《数字信号处理》课程教学课件（2020讲稿）第五章 数字滤波器（FIR数字滤波器频率取样设计法）

第一种抽样N=6偶对称偶数点16[H(ei) I H,(el) I14I H,(k) 1[H(k) I12108642J000.61.620.20.40.81.21.41.8强行工零

强行置零 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 2 4 6 8 10 12 14 16 | H(e j ) | | Hd (e j ) | | Hd (k) | | H(k) | N = 6 第一种抽样 偶对称 偶数点

ha(n)[arg[H.(eiw)l:nonlinearphaseresponse205-102346[Ha()H151010S.0T01235462Pa(k)320.10.20.30.40.50.60.70.80.920123456h(n)3F2arg[H(ew)l:linearphaseresponse100235420[H(K)-1510505075054p(K)220-20234060.10.20.30.50.60.70.80.9-10.4

-1 0 1 2 3 4 5 6 0 1 2 3 4 -1 0 1 2 3 4 5 6 0 5 10 15 20 -1 0 1 2 3 4 5 6 -4 -2 0 2 4 hd(n) |Hd(k)| d(k) -1 0 1 2 3 4 5 6 0 1 2 3 4 -1 0 1 2 3 4 5 6 0 5 10 15 20 -1 0 1 2 3 4 5 6 -4 -2 0 2 4 h(n) |H(k)| (k) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 -4 -3 -2 -1 0 1 2 3 4 arg[Hd(ejw)]: nonlinear phase response 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 -4 -3 -2 -1 0 1 2 3 4 arg[H(ejw)]: linear phase response