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Re: [Discuss-gnuradio] BBN 802.11b updated: Barker spreading works
From: |
Eric Blossom |
Subject: |
Re: [Discuss-gnuradio] BBN 802.11b updated: Barker spreading works |
Date: |
Mon, 15 Jun 2009 07:31:03 -0700 |
User-agent: |
Mutt/1.5.18 (2008-05-17) |
On Sun, Jun 14, 2009 at 07:45:32PM -0700, Colby Boyer wrote:
> Hey All,
>
> I fixed the code in the pkt.py file so that DSSS with the barker code now
> works. The main issue was the length of the barker interpolation filter was
> way too short (like 8). I changed it so that it is now sample per baud *
> 11. Additionally the barker sequence needs to be time reversed on the
> receive side so that the correct match filter is formed. Otherwise the nice
> autocorrelation properties of barker will go away.
>
> I am only able to test it using the test script with a channel filter and
> gaussian noise and so far it has been a success there with both 1 and 2 Mbps
> modulation rates. Can someone test with USRP2? Also the BER seems to be
> much better as compared to just the RRC filter. Hopefully this will make
> TX/RX much more robust.
>
> The code is uploaded to the CGRAN svn under the branch/usrp2_version in the
> bbn project directory.
>
> Cheers,
> Colby Boyer
Thanks, Colby!