Bit interleaver for low-density parity check codeword having length of 16200 and code rate of 2/15 and 64-symbol mapping, and bit interleaving method using same
A bit interleaver, a bit-interleaved coded modulation (BICM) device and a bit interleaving method are disclosed herein. The bit interleaver includes a first memory, a processor, and a second memory. The first memory stores a low-density parity check (LDPC) codeword having a length of 16200 and a code rate of 2/15. The processor generates an interleaved codeword by interleaving the LDPC codeword on a bit group basis. The size of the bit group corresponds to a parallel factor of the LDPC codeword. The second memory provides the interleaved codeword to a modulator for 64-symbol mapping.
1. A bit-interleaved coded modulation (BICM) reception device, comprising:
a demodulator configured to perform demodulation corresponding to 64-symbol mapping;
a bit deinterleaver configured to perform group-unit deinterleaving after the demodulation; and
a decoder configured to restore information bits by LDPC-decoding deinterleaved values generated based on the group-unit deinterleaving, the deinterleaved values corresponding to a LDPC codeword having a length of 16200 and a code rate of 2/15,
wherein the group-unit deinterleaving is performed on a group basis, the size of the group corresponding to a parallel factor of the LDPC codeword,
wherein the group-unit deinterleaving corresponds to a reverse process of interleaving performed by using a permutation order, and wherein the permutation order corresponds to an interleaving sequence represented by the following
interleaving sequence={7 11 4 38 19 25 2 43 15 26 18 14 9 29 44 32 0 5 35 10 1 12 6 36 21 33 37 34 3 31 20 16 40 23 41 22 30 39 13 24 17 42 28 8 27}.
2. The BICM reception device of claim 1 , wherein the 64-symbol mapping is a Non-Uniform Constellation (NUC) symbol mapping which corresponds to 64 constellations.
3. The BICM reception device of claim 2 , wherein the parallel factor is 360, and the group includes 360 values.
4. The BICM reception device of claim 3 , wherein the LDPC codeword is represented by (u 0 , u 1 , . . . , y N ldpc −1 ) (where N ldpc is 16200), and the group corresponds to a bit group of the LDPC codeword in the following equation:
X j ={u k |360 ×j≤k <360×( j +1), 0 ≤k<N ldpc } for 0 j≤N<N group
where X j is an j-th bit group, N ldpc is 16200, and N group is 45.
5. A bit-interleaved coded modulation (BICM) reception method, comprising:
performing demodulation corresponding to 64-symbol mapping;
performing group-unit deinterleaving after the demodulation; and
restoring information bits by LDPC-decoding deinterleaved values generated based on the group-unit deinterleaving, the deinterleaved values corresponding to a LDPC codeword having a length of 16200 and a code rate of 2/15,
wherein the group-unit deinterleaving is performed on a group basis, the size of the group corresponding to a parallel factor of the LDPC codeword,
wherein the group-unit deinterleaving corresponds to a reverse process of interleaving performed by using a permutation order, and
wherein the permutation order corresponds to an interleaving sequence represented by the following
interleaving sequence={7 11 4 38 19 25 2 43 15 26 18 14 9 29 44 32 0 5 35 10 1 12 6 36 21 33 37 34 3 31 20 16 40 23 41 22 30 39 13 24 17 42 28 8 27}.