[liberationtech] Efficient digital one-way communication

[Gregory Maxwell]

On Mon, Mar 4, 2013 at 11:45 AM, Jens Christian Hillerup
<jens at hillerup.net> wrote:
> Yes, and then I can scrap the stereo encoding again. I'd rather have
> it optional than required. And I agree, it would make more sense to
> pick eight notes and use them as a bitmap. We'd face the same problems
> as we did before with the harmonies, but that problem does not get any
> bigger or smaller so I don't see the point in not implementing it.
>
> Idea: parity information in the overtones? Not applicable if we go
> with Reed-Solomon codes, though.

Modem design is a science with something like 70 years of history.
The modem technology is probably a discussion hashed out on places
full of DSP / modem gurus like the GNURadio lists, rather than a list
full of activists.

There are many complex technical considerations that depend on the
properties of the underlying radio transport.  Figuring out what kinds
of hardware and channels (bandwidth, noise characteristics) are
potentially available would be a good thing for activists to get
sorted out before going to the DSP gurus and saying "we want to
support (one/two way) digital comms at this bitrate over this hardware
/ spectrum / under these conditions,  what should we use here"?