A method for decoding a low-density parity-check (LDPC) code, performed by a communication apparatus, includes: updating a variable node; determining n minimum values based on a min-sum algorithm (MSA); determining n indices based on the n minimum values; updating a check node using the n indices; calculating a log-likelihood ratio (LLR) value when the update of the check node is completed; and determining an information bit based on the LLR value.