LDPC encoding algorithm based on optimized sparse LU decomposition in the CMMB standard

The China mobile multimedia broadcasting Standard utilizes a highly structured low density parity check code to guarantee the transmission reliability. With the non-systematic and non-quasi-cyclic characteristics of the parity matrix, an encoding algorithm and its compact matrix store scheme are devised. Due to the sparse requirement, an optimized sparse LU decomposition is proposed based on the modified optimization criterion of the minimal product of row and column weights. Computational results show that, comparing to the existing results, our proposed LU decomposition can achieve a 10% fewer number of the elements "1" in matrices L and U, which contributes the lower complexity of the encoding algorithm. Therefore, the proposed algorithm has a better prospect in the practical CMMB system.