1、数字信号处理实验报告电话拨号音合成与识别精品资料大连理工大学实验报告学院(系): 专业: 班级: 姓 名: 学号: 组: _ 实验时间: 实验室: 实验台: 指导教师签字: 成绩: 实验二 电话拨号音合成与识别一、实验结果与分析数字拨号音频谱分析(代码与频谱):n=1:410;fs=8192;d1=sin(2*pi*697/fs*n)+sin(2*pi*1209/fs*n);D1=fft(d1);t1=(0:length(d1)-1)*fs/length(d1)-fs/2;figure(1);plot(t1,fftshift(abs(D1);title(按键1的频谱);d1=sin(2*pi*
2、697/fs*n)+sin(2*pi*1336/fs*n);D1=fft(d1);figure(2);plot(t1,fftshift(abs(D1);title(按键2的频谱);d1=sin(2*pi*697/fs*n)+sin(2*pi*1477/fs*n);D1=fft(d1);figure(3);plot(t1,fftshift(abs(D1);title(按键3的频谱);d1=sin(2*pi*770/fs*n)+sin(2*pi*1209/fs*n);D1=fft(d1);figure(4);plot(t1,fftshift(abs(D1);title(按键4的频谱);d1=sin
3、(2*pi*770/fs*n)+sin(2*pi*1336/fs*n);D1=fft(d1);figure(5);plot(t1,fftshift(abs(D1);title(按键5的频谱);d1=sin(2*pi*770/fs*n)+sin(2*pi*1477/fs*n);D1=fft(d1);figure(6);plot(t1,fftshift(abs(D1);title(按键6的频谱);d1=sin(2*pi*852/fs*n)+sin(2*pi*1209/fs*n);D1=fft(d1);figure(7);plot(t1,fftshift(abs(D1);title(按键7的频谱);
4、d1=sin(2*pi*852/fs*n)+sin(2*pi*1336/fs*n);D1=fft(d1);figure(8);plot(t1,fftshift(abs(D1);title(按键8的频谱);d1=sin(2*pi*852/fs*n)+sin(2*pi*1477/fs*n);D1=fft(d1);figure(9);plot(t1,fftshift(abs(D1);title(按键9的频谱);d1=sin(2*pi*941/fs*n)+sin(2*pi*1209/fs*n);D1=fft(d1);figure(10);plot(t1,fftshift(abs(D1);title(按
5、键*的频谱);d1=sin(2*pi*941/fs*n)+sin(2*pi*1336/fs*n);D1=fft(d1);figure(11);plot(t1,fftshift(abs(D1);title(按键0的频谱);d1=sin(2*pi*941/fs*n)+sin(2*pi*1477/fs*n);D1=fft(d1);figure(12);plot(t1,fftshift(abs(D1);title(按键#的频谱);频谱图如下: 图形电话拨号面板的制作:首先是框架的搭建:利用callback在.m文件中对各个模块进行代码的编辑(下面列出主要部分):1、数字09的显示与发声(以数字7为例)
6、:% - Executes on button press in pushbutton7.function pushbutton7_Callback(hObject, eventdata, handles)% hObject handle to pushbutton7 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)n0=strcat(get(handles.numshow
7、,string),7); % 获取数字号码 set(handles.numshow,string,n0); % 显示号码 n=1:handles.DTMFnum; % 每个数字 410 个采样点表示d0=sin(2*pi*852/handles.fs*n)+sin(2*pi*1209/handles.fs*n); % 对应行频列频叠加 space=zeros(1,handles.DTMFnum); %400 个 0 模拟静音信号 phone=handles.NUM,d0; handles.NUM=phone,space; % 存储连续的拨号音信号 guidata(hObject, handle
8、s);wavplay(d0,8192);2、删除键*的代码:% - Executes on button press in pushbutton11.function pushbutton11_Callback(hObject, eventdata, handles)% hObject handle to pushbutton11 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDA
9、TA)n=1:1000; num=get(handles.numshow,string); l=length(num); n11=strrep(num,num,num(1:l-1); d11=sin(0.7217*n)+sin(0.9273*n); set(handles.numshow,string,n11); L=length(handles.NUM); handles.NUM=handles.NUM(1:L-820); guidata(hObject, handles);wavplay(d11,8192);3、确认键#的代码:% - Executes on button press in
