Method and apparatus for decoding non-binary low-density parity-check code in communication system

A first communication node comprising at least one processor, wherein the at least one processor causes the first communication node to perform:

• storing a compressed channel message in an a posteriori probability (APP) memory, based on a signal received from a second communication node;
• generating a first variable-to-check (V2C) message using a first APP message and a first check-to-variable (C2V) message respectively obtained from the APP memory and a C2V memory, in a variable node processing (VNP) process;
• obtaining a first minimum vector and a second minimum vector by performing column-wise (CW) sorting on the first V2C message, in a check node processing (CNP) process;
• generating a second V2C message by performing normalization on the first V2C message based on the first minimum vector, in the CNP process;
• obtaining a third minimum vector by performing row-wise (RW) sorting on the second minimum vector based on the first minimum vector, in the CNP process;
• generating a second C2V message based on the third minimum vector, in the CNP process;
• and
• performing an APP update based on the second V2C message and the second C2V message, in an APP update process.