dtmf拨号Ｍ文件程序.txt

模拟双音多频(DTMF)拨号系统的MATLAB仿真,形象画出了每个数字键所代表产生的波形

%DTMF信号的生成和检测
clear all;
tm=[1,2,3,65; 4,5,6,66; 7,8,9,67; 42,0,35,68];
N=205;K=[18 20 22 24 31 34 38 42];
f1=[697 770 852 941];
f2=[1209 1336 1477 1633];
TN=input('输入的6位电话号码＝');
TNr=0;
for m=1:6;
    d=fix(TN/10^(6-m));
    TN=TN-d*10^(6-m);
    for p=1:4;
        for q=1:4;
            if tm(p,q)==abs(d);break,end
        end
            if tm(p,q)==abs(d);break,end
    end
    n=0:1023;
    x=sin(2*pi*n*f1(p)/8000)+sin(2*pi*n*f2(q)/8000);
    sound(x,8000);
    pause(0.3)
    
    X=goertzel(x(1:N),K+1);
    val=abs(X);
    subplot(3,2,m);stem(K,val,'.');grid;xlabel('K');ylabel('|X(K)|');
    axis([10 50 0 120])
    limit=80;
    for s=5:8;
        if val(s)>limit,break,end
    end
    for r=1:4;
        if val(r)>limit,break,end
    end    
    TNr=TNr+tm(r,s-4)*10^(6-m);    
end
disp('接收端检测到的号码为：')
disp(TNr)