Re: [Discuss-gnuradio] Tx Amplitude in USRP N210

[Marcus D. Leech]

On 28/09/11 04:01 AM, Konstantinos wrote:
> Hi,
>
> I am trying to find out how to set the TX-amplitude parameter between 0-1,
>  which
> is given as an option in USRP sink. My attempts 
> to find a clear explanation of
> this parameter have all failed. 
>   
A UHD sink has a "Gain" parameter--is that what you're talking about? 
That parameter sets the
  *analog gain* of the particular daughtercard in use.  The final output
power produced by the
  transmit side will be a product of the analog gain setting, and the
magnitude of the signals
  coming from the Gnu Radio flow-graph.  In UHD, it expects signals that
are normalized into
  {-1.0,+1.0}, and UHD scales that into the range expected by the
particular hardware.

> Also, I would like to understand how to 
> set the receive SNR in the source file?
>
> As for the receive SNR, my guess would be 
> to solve the classic equation, which
> involves estimating the noise figure, 
> transmitted power, gains of antennas etc.,
> however it does not seem to me a very 
> realistic approach. How do you set this value?
>
> I would appreciate anyone's hints.
>
>   
Not sure what you mean by "set the receive SNR in the source file".  The
SNR is a property of a received
  signal.  It's not something you "set" in the hardware, although
hardware/software settings can
  certainly *influence* the received SNR.




-- 
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org