METHOD FOR CREATING PARITY CHECK MATRIX, ENCODING DEVICE, AND RECORDING PLAYBACK DEVICE

摘要

In this method for creating parity check matrix, all of a number N of column vectors within a mask matrix are different. An M row × L column submatrix of successive L columns arbitrarily extracted from the mask matrix include a number B1 of first corrected rows, and a number Bi of i-th corrected rows. The row weight of each of the B1 first corrected rows is 1. The B1 first corrected rows are provided in each of a number A1 of first corrected rows with a total of one or more "1's." Each of the Bi i-th corrected rows is provided in a number Ai-1 of i-th - 1 corrected columns with a total of one or more "1's." Each of the Bi i-th corrected rows is provided with a "1" in any one of a number Ai of i-th - 1 corrected columns included in a column set from which the first corrected column to the i-th - 1 corrected column have been excluded. The Bi i-th corrected rows are provided in each of a number Ai of i-th corrected columns with a total of one or more "1's." The sum from A1 to AI is equal to L. The sum from B1 to BI-1 is equal to adding S to the sum of A1 to AI-1.