Data processing device and data processing method
View Patent ↗The present technology relates to a data processing device and a data processing method, which are capable of securing excellent communication quality in data transmission using an LDPC code. In group-wise interleave, an LDPC code in which a code length N is 16200 bits and an encoding rate r is 10/15 or 12/15 is interleaved in units of bit groups of 360 bits. In group-wise deinterleave, a sequence of the LDPC code that has undergone the group-wise interleave is restored to an original sequence. For example, the present technology can be applied to a technique of performing data transmission using an LDPC code.
1. A transmitting device for generating a digital television broadcast signal and for decreasing a signal-to-noise power ratio of the generated digital television broadcast signal, the transmitting device comprising:
circuitry configured to:
receive data to be transmitted in a digital television broadcast signal;
perform low density parity check (LDPC) encoding by an LDPC encoder circuit on input bits of the received data according to a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 10/15 to generate an LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal;
the LDPC code includes information bits and parity bits, the parity bits being processed by a receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
352 747 894 1437 1688 1807 1883 2119 2159 3321 3400 3543 3588 3770
3821 4384 4470 4884 5012 5036 5084 5101 5271 5281 5353
505 915 1156 1269 1518 1650 2153 2256 2344 2465 2509 2867 2875
3007 3254 3519 3687 4331 4439 4532 4940 5011 5076 5113 5367
268 346 650 919 1260 4389 4653 4721 4838 5054 5157 5162 5275 5362
220 236 828 1590 1792 3259 3647 4276 4281 4325 4963 4974 5003 5037
381 737 1099 1409 2364 2955 3228 3341 3473 3985 4257 4730 5173
5242
88 771 1640 1737 1803 2408 2575 2974 3167 3464 3780 4501 4901 5047
749 1502 2201 3189
2873 3245 3427
2158 2605 3165
1 3438 3606
10 3019 5221
371 2901 2923
9 3935 4683
1937 3502 3735
507 3128 4994
25 3854 4550
1178 4737 5366
2 223 5304
1146 5175 5197
1816 2313 3649
740 1951 3844
1320 3703 4791
1754 2905 4058
7 917 5277
3048 3954 5396
4804 4824 5105
2812 3895 5226
0 5318 5358
1483 2324 4826
2266 4752 5387,
group-wise interleave the LDPC code word in units of bit groups of 360 bits to generate a group-wise interleaved LDPC code word;
wherein, in the group-wise interleaving, when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
27, 11, 20, 1, 7, 5, 29, 35, 9, 10, 34, 18, 25, 28, 6, 13, 17, 0, 23, 16, 41, 15, 19, 44, 24, 37, 4, 31, 8, 32, 14, 42, 12, 2, 40, 30, 36, 39, 43, 21, 3, 22, 26, 33, and 38;
map the group-wise interleaved LDPC code word to any one of 16 signal points in a modulation scheme in units of 4 bits;
perform interleaving in a time direction by time interleaving the mapped group-wise interleaved LDPC code word; and
transmit the digital television broadcast signal including the time-interleaved mapped group-wise interleaved LDPC code word in units of 4 bits.
