2020年(完整版)南理工数字信号处理课程实验报告

数字信号处理 project

实验报告

学院电子工程与光电技术学院

专业通信工程

学号

姓名

一、 IIR 低通滤波器设计

滤波器要求

Using bilinear transform methods ,design a IIR low-pass filter

with the

following specifications:

p

.2A ,

s

.4A

; the passband ripple

-.5dB,

the stopband attenuation

2dB.

where A is the last nomber of your student number

(1)Write a program to compute the required order of the Butterworth or Chebyshev analog filters;

Using bilinear transform methods ,transform the analog filters to the

corresponding digital filters;

Sketch the frequency response of the filters.

滤波器设计程序如下

wp=.25*pi;

ws=.45*pi;

Wp=tan(wp/2);

Ws=tan(ws/2);

ap=.5;

as=2;

[N,Wn]=cheb1ord(Wp,Ws,ap,as,

[B,A]=cheby1(N,1,Wn, 's'

[num,den]=bilinear(B,A,.5);

[h,w]=freqz(num,den);

subplot(211);

plot(w/pi,2*log1(abs(h)));

ylim([-5 5]);

xlim([ 1]);

xlabel( '\Omega/\pi' );

);

's'