Mat Lab Program to Generate ‘FIR Filter-Low Pass’ Coefficients

[seminar class]

Code:

% FIR Low  pass filters using rectangular, triangular and kaiser windows
% sampling rate – 8000
order = 50;
cf=[500/4000,1000/4000,1500/4000];     cf--> contains set of cut-off  frequencies[Wc ]

% cutoff frequency – 500
b_rect1=fir1(order,cf(1),boxcar(51));    %Rectangular
b_tri1=fir1(order,cf(1),bartlett(51));    %Triangular
b_kai1=fir1(order,cf(1),kaiser(51,8));    %Kaisar [Where 8-->Beta Co-efficient]

% cutoff frequency - 1000
b_rect2=fir1(order,cf(2),boxcar(51));
b_tri2=fir1(order,cf(2),bartlett(51));
b_kai2=fir1(order,cf(2),kaiser(51,8));

% cutoff frequency - 1500
b_rect3=fir1(order,cf(3),boxcar(51));
b_tri3=fir1(order,cf(3),bartlett(51));
b_kai3=fir1(order,cf(3),kaiser(51,8));

fid=fopen('FIR_lowpass_rectangular.txt','wt');
fprintf(fid,'\t\t\t\t\t\t%s\n','Cutoff -400Hz');
fprintf(fid,'\nfloat b_rect1[31]={');
fprintf(fid,'%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,\n',b_rect1);
fseek(fid,-1,0);
fprintf(fid,'};');
fprintf(fid,'\n\n\n\n');
fprintf(fid,'\t\t\t\t\t\t%s\n','Cutoff -800Hz');


fprintf(fid,'\nfloat b_rect2[31]={');
fprintf(fid,'%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,\n',b_rect2);
fseek(fid,-1,0);
fprintf(fid,'};');
fprintf(fid,'\n\n\n\n');
fprintf(fid,'\t\t\t\t\t\t%s\n','Cutoff -1200Hz');
fprintf(fid,'\nfloat b_rect3[31]={');
fprintf(fid,'%f,%f,%f,%f,%f,%f,%f,%f,%f,%f,\n',b_rect3);
fseek(fid,-1,0);
fprintf(fid,'};');

fclose(fid);
winopen('FIR_highpass_rectangular.txt');