[Discuss-gnuradio] Re: .wav file fm tx

[Patrick Strasser]

Max Moser schrieb:
> well i managed to edit the files to rx my frequencies and file_sink it 
> to a file and use tx to resend it. But the resulting signal looks to 
> "soft/analog" so my keyboard receiver does not correctly interpret the 
> signal. Is there a way of reading from a wav file and fm_tx it? Or is 
> there a converter from .wav to raw float format that gnuradio wants?

Hello Max!

Do you have a special reason for using .wav files? The native format of 
GNU Radio is single precision complex float interleaved, which is what 
usrp_rx_cfile.py dumps to file.

You can modify the receive script to make it transmit it a given file. 
Of course you are allowed to send at your given frequency with your 
given power, are you (radio amateur?)...

You have not told us anything about your very parameters:
* frontend to the USRP
* antenna
* frequency
* bandwidth
* what you did to get where and what did not work (in detail and with 
motivation)

If I was a radio keyboard manufacturer I'd ensure that two keyboards in 
the same room don't interfere (some access code, different frequencies 
or logical channel to be established between keyboard and base station) 
and I'd add some measures to prevent other stations to listen to or 
replay the communication.
I'd expect some difficulties with a simple replay "attack".

Patrick
--
Engineers motto: cheap, good, fast: choose any two
Patrick Strasser <patrick dot strasser at tugraz dot at>
Student of Telematik, Techn. University Graz, Austria