Note: for more informations on contrast functions (and particularly on quadratic contrast functions), see the references.
We give here is a brief description of the different contrast
functions proposed in the toolbox. We denote by the output of
the separating filter. When calling [Source,Contribution,W] =
Deflation(x,Param,FreqCycl);, the following contrast functions have
been implemented depending on the value of Param.Method:
Case of stationnary sources:
If Param.Method='kurtosisRealValued', the contrast:
is maximized under the constraint
. This contrast
function is valid for real-valued stationnary sources.
If Param.Method='kurtosis', the contrast:
is maximized under the constraint
. This contrast
function is valid for both real-valued and complex-valued
stationnary sources.
If Param.Method='quadratic', the contrast:
is maximized under the constraint
, where:
is a fixed ``reference'' signal. This contrast function is valid
for both real-valued and complex-valued stationnary sources. See
the references on quadratic contrasts for more information.
Case of cyclo-stationnary sources: If
Param.Method='cyclostat', then the contrast:
is maximized under the constraint
(where (
is the time average operator). This contrast function is valid for
both real-valued and complex-valued sources which are cyclo-stationnary.