Bit interleaver for low-density parity check codeword having length of 64800 and code rate of 4/15 and 1024-symbol mapping, and bit interleaving method using same

• US 10,447,305 B2
• Filed: 03/20/2015
• Issued: 10/15/2019
• Est. Priority Date: 02/16/2015
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Park, Sung-Ik, Kwon, Sun-Hyoung, Lee, Jae-Young, Kim, Heung-Mook, Hur, Nam-Ho
• Primary Examiner(s): Decady, Albert
• Assistant Examiner(s): Ahmed, Enam
• Application Number:
  US14/664,718
• Publication Number:
  US 20160241265A1
• Time in Patent Office: 1,670 Days
• Field of Search: 714752
• CPC Class Codes: H03M 13/1165 QC-LDPC codes as defined for the digital video broadcasting [DVB] specifications, e.g. DVB-Satellite [DVB-S2]
• CPC Class Codes: H03M 13/255 with Low Density Parity Check [LDPC] codes
• CPC Class Codes: H03M 13/271 Row-column interleaver with permutations, e.g. block interleaving with inter-row, inter-column, intra-row or intra-column permutations
• CPC Class Codes: H03M 13/2778 Interleaver using block-wise interleaving, e.g. the interleaving matrix is sub-divided into sub-matrices and the permutation is performed in blocks of sub-matrices

Abstract

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 64800 and a code rate of 4/15. 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 1024-symbol mapping.

Claims

1. A broadcast transmission device, comprising:

a first memory configured to store a low-density parity check (LDPC) codeword having a length of 64800 and a code rate of 4/15;

a processor configured to generate an interleaved codeword by interleaving the LDPC codeword on a bit group basis, the size of the bit group corresponding to a parallel factor of the LDPC codeword;

a second memory configured to output the interleaved codeword;

a modulator configured to perform 1024-symbol mapping corresponding to the interleaved codeword to generate a modulated signal; and

an antenna configured to broadcast a transmission signal corresponding to the modulated signal over a physical channel to a reception device, the broadcasted transmission signal being an electromagnetic signal having a radio frequency,

wherein the LDPC codeword is generated by performing accumulation at parity bit addresses which are updated using a predetermined sequence,

wherein the interleaving is performed using the following equation using a permutation order;

Y_j=X<sub>π

(j)</sub> 0≤

j<

N_group

where X<sub>π

(j)</sub> is a π

(j)th bit group, Y_j is an interleaved j-th bit group, N_group is the number of bit groups, and π

(j) is a permutation order for bit group-based interleaving,

wherein the permutation order corresponds to an interleaving sequence, the interleaving sequence being for the LDPC codeword having the length of 64800 and the code rate of 4/15 and being represented by the following equation;

interleaving sequence={114 133 4 73 8 139 7 5 177 88 66 11 24 74 49 45 167 81 117 137 46 22 165 51 68 110 6 1 16 132 130 143 169 2 20 140 94 21 91 126 172 27 162 34 113 142 166 115 106 160 84 136 175 0 26 151 69 174 59 159 161 170 52 164 80 108 3 23 101 33 125 111 63 124 98 40 145 9 39 155 149 147 67 76 48 120 119 53 54 138 179 156 127 13 152 129 123 141 109 89 121 50 10 37 104 144 86 178 96 148 128 56 64 153 95 12 105 41 154 99 25 171 92 17 134 19 61 32 85 102 14 71 146 163 173 118 57 18 36 42 78 31 97 55 58 116 90 168 43 72 15 112 93 60 38 103 87 158 35 29 176 150 77 79 122 47 28 135 100 83 65 131 75 157 62 70 44 30 107 82}, and

wherein the interleaved codeword is interleaved by the interleaving sequence on the bit group basis before performing the 1024-symbol mapping so as to distribute burst errors occurring in the transmission signal when the transmission signal is transmitted over the physical channel.

2. The broadcast transmission device of claim 1, wherein the 1024-symbol mapping is a Non-Uniform Constellation (NUC) symbol mapping which corresponds to 1024 constellations.

3. The broadcast transmission device of claim 2, wherein the parallel factor is 360, and the bit group includes 360 bits.

4. The broadcast transmission device of claim 3, wherein the LDPC codeword is represented by (u₀, u₁, . . . , u_Nldpc−

1) (where N_ldpc is

     64800), and is divided into 180 bit groups each including 360 bits, as in the following equation;

X_j={u_k|360×

j≤

k<

360×

(j+1),0≤

k<

N_ldpc} for 0≤

j<

N_group

where X_j is a j-th bit group, N_ldpc is 64800, and N_group is 180.