Discontinuous OFDM implementation?

GNU Radio
1

Hi all,

Has anyone out there implemented discontinuous OFDM on GNU Radio and the
USRP? I’ve seen a couple papers with an implementation on GNU Radio in
DySPAN and some other conferences, but nobody has responded to my
requests
for the implementation.

  • George
2

On Sun, Apr 25, 2010 at 2:37 PM, George N. [email protected] wrote:

Hi all,

Has anyone out there implemented discontinuous OFDM on GNU Radio and the
USRP? I’ve seen a couple papers with an implementation on GNU Radio in
DySPAN and some other conferences, but nobody has responded to my requests
for the implementation.

  • George

Do you mean discontinuous in time or frequency? If you’re talking
about frequency (selectively turning off subcarriers, which I’ve heard
referred to as non-contiguous OFDM mostly), then there are definitely
a few implementations out there. I saw two groups at the latest IEEE
DySPAN conference demoing just such a system. I’ve been meaning to get
in touch with both groups to see if they would be willing to let us
take their updates to our OFDM code and put it in the tree.

Tom

3

Do you mean discontinuous in time or frequency? If you’re talking
about frequency (selectively turning off subcarriers, which I’ve heard
referred to as non-contiguous OFDM mostly), then there are definitely
a few implementations out there. I saw two groups at the latest IEEE
DySPAN conference demoing just such a system. I’ve been meaning to get
in touch with both groups to see if they would be willing to let us
take their updates to our OFDM code and put it in the tree.

In frequency, yep with subcarrier suppression. That would be great to
have
with the rise of DSA in the GNU Radio branch. Do you remember who
exactly
did the demo? Was it "*Software Defined Radio Implementation of SMSE
Based
Overlay Cognitive
Radiohttp://cms.comsoc.org/SiteGen/Uploads/Public/Docs_DYSPAN_2010/wright_dyspan_2010.pdf
"

*Their slides appear to have subcarrier suppression in them. Reginald
goes
to school here, he’s part of another wireless group. I will poke him
for
the code :slight_smile:

  • George
4

On Sun, Apr 25, 2010 at 11:54 PM, George N. [email protected] wrote:

In frequency, yep with subcarrier suppression. That would be great to have
with the rise of DSA in the GNU Radio branch. Do you remember who exactly
did the demo? Was it “Software Defined Radio Implementation of SMSE Based
Overlay Cognitive Radio”

Their slides appear to have subcarrier suppression in them. Reginald goes
to school here, he’s part of another wireless group. I will poke him for
the code :slight_smile:

  • George

Yes, that was one of the teams. I met and talked a bit with
Bullmaster, but it sounded like Roulin was the one who did the actual
coding of that part.

The other team was from Aachen. They also implemented per-carrier
modulation, which is another useful trick to have for OFDM and DSA
apps.

Tom