Patent ID: 6789227
Filing Date: 2004-09-07
Classification: G06F,H03M

Abstract:
A computer-implemented method for generating low-density parity check (LDPC) codes comprising:(a) constructing an mÃ—n matrix H having m rows of check nodes and n columns of bit nodes, wherein the jth column has weight aj, each row, r, has a weight at most br the matrix H is representable by a Tanner graph having a girth g; (b) iteratively adding an (n+1)th column (U1) to matrix H, wherein the size of U1 is initially empty and is at most an+1, and wherein U1 comprises a set of i check nodes such that i is greater than or equal to 0 and i is less than an+1; (c) iteratively adding check nodes to U1 such that each check node does not violate predetermined girth constraint g, and check-degree constraint deg (c)(d) updating matrix H when a new column is added; and (e) terminating the iterations if there are no new check nodes that do not violate the girth and check-degree constraints.