2010届电子信息工程专业毕业设计（论文）
Wn=(0.3+0.5)*pi/2;
b=firl(N,Wn/pi,hanning(N+1)); freqz(b,1,512)
矩形窗：
wp=0.3*pi; ws=0.5*pi; wdelta=ws-wp; N=ceil(8*pi/wdelta); Wn=(0.3+0.5)*pi/2;
b=firl(N,Wn/pi,hanning(N)); freqz(b,1,512)
瑞米兹(瑞米兹沃特)：
fedge=[800 1000];
mval=[1 0];dev=[0.0559 0.01]; fs=4000;
[N,fpts,mag,wt]=remezord(fedge,mval,dev,fs); b=remez(N,fpts,mag,wt); [h,w]=freqz(b,1,256);
plot(w*2000/pi,20*log10(abs(h))); grid;
xlabel('频率/Hz') ylabel('幅度/dB')
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2010届电子信息工程专业毕业设计（论文）
The Design of FIR Digital Filters Based on Window function Method
Hao Hai
Electrical & Information Engineering, Chongqing Three Gorges University, Wanzhou 404100
Abstract Description of the digital filter unit of the finite length impulse response (FIR) filter
principle, the FIR filter window function design method is studied. Window function method in the design of FIR digital filter has a wide range of applications. Such as corrugated paper, a Chebyshev approximation criteria for the design method of FIR digital filter through the MATLAB simulation to achieve. Conventional digital filter design method is cumbersome and results are not intuitive, this paper, MATLAB has a powerful scientific computing and graphics display the advantages, with the window function method combines design theory to design FIR digital filter design results not only more intuitive, but also improve the accuracy of the filter design to better achieve the desired results.
Key words FIR digital filter；window function；equivalent ripple Chebyshev approximation；
MATLAB simulation
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