VARA FM Deep Dive - Part 1
VARA & VARA-FM irritate me enough to motivate me to spend hours studying OFDM theory and technology. As a "sound card" mode I know no-one who as managed to get VARA's advertised speed or close to it in my area. Closed-source, Windows-only, fee based... What would really make a difference to amateur radio data communications is I/Q inputs and outputs on the amateur mass-market transceivers. That would free us from the tyranny of baseband sound card modes, wasted bandwidth, and the accompanying pitiful data rates, and open things up for some real experimentation with sound cards, which can easily manage 48kHz bandwidth (what the military uses for HF data communications), and with a bit more money go to 96, 192 and beyond.
I think GNU is good for experimentation, but for a production system there are better choices, I think - even C. It should start with a very focused communications API for efficient protocols that can adapt to the different propagations conditions amateurs encounter.