• (v)  Minimize                                           
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• over Dw Î D  point-wise across frequency. The minimization itself produces a new scaling function       .
• (vi) Compare      with the previous estimate Dw , Stop if they are close, otherwise, replace Dw with       and return to step (ii).
qThe joint optimization of D and K is not convex and the global convergence is not guaranteed, many designs have shown that this approach works well.
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