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*To*: STDS-802-3-10GBT@listserv.ieee.org*Subject*: Re: [10GBT] Updated Tables*From*: sailesh rao <sailesh_rao@HOTMAIL.COM>*Date*: Tue, 20 Jul 2004 18:41:13 -0400*Reply-To*: "IEEE P802.3an" <STDS-802-3-10GBT@listserv.ieee.org>*Sender*: stds-802-3-10gbt@IEEE.ORG

Hiroshi, I am afraid we need to integrate in order to go from the frequency domain to time domain. If we assume that the optimum matched filter for PAM8 is a frequency scaled version of the optimum matched filter for PAM12, then the amount of noise power in the time domain for PAM8 is 0.84dB higher than that for PAM12, for a given AWGN PSD. Therefore, PAM8 is able to tolerate 1.84dB (for new cabling) to 3.24dB (for existing cabling) higher AWGN power at the slicer than PAM12. Regards, Sailesh Rao. srao@phyten.com >From: hiroshi takatori <hiroshi.takatori@KEYEYE.NET> >Reply-To: "IEEE P802.3an" <STDS-802-3-10GBT@listserv.ieee.org> >To: STDS-802-3-10GBT@listserv.ieee.org >Subject: Re: [10GBT] Updated Tables >Date: Tue, 20 Jul 2004 14:21:04 -0700 > >Sailesh, >Again, do not integrate to fs/2. That is WRONG because it depends on >spectral of the "EXTERNAL NOISE". My results say that PAM8 can tolerate >1dB higher power spectral density than PAM12 if "EXTERNAL NOISE" is flat >in frequency. In order to calculate how robust the receiver is against >"EXTERNAL NOISE", we need to know the spectral of it. If it contains >higher energy in higher frequency (400MHz or up), PAM8 could be worse >than PAM12. > >Again, I would like to get Model-5 that tests the immunity against >"EXTERNAL NOISE". As Dan suggested yesterday, this could be the >transient noise, so no EQL adaptation can be assumed to this type of >noise. Once EQL is trained over A-Crosstalk and BGN, freeze EQL and test >receiver noise tolerance against noise pulses, such as 3~20mV with >60~70Hz apart. Again, the key is the frequency content of the noise >pulses. > >Hiroshi Takatori >Keyeye Communications, Inc. > >-----Original Message----- >From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On >Behalf Of sailesh rao >Sent: Tuesday, July 20, 2004 5:45 AM >To: STDS-802-3-10GBT@listserv.ieee.org >Subject: Re: [10GBT] Updated Tables > >Hiroshi, > >You are effectively getting 2.3dB Total EMI penalty for PAM12 over PAM8 >on >Model 1 and 3.6dB penalty for PAM12 over PAM8 on Model 2. > >This is close to the 2.6dB and 4.0dB, respectively, that I was >calculating. >In other words, it looks like we are converging... > >Please call me once you take a look at the code I sent and we can sort >out >the discrepancies. > >Regards, >Sailesh Rao. >srao@phyten.com > > >From: hiroshi takatori <hiroshi.takatori@KEYEYE.NET> > >Reply-To: "IEEE P802.3an" <STDS-802-3-10GBT@listserv.ieee.org> > >To: STDS-802-3-10GBT@listserv.ieee.org > >Subject: Re: [10GBT] Updated Tables > >Date: Mon, 19 Jul 2004 21:31:15 -0700 > > > >Sailesh, > > > >Following is my results of your requested simulation. Note that the > >purpose of the simulation is to repeat what you did so that we can talk > >with the same language. Although I am not sure why PAM12 has penalty in > >coding gain, I used 10.2dB coding gain for PAM8 and 9.8dB for PMA12. I > >think these are what you used (Correct me if I am wrong). I also added > >your numbers in red for "BGN for 0dB margin" for the comparison. > > > > > > > >Model 1, CAT7 100m > > > >PAM Level > > > >TX Digital Shape > > > >Assumed Coding Gain > > > >TX Power > > > >Assuming 2Vpp with simple LPF at Fs/2 > > > >SNR > > > >Noise margin with BGN = > > > >- 150dBm/Hz > > > >BGN for 0dB margin > > > >Difference between PAM8 and PAM12 > > > >PAM8 > > > >0.75+0.25/z > > > >10.2dB > > > >3.3dBm > > > >25.4dB > > > >5.5dB > > > >-137.4dBm/Hz > > > > > > > >2dB worse > > > >NONE > > > >4.8 > > > >25.6 > > > >25.5 > > > >5.7 > > > >5.6 > > > >-135.4 > > > >-133.2(Sailesh) > > > >Normalized to 0dB > > > >PAM12 > > > >NONE > > > >9.8 > > > >4.6 > > > >29.7 > > > >29.6 > > > >5.9 > > > >5.8 > > > >-136.1 > > > >-134.2(Sailesh) > > > >0.7dB worse > > > >1.0dB worse > > > >Note: Red is from Sailesh results > > > > > > > >Model 2, CAT6 55m > > > >PAM Level > > > >TX Digital Shape > > > >Assumed Coding Gain > > > >TX Power > > > >Assuming 2Vpp with simple LPF at Fs/2 > > > >SNR > > > >Noise margin with BGN = > > > >- 150dBm/Hz > > > >BGN for 0dB margin > > > >Difference between PAM8 and PAM12 > > > >PAM8 > > > >0.75+0.25/z > > > >10.2dB > > > >3.3dBm > > > >26.0dB > > > >6.1dB > > > >-124.9dBm/Hz > > > > > > > >2.2dB worse > > > >NONE > > > >4.8 > > > >26.0 > > > >26.0 > > > >6.1 > > > >6.1 > > > >-122.7 > > > >-120.7(Sailesh) > > > >Normalized to 0dB > > > >PAM12 > > > >NONE > > > >9.8 > > > >4.6 > > > >29.1 > > > >29.1 > > > >5.3 > > > >5.3 > > > >-124.7 > > > >-123.1(Sailesh) > > > >2dB