[Discuss-gnuradio] USRP2 LFTX maximum real baseband bandwidth?

[TANGUY Philippe]

Hi all,

I would like to send a real signal with a bandwith from DC to 25MHZ 
thanks to the USRP2 and the LFTX daughterboard.

So, I generate a Real baseband signal and I use only the "I" channel. 
But, it seems that the minimun interpolation of USRP2 is 4 (USRP2faq) 
that's why I use interp=4. So, I have a bandwidth of 12.5 MHz because 
the sampling frequency is fs=25 MS/s ==> fs/2 = 12.5 MS/s. For me, it 
seems good.

So, my first question is:
Is it possible to use an interpolation of only 2 to have bandwidth=25 Mhz?

Secondly, I'm not sure but if we use interp=2 we have before the DUC a 
data rate = 50 MS/s * 32 (float32) = 1600 Mbits/s ==> > Gb/s.
However, if we use interp=2 and "short" format, we have a data rate = 50 
MS/s * 16 (short) = 800 Mbits/s ==> < Gb/s.

Is it correct?

Thanks,

Philippe.