On 15 Jan,
Andy Wade wrote:

So what? A digital representation doesn't have to be binary. Digital
data - that could, for example, represent an audio signal after sampling
and A/D conversion - is frequently transmitted over wires or radio
channels as a sequence of 'symbols' each symbol representing one *or
more* bits. Increasing the number of bits per symbol generally allows
more data to be sent over a given spectral bandwidth but the signal
remains digital - each symbol represents one of a finite number of
discrete states.

Several symbols (carriers) are usually used simultaneusly (together with the
baseband audio signal) The signal is analogue -- any amplification etc. has
to be (analogue) linear or the quality (BER) is reduced by crosstalk and
intermodulation.

It may represent binary digits, but it must be treated as an analogue signal.

--
B Thumbs
Change lycos to yahoo to reply