Hi! Craig,

On 27 Sep 96  09:09:00, Craig Peacock whispered to ALL:

 CP> Can anyone tell me what Trellis Coded Modulation (TCM) or Quadrature
 CP> Amplitude Modulation (QAM) is, in relation to modems.

I don't understand it (fully), just repeating it:

  TCM - (T)rellis (C)oded (M)odulation.  TCM is an optional error correction
  method included in the V.32 standard.  TCM allows modems to check for
  transmission errors with a redundancy bit, which results in fewer errors on
  noisy lines.  Modems can tolerate twice the noise in the channel than
  otherwise, using only QAM.  Trellis Encoding works with other error
  correction methods such as V.42.  Unlike other methods, TCM is true error
  correction, in that for small errors, it does not force a retransmit, but
  actually fixes them.

For a full explanation, you could look on your favourite BBS for a Fido echo
called COMM, where these and many other mysteries are revealed in a monthly
release by the moderator, called: "Echo Primer".  Every new
caller gets a copy
on their first call here.  :)

Cheers,
Paul.


... Sure when...  OINK FLAP.  OINK FLAP.  Well, I'll be damned...
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