Parallel bit interleaver

Abstract

A bit interleaving method involves applying a bit permutation process to a QC-LDPC codeword made up of N cyclic blocks each including Q bits, and dividing the codeword after the permutation process into a plurality of constellation words each including M bits, the codeword being divided into F×N/M folding sections, each of the constellation words being associated with one of the F×N/M folding sections, and the bit permutation process being applied such that each of the constellation words includes F bits from each of M/F different cyclic blocks in a given folding section associated with a given constellation word.

1 - 17 . (canceled) 
     
     
         18 . 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:   an allocation step of allocating codeword bits of the codeword made up of N cyclic blocks each including Q bits to Q×N/M constellation words, each of the constellation words being made up of M bits, wherein   N is a multiple of M/F,   F is an integer greater than one, and is a divisor of M and Q, and   in the allocation step, the M bits in each of the Q/F constellation words include F bits from each of M/F different cyclic blocks in F×N/M folding sections each made up of M/F cyclic blocks.   
     
     
         19 . A bit interleaver interleaving a codeword of quasi-cyclic low-density parity check codes, including repeat-accumulate quasi-cyclic low-density parity check codes,
 the bit interleaver comprising:   an allocation unit allocating codeword bits of the codeword made up of N cyclic blocks each including Q bits to Q×N/M constellation words, each of the constellation words being made up of M bits, wherein   N is a multiple of M/F,   F is an integer greater than one, and is a divisor of M and Q, and   the allocation unit allocates the M bits in each of the Q/F constellation words include F bits from each of M/F different cyclic blocks in F×N/M folding sections each made up of M/F cyclic blocks.   
     
     
         20 . A decoding method, comprising:
 a demodulation step of generating a demodulated signal by demodulating a signal transmitted by modulating M bits allocated to each of a plurality of constellation words using the bit interleaving method of  claim 18 ; and   a decoding step of decoding the demodulated signal and generating original data according to quasi-cyclic low-density parity check codes.   
     
     
         19 . A decoder, comprising:
 a demodulating unit generating a demodulated signal by demodulating a signal transmitted by modulating M bits allocated to each of a plurality of constellation words using the bit interleaver of  claim 19 ; and   a decoding unit decoding the demodulated signal and generating original data according to quasi-cyclic low-density parity check codes.