Ideal Filter Digital Signal Processing--FIR Digital Filter Design Lowpass H() -2π 一元 0 2π Highpass (e 0 -2元 一元 0 2w Bandpass H() -0 -2元 一元 0 2π Bandstop He -2元 一元 0 2元 Fig 10.1.1 ideal Lowpass Highpass,Bandpass Bandstop Magnitude Response 上游充通大学Digital Signal Processing—— FIR Digital Filter Design Ideal Filter Fig 10.1.1 ideal Lowpass、Highpass、Bandpass、Bandstop Magnitude Response (e ) j H (e ) j H (e ) j H (e ) j H 0 Lowpass 0 Highpass 0 Bandpass 0 Bandstop     2π 2π 2π 2π ππππ π π π π 2π 2π 2π 2π