Patent ID: 7536623

Claim:
A method of generating a low density parity check (LDPC) code, comprising the steps of: (1) forming a parity check matrix having (N−K) rows for check nodes and N columns for variable nodes to encode an information sequence of length K to a codeword of length N; (2) dividing the parity check matrix into an information part matrix having K columns and a parity part matrix having (N−k) columns; (3) dividing the parity part matrix into P×P subblocks, P being a divisor of (N−K); (4) defining a first diagonal and a second diagonal in the parity part matrix, the second diagonal being a shift of the first diagonal by f subblocks; (5) placing shifted identity matrices with shift indexes in subblocks that lie on the first and second diagonals; (6) filling zero matrices in the remaining subblocks other than the subblocks of the first and second diagonals; (7) placing an odd number of delta matrices in one subblock column of the parity part matrix, each delta matrix comprising one element of 1 and the other elements of 0; and (8) storing the parity check matrix.