2. A method for generating a digital television broadcast signal and for decreasing a signal-to-noise power ratio of the generated digital television broadcast signal, the method comprising:
receiving data to be transmitted in a digital television broadcast signal;
performing low density parity check (LDPC) encoding, by an LDPC encoder circuit, on input bits of the received data according to a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 10/15 to generate an LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal;
the LDPC code includes information bits and parity bits, the parity bits being processed by a receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
352 747 894 1437 1688 1807 1883 2119 2159 3321 3400 3543 3588 3770
3821 4384 4470 4884 5012 5036 5084 5101 5271 5281 5353
505 915 1156 1269 1518 1650 2153 2256 2344 2465 2509 2867 2875
3007 3254 3519 3687 4331 4439 4532 4940 5011 5076 5113 5367
268 346 650 919 1260 4389 4653 4721 4838 5054 5157 5162 5275 5362
220 236 828 1590 1792 3259 3647 4276 4281 4325 4963 4974 5003 5037
381 737 1099 1409 2364 2955 3228 3341 3473 3985 4257 4730 5173
5242
88 771 1640 1737 1803 2408 2575 2974 3167 3464 3780 4501 4901 5047
749 1502 2201 3189
2873 3245 3427
2158 2605 3165
1 3438 3606
10 3019 5221
371 2901 2923
9 3935 4683
1937 3502 3735
507 3128 4994
25 3854 4550
1178 4737 5366
2 223 5304
1146 5175 5197
18162313 3649
740 1951 3844
1320 3703 4791
1754 2905 4058
7 917 5277
3048 3954 5396
4804 4824 5105
2812 3895 5226
0 5318 5358
1483 2324 4826
2266 4752 5387;
group-wise interleaving, by interleaving circuitry, the LDPC code word in units of bit groups of 360 bits to generate a group-wise interleaved LDPC code word;
wherein, in the group-wise interleaving, when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
27, 11, 20, 1, 7, 5, 29, 35, 9, 10, 34, 18, 25, 28, 6, 13, 17, 0, 23, 16, 41, 15, 19, 44, 24, 37, 4, 31, 8, 32, 14, 42, 12, 2, 40, 30, 36, 39, 43, 21, 3, 22, 26, 33, and 38;
mapping, by mapping circuitry, the group-wise interleaved LDPC code word to any one of 16 signal points in a modulation scheme in units of 4 bits;
performing, by time interleaving circuitry, interleaving in a time direction by time interleaving the mapped group-wise interleaved LDPC code word, and
transmitting, by a broadcast transmitter, the digital television broadcast signal including the time-interleaved mapped group-wise interleaved LDPC code word in units of 4 bits.
3. A receiving device for use in an environment where a signal-to-noise power ratio of a received digital television broadcast signal can be reduced, the receiving device comprising:
a tuner configured to receive a digital television broadcast signal including a time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word; and
circuitry configured to
deinterleave in a time direction by time deinterleaving the time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word to generate a mapped group-wise interleaved LDPC code word;
demap the mapped group-wise interleaved LDPC code word to produce a group-wise interleaved LDPC code word, wherein each unit of 4 bits of the group-wise interleaved LDPC code word is mapped to one of 16 signal points of a modulation scheme;
deinterleave the group-wise interleaved LDPC code word in units of bit groups of 360 bits to produce an LDPC code word;
decode the LDPC code word; and
process the decoded LDPC code word for presentation, wherein
input bits of data to be transmitted in the digital television broadcast signal are LDPC encoded according to
a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 10/15 to generate the LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal,
the LDPC code includes information bits and parity bits, the parity bits being processed by the receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
352 747 894 1437 1688 1807 1883 2119 2159 3321 3400 3543 3588 3770
3821 4384 4470 4884 5012 5036 5084 5101 5271 5281 5353
505 915 1156 1269 1518 1650 2153 2256 2344 2465 2509 2867 2875
3007 3254 3519 3687 4331 4439 4532 4940 5011 5076 5113 5367
268 346 650 919 1260 4389 4653 4721 4838 5054 5157 5162 5275 5362
220 236 828 1590 1792 3259 3647 4276 4281 4325 4963 4974 5003 5037
381 737 1099 1409 2364 2955 3228 3341 3473 3985 4257 4730 5173
5242
88 771 1640 1737 1803 2408 2575 2974 3167 3464 3780 4501 4901 5047
749 1502 2201 3189
2873 3245 3427
2158 2605 3165
1 3438 3606
10 3019 5221
371 2901 2923
9 3935 4683
1937 3502 3735
507 3128 4994
25 3854 4550
1178 4737 5366
2 223 5304
1146 5175 5197
1816 2313 3649
740 1951 3844
1320 3703 4791
1754 2905 4058
7 917 5277
3048 3954 5396
4804 4824 5105
2812 3895 5226
0 5318 5358
1483 2324 4826
2266 4752 5387,
the LDPC code word is group-wise interleaved in units of bit groups of 360 bits to generate the group-wise interleaved LDPC code word such that
when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
27, 11, 20, 1, 7, 5, 29, 35, 9, 10, 34, 18, 25, 28, 6, 13, 17, 0, 23, 16, 41, 15, 19, 44, 24, 37, 4, 31, 8, 32, 14, 42, 12, 2, 40, 30, 36, 39, 43, 21, 3, 22, 26, 33, 38,
the group-wise interleaved LDPC code word is mapped to one of the 16 signal points in the modulation scheme in units of 4 bits, and
the mapped group-wise interleaved LDPC code word is interleaved in a time direction by time interleaving the mapped group-wise interleaved LDPC code word.
