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Entry  Thu Sep 29 12:56:27 2011, Jenne, Update, Adaptive Filtering, Meditations on the OAF 
    Reply  Mon Oct 3 16:18:05 2011, Jenne, Update, Adaptive Filtering, Meditations on the OAF 
Message ID: 5602     Entry time: Mon Oct 3 16:18:05 2011     In reply to: 5576
Author: Jenne 
Type: Update 
Category: Adaptive Filtering 
Subject: Meditations on the OAF 


[Mirko, Den, Jenne]

We're modifying the c1oaf model, and we got to talking about the "Fx" part of "FxLMS".  In the past, we put in a guess for the filter.  What if we use the static wiener filter as the F, and send the wiener filtered witness channels to the adaptation algorithm? 

Are the wiener filter and the plant compensation filter ("Fx") the same?  Will this work?  Or is there some reason that they must be different?

Also:  Notes to self:  Put in filtered witness channels as well as regular into Adapt block.  Make sure that the order/number of inputs is correct.

 More meditations...

Mirko and I were talking about the tunability required for each DoF.  For right now, we're going to give each DoF its own mu and tau (adaptation gain and adaptation decay), but we're leaving all of the other things (number of taps, number of witnesses, delay, downsample rate) the same for each DoF's adaptation.  This may need to change later, but we'll get there when we get there. 

The one I'm most concerned about is the number of witnesses...  Mirko is suggesting that we give each adaptation algorithm all witnesses, and unused ones should converge to ~0.  I agree in principle, but I'm not sure that it's actually going to work that way.  I think we may need to be able to tell the algorithm which witnesses to look at for which DoF. 

Also, the Delay.... we may need to adjust it for each DoF.  In Matt's OAF "manual" in elog 395, he mentions the need to calculate the delay based on a plant TF.  Presumably since (except for the MC) all the witnesses come in together, and all the DoFs come in together, the delay should be about the same for all?  We'll have to see...

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