HARQ for advanced channel codes
A method ( 2200 ) and apparatus for transmitting data using low density parity check, LDPC, encoding and hybrid automatic repeat request-incremental redundancy, HARQ-IR, is disclosed. The method may comprise selecting ( 2206 ) a protograph sub-matrix from a family of protograph matrices based on one or more of an initial code rate, an information block size, a maximum retransmission count or a maximum number of redundancy versions, wherein the selected protograph sub-matrix supports HARQ-IR. A parity check matrix may be determined based on the selected protograph sub-matrix ( 2208 ). One or more data blocks may be encoded using LDPC based on the parity check matrix ( 2218 ) and the LDPC encoded data block may be transmitted ( 2220 ) to an LDPC HARQ-IR configured receiver.
1. A method for transmitting data using one or more low density parity check (LDPC) codes, the method comprising:
selecting a base graph and a lifting size;
obtaining a lifted graph by lifting the base graph based on the lifting size;
LDPC encoding a sequence of bits based on the lifted graph;
writing the sequence of encoded bits into a circular buffer;
transmitting a first portion of the sequence of encoded bits, wherein the first portion is selected based on a first redundancy version; and
transmitting a second portion of the sequence of encoded bits, wherein the second portion is selected based on the lifting size and a second redundancy version;
wherein the first redundancy version and the second redundancy version are different redundancy versions.
2. The method of claim 1 , further comprising:
transmitting a third portion of the sequence of encoded bits, wherein the third portion is selected based on the lifting size and a third redundancy version.
3. The method of claim 2 , further comprising:
transmitting a fourth portion of the sequence of encoded bits, wherein the fourth portion is selected based on the lifting size and a fourth redundancy version.
4. The method of claim 3 , wherein the first redundancy version, the second redundancy version, the third redundancy version and the fourth redundancy version are different redundancy versions.
5. The method of claim 3 , wherein the first portion, the second portion, the third portion and the fourth portion are different portions of the sequence of encoded bits.
6. The method of claim 3 , wherein the first portion, the second portion, the third portion and the fourth portion are overlapping portions of the sequence of encoded bits.
7. The method of claim 1 , wherein lifting the base graph comprises replacing 0 values of the base graph with an all zero matrix and replacing 1 values of the base graph with a circular permutation matrix.
8. The method of claim 1 , wherein the second redundancy version is indicated, by a next generation Node B (gNB), via downlink control information (DCI).
9. The method of claim 1 , wherein the lifting size is based on the second redundancy version.
10. The method of claim 1 , wherein encoding the sequence of bits comprises LDPC encoding the sequence of bits.
11. A wireless transmit/receive unit (WTRU) configured to transmit data using one or more low density parity check (LDPC) codes, the WTRU comprising:
circuitry configured to select a base graph and a lifting size;
circuitry configured to lift the base graph, based on the lifting size, to obtain a lifted graph;
an LDPC encoder configured to encode a sequence of bits based on the lifted graph;
a circular buffer configured to receive the sequence of encoded bits;
a transmitter configured to transmit, a first portion of the sequence of encoded bits, wherein the first portion is selected based a first redundancy version; and
the transmitter configured to transmit, a second portion of the sequence of encoded bits, wherein the second portion is selected based on the lifting size and a second redundancy version;
wherein the first redundancy version and the second redundancy version are different redundancy versions.
12. The WTRU of claim 11 , further comprising:
the transmitter configured to transmit, a third portion of the sequence of encoded bits, wherein the third portion is selected based on the lifting size and a third redundancy version.
13. The WTRU of claim 12 , further comprising:
the transmitter configured to transmit, a fourth portion of the sequence of encoded bits, wherein the fourth portion is selected based on the lifting size and a fourth redundancy version.
14. The WTRU of claim 13 , wherein the first redundancy version, the second redundancy version, the third redundancy version and the fourth redundancy version are different redundancy versions.
15. The WTRU of claim 13 , wherein the first portion, second portion, third portion and fourth portion are different portions of the sequence of encoded bits.
16. The WTRU of claim 13 , wherein the first portion, second portion, third portion and fourth portion are overlapping portions.
17. The WTRU of claim 11 , wherein the circuitry configured to lift the base graph is configured to replace 0 values of the base graph with an all zero matrix and replace 1 values of the base graph with a circular permutation matrix.
18. The WTRU of claim 11 , wherein the second redundancy version is indicated, by a next generation Node B (gNB), via downlink control information (DCI).
19. The WTRU of claim 11 , wherein the lifting size is based on the second redundancy version.
20. The WTRU of claim 11 , wherein the encoder is an LDPC encoder.