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Re: [Discuss-gnuradio] USRP Synchronization
From: |
Matt Ettus |
Subject: |
Re: [Discuss-gnuradio] USRP Synchronization |
Date: |
Fri, 12 May 2006 13:31:45 -0700 |
> Why would it take 8 clocks? Surely the hardware could do the hard
> part (jam it to zero immediately) and the software could do the rest
> (if it needs to taper off over 8 clocks, end with the right samples).
>
Ramping down results in a cleaner spectrum. Immediate shutoff splatters
the band.
> Hmm, in fact, why is this a problem at all? Why can't the software
> ensure that the final sample before underrun is a zero? The hardware
> will then keep repeating this final sample forever.
That would be the best way to go.
> (I suppose this would be possible if you aren't using any of the
> upconverters -- but if the FPGA or the DAC is upconverting, then you
> have to jam a real zero, not an upconverted zero? Is this even
> possible?)
An upconverted zero is still a zero. It's a multiplicative process.
Matt