Apparatus and method for performing hybrid automatic repeat request operation in wireless communication system supporting carrier aggregation
Provided is a method of performing HARQ by a UE in a wireless communication system that supports carrier aggregation (CA). The method includes: receiving, from an evolved nodeB (eNB), a downlink grant on a first Physical Downlink Control Channel (PDCCH), the downlink grant including an accumulated downlink assignment indicator (A-DAI) field and a total DAI (T-DAI) field; receiving a first PDSCH indicated by the first PDCCH, the first PDSCH being transmitted from the eNB; receiving, from the eNB, an uplink grant on a second PDCCH, the uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH); determining a size of a HARQ-ACK codebook to which a HARQ-ACK with respect to the first PDSCH is to be mapped, based on the A-DAI and the T-DAI; and transmitting, to the eNB, the HARQ-ACK with respect to the first PDSCH on the PUSCH.
1. A method comprising:
receiving, by a user equipment (UE), from a first serving cell, and via a first Physical Downlink Control Channel (PDCCH) in a first subframe, a first downlink grant comprising a first accumulated downlink assignment indicator (A-DAI) field and a first total DAI (T-DAI) field;
receiving, by the UE, from a second serving cell, and via a second PDCCH in the first subframe, a second downlink grant comprising a second A-DAI field and a second T-DAI field;
determining a value of the first A-DAI field and a value of the first T-DAI field, wherein the value of the first T-DAI field indicates an integer T1, wherein the value of the first A-DAI field indicates an integer A smaller than or equal to the integer T1, and wherein the value of the first T-DAI field is mapped to a set including a plurality of T-DAI values;
determining a value of the second A-DAI field and a value of the second T-DAI field, wherein the value of the second T-DAI field indicates the integer T1, and wherein the value of the second A-DAI field indicates an integer B smaller than or equal to the integer T1;
receiving a first PDSCH indicated by the first PDCCH and receiving a second PDSCH indicated by the second PDCCH;
determining that the integer B is the highest value among values indicated by A-DAI field values determined from PDCCHs received in the first subframe;
determining one of the plurality of T-DAI values, which is the closest integer to the integer B;
receiving an uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH);
determining a size of a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook to which an HARQ-ACK associated with the first PDSCH and an HARQ-ACK associated with the second PDSCH are to be mapped, wherein the size of the HARQ-ACK codebook is determined based on the determined one of the plurality of T-DAI values; and
transmitting, via the PUSCH, the HARQ-ACK associated with the first PDSCH and the HARQ-ACK associated with the second PDSCH.
2. The method of claim 1 , further comprising:
receiving, by the UE, from a third serving cell, and via a third PDCCH in a second subframe, a third downlink grant comprising a third A-DAI field and a third T-DAI field;
receiving, by the UE, from a fourth serving cell, and via a fourth PDCCH in the second subframe, a fourth downlink grant comprising a fourth A-DAI field and a fourth T-DAI field;
determining a value of the third A-DAI field and a value of the third T-DAI field, wherein the value of the third T-DAI field indicates an integer T2, and wherein the value of the third A-DAI field indicates an integer C larger than the integer T1 and smaller than or equal to the integer T2; and
determining a value of the fourth A-DAI field and a value of the fourth T-DAI field, wherein the value of the fourth T-DAI field indicates the integer T2, and wherein the value of the fourth A-DAI field indicates an integer D larger than the integer T1 and smaller than or equal to the integer T2.
3. The method of claim 2 , wherein the first T-DAI field and the second T-DAI field indicate that total T1 number of PDSCHs and PDCCH indicating downlink semi persistent release (SPS) are scheduled for the UE in the first subframe, and
wherein total T1 number of different serving cells transmit, in the first subframe, PDCCHs comprising values of A-DAI and T-DAI.
4. The method of claim 3 , wherein the third T-DAI field and the fourth T-DAI field indicate that total (T2−T1) number of PDSCHs and PDCCH indicating downlink SPS are scheduled for the UE in the second subframe, and
wherein total (T2−T1) number of different serving cells transmit, in the second subframe, PDCCHs comprising a value pair of A-DAI and T-DAI fields.
