Patent ID: 7954033

Claim:
A decoding method in a communication system using a Low Density Parity Check (LDPC) code, the method comprising: determining whether an LDPC codeword to be decoded is a general LDPC codeword to which a puncturing scheme is not applied or a punctured LDPC codeword to which the puncturing scheme is applied; if the LDPC codeword to be decoded is the punctured LDPC codeword, generating a child parity check matrix using a mother parity check matrix indicative of a parity check matrix of the general LDPC codeword, and a puncturing pattern applied to the punctured LDPC codeword; and decoding the punctured LDPC codeword using the child parity check matrix; wherein generating the child parity check matrix comprises generating a Tanner graph of the punctured LDPC codeword by deleting parity nodes corresponding to parity bits punctured to generate the punctured LDPC codeword from the general LDPC codeword in a Tanner graph of the general LDPC codeword, and generating the child parity check matrix using the Tanner graph of the punctured LDPC codeword; and wherein deleting parity nodes corresponding to parity bits punctured to generate the punctured LDPC codeword comprises adding each of remaining parity nodes except for parity nodes corresponding to the punctured parity bits of a first parity node corresponding to a non-punctured parity bit preceding the remaining parity node, and all information nodes connected between the first parity node and the remaining parity node in the Tanner graph of the general LDPC codeword.