www.pudn.com > leidaxitong.rar > hunpin.m

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%混频 
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function y1=hunpin(x,f,w1,w2); 
fs=100e6;                               %采样频率100M 
Ts=1/fs; 
T=0.00003;                             %脉冲重复周期30微秒 
t=0:Ts:T-Ts; 
N=length(x); 
y=x.*cos(2*pi*f*t); 
 
n=50;                                   
Wn=[w1,w2];                           
b=fir1(n,Wn);                          %滤波器系数 
y=[y,zeros(1,25)]; 
y1=filter(b,1,y); 
y1=y1(26:length(y1));