4. A method for use by a receiving device in an environment where a signal-to-noise power ratio of a digital television broadcast signal can be reduced, the method comprising:
receiving, by a tuner, a digital television broadcast signal including a time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word;
deinterleaving the time-interleaved mapped group-wise interleaved LDPC code word in a time direction to generate a mapped group-wise interleaved LDPC code word;
demapping the mapped group-wise interleaved LDPC code word to produce a group-wise interleaved LDPC code word, wherein each unit of 4 bits of the group-wise interleaved LDPC code word is mapped to one of 16 signal points of a modulation scheme;
deinterleaving the group-wise interleaved LDPC code word in units of bit groups of 360 bits to produce an LDPC code word;
decoding, by decoding circuitry, the LDPC code word; and
processing the decoded LDPC code word for presentation, wherein
input bits of data to be transmitted in the digital television broadcast signal are LDPC encoded according to a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 10/15 to generate the LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal,
the LDPC code includes information bits and parity bits, the parity bits being processed by the receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
352 747 894 1437 1688 1807 1883 2119 2159 3321 3400 3543 3588 3770
3821 4384 4470 4884 5012 5036 5084 5101 5271 5281 5353
505 915 1156 1269 1518 1650 2153 2256 2344 2465 2509 2867 2875
3007 3254 3519 3687 4331 4439 4532 4940 5011 5076 5113 5367
268 346 650 919 1260 4389 4653 4721 4838 5054 5157 5162 5275 5362
220 236 828 1590 1792 3259 3647 4276 4281 4325 4963 4974 5003 5037
381 737 1099 1409 2364 2955 3228 3341 3473 3985 4257 4730 5173
5242
88 771 1640 1737 1803 2408 2575 2974 3167 3464 3780 4501 4901 5047
749 1502 2201 3189
2873 3245 3427
2158 2605 3165
1 3438 3606
10 3019 5221
371 2901 2923
9 3935 4683
1937 3502 3735
507 3128 4994
25 3854 4550
1178 4737 5366
2 223 5304
1146 5175 5197
1816 2313 3649
740 1951 3844
1320 3703 4791
1754 2905 4058
7 917 5277
3048 3954 5396
4804 4824 5105
2812 3895 5226
0 5318 5358
1483 2324 4826
2266 4752 5387,
the LDPC code word is group-wise interleaved in units of bit groups of 360 bits to generate the group-wise interleaved LDPC code word such that
when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
27, 11, 20, 1, 7, 5, 29, 35, 9, 10, 34, 18, 25, 28, 6, 13, 17, 0, 23, 16, 41, 15, 19, 44, 24, 37, 4, 31, 8, 32, 14, 42, 12, 2, 40, 30, 36, 39, 43, 21, 3, 22, 26, 33, 38,
the group-wise interleaved LDPC code word is mapped to one of the 16 signal points in the modulation scheme in units of 4 bits, and
the mapped group-wise interleaved LDPC code word is interleaved in a time direction by time interleaving the mapped group-wise interleaved LDPC code word.
