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Re: [10GBT] Discussions on ...


the detailed bit-to-symbol mapping will be in the presentation, on which I
am currently working.

Regards, Gottfried

-----Original Message-----
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf
Of sailesh rao
Sent: Montag, 20. September 2004 19:53
Subject: Re: [10GBT] Discussions on ...


Please publish the detailed bit-to-symbol mapping of the Double Square
constellation so that we have a chance to analyze the technical implications
for our presentation, which is due to Brad in two days time.


>From: Gottfried Ungerboeck <g.ungerboeck@BLUEWIN.CH>
>Reply-To: "IEEE P802.3an" <>
>Subject: Re: [10GBT] Discussions on ...
>Date: Mon, 20 Sep 2004 15:57:44 +0200
>128-point checkerboard constellation = 128-point Double Square
>constellation (128-DSQ). The designation "Double Square" alludes to an
>algorithmic symbol construction and labeling method for this type of
>When I concentrated on the question of the optimum modulation rate for
>10GBASE-T, which I found in the 800 Mbaud range (ungerboeck_1_0504.pdf,
>Long Beach; see also takatori_1_0504.pdf), I said nothing about
>specific modulation & coding to accomplish the "achievable bit rates"
>vs modulation rate.
>This time I am speaking about a particular modulation & coding scheme
>(namely 128-DSQ + LDPC), which I find best suited for transmission at
>the around 800 Mbaud rate. I would appreciate if the notions of "12PAM"
>or "8PAM" camp would disappear from our 10GBASE-T discussions. Instead
>let's concentrate on the various not necessarily connected technical
>issues and the proposals made on this issues.
>The specific issues at hand are: (a) in what range should the 10GBASE-T
>modulation rate be; then (b) what modulation & coding should be used to
>accomplish transmission at a modulation rate within this range.
>Regards, Gottfried
>-----Original Message-----
>From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
>Behalf Of sailesh rao
>Sent: Mittwoch, 15. September 2004 20:07
>Subject: Re: [10GBT] Discussions on precoder decisions
>Is the "Double Square" constellation the same as the "Checkerboard"
>constellation you were telling me about last week? If not, this would
>be the 5th constellation I've heard about from the PAM12 camp.
>Here's the list so far:
>1. Original PAM-12 "donut" constellation.
>2. PAM-12 Compapiano-Glazer "cross" constellation.
>3. PAM-12 multi-dimensional "Kabob" constellation.
>4. Checkerboard constellation.
>5. PAM8/16 Double Square constellation.
>A general observation is that instead of researching PAM12
>constellations, the task force would be well served if we can converge
>around the PAM-8 proposal and conduct a working session on the
>standards draft at the interim meeting.
> >From: Gottfried Ungerboeck <g.ungerboeck@BLUEWIN.CH>
> >Reply-To: "IEEE P802.3an" <STDS-802-3-10GBT@LISTSERV.IEEE.ORG>
> >Subject: Re: [10GBT] Discussions on precoder decisions
> >Date: Wed, 15 Sep 2004 10:56:34 +0200
> >
> >George,
> >
> >the 128DSQ constellation ("double square") is the natural
> >go-in-between
> >8 PAM and 16 PAM, much more so than 12PAM. Contrary to 12PAM, all
> >encoding, decoding, and precoding operations are based on
> >powers-of-two
> >128DSQ has been known for a long time in the literature and its good
> >fit with precoding has been well described.
> >
> >On precoding, please see ungerboeck_1_0704.pdf (Portland). One fixed
> >IIR-type precoder is enough. If the group cannot agree on a single
> >fixed precoder, then let it be a very small set (2?) of fixed
> >precoders, one being selected preferrably during auto negotiation.
> >
> >Regards, Gottfried
> >
> >   _____
> >
> >From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
> >Behalf Of George Eisler
> >Sent: Mittwoch, 15. September 2004 06:03
> >To:
> >Subject: Re: [10GBT] Discussions on precoder decisions
> >
> >
> >Hugh,
> >
> >Thanks again for taking the badly needed lead on urging along the
> >decision making. The precoder definition is clearly in need of
> >consideration, although I think it will take simulation work to
> >really nail it down. Of course you can't finish it if you don't get
> >
> >On last week's call, I was surprised by the "double square"
> >contribution, with it's sort of 16/8 PAM flavor. It seems to open the
> >case up rather than converging, but I wonder what's your take on it?
> >I was going to call you, only to realize that I don't have your phone
> >
> >George Eisler
> >310 459-9225
>Express yourself instantly with MSN Messenger! Download today - it's FREE!

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