Since you seem to want to transmit asyc data, can you throw away the
start and stop bits, getting you down to 15.36kbs? Can you apply
compression to the data before transmission?

If you really can get a 30khz carrier through your RF channel, then
you might look at QAM, QPSK or QAM16 or other techniques that modems
(and cablemodems) use to squeeze 33.6kbs into a 3kz wide telephone
channel.

Is this an STL (studio-transmitter link)?

Robert

> >>  >>
>   >>  I would like to inject data into a line level audio signal and recover it
>   >>   at
>   >>  the other end, of course you do not want to hear it and I am also limited
>   >>   by
>   >>  bandwidth of 20-20k, as this audio channel does get wirelessly
>   >>   transmitted.
>   >>  I may have some headroom and be able to put it at say 30K, what would be
>   >>   the
>   >>  best encoder/decoder pair?
>
>   >>  Datarate required 19200bps
>   >>  <<
>
>   >>  So, you are trying to tranmit a 19200bps digital stream over a 10KHz
>   >>  channel.  This is theoretically possible if the 10KHz channel has
>   >>   sufficient
>   >>  signal to noise ratio.  However, this will be quite tricky to do yourself
>   >>  even if the signal to noise ratio is good enough.

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