METHOD AND DEVICE FOR ANALYZING CODE, DECODING METHOD AND DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To perform a code analysis of optional low density parity check codes (Low Density Parity Check codes; hereinafter referred to as LDPC codes) at a high speed. SOLUTION: A code analyzing device 1 analyzes LDPC codes by density evolution using a max product evolution and is provided with a P (u) calculating part 20 for calculating a second probability distribution P (u) being a probability distribution of an outputted message ujon the basis of a first probability distribution P (v) being a message vito be inputted to a check node. The P (u) calculating part 20 selects the message viwith the minimum absolute value among a plurality of messages vito be inputted the check node and calculates the message ujby defining a code sgn for identifying positive and negative as a negative value when the number of negative values in the message viis odd, and defining the code sgn as a positive value when the number of negative values in the message viis even. COPYRIGHT: (C)2004,JPO