dtmfproduce.m

dtmf的计算机仿真程序用于大学的课程设计

function[dtmf,pointnum]=DTMFproduce(freq,fs,sigtime,wholetime)
pointnum=round(wholetime*10^(-3)*fs);
dtmf=zeros(1,pointnum);
dw=2*pi*freq/fs;
dtmf(1,1)=sin(dw);
dtmf(1,2)=sin(2*dw);
for i=3:1:round(sigtime*10^(-3)*fs);
    dtmf(1,i)=2*cos(dw)*dtmf(1,i-1)-dtmf(1,i-2);
end
 %plot(dtmf);
 ans=dtmf