Hi Sven, I can only report on one implementation years ago with a Tandy TRS-80 which processor probably had about the same power as an entry level MCU of today.
The detection circuit was an analog PLL with a pair of passive filters at the front. It worked reasonably well, with good sensitivity but suffered when noise was present. Simple to implement otherwise and with today's ICs the filters should be very simple to implement as well. Hope this helps, Good luck with the project. 73s, John This was fed into a serial interface with a program in assembler on the TRS-80. --- In digitalradio@yahoogroups.com, Sven <sven9...@...> wrote: > > Hi, > I' ve searched the Internet for RTTY decoding methods and found the following: > > - frequency discriminator with IIR resonator. There's a IIR resonator for > mark and one for space. A following mark/space detector try to find > mark/space peaks in the spectrum and then a comparator decides if it's a "0" > or "1" > > - frequency discriminator with FIR bandpass filter > > - analog or digital PLL > > - demodulation with Goertzel algorithm > > - zero crossing detector to identify the frequency of mark and space > > Are there other known methods and who knows something about or can explain > the above decoders ? How do they perform in a noisy environment ? > > 73 > > Sven > > > > > Are > > > > > > > > > > > > > > __________________________________________________ > Do You Yahoo!? > Sie sind Spam leid? Yahoo! Mail verfügt über einen herausragenden Schutz > gegen Massenmails. > http://mail.yahoo.com >
