Problem $4$

$5\mathrm{.}5-1$ In an extreme case of preemphasis filter design, we can choose

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H$\_\{$p$\}($f$)=$j $2\backslash$pi f

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This is simply a differentiator prior to frequency modulation.

Find the corresponding deemphasis filter and show that the overall modulation and demodulation system using this particular pair of preemphasis and deemphasis filters is effectively a PM system.