On Tue, Mar 28, 2006 at 11:51:03PM +0200, Matteo Campanella wrote: > Hello, I am trying to find the best way to implement a bell 202 modem in > gnuradio. The problem I am facing is that I need to produce two tones, one > for mark and one for space, and I have to switch from one to other > depending on which symbol I am sending. The duration of the tone (or tone > switch) must be set exactly according to the baud rate of 1200 I have to > produce. > > I was thinking to use the nco class to generate the tones, and to output n > samples per symbol at a certain fixed sample rate that would be enough for > the 1200 baud, let´s say the standard audio 48000. > > Has anyone better suggestions to work this out? > > MC
Use the gr.frequency_modulator_fc block to generate complex baseband FSK. You'll probably want to use gr.bytes_to_syms to in front of it, or in the more general case: gr.packed_to_unpacked followed by gr_chunks_to_symbols_bf. Eric _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
