双音多频拨号系统中数字信号处理的应用

简介：
本研究探讨了在双音多频（DTMF）拨号系统中应用数字信号处理技术的方法与优势，包括信号检测、噪声抑制及编码优化等方面。 function varargout = key1(varargin) % KEY1 M-file for key1.fig % KEY1, by itself, creates a new KEY1 or raises the existing singleton. % % H = KEY1 returns the handle to a new KEY1 or the handle to the existing singleton. % % KEY1(CALLBACK,hObject,eventData,handles,...) calls the local function named CALLBACK in KEY1.M with the given input arguments. % % KEY1(Property,Value,...) creates a new KEY1 or raises the existing singleton. Starting from the left, property value pairs are applied to the GUI before key1_OpeningFunction gets called. An unrecognized property name or invalid value makes property application stop. All inputs are passed to key1_OpeningFcn via varargin. % % See also: GUIDE, GUIDATA, GUIHANDLES % Copyright 2002-2003 The MathWorks, Inc. % Edit the above text to modify the response to help key1 % Last Modified by GUIDE v2.5 13-Dec-2009 23:16:54 % Begin initialization code - DO NOT EDIT gui_Singleton = 1; gui_State = struct(gui_Name, mfilename, ... gui_Singleton, gui_Singleton, ... gui_OpeningFcn, @key1_OpeningFcn, ... gui_OutputFcn, @key1_OutputFcn, ... gui_LayoutFcn, [], ... gui_Callback, []); if nargin && ischar(varargin{1}) gui_State.gui_Callback = str2func(varargin{1}); end if nargout [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:}); else gui_mainfcn(gui_State, varargin{:}); end % End initialization code - DO NOT EDIT % --- Executes just before key1 is made visible. function key1_OpeningFcn(hObject, eventdata, handles, varargin) % This function has no output args, see OutputFcn. handles.output = hObject; guidata(hObject, handles); % UIWAIT makes key1 wait for user response (see UIRESUME) % --- Outputs from this function are returned to the command line. function varargout = key1_OutputFcn(hObject, eventdata, handles) varargout{1} = handles.output; % --- Executes on button press in pushbutton1. function pushbutton1_Callback(hObject, eventdata, handles) d=1; val=telephone(d); ppu(val) str = get(handles.pushbutton1,string); set(handles.edit1,string,str); % hObject handle to pushbutton1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % --- Executes on button press in pushbutton2. function pushbutton2_Callback(hObject, eventdata, handles) d=2; val=telephone(d); ppu(val) str = get(handles.pushbutton2,string); set(handles.edit1,string,str); % hObject handle to pushbutton2 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % --- Executes on button press in pushbutton3. function pushbutton3_Callback(hObject, eventdata, handles) d=3; val=telephone(d); ppu(val) str = get(handles.pushbutton3,string); set(handles.edit1,string,str); % hObject handle to pushbutton3 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % --- Executes on button press in pushbutton4. function pushbutton4_Callback(hObject, eventdata, handles) d=A; val=telephone(d); ppu(val) str = get(handles.pushbutton4,string); set(handles.edit1,string,str); % hObject handle to pushbutton4 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % --- Executes on button press in pushbutton5. function pushbutton5_Callback(hObject, eventdata, handles) d=4; val=telephone(d); ppu(val) str = get(handles.pushbutton5,string); set(handles.edit1,string,str); % hObject handle to pushbutton5 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) % --- Executes on button press in pushbutton6. function pushbutton6_Callback(hObject, eventdata, handles) d=5; val=telephone(d); ppu(val) str = get(handles.pushbutton6,string); set(handles.edit1,string,str); % hObject handle to pushbutton6 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see