Patent ID: 8583994

Claim:
A coding apparatus handling quasi-cyclic codes in which a given code word cyclically shifted by p symbols provides another code word, the apparatus comprising a circuit configured to generate parity bits for at least one of the quasi-cyclic codes, the circuit being further configured to: determine, based on register symbols, first coefficients corresponding to a register polynomial; obtain second coefficients corresponding to a predetermined number of generator polynomials, wherein: the predetermined number corresponds to an integer multiple of p, the integer exceeding unity; the generator polynomials are ordered in a corresponding sequence; and a degree of a first generator polynomial in the sequence exceeds a degree one or more second generator polynomials disposed at corresponding positions in the sequence below the first generator polynomial; compute (i) first values representative of corresponding information symbols and (ii) second values indicative of products of the first coefficients and corresponding ones of the second coefficients; and generate the parity bits based on differences between corresponding ones of the first and second values.