Patent ID: 8887030

Claim:
Encoder for error correction code encoding input data words (D) into codewords (Z 1 , Z 2 ), comprising: an encoder input for receiving input data words (D) each comprising a first number K ldpc of information symbols, an encoding means for encoding each of the input data words (D) into one of the codewords (Z 1 , Z 2 , Z 3 , Z 4 ) such that each of the codewords comprises a basic codeword portion (B) including a data portion (D) and a basic parity portion (Pb) of a second number N ldpc −K ldpc of basic parity symbols, and an auxiliary codeword portion (A) including an auxiliary parity portion (Pa) of a third number M IR of auxiliary parity symbols, wherein said encoding means is adapted i) for generating said basic codeword portion (B) from one of the input data words (D) according to a first code, wherein each of the basic parity symbols is generated by accumulating an information symbol at a parity symbol address determined according to a first address generation rule, and ii) for generating said auxiliary codeword portion (A) from said one of the input data words (D) according to a second code, wherein each of the auxiliary parity symbols is generated by accumulating an information symbol m at a parity symbol address γ, wherein said parity symbol addresses γ are determined according to a second address generation rule N ldpc −K ldpc +{x+m mod G a ×Q IR } mod M IR if x≧N ldpc −K ldpc , wherein x denotes the addresses of a parity symbol accumulator corresponding to the first information symbol of a group of size G a and Q IR is an auxiliary code rate dependent, predefined constant, and an encoder output for outputting said codewords (Z 1 , Z 2 ).