orthogonality.m

LDPC codes .Using the matlab.

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function lambda = Orthogonality(checkMatrix_H)
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% @author   Andreas Waadt, 13. November 2005
% @param     checkMatrix_H : the parity check matrix of the code
% @return   lambda : the orthogonality of checkMatrix_H
% This function calculates the orthogonality (lambda) of a 
% Parity-Check-Matrix H (checkMatrix_H).
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sizeOfMatrix = size(checkMatrix_H);
j_rows = sizeOfMatrix(1);
n_columns = sizeOfMatrix(2);

		lambda = 0;
		scalar_product = 0;
		for column1 = 1 : 1 : n_columns-1
			for column2 = column1+1 : 1 : n_columns
				scalar_product = 0;
				for row = 1 : 1 : j_rows
					scalar_product = scalar_product + checkMatrix_H(column1,row) * checkMatrix_H(column2,row);
                end;
				if(scalar_product > lambda)
					lambda = scalar_product;
                end;
            end;
        end;

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