双音多频拨号系统DTMF的实验报告

双音多频拨号系统DTMF的实验设计报告所谓双音多频（DTMF），就是用两个频率——行频和列频来表示电话机键盘上的一个数字。

DTMF 电话的指令正在迅速的取代脉冲指令。

除了在电话呼叫信号中使用外，DTMF 还广泛的使用在交互式控制应用，例如电话银行、电子邮件甚至家电远程控制等，用户可以从电话机发送DTMF 信号来做菜单选择。

本文基于MATLAB的双音多频拨号系统的仿真实现。

主要涉及到电话拨号音合成的基本原理及识别的主要方法，利用 MATLAB 软件以及 DFT 算法实现对电话通信系统中拨号音的合成与识别。

并进一步利用 MATLAB 中的图形用户界面 GUI 制作简单直观的模拟界面。

还能够利用矩阵不同的基频合成 0 － 9 不同按键的拨号音，并能够对不同的拨号音加以正确的识别，实现由拨号音解析出电话号码的过程，进一步利用 GUI 做出了简单的图形操作界面。

本文具有界面清楚，画面简洁，易于理解，操作简单的优点，从而实现对电话拨号音系统的简单的信号仿真。

关键词：双音多频（DTMF） MATLAB GUI 信号仿真在电话中，数字0~9的中每一个都用两个不同的单音频传输，所用的8个频率分成高频带和低频带两组，低频带有四个频率：679Hz，770Hz，852Hz和941Hz；高频带也有四个频率：1209Hz，1336Hz，1477Hz和1633Hz.。

