Decoding method and decoder for low-density parity-check code

1. A decoding method for a low-density parity-check (LDPC) code, comprising:

dividing, by a decoder, an LDPC code C whose bit length is n into k divided LDPC codes D, the LDPC code C={c 1 ,c 2 ,c 3 ,K,c n-1 ,c n }, the divided LDPC codes D={D 1 ,D 2 ,K,D k-1 ,D k }, D i ={c (i-1)l+1 ,c (i-1)l+2 ,K,c il-1 ,c il }i=1,2,K,k−1,k, and a bit length of the D i comprising l=n/k;

arranging, by the decoder, the D i ,i=1,2,K,k−1,k by column to obtain transpose codes (D T ) of the divided LDPC codes D, the D T ={D 1 T ,D 2 T ,K,D k-1 T ,D k T }, D i T ={c (i-1)l+1 ,c (i-1)l+2 ,K,c il-1 ,c il } T , and i=1,2,K,k−1,k;

performing, by the decoder, cyclic shift on the D i T ,i=1,2,K,k−1,k by row according to values of corresponding elements in a target check matrix to obtain shift codes (E), the E={E 1 ,E 2 ,K,E t-1 ,E t }, t being equal to a quantity of rows of the target check matrix, E j comprising a result of shifting the D T according to an element of a j th row in the target check matrix, and j=1,2,K,t−1,t;

obtaining, by the decoder, t*m groups of LDPC subcodes according to the E and a bit length of the decoder (d), the LDPC subcodes comprising F 1 ,F 2 ,K,F tm-1 ,F tm , the E j being divided into m groups, the E j ={(E j ) 1 d ,(E j ) d+1 2d ,K,(E j ) (m-2)d+1 (m-1)d ,(E j ) (m-1)d+1 md }={F (j-1)m+1 ,F (j-1)m+2 ,K,F jm-1 ,F jm }, (E j ) (s-1)d+1 sd , s=1,2,K, m−1,m denoting an [(s−1)d+1] th row to an (sd) th row of the E j , and m=┌l/d┐; and

decoding, by the decoder, m groups of the LDPC subcodes to obtain a decoding result of the LDPC code C such that a quantity of parallel decoding operations on the LDPC code C being controlled flexibly.

2. The method of claim 1 , wherein decoding the m groups of the LDPC subcodes to obtain the decoding result of the LDPC code C comprises:

obtaining, by the decoder, log likelihood ratio (LLR) values corresponding to the LDPC subcodes, the LLR values corresponding to the LDPC subcodes comprising G 1 ,G 2 ,K,G tm-1 ,G tm ;

updating, by the decoder, check nodes according to the LLR values in an order of r=1,2,K,tm−1,tm to obtain a row-updated matrix;

updating, by the decoder, variable nodes column by column according to the row-updated matrix to obtain a column-updated matrix; and

performing, by the decoder, decision and checking on the column-updated matrix to obtain the decoding result of the LDPC code C.

3. The method of claim 1 , wherein the LDPC code C comprises a quasi-cyclic LDPC (QC-LDPC) code, and the l comprising an inflation factor of the QC-LDPC code.

4. The method of claim 1 , wherein the d comprises sixty.

5. The method of claim 1 , wherein decoding the m groups of the LDPC subcodes to obtain the decoding result of the LDPC code C comprises decoding, by the decoder, the m groups of the LDPC subcodes using a minimum sum (Min-sum) decoding algorithm to obtain the decoding result of the LDPC code C.

6. The method of claim 1 , wherein the d comprises one hundred eighty.

7. A decoder for a low-density parity-check (LDPC) code, comprising:

a memory comprising instructions; and

a processor coupled to the memory, the instructions causing the processor to be configured to:

divide an LDPC code C whose bit length is n into k divided LDPC codes D, the LDPC code C={c 1 ,c 2 ,c 3 ,K,c n-1 ,c n }, the divided LDPC codes D={D 1 ,D 2 ,K,D k-1 ,D k }, D i ={c (i-1)l+1 ,c (i-1)l+2 ,K,c il-1 ,c il }, i=1,2,K,k−1,k, and a bit length of the D i comprising l=n/k;

arrange the D i ,i=1,2,K,k−1,k by column to obtain transpose codes (D T ) of the divided LDPC codes D, the D T ={D 1 T ,D 2 T ,K,D k-1 T ,D k T }, D i T ={c (i-1)l+1 ,c (i-1)l+2 ,K, c il-1 , c il } T , and i=1,2,K,k−1,k;

perform cyclic shift on the D i T ,i=1,2,K,k−1,k by row according to values of corresponding elements in a target check matrix to obtain shift codes (E), the E={E 1 ,E 2 ,K,E t-1 , E t }, t being equal to a quantity of rows of the target check matrix, and E j comprising a result of shifting the D T according to an element of a j th row in the target check matrix, and j=1,2,K,t−1,t;

obtain t*m groups of LDPC subcodes according to the E and a bit length of the decoder (d), the E j being divided into m groups, the E j ={(E j ) 1 d ,(E j ) d+1 2d ,K,(E j ) (m-2)d+1 (m-1)d ,(E j ) (m-1)d+1 md }={F (j-1)m+1 ,F (j-1)m+2 ,K,F jm-1 ,F jm }, (E j ) (s-1)d+1 sd , s=1,2,K, m−1,m denoting an [(s−1)d+1] th row to an (sd) th row of the E j , and m=┌l/d┐; and

decode m groups of the LDPC subcodes to obtain a decoding result of the LDPC code C such that a quantity of parallel decoding operations on the LDPC code C being controlled flexibly.

