Re: [Discuss-gnuradio] Re: Residual Frequency?

[Brian Padalino]

On Mon, Apr 21, 2008 at 6:16 PM, Johnathan Corgan
<address@hidden> wrote:
>  The "full scale" output to the RFX boards is +-32767.0.  It is not
>  recommended that you actually use this, as it will drive the RFX
>  output stages into a strongly non-linear operating range, increasing
>  noise and spurious signals significantly.  From empirical
>  measurements, the RFX boards can only get to about 15% full scale
>  before they go into gain compression.  That would be about +-5000 into
>  usrp.sink_c.

Just for the knowledge of the list and to better understand the
hardware, in the application defined by the original poster  a
constant envelope GMSK signal is being used.

With that being said:

  a) Should the compression of the output stages really affect his
constant envelope GMSK signal?
  b) Is there any future enhancement scheduled to feed the
daughterboard a normalized signal with a "backoff" in dB which will
try to ensure linearity?

The answer to (a) is just for my own curiosity whereas the answer to
(b) might be helpful for people investigating OFDM, or M-QAM signals
where the PAPR might be upwards of 10 to 12 dB.

Brian