Abstract: A method for creating cyclic permutation matrices P (810), with an arbitrary size Z×Z set by a parameter Z5 and which are used to create one or more LDPC related matrices in OFDMA systems, comprising: defining an integer value Z; creating an initial matrix (810); creating a matrix (810) by using cyclic shifts to each Encoder row; repeating stage 3, up to Z?2 times as required, thus creating up to Z?2 matrices: P(o) . . . P(Z?I); creating an additional stairs matrix P(st). A method for using cyclic per-mutation matrixes P (840), with a fixed size Z×Z set by a parameter Z, and which are used to create one or more LDPC related matrices (820) in OFDMA systems, comprising: defining an integer value Z; storing in memory means an initial matrix (810) and its cyclic shifts permutations (840), thus keeping memory means matrices: P(o) . . . P(Z?I); storing an additional stairs matrix P(st) (840); using these matrices (810) to create LDPC related matrices (840) or LDPC operations.

Abstract: A method for repairing a neighborhood of rows in a memory array using a patch table is disclosed. First data to be stored in row N in a memory array of the memory device, second data, if any, stored in row N-1 in the memory array, and third data, if any, stored in row N+1 in the memory array are stored in a temporary storage area of a memory device. The first data is written in row N, and, in response to an error, the first data, the second data, if any, and the third data, if any, are written in respective rows in a repair area in the memory device. The addresses of rows N-1, N, and N+1 are added to a table stored in the memory device to indicate which rows in the repair area should be used instead of rows N-1, N, and N+1.