discuss-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] Symbol rates. USRP2 vs USRP1


From: Colby Boyer
Subject: Re: [Discuss-gnuradio] Symbol rates. USRP2 vs USRP1
Date: Wed, 22 Apr 2009 20:11:43 -0700

To confirm, you were able to receive 802.11b using the USRP2?

On Wed, Apr 22, 2009 at 5:57 PM, Doug Geiger <address@hidden> wrote:
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Colby Boyer wrote:
> What changes did you have to make to the sample/baud rate?
>
> How high is high SNR? 10dB? 15dB?
>
> I can only establish communication within simulation. When I try to
> transmit stuff over the air, it fails.
>

 I was transmitting with a USB WiFi dongle about 3 feet away and getting
successful packet decoding with some initial success (I've been putting
off getting back to that part of my project, so I don't have much useful
 information about measured SNR, etc.) and I was occasionally picking up
packets from another laptop in the same room. As I understand it that's
about the same performance that the original code did with the USRP1 -
so we ought to be able to better.
 For the samples/baud, it depends on the decimation rate: but since
802.11 uses a 1Mbaud/s symbol rate before spreading (either DBPSK for
1Mbps, or DQPSK for 2Mbps), at -d 4 that ends up being 25 symbols/baud,
 20 sym/baud at -d 5, etc.
 Doug

- --
Doug Geiger
Research Assistant
Communications and Signal Processing Lab
Oklahoma State University
address@hidden
address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.10 (Darwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAknvvRMACgkQPJjTsCiwNz5/EQCePFIFoLxCmDEEBym/pcZjTwBO
VVEAn0S9sPJhacmw4eHGshRK5iAKwoB5
=GGJO
-----END PGP SIGNATURE-----


reply via email to

[Prev in Thread] Current Thread [Next in Thread]