Re: [10GBT] Proposed PAM8 vs. PAM12 resolution process

[Jose Tellado <JTellado@TERANETICS.COM>]

 

All,

I would like to make some further suggestions. The code in solarsep_varlen7a.m was a useful tool to approximate the DFE performance when the potential design space was very large. Therefore it has many parameters to adjust and is prone to operator error if you are not very familiar with it (e.g. as George Z pointed out Sailesh did not adjust the noise bandwidth correctly in his analysis)

When this code was generated there were multiple proposals for coding (TCM, TCM+RS, LDPC), multiple symbol rates (~range of 800-1250MHz), multiple tx voltage levels (~range 1.5-3Vpkpk) and PAM levels from PAM4 to PAM16. Moreover we had multiple channel models.

We have made significant progress in the last couple of meetings, narrowing the PHY channel models to 4, and limiting our solutions to THP+LDPC+{PAM12+825MHz or PAM8+1000MHz}. I would suggest we should narrow down this code to evaluate only the two remaining alternatives over the approved channel models.

This will require additional work, but will likely avoid some the confusion the group had in the last meeting. I will make the necessary updates with input from the interested parties.

Cheers,

Jose

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From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of Sailesh Rao
Sent: Friday, July 16, 2004 4:56 AM
To: STDS-802-3-10GBT@listserv.ieee.org
Subject: [10GBT] Proposed PAM8 vs. PAM12 resolution process

All,

 

I would like to propose the following process for resolving the robustness of PAM8 vs. PAM12 towards external noise.

 

1. Compute the Optimum DFE SNR Margin for PAM8 and PAM12 using solarsep_varlen7a.m for Models 1 and 3 using default cancellation parameters and -150dBm/Hz background noise.

 

2. Compute the input-referred RMS noise power at the slicer by integrating the residual noise in the Optimum DFE solution. I volunteer to add this code to solarsep_varlen7a.m unless someone else wants to do so.

 

3. Compute the input-referred external noise power that can be tolerated for a BER of 1E-12 for both systems using the results from (1) and (2) above. I volunteer to add this code to solarsep_varlen7a.m unless someone else wants to do so.

 

Regards,

Sailesh Rao.