Patent ID: 9385755
Filing Date: 2016-07-05
CPC Classification: H03M,H04L

Claim Text:
1. A bit interleaving method performed by a bit interleaver for interleaving bits of a codeword generated based on a quasi-cyclic low-density parity check coding scheme, including a repeat-accumulate quasi-cyclic low-density parity check coding scheme, the bit interleaver including a non-transitory memory storing information indicating a permutation rule and circuitry that performs the bit interleaving method in accordance with the information indicating the permutation rule, the bit interleaving method comprising: a cyclic block permutation step of applying, using the bit interleaver, a cyclic block permutation process to a codeword made up of N cyclic blocks each consisting of Q bits, to reorder the cyclic blocks in accordance with a cyclic block permutation rule defining a reordering of the cyclic blocks; a bit permutation step of applying, using the bit interleaver, a bit permutation process to the codeword after the cyclic block permutation process, to reorder the bits of the codeword in accordance with a bit permutation rule defining a reordering of the bits; and a dividing step of dividing, using the bit interleaver, the codeword after the bit permutation process into a plurality of constellation words, each of the constellation words being made up of M bits, wherein N is not a multiple of M, the bit permutation rule defines the reordering of the bits of the codeword after the cyclic block permutation process, such that the Q bits in each of N′=N−X cyclic blocks of the N cyclic blocks are each allocated to a bit of an identical bit index in Q constellation words and the Q constellation words are each made up of one bit in each of M cyclic blocks, the M cyclic blocks being common to the Q constellation words, where X is a remainder of N divided by M, and the bit index of the bit in each of the Q constellation words to which the bits in each of the N′=N−X cyclic blocks are each allocated is determined in accordance with the cyclic block permutation rule.