Patent ID: 7143333

Claim:
A method for operating a transmitter that generates parity-check bits p=(p 0 , . . . , p m−1 ) based on a current symbol set s=(s 0 , . . . , s k−1 ), the method comprising the steps of: receiving the current symbol set s=(s 0 , . . . , s k−1 ); using a matrix H to determine the parity-check bits; and transmitting the parity-check bits along with the current symbol set; wherein H is an expansion of a base matrix H b with H b comprising a section H b1 and a section H b2 , with H b2 comprising a first part having a column h b having an odd weight greater than 2, and a second part H′ b2 comprising matrix elements for row i, column j equal to 1 for i=j, 1 for i=j+1, 0 elsewhere; and wherein the expansion of the base matrix H b uses identical submatrices for 1s in each column of the second part H′ b2 , and wherein the expansion uses paired submatrices for an even number of 1s in h b .