Use of LDPC base graphs for NR
An apparatus is provided which comprises at least one processor, at least one memory including computer program code, and the at least one processor, with the at least one memory and the computer program code, being arranged to cause the apparatus to at least perform generating a code block including information bits and parity bits, the parity bits being generated by performing a cyclic redundancy check on the information bits, determining the number of parity bits used in generating the code block based on an applied linear error correcting code base graph and/or based on the number of the information bits, and encoding the code block by using the applied linear error correcting code base graph.
1. An apparatus, comprising:
at least one processor; and
at least one memory including computer program code, the at least one processor, with the at least one memory and the computer program code, being configured to cause the apparatus to at least perform
generating a code block including information bits and parity bits, the parity bits being generated by performing a cyclic redundancy check on the information bits;
determining a number of parity bits used in generating the code block based on the number of the information bits;
selecting an applied linear error correcting code base graph out of a first linear error correcting code base graph and a second linear error correcting code base graph,
wherein the number of parity bits used in generating the code block is smaller for the second linear error correcting code base graph than for the first linear error correcting code base graph; and
encoding the code block by using the applied linear error correcting code base graph.
2. The apparatus according to claim 1 , wherein the at least one processor, with the at least one memory and the computer program code, is configured to cause the apparatus to further perform:
determining the number of parity bits used in generating the code block based on a comparison of the number of the information bits with a threshold,
wherein the threshold is defined by a maximum code block size supported by the applied linear error correcting code base graph.
3. The apparatus according to claim 1 , wherein the at least one processor, with the at least one memory and the computer program code, is configured to cause the apparatus to further perform:
selecting the applied linear error correcting code base graph out of the first linear error correcting code base graph and the second linear error correcting code base graph based on the number of information bits.
4. The apparatus according to claim 1 , wherein the information bits are included in a transport block and no segmentation of the transport block size is applied when the second linear error correcting code base graph is used.
5. The apparatus according to claim 1 , wherein the information bits are included in a transport block, and wherein the at least one processor, with the at least one memory and the computer program code, is configured to cause the apparatus to further perform
segmentation of the transport block into at least two code blocks when the second linear error correcting code base graph is used,
wherein the same number of parity bits is used for each code block as in case no segmentation is applied.
6. The apparatus according to claim 1 , wherein the at least one processor, with the at least one memory and the computer program code, is configured to cause the apparatus to further perform:
referring to a modulation and coding scheme table based on the applied linear error correcting code base graph when determining the number of parity bits used in generating the code block based on the applied LDPC base graph.
7. The apparatus according to claim 1 , wherein the at least one processor, with the at least one memory and the computer program code, is configured to cause the apparatus to further perform:
referring to a modulation and coding scheme table for providing information on modulation and coding schemes,
wherein the table specifies information on modulation and coding schemes which comprises a nested structure, in which different modulation and coding schemes are referred to by respective indices, wherein the indices are constructed by a number of bits, and the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph are indicated by a number of bits which is smaller than the number of bits of indices indicating modulation and coding schemes relating to the first linear error correcting code base graph.
8. The apparatus according to claim 7 , wherein when the number of bits used for the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph is defined as Y, and the number of bits used for the indices indicating modulation and coding schemes relating to the first linear error correcting code base graph is defined as X, first X-Y leading bits in the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph are set to 0.
9. A method, comprising:
generating a code block including information bits and parity bits, the parity bits being generated by performing a cyclic redundancy check on the information bits;
determining a number of parity bits used in generating the code block based on the number of the information bits;
selecting an applied linear error correcting code base graph out of a first linear error correcting code base graph and a second linear error correcting code base graph, wherein the number of parity bits used in generating the code block is smaller for the second linear error correcting code base graph than for the first linear error correcting code base graph; and
encoding the code block by using the applied linear error correcting code base graph.
10. The method according to claim 9 , further comprising:
determining the number of parity bits used in generating the code block based on a comparison of the number of the information bits with a threshold,
wherein the threshold is defined by a maximum code block size supported by the applied linear error correcting code base graph.
11. The method according to claim 9 , further comprising
selecting the applied linear error correcting code base graph out of the first linear error correcting code base graph and the second linear error correcting code base graph based on the number of information bits.
12. The method according to claim 9 , wherein the information hits are included in a transport block and no segmentation of the transport block size is applied when the second linear error correcting code base graph is used.
13. The method according to claim 9 , Wherein the information bits are included in a transport block, and wherein the method further comprises:
performing segmentation of the transport block into at least two code blocks when the second linear error correcting code base graph is used,
wherein same number of parity bits is used for each code block as in case no segmentation is applied.
14. The method according to claim 9 , further comprising:
referring to a modulation and coding scheme table based on the applied linear error correcting code base graph when determining the number of parity bits used in generating the code block based on the applied linear error correcting code base graph.
15. The method according to claim 9 , further comprising:
referring to a modulation and coding scheme table for providing information on modulation and coding schemes,
wherein the table specifies information on modulation and coding schemes which comprises a nested structure, in which different modulation and coding schemes are referred to by respective indices, wherein the indices are constructed by a number of bits, and the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph are indicated by a number of bits which is smaller than the number of bits of indices indicating modulation and coding schemes relating to the first linear error correcting code base graph.
16. The method according to claim 15 , wherein when the number of bits used for the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph is defined as Y, and the number of bits used for the indices indicating modulation and coding schemes relating to the first linear error correcting code base graph is defined as X, the first X-Y leading bits in the indices indicating modulation and coding schemes relating to the second linear error correcting code base graph are set to 0.
17. A computer program product embodied on a non-transitory computer-readable medium, said computer-readable medium being encoded with instructions which, when run on a processor, controls the processor to perform a method according to claim 9 .