www.pudn.com > ofdm_matlab.rar > convbase.m

function  DataOut = convbase(DataIn,CurrBase,NewBase) 
%CONVBASE Converts the number base of the input data (DataIn) 
%	DataOut = convbase(DataIn,CurrBase,NewBase) 
%	from the current base (CurrBase) to the new base required 
%	(NewBase). If the new base is less the the old base, e.g 
%	NewBase = 2 and CurrBase = 8, the DataOut will have more 
%	data words. For the above example DataOut will be 4 times 
%	longer then DataIn. 
%	The actual base used = 2^NewBase, thus NewBase = 8, is base 256 
%	E.g. DataIn = [ 2 64 20 ] with CurrBase = 8, NewBase = 2 
%	DataOut = [0 0 0 2, 1 0 0 0, 0 1 1 0] 
%	Note : Both the input and output data is in a serial format. 
%==================================== 
% Convert the number base of the data 
%==================================== 
if CurrBase > NewBase, 
	%Convert the input data into the base (NewBase) required 
	leftover = DataIn'; 
	DataOut = []; 
	for k = 1:(CurrBase/NewBase) 
		DataOut = [DataOut rem(leftover,2^NewBase)]; 
		leftover = floor(leftover./(2^NewBase)); 
	end 
	DataOut = reshape(DataOut',1,size(DataOut,1)*size(DataOut,2)); 
elseif CurrBase < NewBase, 
	%======================= 
	%Convert back to decimal 
	%======================= 
	remainder = rem(length(DataIn),NewBase/CurrBase); 
	if (remainder > 0), 
		disp('WARNING : Received data length problem when converting base'); 
		disp('Clipping data to make possible'); 
		DataIn = DataIn(1:length(DataIn)-remainder); 
	end 
	Datawords=reshape(DataIn,NewBase/CurrBase,size(DataIn,1)*size(DataIn,2)/... 
		(NewBase/CurrBase))'; 
	DataOut = zeros(size(Datawords,1),1); 
	for k = 1:(NewBase/CurrBase) 
		DataOut = DataOut+Datawords(:,k)*(2^CurrBase)^(k-1); 
	end 
	DataOut = DataOut.'; 
else 
	DataOut = DataIn;	%No change of base. 
end