[ibis-macro] Re: Adaptive Equalization in Statistical Simulations
- From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Tue, 25 Mar 2014 18:35:32 +0000
The other question is what you want to adapt to?
As others pointed out, the Init function modifies the
impulse response of the channel, so adaptation or
optimization is based on the channel's characteristics.
There is no bit pattern involved. Since channels usually
don't change with time (they are Time Invariant), doing
this in the Init function just once is sufficient.
If you want the filters to adapt to the bit pattern
as the pattern might change in time, you will need to
do things in GetWave, since that is the only function
which deals with the bit pattern.
Thanks,
Arpad
==========================================================
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]
On Behalf Of Todd Westerhoff
Sent: Tuesday, March 25, 2014 1:29 PM
To: IBIS-ATM
Subject: [ibis-macro] Re: Adaptive Equalization in Statistical Simulations
Greg,
To a degree, it depends on what you mean by "adaptive". More specifically, it
depends on whether you mean "adapt once" or "adapt continually".
AMI models can modify their equalization based on the impulse response passed
in (and thus support Statistical Analysis). This has been the case since 2008.
Notice, however, that the adaptation is a one-time deal, because the impulse
response is only passed in once. Continual adaptation - i.e. the length of time
it takes taps to settle, and tap drift, can only be modeled in Time-Domain
analysis, because you actually need to be processing lots of bits to do that.
Does that help?
Todd.
Todd Westerhoff
VP, Semiconductor Relations
Signal Integrity Software Inc. * www.sisoft.com<http://www.sisoft.com>
6 Clock Tower Place * Suite 250 * Maynard, MA 01754
(978) 461-0449 x124 * twesterh@xxxxxxxxxx<mailto:twesterh@xxxxxxxxxx>
"I want to live like that"
-Sidewalk Prophets
From: ibis-macro-bounce@xxxxxxxxxxxxx<mailto:ibis-macro-bounce@xxxxxxxxxxxxx>
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Gregory R Edlund
Sent: Tuesday, March 25, 2014 2:09 PM
To: IBIS-ATM
Subject: [ibis-macro] Adaptive Equalization in Statistical Simulations
It is my understanding that adaptive equalization is not possible in AMI
statistical simulations. To model adaptive equalization, I need to first run a
short transient simulation, load the RX tap settings from that simulation into
the model-specific parameters, and then run a statistical simulation.
Question: what is it about modifying the impulse response that prevents RX
adaptive equalization in statistical simulations?
Thanks in advance for your time.
Greg Edlund
Senior Engineer
Signal Integrity and System Timing
IBM Systems & Technology Group
3605 Hwy. 52 N Bldg 050-3
Rochester, MN 55901
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