_complex_only_sin_signal.dat');
t=1:1:100;
plot([real(c(t)), imag(c(t))])
i got for the beginning,
http://img90.imageshack.us/my.php?image=from1to100bits.jpg

And if i do,
t=100:1:164;
plot([real(c(t)), imag(c(t))])
http://img90.imageshack.us/my.php?image=from100to164bits.jpg

Regards Markus