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Re: [Discuss-gnuradio] USRP DDC usage
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] USRP DDC usage |
Date: |
Thu, 26 May 2005 19:34:53 -0700 |
User-agent: |
Mutt/1.5.6i |
On Thu, May 26, 2005 at 01:36:28PM -0400, Krzysztof Kamieniecki wrote:
> Quoting Achilleas Anastasopoulos <address@hidden>:
> > I have a question/observation on this issue:
> >
> > Since the DDC multiplication is complex and since the internal DDC
> > oscilator is noncoherent, I do not see a difference between the MUX
> > settings: 0x33221100 and 0xf3f2f1f0.
> >
> Is the difference between them a phase shift of 45 degrees and a gain ratio of
> sqrt(2)?
That's what I would expect.
> > Similarly, with the setting 0x00003210 you will never be able to
> > separate the two channels coming from ADC0/ADC1 and ADC2/ADC3.
> >
> You can seperate ADC0/ADC1 and ADC2/ADC3 if you set the DDC frequency to zero
> (I
> think you also have to never have set it to a non-zero value after powerup,
> since you can't reset the DDC phase)
I think I'm missing the question. Set nchannels to 2 and the output
of the two DDCs will be interleaved. You deinterleave to separate
them.
See gnuradio-examples/python/usrp/wfm_rcv_many.py for an example that
separates the output from more than one DDC.
Eric
- [Discuss-gnuradio] USRP DDC usage, Philip Balister, 2005/05/25
- Re: [Discuss-gnuradio] USRP DDC usage, Achilleas Anastasopoulos, 2005/05/26
- Re: [Discuss-gnuradio] USRP DDC usage, Achilleas Anastasopoulos, 2005/05/26
- Re: [Discuss-gnuradio] USRP DDC usage, Krzysztof Kamieniecki, 2005/05/26
- Re: [Discuss-gnuradio] USRP DDC usage, Eric Blossom, 2005/05/26
- [Discuss-gnuradio] Delta 44, Bob McGwier N4HY, 2005/05/26
- Re: [Discuss-gnuradio] Delta 44, Eric Blossom, 2005/05/27
- Re: [Discuss-gnuradio] Delta 44, n4hy, 2005/05/27
- Re: [Discuss-gnuradio] Delta 44, Matt Ettus, 2005/05/27
- Re: [Discuss-gnuradio] Delta 44, n4hy, 2005/05/27
- Re: [Discuss-gnuradio] Delta 44, James Cooley, 2005/05/27
- Re: [Discuss-gnuradio] Delta 44, Eric Blossom, 2005/05/28