[Discuss-gnuradio] Using USRP as a DTV channel simulator

[Damien B.]

Hi everyone,

Our project is to use the USRP as a DTV channel simulator to test the
respective quality of DTV set boxes. That means to be able to
attenuate the signal, add noise and simulate echos from reflexions on
mountains for example.

The biggest question is how to do it. One way would be to record a
signal on the PC, then filter it and fire it back to the set box. But
we don't know if the speed of the hdd is fast enough for the mass of
data.

And other way would be to tune the FPGA firmware to implement all the
function inside. That is to receive the signal, create a really long
FIR with only a few non null coefficients and add a noise before
sending it back. Ideally the FIR should be configurable but we can
imagine to use a set of precompiled firmware to suit the testing
procedure.

Which approach is more sensible? I'm efficient in VHDL and verilog
doesn't seams to hard to learn. Does the existing FIR could be tune
for this application? Would the community be interested in this
alternative use of an USRP?

Regards
Damien