Synchronized transmission with two USRP2s with independent ethernet port

GNU Radio
1

Hi,

We’ve achieved synchronized receving with two USRP2s with independent
ethernet port. I’ll report in another thread. Here we are beginning to
build
a MIMO transmitter. The question comes again regarding how to get the
samples to two USRP2 aligned. I tried to set the timestamp of metadata
in
tx_sample.cc in order to schedule the transmit occasion. But it seems
doesn’t work. Still we are using external common 10MHz ref and 1PPS.

Thanks in advance.

Bests,
Hanwen

2

I called sync_every_pps(), and set the timestamp of every frame to
999999999. Now I can align the transmitted samples when interporlation
rate
higher than 10 but not for above. I guess this it is because the
datarate is
too high which the buffer on USRP2 can not accommordate. Am I right?
What’s
the size of the buffer for samples from host?

Hanwen

2009/9/23 Doug G. [email protected]