fir48.m

48阶滤波器

n=1:1000;
%h=[-0.025288315,-0.034167931,-0.035752323,-0.016733702, 0.021602514, 0.064938487, 0.091002137, 0.081894974, 0.037071157,-0.021998074, -0.060716277,-0.051178658, 0.007874526, 0.084368728, 0.126869306,0.094528345,-0.012839661,-0.143477028,-0.211829088,-0.140513128,0.094601918,0.441387140,0.785875640,1.0,        1.0,0.785875640,0.441387140,0.094601918,-0.140513128,-0.211829088,      -0.143477028,-0.012839661, 0.094528345, 0.126869306, 0.084368728,       0.007874526,-0.051178658,-0.060716277,-0.021998074, 0.037071157,	       0.081894974, 0.091002137, 0.064938487, 0.021602514,-0.016733702,-0.035752323,-0.034167931,-0.025288315];
h=[-207,-280,-293,-137,177,532,745,671,304,-180,-497,-419,65,691,1039,774,-105,-1175,-1735,-1151,775,3616,6438,8192,8192,6438,3616,775,-1151,-1735,-1175,-105,774,1039,691,65,-419,-497,-180,304,671,745,532,177,-137,-293,-280,-207];
%x=round(100*randn(1,1000));
x=round(500*sin(0.2*pi*n)+500*cos(0.9*pi*n));
%x=[72,160,-206,-74,18,53,-55,30,-123,-19,-30,96,-53,-90,-89,28,-75,160,57,32,-15,32,134,-224,129,-38,0,88,58,-161,-150,57,-91,-163,-36,-40,-116,-111,29,-191,131,67,-28,-2,-91,-104,37,90,128,-13,61,196,227,-37,224,-16,-70,56,-5,116,66,-155,-303,54,-101,91,158,-98,101,16,-59,157,-52,123,158,-209,295,136,105,-77,-26,-137,-127,-89,59,184,135,-49,-218,24,-74,-178,45,58,86,-27,-42,-21,-17,22,168,12,65,208,-34,73,29,-85,-253,-238,-35,-61,-41,-142,23,21,-72,76,-164,-106,-25,-130,123,149,24,-140,66,-256,-53,320,44,-115,89,-28,104,-36,134,101,21,-30,26,-19,-8,70,-80,-80,-1,-73,-149,87,-27,-157,-39,-14,-233,-136,-182,111,-14,111,56,48,-68,28,-133,-72,-66,20,-179,-139,20,147,37,-44,-5,8,196,-7,94,-8,-80,31,105,-166,-109,-19,46,-92,-65,62,-134,105,86,-64,66,129,31,86,13,2,-7,-99,-75,-3,99,-60,148,-81,65,-131,-87,-47,22,187,11,-41,51,-120,-10,45,-30,-17,18,42,168,200,70,-137,36,-57,-104,70,48,-19,-38,-89,-184,-163,-117,-42,18,23,-124,70,43,145,-51,-1,-53,72,109,50,277,-16,43,-197,-55,-189,-11,-132,-67,-90,-15,95,155,43,-56,18,-77,-94,-141,-191,-7,67,21,-1,2,-56,189,-22,-141,-30,-57,-12,-39,-84,-174,-45,-155,-10,91,237,52,41,105,43,130,-19,13,-66,-76,-60,81,7,-183,183,65,-154,-38,21,-77,-11,34,103,-140,-103,-64,17,134,194,74,81,-14,-10,-80,49,124,130,-28,22,63,-55,23,36,52,-62,135,97,-238,-109,-33,-201,157,23,65,-113,20,170,73,79,60,-6,-111,214,-135,46,39,207,-32,147,-50,21,75,-95,61,176,9,260,-68,279,-2,27,-91,-195,-32,59,83,-167,-192,-44,4,242,-31,19,95,-53,-112,-159,117,49,165,-45,101,205,60,2,-161,124,68,-78,53,213,35,23,129,-1,-133,-56,76,-91,137,25,12,38,-7,-58,47,130,163,-70,81,-103