Data processing apparatus and data processing method

Abstract

The present technology relates to a data processing apparatus and a data processing method that are able to provide an LDPC code with a good error rate. An LDPC encoder performs coding by an LDPC code having a code length of 16200 bits and a code rate of 12/15. The LDPC code includes an information bit and a parity bit, and a parity check matrix H is configured with an information matrix portion corresponding to the information bit of the LDPC code and a parity matrix portion corresponding to the parity bit. An information matrix portion of the parity check matrix H is represented by a parity check matrix initial value table representing a position of an element of 1 in the information matrix portion at an interval of 360 columns. The present technology may be applied to a case of performing an LDPC coding and an LDPC decoding.

1 . A data processing apparatus comprising:
 a coding unit that encodes an information bit into an LDPC code having a code length of 16200 bits and a code rate of 12/15, based on a parity check matrix of a low density parity check (LDPC) code,   wherein the LDPC code includes an information bit and a parity bit,   wherein the parity check matrix includes an information matrix portion corresponding to the information bit and a parity matrix portion corresponding to the parity bit,   wherein the information matrix portion is represented by a parity check matrix initial value table, and   wherein the parity check matrix initial value table is a table representing positions of elements of 1 in the information matrix portion at an interval of 360 columns, and is   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.   
     
     
         2 . The data processing apparatus according to  claim 1 ,
 wherein if a row of the parity check matrix initial table is represented by i and a parity length of the LDPC code is represented by M,   a (2+360×(i−1))-th column of the parity check matrix is a column obtained by cyclically shifting a (1+360×(i−1))-th column of the parity check matrix for which positions of elements of 1 are represented by the parity check matrix initial value table, by q=M/360 in a down direction.   
     
     
         3 . The data processing apparatus according to  claim 2 ,
 wherein for a (1+360×(i−1))-th column of the parity check matrix, an i-th row of the parity check matrix initial value table represents row numbers of elements of 1 in a (1+360×(i−1))-th column of the parity check matrix, and   wherein for each column of (2+360×(i−1))-th column to (360×i)-th column which are columns other than the (1+360×(i−1))-th column of the parity check matrix, if a numerical value in an i-th row and a j-th column of the parity check matrix initial value table is represented by h i,j , and a row number of a j-th element of 1 in a w-th column of the parity check matrix H is represented by H w-j , a row number H w-j  of an element of 1 in a w-th column which are columns other than the (1+360×(i−1))-th column of the parity check matrix is expressed by an equation H w-j =mod {h i,j +mod((w−1), 360)×M/360, M).   
     
     
         4 . The data processing apparatus according to  claim 1 , further comprising:
 a parity interleave unit that interleaves only a parity bit of a code bit of the LDPC code.   
     
     
         5 . The data processing apparatus according to  claim 1 , further comprising:
 a column twist interleave unit that performs column twist interleave by storing a code bit of the LDPC code by shifting it in a column direction.   
     
     
         6 . The data processing apparatus according to  claim 1 , further comprising:
 a replacement unit that replaces a code bit of the LDPC code with a symbol bit of a symbol corresponding to any one of signal points of a predetermined number which is determined by a predetermined digital modulation scheme.   
     
     
         7 . The data processing apparatus according to  claim 6 ,
 wherein the replacement unit replaces the code bit which is stored in the column direction and read in the row direction.   
     
     
         8 . The data processing apparatus according to  claim 1 ,
 wherein the parity check matrix is a parity check matrix in which a cycle 4 does not exist.   
     
     
         9 . The data processing apparatus according to  claim 1 ,
 wherein the parity check matrix is a parity check matrix of the LDPC code belonging to an ensemble of the LDPC code in which a performance threshold is a predetermined value or less, which e, the performance threshold being E b /N 0  at which BER starts falling.   
     
     
         10 . A data processing method comprising:
 a coding step of encoding an information bit into an LDPC code having a code length of 16200 bits and a code rate of 12/15, based on a parity check matrix of a low density parity check (LDPC) code,   wherein the LDPC code includes an information bit and a parity bit,   wherein the parity check matrix includes an information matrix portion corresponding to the information bit and a parity matrix portion corresponding to the parity bit,   wherein the information matrix portion is represented by a parity check matrix initial value table, and   wherein the parity check matrix initial value table is a table representing positions of elements of 1 in the information matrix portion at an interval of 360 columns, and is   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 1959   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.   
     