5. A transmitting device for generating a digital television broadcast signal and for decreasing a signal-to-noise power ratio of the generated digital television broadcast signal, the transmitting device comprising:
circuitry configured to:
receive data to be transmitted in a digital television broadcast signal;
perform low density parity check (LDPC) encoding by an LDPC encoder circuit on input bits of the received data according to a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 12/15 to generate an LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal;
the LDPC code includes information bits and parity bits, the parity bits being processed by a receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
3 394 1014 1214 1361 1477 1534 1660 1856 2745 2987 2991 3124 3155
59 136 528 781 803 928 1293 1489 1944 2041 2200 2613 2690 2847
155 245 311 621 1114 1269 1281 1783 1995 2047 2672 2803 2885 3014
79 870 974 1326 1449 1531 2077 2317 2467 2627 2811 3083 3101 3132
4 582 660 902 1048 1482 1697 1744 1928 2628 2699 2728 3045 3104
175 395 429 1027 1061 1068 1154 1168 1175 2147 2359 2376 2613 2682
1388 2241 3118 3148
143 506 2067 3148
1594 2217 2705
398 988 2551
1149 2588 2654
678 2844 3115
1508 1547 1954
1199 1267 1710
2589 3163 3207
1 2583 2974
2766 2897 3166
929 1823 2742
1113 3007 3239
1753 2478 3127
0 509 1811
1672 2646 2984
965 1462 3230
3 1077 2917
1183 1316 1662
968 1593 3239
64 1996 2226
1442 2058 3181
513 973 1058
1263 3185 3229
681 1394 3017
419 2853 3217
3 2404 3175
2417 2792 2854
1879 2940 3235
647 1704 3060,
group-wise interleave the LDPC code word in units of bit groups of 360 bits to generate a group-wise interleaved LDPC code word;
wherein, in the group-wise interleaving, when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
3, 6, 7, 27, 2, 23, 10, 30, 22, 28, 24, 20, 37, 21, 4, 14, 11, 42, 16, 9, 15, 26, 33, 40, 5, 8, 44, 34, 18, 0, 32, 29, 19, 41, 38, 17, 25, 43, 35, 36, 13, 39, 12, 1, and 31;
map the group-wise interleaved LDPC code word to any one of 16 signal points in a modulation scheme in units of 4 bits;
perform interleaving in a time direction by time interleaving the mapped group-wise interleaved LDPC code word; and
transmit the digital television broadcast signal including the time-interleaved mapped group-wise interleaved LDPC code word in units of 4 bits.
6. A method for generating a digital television broadcast signal and for decreasing a signal-to-noise power ratio of the generated digital television broadcast signal, the method comprising:
receiving data to be transmitted in a digital television broadcast signal;
performing low density parity check (LDPC) encoding, by an LDPC encoder circuit, on input bits of the received data according to a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 12/15 to generate an LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal;
the LDPC code includes information bits and parity bits, the parity bits being processed by a receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
3 394 1014 1214 1361 1477 1534 1660 1856 2745 2987 2991 3124 3155
59 136 528 781 803 928 1293 1489 1944 2041 2200 2613 2690 2847
155 245 311 621 1114 1269 1281 1783 1995 2047 2672 2803 2885 3014
79 870 974 1326 1449 1531 2077 2317 2467 2627 2811 3083 3101 3132
4 582 660 902 1048 1482 1697 1744 1928 2628 2699 2728 3045 3104
175 395 429 1027 1061 1068 1154 1168 1175 2147 2359 2376 2613 2682
1388 2241 3118 3148
143 506 2067 3148
1594 2217 2705
398 988 2551
1149 2588 2654
678 2844 3115
1508 1547 1954
1199 1267 1710
2589 3163 3207
1 2583 2974
2766 2897 3166
929 1823 2742
1113 3007 3239
1753 2478 3127
0 509 1811
1672 2646 2984
965 1462 3230
3 1077 2917
1183 1316 1662
968 1593 3239
64 1996 2226
1442 2058 3181
513 973 1058
1263 3185 3229
681 1394 3017
419 2853 3217
3 2404 3175
2417 2792 2854
1879 2940 3235
647 1704 3060,
group-wise interleaving, by interleaving circuitry, the LDPC code word in units of bit groups of 360 bits to generate a group-wise interleaved LDPC code word;
wherein, in the group-wise interleaving, when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
3, 6, 7, 27, 2, 23, 10, 30, 22, 28, 24, 20, 37, 21, 4, 14, 11, 42, 16, 9, 15, 26, 33, 40, 5, 8, 44, 34, 18, 0, 32, 29, 19, 41, 38, 17, 25, 43, 35, 36, 13, 39, 12, 1, and 31;
mapping, by mapping circuitry, the group-wise interleaved LDPC code word to any one of 16 signal points in a modulation scheme in units of 4 bits;
performing, by time interleaving circuitry, interleaving in a time direction by time interleaving the mapped group-wise interleaved LDPC code word, and
transmitting, by a broadcast transmitter, the digital television broadcast signal including the time-interleaved mapped group-wise interleaved LDPC code word in units of 4 bits.
