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Re: [10GBT] More on the PAM12 emissions


Please go ahead and fix it yourself. Your observations don't negate the
point I've been trying to make for the past three days - if we keep sending
the same patterns repeatedly as proposed in powell_1_0704.pdf, spiky stuff
happens in the PSD.

Sailesh Rao.

>From: Jose Tellado <JTellado@TERANETICS.COM>
>Reply-To: "IEEE P802.3an" <>
>Subject: Re: [10GBT] More on the PAM12 emissions
>Date: Mon, 26 Jul 2004 13:44:26 -0700
>Please check your code more carefully before sending it to the
>You made a 20dB mistake this time for the 0.5ms case. You forgot to
>normalize the PSD as the size of the vectors increases.
>PS. It appears you also got the X-axis wrong. Fs/2 is 416MHz, not
>-----Original Message-----
>From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
>Behalf Of sailesh rao
>Sent: Monday, July 26, 2004 11:18 AM
>Subject: [10GBT] More on the PAM12 emissions
>Hi All,
>I'm attaching the corrected glenn.m code with the proper repetition rate
>(4224 symbols). For those of you who don't have access to matlab, I'm
>also attaching the output of this code with 4224 (5us) and 422224
>(0.5ms) as pdf plots. This illustrates the actual energy buildup we can
>expect in the PAM12 framing scheme, as depicted on slide 22 of
>Another issue with the PAM12 proposal is that the bit-to-symbol mapping
>on slide 24 of powell_1_0704.pdf will cause a 0.47dB increase in the
>transmit PSD power when the THP coefficients are zero'ed out (e.g., at
>short line lengths). In contrast, in the PAM8 proposal, if the THP
>coefficients are zero, the transmit PSD power will decrease by 0.03dB.
>Therefore, I would like to officially raise the PAM12 emissions penalty
>to 1.3dB from the 0.8dB I had been quoting. In this case, the total EMI
>penalty of  PAM12 is between 4.5dB and 5.1dB over the existing cabling
>infrastructure. It is between 3.1dB and 4.5dB for new cabling.
>Sailesh Rao.
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