Abstract:

The method for constructing a full rank parity-check matrix of nonbinary quasi-cyclic (QC) low-density parity-check (LDPC) codes is proposed. The method is based on the circulant permutation matrices, and the full rank parity-check matrices are obtained using the proposed random masking method. The systematic generator matrix of a QC LDPC code is given in a circulant form from its paritycheck matrix. Correspondingly, the serial and parallel efficient encoders with linear complexity are devised for the nonbinary full rank parity-check matrices. Experimental results show that regular and irregular nonbinary QC LDPC codes constructed by the random masking method achieve a better error performance and convergence than those without masking.