Re: [Discuss-gnuradio] Possible residual carrier not reported correctly

[Eric Blossom]

On Mon, Jul 28, 2008 at 11:34:01AM -0700, isaacgerg wrote:
> 
> Eric,
>   I have answered you questions inline:
> 
> >>Are you seeing any over or underruns ("uOuO" or "uUuU") on the console?
>   Occasionally, I see "u0" on the rx. But, even if i post process data
> offline, i still get the "flip"
> 
> >> How wide is the signal you're trying to send?
>   The rx interp is 256 and the tx interp is 512 giving a BW=250Khz.  Since I
> am just sending random samples, I am using the whole band.
> 
> >> What interpolation and decimation values are you using?
>   See above.
> 
> >> Try sending it at 10MHz.
>   I did.  The Rx cannot see my signal anymore; a PSD confirms this.  Not
> sure why.. maybe an antenna issue. 
> 
> >> What version of GNU Radio are you using?
>   I do not know what version the radios are. How do i find this out? The
> serial numbers are 1460 and 1461 and there is a date on the sticker that
> says 4/16/07.


Sorry, not the board, the GNU Radio software you're running on the host.

There was a problem in the FPGA code that was fixed quite a while
ago (6 or 9 months) where there was some kind of flipping.


> >> Have you isolated the problem to the Tx or Rx path?
>   I believe it is in the Rx path.  The TX path simply reads up a data file
> of samples and sends them to the USRP... very simple.  The RX path receives
> the data and attempts to correlate on the samples I sent.  However, I am
> noticing that the correlation is postive, then negative, and continues this
> way alternating about every 1000 samples or so.
> 
> Isaac

Eric