Hi all,
I am a novice in GNURadio so I am seeking some help in order to achieve
a simple voice transmission between two USRPs (N210). My methodology
copies exactly the one presented in:
http://www.dl8rds.de/index.php/GNURadio_and_USRP2#Transmit_a_simple_FM_signal
and more specifically under the title: Transmit an AM signal, Receive a
AM signal.
So, I replaced the USRPs with the UHD/USRP sink and source respectively,
which in my case does not have any interpolation/decimation values to be
entered. I only have sampling rates. What I do not understand is whether
the FPGA must get the stream at a sample rate of 100MS/s or will perform
the interpolation there by using the DUC automatically. We know that the
sampling rate equals the DAC’s rate times the interpolation rate (tx
side) but it seems that in N210 we cannot set the codec rate. Therefore,
in N210s all it matters is the sampling rate. So assuming a file
recorded at a sample rate of 256KS/s. Do I need to guarantee an
interpolation to 100MS/s prior sending it to the FPGA? If yes, then what
is the role of the sampling rate? For example If I interpolate the
ingoing signal of 256KS/s to 100MS/s with the use of a rational
resampler, then why do I need to set a sampling rate in the UHD/USRP
sink? Sorry but I just cannot get it.
All, I am trying to do is to push an AM .dat file recorded at 256KS/s
from one end and listen it on the other end.
Thanks for your time in reading this long stuff.
BR,
Alex