Low density parity check code decoder and decoding method thereof

A decoding method for a low-density parity check (LDPC) decoder, the LDPC decoder recording an M×N parity check matrix related to M number of check nodes and N number of variable nodes, the decoding method comprising:

• determining, by the LDPC decoder, j number of variable nodes related to a first check node according to the M×N parity check matrix;
• calculating, by the LDPC decoder, j number of node Logarithm Likelihood Ratio (LLR) values corresponding to the j number of variable nodes in a channel;
• determining, by the LDPC decoder, j number of initial check node to variable node (CN-VN) LLR values of the j number of variable nodes related to the first check node;
• calculating, by the LDPC decoder, j number of variable node to check node (VN-CN) LLR values according to the j number of node LLR values and the j number of initial CN-VN LLR values;
• calculating, by the LDPC decoder, j number of updated CN-VN LLR values of the j number of variable nodes related to the first check node according to the j number of VN-CN LLR values;
• calculating, by the LDPC decoder, j number of updated node LLR values according to the j number of updated CN-VN LLR values and the j number of VN-CN LLR values;
• and
• updating, by the LDPC decoder, the j number of node LLR values corresponding to the j number of variable nodes by using the j number of updated node LLR values.