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Re: [Patch-gnuradio] gr_rotator fix/optimization
From: |
Matt Ettus |
Subject: |
Re: [Patch-gnuradio] gr_rotator fix/optimization |
Date: |
Fri, 07 Sep 2007 15:15:46 -0700 |
User-agent: |
Thunderbird 2.0.0.0 (X11/20070326) |
Dan Halperin wrote:
> I ran some quick trials and found that C takes around 18k (I was
> surprised it was this fast, actually!) iterations for the phaser
> amplitude to be off by 0.1%. So K around a hundred or a thousand should
> be good.
0.1% is -60dBc. After 100K interations, it will be 0.55% ( 0.999 ^
(100K/18K) ), which is only 45dB down. On the other hand, if we do the
correction every 1000 points, the error will be -85 dBc ( 0.999 ^
(1K/18K) ).
Thanks for investigating this!
Matt