ofdmguifn.m

本程序实现了OFDM系统详尽的方针

function OFDMguiFn(action)
% Consolidates all of the GUI callbacks into one main function

stringArray = [...
	% Slide 1
	'Welcome to the basic OFDM (Orthogonal Frequency       '...
	'Division Multiplexing) demo. Please click the Next    '...
	'button to get started.                                '...
	'                                                      '...
	'                                                      '...
	'                                                      '...
	'                                                      ';...
	% Slide 2
	'Assume that we want to transmit the following binary  '...
	'data using OFDM: [0 0 0 1 1 0 1 1].                   '...
	'The plot shows this binary data.                      '...
	'                                                      '...
	'                                                      '...
	'                                                      '...
	'                                                      ';...
	% Slide 3
	'In OFDM an IFFT (Inverse Fast Fourier Transform) is   '...
	'used to put the binary numbers onto many frequencies. '...
	'Due to the math involved in an IFFT, these            '...
	'frequencies do not interfere with eath other (in      '...
	'communication terms, this is called "Orthogonality"). '...
	'The plot shows that each group of 2 blue data points  '...
	'under a red hump will be put onto one frequency.      ';...
 	% Slide 4
	'The IFFT math is now complete. It has generated an    '...
	'OFDM signal that corresponds to the binary data.      '...
	'The plot shows the signal generated by the IFFT.      '...
	'                                                      '...
	'                                                      '...
	'                                                      '...
	'                                                      ';...
	% Slide 5 - same plot
	'Now, this OFDM signal can be transmitted through a    '...
	'media and then received. This media (or "Channel" in  '...
	'communication) could be wired or wireless. Once the   '...
	'signal is received, the reverse process is done to    '...
	'recover the original binary data.                     '...
	'                                                      '...
	'                                                      ';...
	% Slide 6
	'Finally, an FFT (Fast Fourier Transform) is used to   '...
	'recover the binary data as shown in the plot. Note    '...
	'that the FFT is the opposite of the IFFT used to      '...
	'generate the OFDM signal. As long as the Channel does '...
	'not distort the OFDM signal too much, the original    '...
	'binary data can be recovered.                         '...
	'                                                      '];


switch(action)
	case 'next'		%---------------------------------------
		textHnd1=findobj('Tag','StaticTextFeedback');
		nextHnd1=findobj('Tag','PushbuttonNext'); % handler for the Next button
		axisHnd1=findobj('Tag','Axes1');
		global COUNTER
		if isempty(COUNTER)
			COUNTER = 0;	% initialize COUNTER if doesn't exist
		end
		COUNTER = COUNTER + 1;
		[r c]=size(stringArray);
		if COUNTER > r
			COUNTER = 0;
         close(gcf)
         % basicGUI
			basicGUI_win	% for windows version
		else
			set(textHnd1,'String',stringArray(COUNTER,:))
			switch(COUNTER)
				case 1
					% disp('Slide 1')
				case 2
					% disp('Slide 2')
					setupGUI	% sets up the GUI variables
					set(axisHnd1,'Visible','on')
					% Stem Plot the Binary Data
					stem(data_in,'filled')
				case 3
					% disp('Slide 3')
					setupGUI	% sets up the GUI variables
					% add groupings around the stem plot
					y=1.2*abs(sin(linspace(0,4*pi,80))).^(1/5);
					x=linspace(0.5,8.5,80);
					plot(x,y,'r'),hold on
					stem(data_in,'filled'),hold off
				case 4
					% disp('Slide 4')
					setupGUI
					% Perform the ifft and display the results
					tx
					plot(xmit)
				case 5
					% disp('Slide 5')
					% same plot
				case 6
					% disp('Slide 6')
					setupGUI
					tx, ch, rx
					stem(output,'filled')
					
					set(nextHnd1,'String','Start Over')	% repeat if desired
				otherwise
					disp('error')
			end
		end
			
	case 'close'	%--------------------------------------
		clear global COUNTER
		close(gcbf)
	
	case 'figure'	%--------------------------------------
		% this is called whenever the figure is first created -or NOT??
		textHnd1=findobj('Tag','StaticTextFeedback');
		axisHnd1=findobj('Tag','Axes1');
		set(textHnd1,'String','Basic OFDM Demo') % default text messag
		set(axisHnd1,'Visible','off')	% hide Axis to begin
end