Two signals: $d(t)$ and $p(t)$, the matching filter $w(t)$, they have $d(t)*w(t)=p(t)$ ( $*$ denotes **convolution**), $w(t)$ may be calculated in frequency domain: $w(t)=F^{-1}\left[\frac{F[p(t)]\overline{F[d(t)]}}{F[d(t)]\overline{F[d(t)]}+\epsilon}\right]$
How can I get the derivative of the the filter $w(t)$ with respect to $p(t)$ :
$$\frac{\partial{w}}{\partial{p}}=?$$