By a real signal, I mean a signal like a real valued sinusoid. Say in a grc graph, I have this: signal generator (sine, float o/p) ----> float to short converter ----> usrp sink (short i/p). In this example, I'm inputting a stream of shorts representing a pure sine wave to the usrp module. I wanted to ask how I can do this exactly when I call the send() to the UHD inside a C++ program? (an array of float values represent the pure sinusoid, which is the waveform I wish to transmit).
Arya On Wed, Apr 6, 2011 at 10:47 PM, Josh Blum <[email protected]> wrote: > > > On 04/06/2011 08:42 PM, Arya Santini wrote: >> Hello.. >> >> The I/O types defined in the uhd::io_type_t class lists 4 COMPLEX >> types and a CUSTOM type. What I/O type should I specify in the call to >> send()/recv() if my baseband signal is real and not complex, say I'm >> transmitting from a file containing real samples of float type. How is >> a sample type of real float or real short interpreted and/or converted >> by the UHD library to shorts over the wire? >> > > I think this is a misunderstanding. A complex baseband signal represents > 1/fs bandwidth of spectral content which the USRP will modulate to the > center frequency -> fc. > > To have a "real" signal is to leave half of your spectrum undefined. Is > it symmetric about fc? or is it really a complex signal centered at fc+fs/4? > > -Josh > > _______________________________________________ > Discuss-gnuradio mailing list > [email protected] > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
