Patent ID: 8392792

Claim:
A method for encoding an LDPC (Low Density Parity Check) code using the result of checking a previously specified parity, wherein a procedure of determining parity bit parts in an H matrix used for LDPC code encoding of an information sequence of length K to a codeword of length N comprises the steps of: forming, by a computer, a parity bit check matrix having a dual diagonal structure consisting of (N-K) rows for check nodes and (N-K) columns on the basis of the H matrix; calculating the values of all the parity bits by inserting a given binary value in sub-blocks, with the parity bit check matrix formed on the H matrix; if the values of the parity bits are incorrect as the result of checking the calculated values of the parity bits, checking the parity bit corresponding to the sub-block located in the last part of the H matrix; searching the parity bit parts where the parity bit check result is represented as “1” based on the result of checking the parity bits; performing an XOR operation in sub-blocks on the parity bit part obtained through simultaneous equations including a modulo 2 operation between the parity bits of the searched parity bit parts and the parity bit parts into which an initially given binary value is inserted; and determining, as the value of the parity bit of the H matrix, the value of the parity bit satisfying the condition that the value obtained by multiplying the H matrix by a code word vector, which is encoded by the H matrix, corresponds to zero (“0”).