8. The decoder of claim 7 , wherein the instructions further cause the processor to be configured to:

obtain log likelihood ratio (LLR) values corresponding to the LDPC subcodes, the LLR values corresponding to the LDPC subcodes comprising G 1 ,G 2 ,K,G tm-1 ,G tm ;

update check nodes according to the LLR values in an order of r=1,2,K,tm−1,tm to obtain a row-updated matrix;

update variable nodes column by column according to the row-updated matrix to obtain a column-updated matrix; and

perform decision and checking on the column-updated matrix to obtain the decoding result of the LDPC code C.

9. The decoder of claim 7 , wherein the LDPC code C comprises a quasi-cyclic LDPC (QC-LDPC) code, and the l comprising an inflation factor of the QC-LDPC code.

10. The decoder of claim 7 , wherein the d comprises sixty.

11. The decoder of claim 7 , wherein the instructions further cause the processor to be configured to decode the m groups of the LDPC subcodes using a minimum sum (Min-sum) decoding algorithm to obtain the decoding result of the LDPC code C.

12. The decoder of claim 7 , wherein the d comprises one hundred eighty.

13. A computer program product comprising a non-transitory computer readable storage medium storing program code thereon for decoding a low-density parity-check (LDPC) code, the program code comprising instructions for executing a method that comprises:

dividing, by a decoder, an LDPC code C whose bit length is n into k divided LDPC codes D, the LDPC code C={c 1 ,c 2 ,c 3 ,K,c n-1 ,c n }, the divided LDPC codes D={D 1 ,D 2 ,K,D k-1 ,D k }, D i ={c (i-1)l+1 ,c (i-1)l+2 ,K,c il-1 ,c il }, i=1,2,K,k−1,k, and a bit length of the D i comprising l=n/k;

arranging, by the decoder, the D i ,i=1,2,K,k−1,k by column to obtain transpose codes (D T ) of the divided LDPC codes D, the D T ={D 1 T ,D 2 T ,K,D k-1 T ,D k T }, D i T ={c (i-1)l+1 ,c (i-1)l+2 ,K,c il-1 ,c il } T ,i=1,2,K,k−1,k;

performing, by the decoder, cyclic shift on the D i T i=1,2K,k−1,k by row according to values of corresponding elements in a target check matrix to obtain shift codes (E), the E={E 1 ,E 2 ,K,E t-1 ,t}, t being equal to a quantity of rows of the target check matrix, E j comprising a result of shifting the D T according to an element of a j th row in the target check matrix, and j=1,2,K,t−1,t;

obtaining, by the decoder, t*m groups of LDPC subcodes according to the E and a bit length of the decoder (d), the LDPC subcodes comprising F 1 ,F 2 ,K,F tm-1 ,F tm , the E j being divided into m groups, the E j ={(E j ) 1 d ,(E j ) d+1 2d ,K,(E j ) (m-2)d+1 (m-1)d ,(E j ) (m-1)d+1 md }={F (j-1)m+1 ,F (j-1)m+2 ,K,F jm-1 ,F jm }, (E j ) (s-1)d+1 sd , s=1,2,K,m−1,m denoting an [(s−1)d+1] th row to an (sd) th row of the E j , and m=┌l/d┐; and

decoding, by the decoder, m groups of the LDPC subcodes to obtain a decoding result of the LDPC code C such that a quantity of parallel decoding operations on the LDPC code C being controlled flexibly.

14. The computer program product of claim 13 , wherein decoding the in groups of the LDPC subcodes to obtain the decoding result of the LDPC code C comprises:

obtaining, by the decoder, log likelihood ratio (LLR) values corresponding to the LDPC subcodes, the LLR values corresponding to the LDPC subcodes comprising G 1 ,G 2 ,K,G tm-1 ,G tm ;

updating, by the decoder, check nodes according to the LLR values in an order of r=1,2,K,tm−1,tm to obtain a row-updated matrix;

updating, by the decoder, variable nodes column by column according to the row-updated matrix to obtain a column-updated matrix; and

performing, by the decoder, decision and checking on the column-updated matrix to obtain the decoding result of the LDPC code C.

15. The computer program product of claim 13 , wherein the LDPC code C comprises a quasi-cyclic LDPC (QC-LDPC) code, and the l comprising an inflation factor of the QC-LDPC code.

16. The computer program product of claim 13 , wherein the d comprises sixty.

17. The computer program product of claim 13 , wherein the d comprises one hundred eighty.

18. The computer program product of claim 13 , wherein decoding the m groups of the LDPC subcodes to obtain the decoding result of the LDPC code C comprises decoding, by the decoder, the m groups of the LDPC subcodes using a minimum sum (Min-sum) decoding algorithm to obtain the decoding result of the LDPC code C.