每一个数字均由高、低频带中各一个频率构成，例如1用697Hz和1209Hz两个频率，信号用表示，其中，。

这样8个频率形成16种不同的双频信号。

一,利用GUI 作图（简单的电话界面）如下：利用 GUI 图形用户界面设计工具制作电话拨号面板，把 DTMF 信号和电话机的键盘矩阵对应起来。

其中选用我们熟悉的 10 个数字键0 — 9 ， 3 个功能键“ 回删”、“拨号”，“解码”。

按照图电话机键盘矩阵的排列方式制作五行三列的按键控件。

每个按键可用（ Push Button ）添加。

静态文本框可用（ Static Text ）添加，如图再加个解码键（ Push Button ）二，再点运行，得出与上图对应的m文件，再用鼠标右击上图的每个键，点callback导入每个键的编译程序如下：1，按键1的程序：% --- Executes on button press in pushbutton4. function pushbutton4_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); % 把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];%每个数字1000个采样点y=sin(0.5345*n)+sin(0.9272*n);%对应行频列频时域叠加，数字1的低频697Hz和高频1209Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);%100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; % 储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'1'];set(handles.text1,'string',[NoCtrl]);end2，按键2的程序：function pushbutton5_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is tooelsen=[1:1000];% 每个数字1000个采样点y=sin(0.5345*n)+sin(1.0247*n);% 对应行频列频时域叠加，数字2的低频697Hz和高频1336Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);% 100个0模拟静音信号global NUMphone=[NUM,y]; %循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'2'];set(handles.text1,'string',[NoCtrl]);end3．按键3的程序：% --- Executes on button press in pushbutton6. function pushbutton6_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is tooelsen=[1:1000];% 每个数字1000个采样点y=sin(0.5345*n)+sin(1.1328*n);% 对应行频列频时域叠加，数字3的低频697Hz和高频1477Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);% 100个0模拟静音信号global NUMphone=[NUM,y]; %循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'3'];set(handles.text1,'string',[NoCtrl]);end4，按键4的程序：% --- Executes on button press in pushbutton10. function pushbutton10_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is tooelsen=[1:1000];% 每个数字1000个采样点y=sin(0.5905*n)+sin(0.9272*n);% 对应行频列频时域叠加，数字4的低频770Hz和高频1209Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);% 100个0模拟静音信号global NUMphone=[NUM,y]; %循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'4'];set(handles.text1,'string',[NoCtrl]);end5，按键5的程序：% --- Executes on button press in pushbutton9. function pushbutton9_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];%每个数字1000个采样点vy=sin(0.5905*n)+sin(1.0247*n);% 对应行频列频时域叠加，数字5的低频770Hz和高频1336Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100); %100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'5'];set(handles.text1,'string',[NoCtrl]);end6，按键6的程序：% --- Executes on button press in pushbutton8. function pushbutton8_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];% 每个数字1000个采样点y=sin(0.5905*n)+sin(1.1328*n);% 对应行频列频时域叠加，数字6的低频770Hz和高频1477Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);% 100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'6'];set(handles.text1,'string',[NoCtrl]);end7，按键7的程序：% --- Executes on button press in pushbutton13. function pushbutton13_Callback(hObject, eventdata,handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];% 每个数字1000个采样点y=sin(0.6534*n)+sin(0.9272*n);% 对应行频列频时域叠加，数字7的低频852Hz和高频1209Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100); %100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'7'];set(handles.text1,'string',[NoCtrl]);end8，按键8的程序：% --- Executes on button press in pushbutton12.function pushbutton12_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];% 每个数字1000个采样点y=sin(0.6534*n)+sin(1.0247*n);% 对应行频列频时域叠加，数字8的低频852Hz和高频1336Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100);% 100个0模拟静音信号global NUMphone=[NUM,y]; %循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'8'];set(handles.text1,'string',[NoCtrl]);end% --- Executes on button press in pushbutton14. function pushbutton14_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];% 每个数字1000个采样点y=sin(0.6534*n)+sin(1.1328*n);% 对应行频列频时域叠加，数字9的低频852Hz和高频1477Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100); %100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'9'];set(handles.text1,'string',[NoCtrl]);end% --- Executes on button press in pushbutton17. function pushbutton17_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); %把数字显示在屏幕上if(length(x)>15)errordlg('Sorry . The number you have input is too long !','Input Error•','modal')elsen=[1:1000];每个数字1000个采样点y=sin(0.7217*n)+sin(1.0247*n);% 对应行频列频时域叠加，数字0的低频941Hz和高频1336Hz叠加wavplay(y,8192) %产生拨号音space=zeros(1,100); %100个0模拟静音信号global NUMphone=[NUM,y];% 循环储存NUM=[phone,space]; %储存连续的拨号音信号NoCtrl=x;NoCtrl=[NoCtrl,'0'];set(handles.text1,'string',[NoCtrl]);end11，按键#号程序：% --- Executes on button press in pushbutton16. function pushbutton16_Callback(hObject, eventdata, handles)set(handles.text1,'string',['']);set(handles.tbutton,'visible',['off']);set(handles.tbutton,'value',[0]);clear all12，按键*的程序：% --- Executes on button press in pushbutton18. function pushbutton18_Callback(hObject, eventdata, handles)set(handles.text1,'string',['']);set(handles.tbutton,'visible',['off']);set(handles.tbutton,'value',[0]);clear all13，回删键的程序：% --- Executes on button press in pushbutton20. function pushbutton20_Callback(hObject, eventdata, handles)x=get(handles.text1,'string');% 把数字显示在屏幕上if(isempty(x))errordlg('Please input the phone No.','Input error','modal')elsexll=length(x);x(xll)=[];%去掉末尾号在面板上的显示set(handles.text1,'string',[x]);global NUMll=length(NUM);%删除末尾号码在拨号音信号中的储存for i=ll-1100+1:llNUM(ll)=[];ll=length(NUM);endend14，拨号键的程序：% --- Executes on button press in pushbutton21. function pushbutton21_Callback(hObject, eventdata, handles)x=get(handles.text1,'string'); % 把数字显示在屏幕上xx=str2num(x);if(isempty(NUM))errordlg('Please input the phone No.','Input error','modal')elsewavplay(NUM,8192);msgbox('拨号成功！若需再次拨号请按#号复位！','Done','help')set(handles.tbutton,'visible',['on']);set(handles.text1,'string',['Dieling Done.']); end14，关闭键的程序：% --- Executes on button press in pushbutton22. function pushbutton22_Callback(hObject, eventdata, handles)clear allclose all15，解码的程序：% --- Executes on button press in tbotton.function tbotton_Callback(hObject, eventdata, handles)L=length(NUM);n=L/1100;number='';for i=1:nj=(i-1)*1100+1;d=NUM(j:j+999); %截取出每个数字f=fft(d,2048); %以N=2048作FFT变换a=abs(f);p=a.*a/10000; %计算功率谱num(1)=find(p(1:250)==max(p(1:250))); % 找行频通过计算得出数值范围num(2)=300+find(p(300:380)==max(p(300:380))); % 找列频通过计算得出数值范围if (num(1) < 180) row=1; % 确定行数elseif (num(1) < 200) row=2;elseif (num(1) < 220) row=3;else row=4;endif (num(2) < 320) column=1; %确定列数elseif (num(2) < 340) column=2;else column=3;endz=[row,column]; % 确定数字if z==[4,2] tel=0; %0在4行2列elseif z==[1,1] tel=1; %1在1行1列elseif z==[1,2] tel=2; %2在1行2列elseif z==[1,3] tel=3; %3在1行3列elseif z==[2,1] tel=4; %4在2行1列elseif z==[2,2] tel=5; %5在2行2列elseif z==[2,3] tel=6; %6在2行3列elseif z==[3,1] tel=7; %7在3行1列elseif z==[3,2] tel=8; %8在3行2列elseif z==[3,3] tel=9; %9在3行3列endt(i)=tel;c=strcat(number,int2str(tel));number=c;i=i+1;endset(handles.text1,'string',['解码中...']);h = waitbar(0,'Decoding...Please wait...'); steps = 1500;for step = 1:steps% computations take place herewaitbar(step / steps)endclose(h);set(handles.text1,'string',number);% hObject handle to tbotton (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)三，运行以上程序调出如下图界面：即可以进行仿真拨号。