All,
I am trying to use both transceivers to transmit and receive data, which
is
fine with the current GNU Radio blocks. On one of the transceivers I am
currently using an independent piece of software to do a rough TDMA type
waveform. Basically, the GNU Radio flow graph for one side looks like:
SIDEA
usrp_source_c => deinterleave => multiply_const_cc =>
file_descriptor_sink
usrp_sink_c <= interleave <= multiply_const_cc <=
file_descriptor_source
SIDEB
(same source /deinterleave as above) => FM demod
(same sink / inteleave as above) <= FM mod
When I am running the TDMA code (connected through TCP sockets), the
USRP
underruns (uU) when no data is sent. That’s no big deal when I have one
transceiver, but when I am running with two transceivers this REALLY
messes
with things because of the interleaving. What I have tried to do is
patch
the file_descriptor_source by checking the socket for data (with a
select()
call with a timeout of 0) and then sending noutput_items complex zeros
to
the USRP to allow the data to be interleaved. I still seem to be having
problems with underruns. I know that mblocks will solve my problems in
this
area, but I need a solution in a couple of weeks. Should I throw my
hands
up and wait? or do I need to make my own scheduler? gr_buffer? HELP!
Thanks for any guidance,
David