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RE: PAM-5 at 5 Gbaud


it seems i don't have a copy of that one anywhere, and in any event 
it's likely better to let Oscar comment on results.

i also looked in the reflector archive and didn't find a copy in the 
'January' directory.  meanwhile i'd like to see a copy, can someone
forward one to me or forward a link?  thanks in advance.
J M Wincn
Cielo Communications, Inc.
325 Interlocken Pkwy, Bldg A
Broomfield, CO 80021-3497
Voice: 303-464-2264
Cell:    408-394-5283

At 05:11 PM 28-02-2000 -0500, Edward Chang wrote:
>The presentation I am referring is page 8 (sorry not pager 7), of "10
>Gb/sPMD Using PAM-5 Modulation" by Oscar in January.
>Edward S. Chang
>NetWorth Technologies, Inc.
>Tel: (610)292-2870
>Fax: (610)292-2872
>-----Original Message-----
>From: jmw [mailto:mwincn@xxxxxxxxxxxx]
>Sent: Monday, February 28, 2000 4:43 PM
>To: Edward Chang; rtaborek@xxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
>Subject: RE: PAM-5 at 5 Gbaud
>Perhaps i can help with this, Rich and i were at the same place when
>the early MAS tutorials were presented:
>At 02:20 PM 28-02-2000 -0500, Edward Chang wrote:
> >Richard:
> >The 5 GBaud, PAM-5 waveform at page 7 makes me very uncomfortable.  For
> >example, the one in the middle has three transitions, of which the
> >peak-to-peak amplitudes are 2250 unit(mv?), 1300 unit (mv?), and 1000
> >unit(mv?) with estimated transition times, (0%-100%)65 ps, 60 ps, and 60
> >respectively. For a five level coding, they seems to match with the +2, +1,
> >0, -1, -2 level definition with equally spaced timing interval.
> >
> >If they are not part of the coding, but a ringing or some other noise, they
> >will confuse the level and timing detecting circuits to cause undesirable
> >results.  If it is supposed to have only one transition per a cell time,
> >ps, then those extra transitions will cause the PLL being out of
> >synchronization with the receiving data, or excessive clock-jitter to
> >high BER.  With the near equal magnitude of amplitudes, and timing
> >intervals, no way a ordinary filter can differentiate the needed transition
> >from the unwanted transitions.
>which presentation do you have?  i looked at the links posted earlier
>("mastut.pdf"), but "page 7" in those that i saw was text, not wave forms.
>is there some other one that i missed?
> >One way or the other, these issues should be resolved before July decision
> >date.
>you betcha!
> >J M Wincn
> >Cielo Communications, Inc.
> >325 Interlocken Pkwy, Bldg A
> >Broomfield, CO 80021-3497
> >mwincn@xxxxxxxxxxxx
> >Voice: 303-464-2264
> >Cell:    408-394-5283