5. The method of claim 4 , wherein one or more downlink SPS PDSCH transmissions are excluded in determining the values of first T-DAI field, the second T-DAI field, the third T-DAI field, and the fourth T-DAI field.
6. The method of claim 1 , further comprising determining to increase the size of the HARQ-ACK codebook based on one or more downlink semi persistent release (SPS) PDSCH transmissions.
7. A method comprising:
receiving, by a user equipment (UE), from a first serving cell, and via a first Physical Downlink Control Channel (PDCCH) in a first subframe, a first downlink grant comprising a first accumulated downlink assignment indicator (A-DAI) field and a first total DAI (T-DAI) field;
receiving, by the UE, from a second serving cell, and via a second PDCCH in the first subframe, a second downlink grant comprising a second A-DAI field and a second T-DAI field;
determining a value of the first A-DAI field and a value of the first T-DAI field, wherein the value of the first T-DAI field indicates an integer T1, and wherein the value of the first A-DAI field indicates an integer A smaller than or equal to the integer T1;
determining a value of the second A-DAI field and a value of the second T-DAI field, wherein the value of the second T-DAI field indicates the integer T1, and wherein the value of the second A-DAI field indicates an integer B smaller than or equal to the integer T1;
receiving a first PDSCH indicated by the first PDCCH and receiving a second PDSCH indicated by the second PDCCH;
receiving an uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH);
determining a size of a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook to which an HARQ-ACK associated with the first PDSCH and an HARQ-ACK associated with the second PDSCH are to be mapped, wherein determining the size of the HARQ-ACK comprises determining to increase the size of the HARQ-ACK codebook based on one or more downlink semi persistent release (SPS) PDSCH transmissions; and
transmitting, via the PUSCH, the HARQ-ACK associated with the first PDSCH and the HARQ-ACK associated with the second PDSCH.
8. The method of claim 7 , further comprising:
receiving, by the UE, from a third serving cell, and via a third PDCCH in a second subframe, a third downlink grant comprising a third A-DAI field and a third T-DAI field;
receiving, by the UE, from a fourth serving cell, and via a fourth PDCCH in the second subframe, a fourth downlink grant comprising a fourth A-DAI field and a fourth T-DAI field;
determining a value of the third A-DAI field and a value of the third T-DAI field, wherein the value of the third T-DAI field indicates an integer T2, and wherein the value of the third A-DAI field indicates an integer C larger than the integer T1 and smaller than or equal to the integer T2; and
determining a value of the fourth A-DAI field and a value of the fourth T-DAI field, wherein the value of the fourth T-DAI field indicates the integer T2, and wherein the value of the fourth A-DAI field indicates an integer D larger than the integer T1 and smaller than or equal to the integer T2.
9. The method of claim 8 , wherein the first T-DAI field and the second T-DAI field indicate that total T1 number of PDSCHs and PDCCH indicating downlink semi persistent release (SPS) are scheduled for the UE in the first subframe, and
wherein total T1 number of different serving cells transmit, in the first subframe, PDCCHs comprising values of A-DAI and T-DAI.
10. The method of claim 9 , wherein the third T-DAI field and the fourth T-DAI field indicate that total (T2−T1) number of PDSCHs and PDCCH indicating downlink SPS are scheduled for the UE in the second subframe, and
wherein total (T2−T1) number of different serving cells transmit, in the second subframe, PDCCHs comprising a value pair of A-DAI and T-DAI fields.
11. The method of claim 10 , wherein one or more downlink SPS PDSCH transmissions are excluded in determining the values of first T-DAI field, the second T-DAI field, the third T-DAI field, and the fourth T-DAI field.
12. The method of claim 7 , wherein the value of the first T-DAI field is mapped to a set including a plurality of T-DAI values.
