HARQ codebook determination in wireless communications

1. A user equipment (UE), comprising:

a transceiver configured to communicate with a base station; and

a processor communicatively coupled to the transceiver and configured to perform operations comprising:

receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs);

receiving a time domain resource allocation (TDRA) table configuration from the base station;

determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration;

grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC;

determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and

generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group.

2. The UE of claim 1 , wherein DCI transmission comprises:

a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and

a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group.

3. The UE of claim 1 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group.

4. The UE of claim 3 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group.

5. The UE of claim 1 , wherein the operations further comprise:

performing a HARQ compression on the plurality of HARQ bits based on a HARQ compression scheme.

6. The UE of claim 5 , wherein the HARQ compression scheme includes applying a compression factor to the maximum number of PDSCH transmissions per group to determine a bundling window size.

7. The UE of claim 6 , wherein if the bundling window is greater than or equal to a number of PDSCH transmissions scheduled by the DCI transmission, the plurality of HARQ bits include a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the number of multiple PDSCH transmissions and the bundling window size.

8. The UE of claim 6 , wherein if the bundling window is less than a number of PDSCH transmissions scheduled by the DCI transmission, the operations further comprise:

determining a HARQ bit for each of the multiple PDSCH transmissions to obtain multiple HARQ bits, wherein the HARQ bit is based on a result of decoding a corresponding one of the multiple PDSCH transmissions;

determining a first sub-window corresponding to a first subset of the multiple HARQ bits and a second sub-window corresponding to a second subset of the multiple HARQ bits.

9. A processor configured to perform operations comprising:

receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from a base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs);

receiving a time domain resource allocation (TDRA) table configuration from the base station;

determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration;

grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC;

determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and

generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group.

10. The processor of claim 9 , wherein DCI transmission comprises:

a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and

a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group.

11. The processor of claim 9 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group.

12. The processor of claim 9 , wherein the operations further comprise:

performing a HARQ compression on the plurality of HARQ bits based on a HARQ compression scheme.

13. The processor of claim 12 , wherein the HARQ compression scheme includes applying a compression factor to the maximum number of PDSCH transmissions per group to determine a bundling window size.

14. The processor of claim 13 , wherein if the bundling window is greater than or equal to a number of PDSCH transmissions scheduled by the DCI transmission, the plurality of HARQ bits include a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the number of multiple PDSCH transmissions and the bundling window size.

15. The processor of claim 13 , wherein if the bundling window is less than a number of PDSCH transmissions scheduled by the DCI transmission, the operations further comprise:

determining a HARQ bit for each of the multiple PDSCH transmissions to obtain multiple HARQ bits, wherein the HARQ bit is based on a result of decoding a corresponding one of the multiple PDSCH transmissions;

determining a first sub-window corresponding to a first subset of the multiple HARQ bits and a second sub-window corresponding to a second subset of the multiple HARQ bits.

16. The processor of claim 11 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group.

17. A method, comprising:

receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs);

receiving a time domain resource allocation (TDRA) table configuration from the base station;

determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration;

grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC;

determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and

generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group.

18. The method of claim 17 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group.

19. The method of claim 18 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group.

20. The method of claim 17 , wherein the DCI transmission comprises:

a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and

a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group.