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Re: [Discuss-gnuradio] Re: Frequency dependent problem after syncronizin
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] Re: Frequency dependent problem after syncronizing , Please help! |
Date: |
Mon, 16 Feb 2009 12:55:14 -0800 |
User-agent: |
Mutt/1.5.18 (2008-05-17) |
On Thu, Feb 12, 2009 at 02:17:05PM -0800, Johnathan Corgan wrote:
> On Thu, Feb 12, 2009 at 1:20 PM, Bruhtesfa Ebrahim <address@hidden> wrote:
>
> > What makes it strange is the dependence on gain.when the linear gain in
> > the spectrum panel(usrp_fft.py)is set to 0,the signal at the center(the
> > DC)is 5dB higher than the noise level.When I increase the gain, the
> > difference between the DC and noise level keeps decreasing and finally
> > the DC level is equal to the noise level.
> > Specifically, for a linear gain >=20, the signal around DC is not
> > visible(it is equal to the noise level).
>
> Actually, what you're now describing is more like not receiving any
> signal at all--the small line at DC is residual DC offset from the
> ADC, and the noise is simply that, noise that gets amplified according
> to the gain setting. At a certain point the noise power exceeds the
> small DC offset.
>
> Johnathan
Agreed about no (or low) signal, though I think the small line at DC
is a truncation artifact in the FPGA.
Eric
- [Discuss-gnuradio] Frequency dependent problem after syncronizing , Please help!, Bruhtesfa Ebrahim, 2009/02/12
- Re: [Discuss-gnuradio] Frequency dependent problem after syncronizing , Please help!, Johnathan Corgan, 2009/02/12
- [Discuss-gnuradio] Re: Frequency dependent problem after syncronizing , Please help!, Bruhtesfa Ebrahim, 2009/02/12
- Re: [Discuss-gnuradio] Re: Frequency dependent problem after syncronizing , Please help!, Johnathan Corgan, 2009/02/12
- [Discuss-gnuradio] gnuradio mentioned in cnet article on phone snooping, ematlis, 2009/02/12
- Re: [Discuss-gnuradio] Re: Frequency dependent problem after syncronizing , Please help!,
Eric Blossom <=
- [Discuss-gnuradio] Re: Re: Frequency dependent problem after syncronizing , Please help!, Bruhtesfa Ebrahim, 2009/02/16