Encoder and encoding method providing incremental redundancy

Abstract

The present invention relates to an encoder for error correction code encoding input data words (D) into codewords (Z1, Z2), comprising: an encoder input (1451) for receiving input data words (D) each comprising a first number Kldpc of information symbols, an encoding means (1452) for encoding an input data word (D) into a codeword (Z1, Z2, Z3, Z4) such that a codeword comprises a basic codeword portion (B) including a data portion (D) and a basic parity portion (Pb) of a second number Nldpc−Kldpc of basic parity symbols, and an auxiliary codeword portion (A) including an auxiliary parity portion (Pa) of a third number MIR of auxiliary parity symbols, wherein said encoding means (14) is adapted i) for generating said basic codeword portion (B) from an input data word (D) according to a first code, wherein a basic parity symbol 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 an input data word (D) according to a second code, wherein an auxiliary parity symbol 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 Nldpc−Kldpc+{x+m mod Ga×QIR} mod MIR if x>Nldpc−Kldpc, wherein x denotes the addresses of a parity symbol accumulator corresponding to the first information symbol of a group of size Ga and QIR is an auxiliary code rate dependent, predefined constant, and an encoder output (1454) for outputting said codewords (Z1, Z2).

Dependencies are inferred from the claim text.