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Re: [10GMMF] TP3 Meeting minutes, November 23rd


It is an interesting proposal, at least theoretically. Assuming infinite
length FFE, I guess zero forcing solution would be possible (in
principle). This means no residual ISI at sampling instant (not just
minimum error modulus like MMSE). As a consequence, noise enhancement is
strongly expected to be the limiting factor for EDC performances. I am
quite curious to see how much would be the optical penalty since I
calculated some month ago the PID-L for the zero forcing (linear)
equalizer in term of noise bandwidth enhancement( I sent a ppt copy to
Sudeep for comparison with PIE-D/L reported metrics). Does zero forcing
PIE-D expected to be different from noise bandwidth enhancement due to
full frequency compensation for a given output ISI free spectrum
(raised-cosine for example)?

Thank you for posting this issue...

Best regards


-----Original Message-----
From: owner-stds-802-3-10gmmf@IEEE.ORG
[mailto:owner-stds-802-3-10gmmf@IEEE.ORG] On Behalf Of Abbott, John S Dr
Sent: Dienstag, 30. November 2004 15:48
Subject: Re: [10GMMF] TP3 Meeting minutes, November 23rd

In regard to Lew's and Sudeep's points, are there conditions where we
should calculate the zero forcing PIE-D as well as the MSE PIE-D?  At
the San Antonio meeting there seemed to be comments supporting both.


John Abbott

-----Original Message-----
From: Sudeep Bhoja [mailto:sbhoja@BIGBEARNETWORKS.COM]
Sent: Monday, November 29, 2004 5:39 PM
Subject: Re: [10GMMF] TP3 Meeting minutes, November 23rd


This in response to your Comment #1 below.

The PIE-D equations from bhoja_1_0704 targets an infinite length DFE
that minimizes mean square error (MMSE). MMSE Equalizers perform better
than Zero forcing Equalizers. Conventional adaptation algorithms such as
LMS, minimize mean squared error.

If we agree on an MMSE based infinite length DFE, there are
two variables that enter into the calculation:

1) The first variable is easy and follows directly from the link budget.

sigma^2 -> This is the Electrical noise floor at the input
of the ideal EDC and is easily derived from the link budget.
We had previously set sigma^2 = 10^(-17-2*6)/10 since we had allocated
6dB of total dispersion budget.

However since the connector loss was updated to 1.5dB from 2dB Page 5 in
lawton_1_1104 allocated 6.5dB to the total dispersion budget.

Hence we need to update sigma^2 = 10^(-17-2*6.5)/10 = 10^(-30/10) in our
PIE-D calculations.

2) The rise time used in deriving the fiber pulse response in
bhoja_1_0104 was set to 47.1ps (20-80% Gaussian). This number was chosen
from -LR.

For the purpose of the TP3 stressed tests, we only need to represent the
rise time of the test setup of Fig 68.6 in D0.2. For this purpose 47.1ps
is probably an adequate rise time.

Best Regards,


-----Original Message-----
From: owner-stds-802-3-10gmmf@IEEE.ORG
[mailto:owner-stds-802-3-10gmmf@IEEE.ORG]On Behalf Of Lew Aronson
Sent: Monday, November 29, 2004 12:47 AM
Subject: Re: [10GMMF] TP3 Meeting minutes, November 23rd

Some comments:

1) I think it is very important that all are aligned on the PIE-D
calculation.  I would be interested in a discussion on the variables
mentioned below, what differences exist now between different task force
members algorithms and the likely impact of changes of each of these


-----Original Message-----
From: Michael Lawton [mailto:mike_lawton@AGILENT.COM]
Sent: Wednesday, November 24, 2004 6:10 AM
Subject: [10GMMF] TP3 Meeting minutes, November 23rd

Dear TP3ers,

Here are my notes from yesterdays call.

Key issues which were raised:-
        PIE-D has variables associated with it (rise time, sigma^2, ZF
vs MMSE calculation) - how do we handle that?

Any comments/corrections please get back with me.

Best Regards