[PD] ssb tutorial patch

[Andy Farnell]

Single sideband modulation.

It comes from radio culture really. In the modulation schemes for analogue
broadcast you havethe same spectral model with radio waves as we
use for sound synthesis. But using up more bandwidth by having two sidebands
is less desirable if you want to squeeze more channels into the same spectrum,
so SSB was devised to minimise interference between stations.

The tradeoff is that fewer sidebands mean less information is carried by
the signal.

If you research 'modulation' in a communications context you'll see a whole
fascinating history of AM, quadrature, suppressed carrier, and other schemes.

The SSB for frequency shifting in audio derives from the same idea in radio
transmitter oscillators, to make copies of the sidebands 180 degree out
of phase and mix them so that you end up with only one (upper or lower
sideband).

The Hilbert transform does this to a single sinusoid after generation, turning
it into a complex signal (I forget what the mathematical word is, but it's
really a sort of integration)


Anyone know any novel or unusual patches for SSB. Presumably, for a single frequency
you need only a fixed delay.

a.

On Mon, 01 Sep 2008 16:46:09 -0400
marius schebella <marius.schebella at gmail.com> wrote:

> hi,
> it's labour day, and I am really bored :)), so I was wondering, does ssb 
> stand for single sideband or signal sideband?
> the tutorial patch uses both, and a single sideband is always a signal 
> sideband, or not?? just curious. thanks.
> marius.
> 
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