Re: [Discuss-gnuradio] Multiplexing modulators

[Marcus D. Leech]

On 06/21/2011 04:40 PM, John Ackermann N8UR wrote:
> Thanks, Nick.  I missed the sample rate factor because I was thinking of USRP1. 
>  I'll fix that and the fallacy of adding rates, and try again.
>
> Thanks,
>
> John
I have an example, in GRC, attached.

It uses an audio source, which is common to all three modulators, this 
goes to a fractional interpolator to interpolate up to the basic
  sample rate of 200Ksps, which is an integral divisor of 100Msps.

I don't actually send it to a USRP2, but you can see the basic 
structure, with complex multipliers acting as mixers, and a pair of
  30Khz signal sources, sampled at the 200Ksps sample rate, one set for 
30KHz, the other set for -30KHz.  An FFT display shows
  you the composite spectrum.

The bandwidth of the modulators is set by changing the "sensitivity" 
parameter.

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

three_fm_modulators.grc
Description: application/gnuradio-grc

three_fm_modulators.py
Description: Text Data