Re: [10GMMF] TP3 Meeting minutes, November 23rd
John,
In my view, the zero forcing P_DFE is a better characterization of the
fiber, not related to any implementation. For most
fibers, the difference is small. For limit cases, the difference can be
significant.
Petre
Abbott, John S Dr wrote:
>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.
>
>Regards,
>
>John Abbott
>
>-----Original Message-----
>From: Sudeep Bhoja [mailto:sbhoja@BIGBEARNETWORKS.COM]
>Sent: Monday, November 29, 2004 5:39 PM
>To: STDS-802-3-10GMMF@listserv.ieee.org
>Subject: Re: [10GMMF] TP3 Meeting minutes, November 23rd
>
>
>Lew,
>
>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,
>
>Sudeep
>
>
>-----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
>To: STDS-802-3-10GMMF@listserv.ieee.org
>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 parameters.
>
>
>Lew
>
>
>
>-----Original Message-----
>From: Michael Lawton [mailto:mike_lawton@AGILENT.COM]
>Sent: Wednesday, November 24, 2004 6:10 AM
>To: STDS-802-3-10GMMF@listserv.ieee.org
>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
>
>Mike
>
>
>
>