,129,1,22,171,-208,11,-109,-156,64,-40,-40,8,-44,-56,88,-81,-26,49,-80,-1,63,15,258,-131,102,78,-83,-59,7,-1,-8,-156,170,-47,9,29,92,51,25,-140,97,159,-144,-153,-7,8,-84,-56,-3,-124,73,6,15,160,-78,155,106,-17,31,142,33,48,40,-7,131,98,172,-41,57,74,22,131,63,-111,-45,-73,35,-51,-210,-66,145,-33,270,-163,-54,55,149,-46,-50,124,4,75,123,30,108,77,-132,-51,56,-196,-76,-244,-66,-11,30,-58,-307,155,-41,143,-135,90,54,-47,243,202,80,3,54,68,-59,-26,152,101,30,-82,-49,87,36,-8,75,-179,121,-6,-39,61,64,102,93,123,-25,-71,-59,-26,124,-155,-39,28,83,-98,-10,13,6,37,-10,-70,-39,2,137,42,7,29,47,178,26,151,32,80,58,178,-94,-92,38,91,15,-20,149,-62,81,193,40,-86,243,-84,28,82,123,-6,65,-177,6,-76,-169,110,146,24,-110,242,-40,91,-14,131,32,-48,8,-11,142,71,37,-60,-85,66,147,-81,-128,172,10,-80,-125,124,153,178,63,8,214,126,-175,-1,247,-67,26,-37,132,-65,6,-74,-18,108,14,-2,-94,-148,36,48,32,-188,68,23,124,13,18,-61,-104,-30,146,180,-133,39,-2,11,81,-101,-100,28,29,-25,-22,90,-64,-18,72,30,155,-4,-3,-38,-55,93,-132,-30,-260,78,60,94,-102,-7,8,-177,-178,-66,135,214,17,-171,28,39,-10,18,-184,-150,82,-23,-163,-32,-80,69,-4,32,51,-103,10,-12,69,188,33,-10,3,-61,-173,48,-45,39,5,-49,24,72,15,13,-101,131,120,-258,-209,39,-86,-123,264,-90,-122,30,-73,-114,-141,-59,52,-149,-9,-1,-35,99,64,292,-125,16,79,-58,53,167,80,88,-22,30,-52,-16,-10,100,43,-3,-38,-24,-117,76,116,-102,170,-49,17,35,-25,-15,-117,-2,62,187,8,161,-38,-130,-72,-56,62,-134,-12,-110,-275,25,-86,114,-30,115,105,213,-66,-114,95,-40,-38,48,44,38,110,86,-118,40,-58,-98,12,7,-53,54,68,54,-51,-132,-61,-57,9,69,213,0,-9,-25,-87,42,-13,54,88,-125,87,-80,-75,-75,-31,-152,83,-61,96,197,29,-39,58,-114,6,1,-17,-69,-99,-5,72,-28,-142,46,109,-104,-284,100,8,-187,-61,117,-58,-26,0,-4,-51,-116,71,73,87,243,11,3,97,-1,141,176,89,114,40,19,-69,1,-111,191,-17,-73,-99,89,45,89,107,-10,155,17,80,-172,17,-48,-73,-213,-181,-5,-9,-119,-75,95,-18,-7,91,146,-112,181,15,-28,165,67,-35,-26,-64,-91,72,-1,-281,-15,58,75,-17,-58,37,-55,58,-196,52,160,73,56,-81,-54,131,-48,-175,-93,92,4,41,60,192,71,-231,138,139,-45,-63,102,-49,-40,140,28,188,-80,-56,171,-64,-142,-76,16,38,18];
z=zeros(1,48);
y=zeros(1,1000);
m=0;
for i=1:1000;
    for k=1:47
        z(1,49-k)=z(1,48-k);
    end
    z(1,1)=x(1,i);
    c=z.*h;
    y(1,i)=sum(c);
end
y=round(y./2^13);
w_y=fft(y);
amplitude_y=abs(w_y);
phase_y=angle(w_y);
b=1:1000;
a=2*pi*b/1000;
subplot(3,1,1);plot(b,y(1,b));xlabel('sequence y(n) n');
subplot(3,1,2);plot(a(b),amplitude_y(1,b));xlabel('frequency red');
subplot(3,1,3);plot(a(b),phase_y(1,b));xlabel('phase red');