ʵÑéÖ¸µ¼Êé2011.3.8ÐźŷÖÎöÓë´¦Àí

1.510.50-0.5-1-1.5-202468101214161820£¨3£©ÓÃimpzº¯Êý a1=[1,0.75,0.125]; b1=[1,-1];

impz(b1,a1,21);

Impulse Response1.510.5ed0utilpmA -0.5-1-1.5-202468101214161820n (samples)b. µ¥Î»½×Ô¾ÏìÓ¦£º (1)ÓÃfilterº¯Êý a1=[1,0.75,0.125]; b1=[1,-1]; n=0:20;

x2=ones(1,21);

y1filter=filter(b1,a1,x2); stem(n,y1filter); title('y1filter_step'); xlabel('x'); ylabel('y');

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£¨2£©ÓÃconvº¯Êý a1=[1,0.75,0.125]; b1=[1,-1]; x2=ones(1,21);

[h]=impz(b1,a1,20); y1=conv(h,x2);

y1conv=y1(1:21); %ΪºÎy1convҪȡy1ÖÐ1£º21µÄÖµ£¬½âÊͼûn1=0:20; %y2?µ¥Î»½×Ô¾ÏìÓ¦?ÓÃconvº¯ÊýÖÐ×¢ÊÍ stem(n1,y1conv,'filled'); title('y1conv'); xlabel('n'); ylabel('y1[n]');

y1conv10.80.60.4]0.2n[1y0-0.2-0.4-0.6-0.802468101214161820n

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£¨3£©ÓÃimpzº¯Êý a=[1,0.75,0.125]; b=1;

impz(b,a)

Impulse Response10.80.60.4edu0.2tilpmA0 -0.2-0.4-0.6-0.80510152025303540n (samples)

II. y[n]=0.25(x[n-1]+x[n-2]+x[n-3]+x[n-4]) a. µ¥Î»³å¼¤ÏìÓ¦£º (1)ÓÃfilterº¯Êý a2=1;

b2=[0 0.25*ones(1,4)]; n=0:9;

x1=[1 zeros(1,9)];

y2filter=filter(b2,a2,x1); stem(n,y2filter); title('y2filter'); xlabel('x'); ylabel('y')

y2filter0.250.20.15y0.10.0500123456789x

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£¨2£©ÓÃconvº¯Êý a2=1;

b2=[0 0.25*ones(1,4)]; x1=[1 zeros(1,5)]; [h]=impz(b2,a2,5); y2conv=conv(h,x1); n=0:9;

stem(n,y2conv,'filled')

0.250.20.150.10.0500123456789£¨3£©ÓÃimpzº¯Êý a2=1;

b2=[0 0.25*ones(1,4)]; impz(b2,a2,10);

Impulse Response0.250.2e0.15dutilpmA 0.10.0500123456789n (samples)b. µ¥Î»½×Ô¾ÏìÓ¦£º (1)ÓÃfilterº¯Êý a2=1;

b2=[0 0.25*ones(1,4)]; n=0:20;

x2=ones(1,21);

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