Patent ID: 9100049
Filing Date: 2015-08-04
Classification: H03M,H04L

Abstract:
1. A bit interleaving method interleaving a codeword of quasi-cyclic low-density parity check codes, including repeat-accumulate quasi-cyclic low-density parity check codes, the bit interleaving method comprising: a permutation step of applying a permutation process to the codeword made up of N cyclic blocks each including Q cyclic block bits in accordance with a cyclic block permutation rule defining a reordering of the cyclic blocks; and an allocation step of allocating codeword bits of the codeword, after the-permutation process, to Q×N/M constellation words, each of the constellation words being made up of M constellation word bits, wherein F is a divisor of M and Q, N is not a multiple of M/F, N′ is equal to (M/F)×floor(N/(M/F)), each of N′ cyclic blocks among the N cyclic blocks is allocated to one among F×N′/M folding sections according to the cyclic block permutation rule, each of the folding sections including M/F of the cyclic blocks, (N−N′) of the cyclic blocks are excluded from the N′ cyclic blocks and include a parity section of the codeword, the cyclic block permutation rule defines allocation of the N′ cyclic blocks to the folding sections, and in the allocation step, the allocation process is applied such that the M bits include F cyclic block bits from each of M/F of the cyclic blocks in each of the folding sections, and such that the M bits are allocated to each of Q/F of the constellation words.