Patent Document ID: 8225173
Application ID: 12281279
Patent Flag: 1

Claim One:
1. A communications system which uses LDPC and comprises permutation matrices P of size Z×Z comprising a plurality of matrices P(0). .. P(Z−1) and a stairs matrix P(st), from which a block parity check matrix H b is constructed, using only the permutation matrices P:P(0). .. P(Z−1), the stairs matrix P(st) and a zero matrix 0, wherein the initial dimensions of H b are: 0.5 Nm×Nm or 0.5 n×n, wherein n is an integer representing a codeword vector length, wherein the height of the block parity check matrix H b is half of its width and wherein the initial code rate represented by the block parity check matrix H b is: R=(n−k)/n=0.5, wherein the initial H b is as shown with regards to FIG. 7 .