"David" wrote in message
...
The only thing that keeps us from hearing the digital sidebands is
their symmetry (the digital sidebands are out of phase with each other
and cancel out in the receiver).

I'm still trying to figure out how this is supposed to work.. I understand
the concept, FM stereo does something similar by using phasing to reduce the
bandwidth needed for the L-R signal. The peaks of the L-R fit nicely into
the valleys of the L+R signal and vice versa.

But this doesn't seem like it would work as advertised on a store-stock AM
radio, because the ordinary envelope detector does not detect both
sidebands, only one of them. So how does it cancel?