shiyan1.m

用matlab实现信号系统及系统响应

                                                                                                                         function varargout = shiyan1(varargin)


if nargin == 0  % LAUNCH GUI

	fig = openfig(mfilename,'reuse');

	
	handles = guihandles(fig);
	guidata(fig, handles);
    global Xb;%定义全变量，因为下面有两处要用到。 
    Xb=exp1_impseq(0,0,1);                 %单位脉冲
%     Ha=exp1_stepseq(1,1,10);               %矩阵序列，N=10
%     Hb=exp1_impseq(0,0,3)+2.5*exp1_impseq(1,0,3)+2.5*exp1_impseq(2,0,3)+exp1_impseq(3,0,3);       %序列bn(n)的产生
    
	if nargout > 0
		varargout{1} = fig;
	end

elseif ischar(varargin{1}) % INVOKE NAMED SUBFUNCTION OR CALLBACK

	try
		if (nargout)
			[varargout{1:nargout}] = feval(varargin{:}); % FEVAL switchyard
		else
			feval(varargin{:}); % FEVAL switchyard
		end
	catch
		disp(lasterr);
	end

end

% --------------------------------------------------------------------
function varargout = pushbutton1_Callback(h, eventdata, handles, varargin)


A=get(handles.T_edit1,'string');  A=str2num(A);
a=get(handles.T_edit2,'string');  a=str2num(a);    %读各编辑框的输入
w=get(handles.T_edit3,'string');  w=str2num(w);
fs=get(handles.T_edit4,'string'); fs=str2num(fs);

Xa=exp1_FF(A,a,w,fs); %产生Xa(n)信号
[c,l]=e_DFT(Xa,50);    %对Xa进行DFT变换 

axes(handles.T_axes1);

n=0:49;
stem(n,Xa,'.');         %以n为横坐标,x为纵坐标画离散图
xlabel('n');
ylabel('xa(n)');
title('原始信号');
str=['fs=',num2str(fs)];
text(20,(0.8*max(Xa)),str);%加注释

%画频谱图
maXc=abs(c);
axes(handles.T_axes2);
plot(l/pi,maXc);
% axis([0,500,0,1]);
xlabel('w/pi');
ylabel('|Y(jw)|');
title('频谱');

% --------------------------------------------------------------------
function varargout = popupmenu3_Callback(h, eventdata, handles, varargin)
% --------------------------------------------------------------------
function varargout = pushbutton2_Callback(h, eventdata, handles, varargin)
l=get(handles.T_popupmenu3,'value');
if l==1
global Xb;
axes(handles.T_axes1);
n=0:1;
stem(n,Xb,'.');
xlabel('n');
ylabel('Xb');
title('Xb信号离散图');

[c,l]=e_DFT(Xb,2);
axes(handles.T_axes2);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xb的频谱');

Hb=exp1_impseq(0,0,3)+2.5*exp1_impseq(1,0,3)+2.5*exp1_impseq(2,0,3)+exp1_impseq(3,0,3);%序列bn(n)的产生
[c,l]=e_DFT(Hb,4);

axes(handles.T_axes3);
% subplot(2,3,2);
n=0:3;
stem(n,Hb,'.');
xlabel('n');
ylabel('Hb');
title('Hb信号离散图');

axes(handles.T_axes4);
% subplot(2,3,5);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Hb的频谱');
axes(handles.T_axes5);
m=conv(Xb,Hb);
n=0:4;
stem(n,m,'.');
xlabel('n');
ylabel('Xb*Hb');
title('两信号卷积后信号离散图');

axes(handles.T_axes6);
[c,l]=e_DFT(m,5);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xb*Hb后的频谱');
end
if l==2
  Ha=exp1_stepseq(1,1,10);
axes(handles.T_axes1);
n=1:10;
stem(n,Ha,'.');
xlabel('n');
ylabel('Ha');
title('Ha信号离散图');

[c,l]=e_DFT(Ha,10);
axes(handles.T_axes2);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Ha的频谱');

axes(handles.T_axes3);
n=1:10;
stem(n,Ha,'.');
xlabel('n');
ylabel('Ha');
title('Ha信号离散图');

axes(handles.T_axes4);
[c,l]=e_DFT(Ha,10);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Ha的频谱');

axes(handles.T_axes5);
m=conv(Ha,Ha);
n=0:18;
stem(n,m,'.');
xlabel('n');
ylabel('Ha*Ha');
title('Ha自卷后信号离散图');

axes(handles.T_axes6);
[c,l]=e_DFT(m,19);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Ha*Ha后的频谱');  
end
if l==3
Ha=exp1_stepseq(1,1,10);
axes(handles.T_axes1);
n=1:10;
stem(n,Ha,'.');
xlabel('n');
ylabel('Ha');
title('Ha信号离散图');

[c,l]=e_DFT(Ha,10);
axes(handles.T_axes2);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Ha的频谱');

% Hb=exp1_impseq(0,0,3)+2.5*exp1_impseq(1,0,3)+2.5*exp1_impseq(2,0,3)+exp1_impseq(3,0,3);%序列bn(n)的产生
% [c,l]=e_DFT(Hb,4);
Xc=exp1_stepseq(1,1,5);
axes(handles.T_axes3);
n=1:5;
stem(n,Xc,'.');
xlabel('n');
ylabel('Xc');
title('Xc信号离散图');

axes(handles.T_axes4);
[c,l]=e_DFT(Xc,5);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xc的频谱');

axes(handles.T_axes5);
m=conv(Xc,Ha);
n=0:13;
stem(n,m,'.');
xlabel('n');
ylabel('Xc*Ha');
title('卷积后信号离散图');


axes(handles.T_axes6);
[c,l]=e_DFT(m,14);
plot(l/pi,abs(c));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xc*Ha后的频谱');
end

% --------------------------------------------------------------------
function varargout = pushbutton4_Callback(h, eventdata, handles, varargin)
A=1;a=0.5;w=2.0734;fs=1;%产生Xa1信号
Xa1=exp1_FF(A,a,w,fs);
[Xs,w]=e_DFT(Xa1,50);%对Xa1信号进行DFT变换
axes(handles.T_axes1);

n=0:49;
stem(n,Xa1,'.');%画出Xa1信号的离散图
xlabel('n');
ylabel('Xa1');
title('Xa1信号离散图');

axes(handles.T_axes2);%画出Xa1信号的频谱图
plot(w/pi,abs(Xs));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xa1信号频谱图');

 Hb=exp1_impseq(0,0,3)+2.5*exp1_impseq(1,0,3)+2.5*exp1_impseq(2,0,3)+exp1_impseq(3,0,3);%产生Hb信号
[Xs1,w]=e_DFT(Hb,4);
axes(handles.T_axes3);
n=0:3;
stem(n,Hb,'.');
xlabel('n');
ylabel('Hb');
title('Hb信号离散图');

axes(handles.T_axes4);
plot(w/pi,abs(Xs1));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Hb信号频谱');

Hc=conv(Xa1,Hb);%对两信号进行卷积
[Xs2,w]=e_DFT(Hc,53);%对卷积结果进行DFT变换
axes(handles.T_axes5);
plot(w/pi,abs(Xs2));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('Xa1*Hb后的频谱');

Xs3=Xs.*Xs1;%对两信号的DFT进行点乘
axes(handles.T_axes6);
plot(w/pi,abs(Xs3));
xlabel('w/pi');
ylabel('|Y(jw)|');
title('FT(Xa1).FT(Hb)');