Method and apparatus for reducing uplink overhead in mobile communications

1. A method, comprising:

determining, by a processor of an apparatus, whether to multiplex hybrid automatic repeat request-acknowledgement (HARQ-ACK) information in a physical uplink shared channel (PUSCH) transmission;

determining, by the processor, that only a physical downlink shared channel (PDSCH) is received;

receiving, by the processor, a downlink control information (DCI) transmission;

generating, by the processor, only the HARQ-ACK information corresponding to the PDSCH in an event that only the PDSCH is received and despite determining to multiplex the HARQ-ACK information; and

transmitting, by the processor, the HARQ-ACK information in the PUSCH transmission,

wherein, in response to a downlink assignment index (DAI) field in the DCI being assigned or the PDSCH being received from a primary cell (PCell), the HARQ-ACK information comprises a single HARQ-ACK corresponding to the received PDSCH instead of a full HARQ-ACK codebook to result in reduced uplink overhead.

2. The method of claim 1 , wherein the PUSCH transmission is not scheduled by a downlink control information (DCI) format.

3. The method of claim 1 , wherein the PUSCH transmission is scheduled by a downlink control information (DCI) format 0_0.

4. The method of claim 1 , wherein the PUSCH transmission is scheduled by a downlink control information (DCI) format 0_1.

5. The method of claim 1 , wherein the PDSCH comprises a semi-persistent scheduling (SPS) PDSCH release or a SPS PDSCH reception.

6. The method of claim 1 , wherein the PDSCH is scheduled by a downlink control information (DCI) format 1_0.

7. The method of claim 1 , wherein the generating comprises cancelling generation of a full HARQ-ACK codebook.

8. The method of claim 1 , wherein the generating comprises reducing a control overhead of the HARQ-ACK information.

9. The method of claim 1 , further comprising:

determining, by the processor, whether no PDSCH is received; and

cancelling, by the processor, generation of the HARQ-ACK information in an event that no PDSCH is received.

10. An apparatus, comprising:

a transceiver capable of wirelessly communicating with a network node of a wireless network; and

a processor communicatively coupled to the transceiver, the processor capable of:

determining whether to multiplex hybrid automatic repeat request-acknowledgement (HARQ-ACK) information in a physical uplink shared channel (PUSCH) transmission;

determining that only a physical downlink shared channel (PDSCH) is received;

receiving, via the transceiver, a downlink control information (DCI) transmission;

generating only the HARQ-ACK information corresponding to the PDSCH in an event that only the PDSCH is received and despite determining to multiplex the HARQ-ACK information; and

transmitting, via the transceiver, the HARQ-ACK information in the PUSCH transmission to the network node,

wherein, in response to a downlink assignment index (DAI) field in the DCI being assigned or the PDSCH being received from a primary cell (PCell), the HARQ-ACK information comprises a single HARQ-ACK corresponding to the received PDSCH instead of a full HARQ-ACK codebook to result in reduced uplink overhead.

11. The apparatus of claim 10 , wherein the PUSCH transmission is not scheduled by a downlink control information (DCI) format.

12. The apparatus of claim 10 , wherein the PUSCH transmission is scheduled by a downlink control information (DCI) format 0_0.

13. The apparatus of claim 10 , wherein the PUSCH transmission is scheduled by a downlink control information (DCI) format 0_1.

14. The apparatus of claim 10 , wherein the PDSCH comprises a semi-persistent scheduling (SPS) PDSCH release or a SPS PDSCH reception.

15. The apparatus of claim 10 , wherein the PDSCH is scheduled by a downlink control information (DCI) format 1_0.

16. The apparatus of claim 10 , wherein, in generating only the HARQ-ACK information corresponding to the PDSCH, the processor is capable of cancelling generation of a full HARQ-ACK codebook.

17. The apparatus of claim 10 , wherein, in generating only the HARQ-ACK information corresponding to the PDSCH, the processor is capable of reducing a control overhead of the HARQ-ACK information.

18. The apparatus of claim 10 , wherein the processor is further capable of:

determining whether no PDSCH is received; and

cancelling generation of the HARQ-ACK information in an event that no PDSCH is received.