Lately I've been working on some digital decoders for PSK31 and RTTY. Many signal processing questions come to mind, regarding filtering, equalization, channel coding, and so on. Examples:
- Applying Viterbi algorithm to compensate for ISI in PSK31
- Determining pulse shape for Viterbi Equalization
- Filtering for PSK31 demodulation
Should I ask those questions here? Or on dsp.stackexchange.com? I don't think they'd be strictly off topic in either place, yet there's still a question of the more appropriate forum.
On one hand, these questions are mostly about signal processing, and it just happens to be the signal in question is used in amateur radio. Of all hams, those well-versed in signal processing algorithms are a small subset, and I'll probably get a more knowledgeable (for the particular problem) set of people reading my question on DSP.se. (Though anecdotally, DSP.se hasn't been especially helpful for me so far.)
On the other hand, these modes are very relevant to hams. Among DSP, RF communication is a specialization. And even among that, HF communications (my particular area of interest) is far more common in amateur radio than it is in the RF communication community generally.
Ostensibly, hams are involved in the understanding of these modes, their implementation, and improvement thereof; and the development of new modes or techniques on existing modes with improved performance. I believe this isn't really the case, and current practice in amateur radio is years to decades behind common practice everywhere else, most of the common digital modes are anachronistic, and in some cases outright poorly designed. But if I want to change that, shouldn't conversation be in the amateur radio community?