13. The method of claim 12 , further comprising:
determining that the integer B is the highest A-DAI field value among values indicated by A-DAI field values determined from PDCCHs received in the first subframe; and
determining one of the plurality of T-DAI values, which is the closest integer to the integer B,
wherein the size of the HARQ-ACK codebook is determined based on the determined one of the plurality of T-DAI values.
14. A method comprising:
receiving, by a user equipment (UE), from a first serving cell, and via a first Physical Downlink Control Channel (PDCCH) in a first subframe, a first downlink grant comprising a first accumulated downlink assignment indicator (A-DAI) field and a first total DAI (T-DAI) field;
receiving, by the UE, from a second serving cell, and via a second PDCCH in the first subframe, a second downlink grant comprising a second A-DAI field and a second T-DAI field;
receiving, by the UE, from a third serving cell, and via a third PDCCH in a second subframe, a third downlink grant comprising a third A-DAI field and a third T-DAI field;
receiving, by the UE, from a fourth serving cell, and via a fourth PDCCH in the second subframe, a fourth downlink grant comprising a fourth A-DAI field and a fourth T-DAI field;
determining a value of the first A-DAI field and a value of the first T-DAI field, wherein the value of the first T-DAI field indicates an integer T1, and wherein the value of the first A-DAI field indicates an integer A smaller than or equal to the integer T1;
determining a value of the second A-DAI field and a value of the second T-DAI field, wherein the value of the second T-DAI field indicates the integer T1, and wherein the value of the second A-DAI field indicates an integer B smaller than or equal to the integer T1;
determining a value of the third A-DAI field and a value of the third T-DAI field, wherein the value of the third T-DAI field indicates an integer T2, and wherein the value of the third A-DAI field indicates an integer C larger than the integer T1 and smaller than or equal to the integer T2;
determining a value of the fourth A-DAI field and a value of the fourth T-DAI field, wherein the value of the fourth T-DAI field indicates the integer T2, and wherein the value of the fourth A-DAI field indicates an integer D larger than the integer T1 and smaller than or equal to the integer T2
receiving a first PDSCH indicated by the first PDCCH and receiving a second PDSCH indicated by the second PDCCH;
receiving an uplink grant indicating a transmission of a Physical Uplink Shared Channel (PUSCH);
determining a size of a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook to which an HARQ-ACK associated with the first PDSCH and an HARQ-ACK associated with the second PDSCH are to be mapped; and
transmitting, via the PUSCH, the HARQ-ACK associated with the first PDSCH and the HARQ-ACK associated with the second PDSCH,
wherein the first T-DAI field and the second T-DAI field indicate that total T1 number of PDSCHs and PDCCH indicating downlink semi persistent release (SPS) are scheduled for the UE in the first subframe, and
wherein PDCCHs comprising values of A-DAI and T-DAI are transmitted, in the first subframe, from total T1 number of different serving cells.
15. The method of claim 14 , wherein the third T-DAI field and the fourth T-DAI field indicate that total (T2−T1) number of PDSCHs and PDCCH indicating downlink SPS are scheduled for the UE in the second subframe, and
wherein total (T2−T1) number of different serving cells transmit, in the second subframe, PDCCHs comprising a value pair of A-DAI and T-DAI fields.
16. The method of claim 15 , wherein one or more downlink SPS PDSCH transmissions are excluded in determining the values of first T-DAI field, the second T-DAI field, the third T-DAI field, and the fourth T-DAI field.
17. The method of claim 14 , wherein the value of the first T-DAI field is mapped to a set including a plurality of T-DAI values.
18. The method of claim 17 , further comprising:
determining that the integer B is the highest A-DAI field value among values indicated by A-DAI field values determined from PDCCHs received in the first subframe; and
determining one of the plurality of T-DAI values, which is the closest integer to the integer B,
wherein the size of the HARQ-ACK codebook is determined based on the determined one of the plurality of T-DAI values.
19. The method of claim 14 , further comprising determining to increase the size of the HARQ-ACK codebook based on one or more downlink semi persistent release (SPS) PDSCH transmissions.