Re: [Discuss-gnuradio] USRP2 transmit to USRP1 issue

[Tom Rondeau]

On Fri, Mar 26, 2010 at 7:38 PM, Phillip Walsh
<address@hidden> wrote:
> The question: Has anyone gotten benchmark_tx.py (or tunnel.py) to work from
> USRP2 to USRP1?
>
> I have built a fairly in-depth CSMA/CA MAC on top of the simple carrier
> sensing in 'tunnel.py' to test the performance in some protocol variations.
> My setup works great with the USRP1s which I designed on.  The problem is we
> ordered a USRP2 in edition to the 3 USRP1's we have and I've had no luck
> getting it to work with the rest.  I am using RFX2400 d'boards.
>
> The problem is packets sent by USRP2 are either not received at all by the
> USRP1 or occasionally received but with bit errors.  The USRP2 IS able to
> receive USRP1 packets using DBPSK at 100Kbps successfully.  I have tried
> different rates making sure both give the same actual bitrate using the
> verbose option.  I set tx-amplitude=0.05.
>
> I am using the 3.2.2 release, but have also tried the benchmark_tx/rx2.py
> using 'dbpsk2' in the developers branch with no luck.
>
> Thanks for any input,
>
> Phil Walsh
> Auburn University


Yes, I developed the v2 of the digital stuff by testing them out
communicating between a USRP1 and USRP2 (both ways). Try increasing
the amplitude. Is this over-the-air or through a cable connection? You
can start with a cable (and a low tx-amplitude, < 0.2) to get a feel
for the received power you are seeing. But in general, it should work,
especially with the new dbpsk2/dqpsk2 since they have arbitrary bit
rates and you don't have to worry about matching them between the
devices.

Tom