At the Interim Meeting, during
the Q&A session after our presentation (http://www.ieee802.org/3/bj/public/jan12/cole_02a_0112.pdf),
Chris DiMinico suggested that we extend our analysis to include skin loss
effects.
Since the result leads to
interesting observations, we would like to share these with the Task
Force.
The Salz SNR bound as a
function of dielectric loss from the presentation is:
SNR = rho – ½ * IL(NRZ
Nyquist)
(for NRZ)
SNR = rho – ¼ * IL(NRZ
Nyquist)
(for PAM-4)
The newly derived Salz SNR
bound as a function of skin loss is:
SNR = rho – 2/3 * IL(NRZ
Nyquist)
(for NRZ)
SNR = rho – sqrt(2)/3 * IL(NRZ
Nyquist) (for
PAM-4)
On the enclosed graph, we
plotted the Delta Salz SNR = PAM-4_Salz_SNR – NRZ_Salz_SNR -
7dB.
Positive Delta means PAM-4 BER
is higher and negative Delta means NRZ BER is higher.
Since loss is caused by both
contributors, the actual Delta lies somewhere in between the two plotted
curves.
Notice how even for such a
simple model, the cross-over point between the modulation schemes can shift by
8dB just by varying the ratio of channel loss
contributors.
Chris &
Ilya
All,
There were some modifications made to the minutes.
Please see the latest update at http://www.ieee802.org/3/bj/public/jan12/minutes_01a_0112_unapproved.pdf.
John