Harold,

Did you look at using CTSS if data is low speed.



> On Feb 2, 2018, at 12:39 PM, Harold Hallikainen <harold@mai.hallikainen.o=
rg> wrote:
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> I'm looking at sending some extremely low speed data under audio to
> identify the audio. The receiver would be an Android device with internal
> microphone. I'm thinking of using direct sequence spread spectrum with th=
e
> level being substantially below the audio so it would appear to be very
> low level noise. But, my experience with spread spectrum is extremely
> limited. I'd appreciate any pointers to information on it, especially at
> audio frequencies, and any open source projects on it.
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> THANKS!
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> Harold
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>=20
>=20
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> Not sent from an iPhone.
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Just my $0.02,

Jean-Paul
N1JPL




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