USRP2 IEEE802.11p and 802.11a

GNU Radio
1

Hi Colby, Hi Doug, Hi all,

In the last months we worked on implementing IEEE802.11p in gnuradio.
We started from scratch because it differs considerably from the BBN
code.

We successfully tested our transmitter against an 802.11p box.

802.11p and 802.11a do not differ too much from each other.
Thus, by changing a few parameters we were also able to receive gnuradio
USRP2-generated frames with an 802.11a atheros chipsets (even at
54Mbps).

We will submit a paper to the 6th Karlsruhe workshop on SDR, describing
the
implementation details.
After some small refinements we will also put our code on CGRAN.

Note that at this moment we only have the transmitter side.
Yes, I know, the receiver is the most challenging part, but step by
step,
i hope we will finally have a full OFDM-based IEEE802.11 transceiver on
CGRAN…
:smiley:

Best Regards,
Danilo

2

On Tue, Nov 24, 2009 at 10:38:54AM +0100, Valerio, Danilo wrote:

Best Regards,
Danilo

Thanks Danilo!

Eric

3

On Tue, Nov 24, 2009 at 10:38:54AM +0100, Valerio, Danilo wrote:

Hi Colby, Hi Doug, Hi all,

In the last months we worked on implementing IEEE802.11p in gnuradio.
We started from scratch because it differs considerably from the BBN code.

We successfully tested our transmitter against an 802.11p box.

Hi Danilo,

pretty cool stuff! I’m looking forward to your code.

802.11p and 802.11a do not differ too much from each other.
Thus, by changing a few parameters we were also able to receive gnuradio
USRP2-generated frames with an 802.11a atheros chipsets (even at 54Mbps).

I’m curious: did you manage to create 54Mbps in realtime and send them
via the USRP2, or did you do some pre-processing? I remember trying out
how far I could push OFDM signal generation in real time, but it was way
lower than 20 MHz.

We will submit a paper to the 6th Karlsruhe workshop on SDR, describing the
implementation details.

See you there – I hope we’ll find time for a chat.

MB

–
Karlsruhe Institute of Technology (KIT)
Communications Engineering Lab (CEL)

Dipl.-Ing. Martin B.
Research Associate

Kaiserstraße 12
Building 05.01
76131 Karlsruhe

Phone: +49 721 608-3790
Fax: +49 721 608-6071
www.cel.kit.edu

KIT – University of the State of Baden-Württemberg and
National Laboratory of the Helmholtz Association

4

Hi Martin,

I’m curious: did you manage to create 54Mbps in realtime and send them
via the USRP2, or did you do some pre-processing? I remember trying out
how far I could push OFDM signal generation in real time, but it was way
lower than 20 MHz.

Actually what the code does is taking a payload, encapsulating it into
an
IEEE802.11 frame, and transmitting it in compliance with the IEEE802.11p
standard (and IEEE802.11a). This means PLCP additions, scrambling,
encoding,
interleaving, OFDM symbols generation, etc.

So, it is not clear to me what you exactly mean by “real-time” in this
regard.
:wink:

We will submit a paper to the 6th Karlsruhe workshop on SDR, describing
the implementation details.

See you there – I hope we’ll find time for a chat.

I would like to be there, but I am not the first author.
So, credits to the others in the team… :slight_smile:
I hope they will also show up soon here in the list.

MB

Bests,
Danilo