Scaling issue on USRP2

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On Sat, Aug 14, 2010 at 18:26, George N. [email protected] wrote:

However, when I transmit using my scaled signal, I get some major clipping:

Aside from clipping, you are probably seeing some distortion due to
non-linearities in the PA of whatever daughterboard you are using.
Depending on your modulation (which looks like OFDM in the screenshot),
you’ll need to back off the digital amplitude to operate in the linear
region of the PA to avoid this. It’s specific to the card and
modulation in
use, but typically about 10-15 dB back off is required.

And yes, you should take into consideration the abs(complex) value.