A question about benchmark_rx.py and benchmark_tx.py


#1

Hello, everyone!

I am just running a demo program to realize communication between two
usrps using benchmark_rx and benchmark_py under the Python/digital dir.
But when I am trying to use dqpsk modulation scheme, the packets
received are totally wrong. What’s wrong with the programs? I am really
confused. Could anybody give me a hint or help me out? Thank you!!!

Bill


#2

On Thursday 09 October 2008 19:47:10 Bill S. wrote:

Hello, everyone!

I am just running a demo program to realize communication between two usrps
using benchmark_rx and benchmark_py under the Python/digital dir. But when
I am trying to use dqpsk modulation scheme, the packets received are
totally wrong. What’s wrong with the programs? I am really confused. Could
anybody give me a hint or help me out? Thank you!!!

Bill

I had a problem with different oscillator frequencies on two boards, not
much
but enough for the digital pll in the receiving gnuradio block to lose
tracking.

As a workaround, I used the usrp_fft.py programm as a receiver, and on
the
sending side just a carrier. This way, I could determine the frequency
offset
between the two boards.

Stefan


Stefan Brüns / Bergstraße 21 / 52062 Aachen
mailto:lurch at gmx.li http://www.kawo1.rwth-aachen.de/~lurchi/
phone: +49 241 53809034 mobile: +49 151 50412019