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Séparation de sources. Principes et algorithmes - Gretsi

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Algebraic tools Statistical tools Criteria Spatial whitening Tensors<br />

Spatial whitening (2)<br />

Standardization via PCA<br />

Definition<br />

PCA is based on second or<strong>de</strong>r statistics<br />

Observed random variable x of dimension K. Then ∃(U, z):<br />

x = Uz, U unitary<br />

where Principal Components zi are uncorrelated<br />

ith column ui of U is called ith PC Loading vector<br />

Two possible calculations:<br />

EVD of Covariance Rx: Rx = UΣ 2 U H<br />

Sample estimate by SVD: X = UΣV H<br />

P.Comon & C.Jutten, Peyresq July 2011 BSS II.Tools and optimization criteria 42

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