%DTMFde解碼子程序
function dtmfde=DTMFde(y)
global n;
global gg;
global dd;
    N=205;                                         %樣本長(zhǎng)度
    k=[18 20 22 24 31 34 38 42];             %DFT樣本序號(hào)
    Y=goertzel(y(1:N),k+1);                         %計(jì)算八點(diǎn)DFT
    val=abs(Y);                                       
 
    limit=80;          %規(guī)定檢測(cè)門(mén)限
    for s=5:8;
        if val(s)>limit,break,end  %查找列號(hào)
    end
    for r=1:4
        if val(r)>limit,break,end   %查找行號(hào)
    end
    tm=[49,50,51,65;52,53,54,66;55,56,57,67;42,48,35,68];  %16個(gè)ASCII碼
    %disp(['接收端檢測(cè)到的號(hào)碼為',setstr(tm(r,s-4))])  %顯示接收到的字符
    dd=setstr(tm(r,s-4));