Suppose I have a dial tone (350, 440 Hz) and I want to broadcast it on
an AM radio station whose center frequency is X using the USRP basic TX
daughter card.
Is there a code snippet I can look at which would describe this?
How do I select the appropriate sampling rate, if_decim, if_rate, etc.?
E.g. if I choose a sampling_rate of 16 kHz to generate the sine waves,
what do I need to set my usrp_tx_interp rate to in order to achieve a
corresponding output? Do I need to further interpolate or decimate this
signal before passing it to the USRP? Also, should I be using
complex_to_float() or something else?
Now, suppose I want to broadcast to N AM radio stations whose center
frequencies are X + [x1, x2, x3 … xn]. What changes? Do I use the
freq_xlating_filter with the offset equal to [x1…xn]? If so, what
parameters do I provide?
I’ve looked through the NBFM files, but they’re more complicated than
what I want at this point.
Thanks,
–Alex