Hi, bodys:)
I’m trying to use the sound card to transferring bits and I find it may
not
be as easy as using USRP.
My efforts are based on the fsk_tx.py and fsk_rx.py.
The audio.sink & audio.source only I/O float type data, and not like
USRP,
we cannot set decimation ratio or interpolation ratio for sound card.
So I set this two ratio to 1 and use complex_to_float & float_to_complex
connecting the sound card with modulating & demodulating blocks.
But I seriously doubt if it is right in this way, and not surprising, I
get
nothing at the rx.
To ensure the validation of the configuration of fsk mod and demod, I
write
another script with framing, modulation, demodulation and deframing
connected in a line without sound card. It works well and the received
frame
seq number can be correctly printed out. Besides, I can here the sound
of
transmitted signal from the sound card, and the line-in input is ok.
Needing some hints about doing communication with sound card. My source
codes are mailed.
Hanwen