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



Jose, I was thinking along the same lines. I have a modified version of the code targeted to specific baud rates which may be a better stating point. I suggest adding a file-driven  transmit psd, and  some easy, default channel models as a starting point.  I'll call you Monday and we'll talk over the logistics.
George A. Zimmerman
cell: 310 920 3860
(sent from my mobile)


-----Original Message-----
    From: "Jose Tellado"<JTellado@TERANETICS.COM>
    Sent: 7/17/04 3:05:48 PM
    To: "STDS-802-3-10GBT@listserv.ieee.org"<STDS-802-3-10GBT@listserv.ieee.org>
    Subject: Re: [10GBT] Proposed PAM8 vs. PAM12 resolution process


    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

    ________________________________

    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.