10、 pushbutton12.function pushbutton12_Callback(hObject, eventdata, handles)% hObject handle to pushbutton12 (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)n0=strcat(get(handles.numshow,string),#); % 获取数字号码 set(han
11、dles.numshow,string,n0); % 显示号码 n=1:handles.DTMFnum; % 每个数字 410 个采样点表示d0=sin(2*pi*941/handles.fs*n)+sin(2*pi*1477/handles.fs*n); % 对应行频列频叠加 guidata(hObject, handles);wavplay(d0,8192);4、清空键Reset的代码:% - Executes on button press in btFW.function btFW_Callback(hObject, eventdata, handles)% hObject handl
12、e to btFW (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)handles.NUM=;set(handles.numshow,string,); % 显示号码 set(handles.numRec,string,); % 显示号码 guidata(hObject, handles);5、显示键的代码:% - Executes on button press in b
13、tRec.function btRec_Callback(hObject, eventdata, handles)% hObject handle to btRec (see GCBO)% eventdata reserved - to be defined in a future version of MATLAB% handles structure with handles and user data (see GUIDATA)L=length(handles.NUM); n=L/handles.DTMFsum; number=; for i=1:n j=(i-1)*handles.DT
14、MFsum+1; d=handles.NUM(j:j+(handles.DTMFnum-1); % 截取出每个数字 f=fft(d,8192); % 以 N=2048 作 FFT 变换 a=abs(f); p=a.*a/handles.fs; % 计算功率谱% p=a.*a/10000; % 计算功率谱 num(1)=find(p(1:1000)=max(p(1:1000); % 找行频 num(2)=1000+find(p(1000:1700)=max(p(1000:1700); % 找列频 if (num(1) 730) row=1; % 确定行数 elseif (num(1) 810)
15、row=2; elseif (num(1) 900) row=3; else row=4; end if (num(2) 1260) column=1; % 确定列数 elseif (num(2) 1400) column=2; else column=3; end z=row,column; % 确定数字 if z=4,2 tel=0; elseif z=1,1 tel=1; elseif z=1,2 tel=2; elseif z=1,3 tel=3; elseif z=2,1 tel=4; elseif z=2,2 tel=5; elseif z=2,3 tel=6; elseif z=
16、3,1 tel=7; elseif z=3,2 tel=8; elseif z=3,3 tel=9; end t(i)=tel; c=strcat(number,int2str(tel); number=c; i=i+1; end set(handles.numRec,string,number); % 显示号码GUI界面的操作: (1)初始化界面 (2)输入数字后的界面 (3)按*后删除一位 (4)按#后确认键 (5)按下显示键显示出来 (6)按下Reset键清空 二、讨论、建议、质疑做本实验分两部分,第一部分是做图形化(GUI)界面的设计,第二部分是做电话信号的频谱分析。做GUI设计中的问
17、题:删除键部分*在ppt模板的基础上,将全局变量global NUM删掉了,而改为用句柄handles.NUM.还有就是用guidata(hObject, handles);进行实时更新从而确保删除后能在内存中也删除。同时注意删除是820个点,不是1100个点。确认键#只需要发声和显示即可,不用放在内存中,显示键用的是ppt上的模板,其他部分都顺利完成。第二部分频谱分析是利用FFT变换实现的,由于抽样过程会出现频谱搬移的现象,为了看到原有信号的频谱,采用:t1=(0:length(d1)-1)*fs/length(d1)-fs/2;从而保证抽样频率不会在频谱中体现出来,一共做出了12个拨音信号的频谱。本实验作为综合性的实验,既让我熟悉了GUI的设计,又强化了信号频谱分析的知识,这是本次实验的体会。
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