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RE: [10GBASE-T] question about the complexity reduction of MIMO




PJ,

Answering your question first, the metric used in the tutorial was operations/second.

Regarding your comment, I agree that the complexity of a realization is a concern for the group, but, not the realization itself.  This distinction avoids excessive consideration for vendor dependent issues which was what I was trying to get at.  So, I think it is not whether MIMO can achieve a 4x or 16x reduction, but rather, that there exists at least one possible realization of a particular technology that can achieve an acceptable level of complexity. In the tutorial, we made the comparison to a multi-port 1000BASE-T part.  One can then argue feasibility by extension to a realized solution. 

This leads to a question for the group.  What strategy or steps are needed to get to an agreement on technical feasibility?  

Bill

-----Original Message-----
From: P.J. Sallaway [mailto:pj@myricanetworks.com]
Sent: Tuesday, January 21, 2003 10:24 AM
To: William Jones
Cc: xichen@marvell.com; stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] question about the complexity reduction of MIMO


Bill,

I believe the complexity of a practical realization is important to the
group as we look at the feasibility of 10 gigabits/second over Cat-5 and
the role that different line codes play.

I am curious as to what complexity measure you are using when discussing
the 16x reduction using MIMO.  Is it power dissipation for a given
technology?  Multiplies per second?  Gate count?

Thanks,

...PJ

On Mon, 2003-01-20 at 13:44, William Jones wrote:
> Xiaopeng
> 
> I would claim the maximum is a 16x reduction.  So, a practical realization is in the range 4x to 16x.  Our approach is somewhere around 7x.  Note, a MIMO realization is not unique.  But, this is not a concern for the study group.
> 
> Bill  
> 
> -----Original Message-----
> From: xichen@marvell.com [mailto:xichen@marvell.com]
> Sent: Monday, January 20, 2003 10:24 AM
> To: William Jones
> Cc: stds-802-3-10gbt@ieee.org
> Subject: [10GBASE-T] question about the complexity reduction of MIMO
> 
> 
> 
> Bill,
> 
> I have a quick question about MIMO.  In your presentation, you stated that
> the MIMO architecture can help to reduce the DSP complexity from 10 to 1.5.
> 
> For a 4x4 MIMO system, the maximum complexity reduction is 4 times if I am
> not wrong.   In this extreme case, a one-channel DSP engine can be reused
> for 4 channels without any modification.  However even in such a case, the
> DSP complexity is still 2.5.
> 
> Xiaopeng
> 
> 
-- 
P.J. Sallaway <pj@myricanetworks.com>
Myrica Networks Inc.