7. A receiving device for use in an environment where a signal-to-noise power ratio of a received digital television broadcast signal can be reduced, the receiving device comprising:
a tuner configured to receive a digital television broadcast signal including a time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word; and
circuitry configured to
deinterleave in a time direction by time deinterleaving the time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word to generate a mapped group-wise interleaved LDPC code word;
demap the mapped group-wise interleaved LDPC code word to produce a group-wise interleaved LDPC code word, wherein each unit of 4 bits of the group-wise interleaved LDPC code word is mapped to one of 16 signal points of a modulation scheme;
deinterleave the group-wise interleaved LDPC code word in units of bit groups of 360 bits to produce an LDPC code word;
decode the LDPC code word; and
process the decoded LDPC code word for presentation, wherein
input bits of data to be transmitted in the digital television broadcast signal are LDPC encoded according to
a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 12/15 to generate the LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal,
the LDPC code includes information bits and parity bits, the parity bits being processed by the receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
3 394 1014 1214 1361 1477 1534 1660 1856 2745 2987 2991 3124 3155
59 136 528 781 803 928 1293 1489 1944 2041 2200 2613 2690 2847
155 245 311 621 1114 1269 1281 1783 1995 2047 2672 2803 2885 3014
79 870 974 1326 1449 1531 2077 2317 2467 2627 2811 3083 3101 3132
4 582 660 902 1048 1482 1697 1744 1928 2628 2699 2728 3045 3104
175 395 429 1027 1061 1068 1154 1168 1175 2147 2359 2376 2613 2682
1388 2241 3118 3148
143 506 2067 3148
1594 2217 2705
398 988 2551
1149 2588 2654
678 2844 3115
1508 1547 1954
1199 1267 1710
2589 3163 3207
1 2583 2974
2766 2897 3166
929 1823 2742
1113 3007 3239
1753 2478 3127
0 509 1811
1672 2646 2984
965 1462 3230
3 1077 2917
1183 1316 1662
968 1593 3239
64 1996 2226
1442 2058 3181
513 973 1058
1263 3185 3229
681 1394 3017
419 2853 3217
3 2404 3175
2417 2792 2854
1879 2940 3235
647 1704 3060,
the LDPC code word is group-wise interleaved in units of bit groups of 360 bits to generate the group-wise interleaved LDPC code word such that
when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
3, 6, 7, 27, 2, 23, 10, 30, 22, 28, 24, 20, 37, 21, 4, 14, 11, 42, 16, 9, 15, 26, 33, 40, 5, 8, 44, 34, 18, 0, 32, 29, 19, 41, 38, 17, 25, 43, 35, 36, 13, 39, 12, 1, and 31
the group-wise interleaved LDPC code word is mapped to one of the 16 signal points in the modulation scheme in units of 4 bits, and
the mapped group-wise interleaved LDPC code word is interleaved in a time direction by time interleaving the mapped group-wise interleaved LDPC code word.