worse > > > >2.4dB worse > > > > > > > > > > > >I, intentionally remove your final columns because it is not CORRECT. >We > >will discuss later on the subject. > > > > > > > >First of all, SNR and noise margin matched very closely, within 0.1dB > >error, however, BGN for 0dB margin are off by about 2dB. We have to >find > >out why but "Difference between PMA8 and 12" are about same. Yours are >a > >little more than what I got but they are off only 0.3 to 0.4dB. At this > >stage, I agree with you that tolerable BGN is bigger for PAM8. However, > >note that PAM8 is the simple one without 0.75+0.25/z that you are > >proposing. Your proposal with 0.75+0.25/z filter is the worst. Albert >is > >now getting similar results witn mine in time domain simulation and he > >is going to release it soon. In anyway, at this stage, I am not >claiming > >simple PAM or with digital filter and let us assume simple PAM for both > >cases to compare. The important issue is whether that is 1~2dB or >2~4dB. > >Let's discuss the issues of intentionally removed columns in which you > >integrated to fs/2. You assumed that "ERXTERNAL NOISE" is fitting just > >fs/2 for both systems. That is not correct. The "EXTERNAL NOISE" could > >be at the higher frequency up to 1GHz or higher. Let's assume that we > >test performance with single tone at 450MHz in which PAM12 can tolerate > >a lot better than PAM8. What I am saying that in order to argue EMI > >tolerance, we need to define the spectral content of the "EXTERNAL > >NOISE". > > > > > > > > > > > >We have had four models for the system comparison back in March >meeting. > >Those models do not have any "EXTERNAL NOISE" other than A-crosstalk. >We > >assumed 10GBaseT is the self-crosstalk limited system. We believed that > >is reasonable and we did intensive study with the good IC > >considerations. As everyone agreed, PAM12 is the best noise margin > >solution in those criteria. Now, Sailesh raised the issue "Immunity for > >the EXTERNAL NOISE" at the last meeting. > > > > > > > >I am very positive to improve IEEE standard within a reasonable time > >frame. If A-crosstalk is not the biggest impairment or EMI noise is as > >big as that, let's redefine that and create 5th model on the top of the > >existing four models. Dan made a good point in his mail today. Will you > >be able to get a data of the frequency content of the EMI noise that > >everyone is comfortable with? I myself want to take a quick look at >that > >even if you can not claim that is the general universal conditions. >That > >should tell how many dB PAM8 is better in EMI tolerance (or non issue) > >and people can judge both A-crosstalk immunity and EMI tolerance at the > >same time. > > > > > > > >Hiroshi Takatori > > > >Keyeye Communications, Inc. > > > > > > > > > > > > > > > >-----Original Message----- > >From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On > >Behalf Of sailesh rao > >Sent: Monday, July 19, 2004 11:16 AM > >To: STDS-802-3-10GBT@listserv.ieee.org > >Subject: [10GBT] Updated Tables > > > > > > > >10GBT'ers: > > > > > > > >In the attached, I've updated the 3 tables in our July presentation > >based on > > > >the following: > > > > > > > >1. Change PAM12 symbol rate to 825Ms/s from 820Ms/s. > > > >2. Delete PAM10 entry. > > > >3. As Luc pointed out, add a 1.2dB emissions penalty for PAM12 due to > >its > > > >higher transmit PSD. > > > >4. As Jose pointed out, subtract 0.4dB from the PAM12 emissions penalty > >due > > > >to the THP peak voltage adjustment. > > > > > > > >Next, I integrated the WGN for 1E-12 BER over the Nyquist frequency > >range to > > > >get a "wideband noise tolerance" measure for the two proposals. >Finally, > >I > > > >summed the noise immunity penalty and the emissions penalty for the > >PAM12 > > > >proposal to form a "Total EMI Penalty" metric over the PAM8 approach. > > > > > > > >In Models 1 and 3, the penalty works out to be 2.6dB and 2.2dB > >respectively > > > >for PAM12 over PAM8. However, in Model 2, which represents the existing > > > >cabling infrastructure, the penalty for PAM12 over PAM8 works out to a > > > >whopping 4.0dB!! > > > > > > > >Regards, > > > >Sailesh Rao. > > > >srao@phyten.com > > > > > > > >_________________________________________________________________ > > > >MSN Toolbar provides one-click access to Hotmail from any Web page - > >FREE > > > >download! http://toolbar.msn.click-url.com/go/onm00200413ave/direct/01/ > > > > > > > >_________________________________________________________________ >Discover the best of the best at MSN Luxury Living. >http://lexus.msn.com/ _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar – get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/

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