這裏先介紹算法原理，再在文中最後放出源碼。我的這個代碼是根據你輸入的信噪比，分別進行估算源餘弦信號的頻率。
因爲編寫成gui的格式，所以，核心代碼在代碼中漢字備註那裏
結果
算法原理
MUSIC 方法（multiple signal classification）
代碼
有個缺陷，就是他只能估算出主峯的頻率，估算出來其他的峯的頻率誤差很大
function varargout = final(varargin)
% FINAL MATLAB code for final.fig
% FINAL, by itself, creates a new FINAL or raises the existing
% singleton*.
%
% H = FINAL returns the handle to a new FINAL or the handle to
% the existing singleton*.
%
% FINAL('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in FINAL.M with the given input arguments.
%
% FINAL('Property','Value',...) creates a new FINAL or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before final_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to final_OpeningFcn via varargin.
%
% *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one
% instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES
% Edit the above text to modify the response to help final
% Last Modified by GUIDE v2.5 06-May-2020 10:47:02
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @final_OpeningFcn, ...
'gui_OutputFcn', @final_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 final is made visible.
function final_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% varargin command line arguments to final (see VARARGIN)
% Choose default command line output for final
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes final wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = final_OutputFcn(hObject, eventdata, handles)
% varargout cell array for returning output args (see VARARGOUT);
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Get default command line output from handles structure
varargout{1} = handles.output;
% --- Executes on button press in pushbutton1.
function pushbutton1_Callback(hObject, eventdata, handles)
% 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)
global xn
global snr
global sig
p=6; %階數；
m=1.5*p;
snr = str2double(get(handles.edit1,'String'));
n=1:128;
%xn=2*sin(2*pi*0.05*n)+sin(2*pi*0.03*n)+sqrt(0.32)*randn(size(n));
xn=2*sin(2*pi*0.05*n)+5*sin(2*pi*0.03*n)
%xn=2*sin(2*pi*0.05*n);
sig = awgn(xn,snr,'measured');
%global sig
%p=6;
%m=p*2;
%-------------------------------------------------------------------------
%1、構成自相關矩陣Rxx
%-------------------------------------------------------------------------
N=length(sig);
rxx1=xcorr(sig,'biased');
rxx=rxx1(N:m+N-1);
Rxx=toeplitz(rxx);
%-------------------------------------------------------------------------
%2、對Rxx特徵分解
%-------------------------------------------------------------------------
[V D]=eig(Rxx);
ev=eig(Rxx); %矩陣分解；
[s i]=min(ev);
U2=V(:,1:m-p);
U1=V(:,m-p+1:m);
%-------------------------------------------------------------------------
% 3、計算Smusic(f)=1/(e’*U2*U2’*e)
%-------------------------------------------------------------------------
f=0.0;
df=0.001;
for k=1:0.5/df;
for i=1:m;
e(i)=exp(-2*pi*(i-1)*f*j);
end
Smusic(k)=1/abs(e*U2*U2'*e');
f=f+df;
end
[va,lo]=findpeaks(Smusic,'MinPeakHeight',0.1)
fx(1:3)=df*lo;
%plot(handles.axes2,log(Smusic));
plot(handles.axes2,Smusic);
set(findobj('Tag','edit3'),'String',fx(1));
set(findobj('Tag','edit4'),'String',fx(2));
set(findobj('Tag','edit5'),'String',fx(3));
function edit1_Callback(hObject, eventdata, handles)
% hObject handle to edit1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of edit1 as text
% str2double(get(hObject,'String')) returns contents of edit1 as a double
% --- Executes during object creation, after setting all properties.
function edit1_CreateFcn(hObject, eventdata, handles)
% hObject handle to edit1 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles empty - handles not created until after all CreateFcns called
% Hint: edit controls usually have a white background on Windows.
% See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
set(hObject,'BackgroundColor','white');
end
function edit3_Callback(hObject, eventdata, handles)
% hObject handle to edit3 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of edit3 as text
% str2double(get(hObject,'String')) returns contents of edit3 as a double
% --- Executes during object creation, after setting all properties.
function edit3_CreateFcn(hObject, eventdata, handles)
% hObject handle to edit3 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles empty - handles not created until after all CreateFcns called
% Hint: edit controls usually have a white background on Windows.
% See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
set(hObject,'BackgroundColor','white');
end
function edit4_Callback(hObject, eventdata, handles)
% hObject handle to edit4 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of edit4 as text
% str2double(get(hObject,'String')) returns contents of edit4 as a double
% --- Executes during object creation, after setting all properties.
function edit4_CreateFcn(hObject, eventdata, handles)
% hObject handle to edit4 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles empty - handles not created until after all CreateFcns called
% Hint: edit controls usually have a white background on Windows.
% See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
set(hObject,'BackgroundColor','white');
end
function edit5_Callback(hObject, eventdata, handles)
% hObject handle to edit5 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of edit5 as text
% str2double(get(hObject,'String')) returns contents of edit5 as a double
% --- Executes during object creation, after setting all properties.
function edit5_CreateFcn(hObject, eventdata, handles)
% hObject handle to edit5 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles empty - handles not created until after all CreateFcns called
% Hint: edit controls usually have a white background on Windows.
% See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
set(hObject,'BackgroundColor','white');
end