8. A method for use by a receiving device in an environment where a signal-to-noise power ratio of a digital television broadcast signal can be reduced, the method comprising:
receiving, by a tuner, a digital television broadcast signal including a time-interleaved mapped group-wise interleaved low density parity check (LDPC) code word;
deinterleaving the time-interleaved mapped group-wise interleaved LDPC code word in the time direction to generate a mapped group-wise interleaved LDPC code word;
demapping the mapped group-wise interleaved LDPC code word to produce a group-wise interleaved LDPC code word, wherein each unit of 4 bits of the group-wise interleaved LDPC code word is mapped to one of 16 signal points of a modulation scheme;
deinterleaving the group-wise interleaved LDPC code word in units of bit groups of 360 bits to produce an LDPC code word;
decoding, by decoding circuitry, the LDPC code word; and
processing the decoded LDPC code word for presentation, wherein
input bits of data to be transmitted in the digital television broadcast signal are LDPC encoded according to
a parity check matrix of an LDPC code in which a code length N is 16200 bits and an encoding rate r is 12/15 to generate the LDPC code word, the LDPC code enabling error correction processing to correct errors generated in a transmission path of the digital television broadcast signal,
the LDPC code includes information bits and parity bits, the parity bits being processed by the receiving device to recover information bits corrupted by transmission path errors,
the parity check matrix includes an information matrix portion corresponding to the information bits and a parity matrix portion corresponding to the parity bits,
the information matrix portion is represented by a parity check matrix initial value table, and
the parity check matrix initial value table, having each row indicating positions of elements ‘1’ in corresponding 360 columns of the information matrix portion as a subset of information bits used in calculating the parity bits in the LDPC encoding, is as follows
3 394 1014 1214 1361 1477 1534 1660 1856 2745 2987 2991 3124 3155
59 136 528 781 803 928 1293 1489 1944 2041 2200 2613 2690 2847
155 245 311 621 1114 1269 1281 1783 1995 2047 2672 2803 2885 3014
79 870 974 1326 1449 1531 2077 2317 2467 2627 2811 3083 3101 3132
4 582 660 902 1048 1482 1697 1744 1928 2628 2699 2728 3045 3104
175 395 429 1027 1061 1068 1154 1168 1175 2147 2359 2376 2613 2682
1388 2241 3118 3148
143 506 2067 3148
1594 2217 2705
398 988 2551
1149 2588 2654
678 2844 3115
1508 1547 1954
1199 1267 1710
2589 3163 3207
1 2583 2974
2766 2897 3166
929 1823 2742
1113 3007 3239
1753 2478 3127
0 509 1811
1672 2646 2984
965 1462 3230
3 1077 2917
1183 1316 1662
968 1593 3239
64 1996 2226
1442 2058 3181
513 973 1058
1263 3185 3229
681 13943017
419 2853 3217
3 2404 3175
2417 2792 2854
1879 2940 3235
647 1704 3060,
the LDPC code word is group-wise interleaved in units of bit groups of 360 bits to generate the group-wise interleaved LDPC code word such that
when an (i+1)-th bit group from a head of the generated LDPC code word is indicated by a bit group i, a sequence of bit groups 0 to 44 of the generated LDPC code word of 16200 bits is interleaved into a following sequence of bit groups
3, 6, 7, 27, 2, 23, 10, 30, 22, 28, 24, 20, 37, 21, 4, 14, 11, 42, 16, 9, 15, 26, 33, 40, 5, 8, 44, 34, 18, 0, 32, 29, 19, 41, 38, 17, 25, 43, 35, 36, 13, 39, 12, 1, and 31,
the group-wise interleaved LDPC code word is mapped to one of the 16 signal points in the modulation scheme in units of 4 bits, and
the mapped group-wise interleaved LDPC code word is interleaved in a time direction by time interleaving the mapped group-wise interleaved LDPC code word.