     
         11 . A data processing apparatus comprising:
 a decoding unit that decodes an LDPC code which is obtained from data transmitted from a transmission apparatus,   wherein the transmission apparatus includes   a coding unit that encodes an information bit into an LDPC code having a code length of 16200 bits and a code rate of 12/15, based on a parity check matrix of a low density parity check (LDPC) code,
 wherein the LDPC code includes an information bit and a parity bit, 
 wherein the parity check matrix includes an information matrix portion corresponding to the information bit and a parity matrix portion corresponding to the parity bit, 
 wherein the information matrix portion is represented by a parity check matrix initial value table, and 
 wherein the parity check matrix initial value table is a table representing positions of elements of 1 in the information matrix portion at an interval of 360 columns, and is 
 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. 
   
     
     
         12 . The data processing apparatus according to  claim 11 ,
 wherein if a row of the parity check matrix initial table is represented by i and a parity length of the LDPC code is represented by M,   a (2+360×(i−1))-th column of the parity check matrix is a column obtained by cyclically shifting a (1+360×(i−1))-th column of the parity check matrix for which positions of elements of 1 are represented by the parity check matrix initial value table, by q=M/360 in a down direction.   
     
     
         13 . The data processing apparatus according to  claim 12 ,
 wherein for a (1+360×(i−1))-th column of the parity check matrix, an i-th row of the parity check matrix initial value table represents row numbers of elements of 1 in a (1+360×(i−1))-th column of the parity check matrix, and   wherein for each column of (2+360×(i−1))-th column to (360×i)-th column which are columns other than the (1+360×(i−1))-th column of the parity check matrix, if a numerical value in an i-th row and a j-th column of the parity check matrix initial value table is represented by h i,j , and a row number of a j-th element of 1 in a w-th column of the parity check matrix H is represented by H w-j , a row number H w-j  of an element of 1 in a w-th column which are columns other than the (1+360×(i−1))-th column of the parity check matrix is expressed by an equation H w-j =mod {h i,j +mod((w−1), 360)×M/360, M).   
     
     
         14 . The data processing apparatus according to  claim 11 , further comprising:
 a column twist deinterleave unit that when column twist interleave is performed by storing a code bit of the LDPC code by shifting it in a column direction, returns the code bit of the LDPC code to an original sequence so as to perform column twist deinterleave.   
     
     
         15 . The data processing apparatus according to  claim 11 , further comprising:
 a reverse replacement unit that when a replacement process of replacing a code bit of the LDPC code with a symbol bit of a symbol corresponding to any one of signal points of a predetermined number which is determined by a predetermined digital modulation scheme is performed, performs a reverse replacement process of returning the code bit of which a position as the symbol bit is replaced, to an original position.   
     
     
         16 . The data processing apparatus according to  claim 15 ,
 wherein the reverse replacement unit performs a reverse replacement process of returning the code bit which is stored in the row direction and read in the column direction, to an original position.   
     
     
         17 . The data processing apparatus according to  claim 11 ,
 wherein the parity check matrix is a parity check matrix in which a cycle 4 does not exist.   
     
     
         18 . The data processing apparatus according to  claim 11 ,
 wherein the parity check matrix is a parity check matrix of the LDPC code belonging to an ensemble of the LDPC code in which a performance threshold is a predetermined value or less, which is detected by a density evolution of multi-edge type, here, the performance threshold being E b /N 0  at which BER starts falling.   
     
     
         19 . A data processing method comprising:
 a decoding step of decoding an LDPC code which is obtained from data transmitted from a transmission apparatus,   wherein the transmission apparatus includes   a coding unit that encodes an information bit into an LDPC code having a code length of 16200 bits and a code rate of 12/15, based on a parity check matrix of a low density parity check (LDPC) code,
 wherein the LDPC code includes an information bit and a parity bit, 
 wherein the parity check matrix includes an information matrix portion corresponding to the information bit and a parity matrix portion corresponding to the parity bit, 
 wherein the information matrix portion is represented by a parity check matrix initial value table, and 
 wherein the parity check matrix initial value table is a table representing positions of elements of 1 in the information matrix portion at an interval of 360 columns, and is 
   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.   
     
     
         20 . A data processing apparatus comprising:
 a decoding unit that decodes an LDPC code having a code length of 16200 bits and a code rate of 12/15, based on a parity check matrix of a low density parity check (LDPC) code,   wherein the LDPC code includes an information bit and a parity bit,   wherein the parity check matrix includes an information matrix portion corresponding to the information bit and a parity matrix portion corresponding to the parity bit,   wherein the information matrix portion is represented by a parity check matrix initial value table, and   wherein the parity check matrix initial value table is a table representing positions of elements of 1 in the information matrix portion at an interval of 360 columns, and is   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.