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Re: [10GBT] More on the PAM12 emissions


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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