Type-2 HARQ-ACK codebook for multi-cell scheduling DCI
A user equipment (UE) is configured to receive at least a first downlink control information (DCI) from a base station of a network, the first DCI scheduling multiple physical downlink shared channels (PDSCH) across multiple cells of the UE, construct a Type 2 hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) codebook based at least on a number of DCI scheduling PDSCH corresponding to the Type 2 HARQ-ACK codebook and transmit the Type 2 HARQ-ACK codebook feedback in a physical uplink channel.
1 . A processor of a base station configured to perform operations comprising:
transmitting at least a first downlink control information (DCI) to a user equipment (UE), the first DCI scheduling multiple physical downlink shared channels (PDSCH) across multiple cells of the UE;
receiving a Type 2 hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) codebook, wherein the Type 2 HARQ-ACK codebook is constructed by adding a total number of HARQ-ACK bits for a first sub-codebook and a total number of HARQ-ACK bits for a second sub-codebook, wherein determining the total number of HARQ-ACK bits for the second sub-codebook is based on at least a parameter indicating a maximum number of serving cells for PDSCH when spatial bundling is enabled; and
processing the physical uplink channel according to the Type 2 HARQ-ACK codebook construction to determine HARQ-ACK feedback for the PDSCH.
2 . The processor of claim 1 , wherein the operations further comprise transmitting a radio resource control (RRC) configuration to the UE enabling the HARQ-ACK bundling across multiple cells.
3 . The processor of claim 2 , wherein the RRC configuration provides at least one list of cell IDs, wherein each list of cell IDs indicates cells to bundle into a respective cell group.
4 . The processor of claim 2 , wherein the RRC configuration indicates a number of cells per group, wherein the UE determines which cells to bundle together based on a number of cells scheduled by the first DCI and the number of cells per group indicated in the RRC configuration.
5 . The processor of claim 2 , wherein a HARQ-ACK feedback bit for a cell group is generated as a result of a binary AND operation for HARQ-ACK feedback bits of the cell within the cell group.
6 . The processor of claim 1 , wherein the operations further comprise transmitting a radio resource control (RRC) configuration to the UE indicating a maximum number N of cells that can be scheduled with a single DCI, wherein the UE determines a number M of cell groups for the N cells based on an RRC configuration from a network enabling the HARQ-ACK bundling across multiple cells.
7 . The processor of claim 6 , wherein a fixed number of HARQ-ACK bits are added to the Type 2 HARQ-ACK codebook for each DCI scheduling a PDSCH corresponding to the HARQ-ACK codebook.
8 . The processor of claim 7 , wherein a counter downlink assignment indicator (C-DAI) and a total DAI (T-DAI) are incremented per DCI received corresponding to the HARQ-ACK codebook.
9 . The processor of claim 8 , wherein, for each incremented DAI value, N bits are added to the Type 2 HARQ-ACK codebook when a single transport block (TB) is configured per PDSCH or two transport blocks are configured per PDSCH with HARQ-ACK spatial bundling.
10 . The processor of claim 8 , wherein, for each incremented DAI value, N*2 bits are added to the Type 2 HARQ-ACK codebook when two transport blocks (TB) are configured per PDSCH without HARQ-ACK spatial bundling.
11 . The processor of claim 1 , wherein the Type 2 HARQ-ACK codebook is constructed using a first sub-codebook and a second sub-codebook.
12 . The processor of claim 11 , wherein the first sub-codebook is constructed for DCI scheduling a single cell or PDSCH belonging to a same cell group for HARQ-ACK bundling and the second sub-codebook is constructed for DCI scheduling more than one cell or PDSCH belonging to more than one cell group for HARQ-ACK bundling.
13 . The processor of claim 12 , wherein a fixed number of HARQ-ACK bits are added to the first sub-codebook for each DCI scheduling a single cell or PDSCH corresponding to the HARQ-ACK codebook.
14 . The processor of claim 11 , wherein a counter downlink assignment indicator (C-DAI) and a total DAI (T-DAI) are incremented independently for DCI corresponding to the respective first and second sub-codebooks.
15 . The processor of claim 14 , wherein, for each incremented DAI value, M bits are added to the second sub-codebook when HARQ-ACK spatial bundling is enabled and N bits are added to the second sub-codebook when a single transport block (TB) is configured per PDSCH without HARQ-ACK spatial bundling.
16 . The processor of claim 14 , wherein, for each incremented DAI value, N*2 bits are added to the Type 2 HARQ-ACK codebook when two transport blocks (TB) are configured per PDSCH without HARQ-ACK spatial bundling.
17 . The processor of claim 1 , wherein the Type 2 HARQ-ACK codebook is constructed using three or more sub-codebooks.
18 . The processor of claim 17 , wherein a counter downlink assignment indicator (C-DAI) and a total DAI (T-DAI) are incremented independently for DCI corresponding to each respective one of the three or more sub-codebooks.
19 . The processor of claim 17 , wherein, for each incremented DAI value, K HARQ-ACK bits are added to a corresponding sub-codebook, wherein K is a maximum number of HARQ-ACK bits for DCI corresponding to the respective sub-codebooks.
20 . The processor of claim 17 , wherein a first sub-codebook includes any DCI scheduling a single cell or PDSCH belonging to a same cell group for HARQ-ACK bundling and wherein remaining sub-codebooks include any DCI scheduling multiple cells or PDSCH belonging to a respective number of cell groups for HARQ-ACK bundling.