Method and device for improving HARQ feedback performance of eMBB

Abstract

Methods and apparatus for improving HARQ feedback performance of an eMBB are described herein. Methods and apparatus for providing single-bit HARQ feedback and multi-bit HARQ feedback in a wireless transmit / receive unit (WTRU) are described herein. For example, a WTRU may receive DCI via a physical downlink control channel (PDCCH). The DCI may include a field for indicating a code block group (CBG)-based retransmission related to at least one transport block (TB). If the DCI does not include the field, the WRTU may transmit a single bit HARQ feedback for a TB-based retransmission via a physical uplink control channel (PUCCH). If the DCI contains the field, the WTRU may transmit a multi-bit HARQ feedback for the CBG-based retransmission via a PUCCH (Physical Uplink Control Channel). The WTRU may be configured to provide the single bit HARQ feedback for the TB-based retransmission as well as a multi-bit HARQ feedback for the CBG-based retransmission.

Claims

1. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information indicating a maximum number of code block group (CBG) hybrid automatic repeat request (HARQ) feedback for CBG; receiving an initial physical downlink shared channel transmission, the initial physical downlink shared channel transmission comprising a plurality of CBGs; determining that at least a first CBG of the plurality of CBGs included in the initial physical downlink shared channel transmission is successfully received, at least a second CBG of the plurality of CBGs is not successfully received, and at least a third CBG of the plurality of CBGs is not successfully received; Sending first HARQ feedback, the first HARQ feedback including a HARQ acknowledgement (HARQ-ACK) bit for the first CBG, a HARQ negative acknowledgement (HARQ-NACK) bit for the second CBG, and a HARQ-NACK bit for the third CBG; receiving a retransmission including the second CBG among the plurality of CBGs, wherein the first CBG is not included in the retransmission; determining that at least the second CBG is successfully received; determining that the third CBG is not included in the retransmission; as well as Send a second HARQ feedback in response to the retransmission, wherein the second HARQ feedback sent in response to the retransmission includes a HARQ-ACK bit for the first CBG not included in the retransmission, a HARQ-ACK bit for the second CBG included in the retransmission, and a HARQ-NACK bit for the third CBG.

2. The method according to claim 1, wherein The number of bits included in each of the first HARQ feedback and the second HARQ feedback is equal to the maximum number of CBGs for CBG-based HARQ feedback indicated in the configuration information.

3. The method according to claim 1, wherein the plurality of CBGs correspond to transport blocks (TBs), the method further comprising: receiving a retransmission of the TB; Determining that the TB is not successfully received; as well as A third HARQ feedback is sent in response to determining that the TB is not successfully received, wherein, based on determining that the TB is not successfully received, the HARQ-NACK bit is repeated a number of times corresponding to the maximum number of CBGs of the CBG-based HARQ feedback.

4. The method according to claim 1, wherein the plurality of CBGs correspond to transport blocks (TBs), the method further comprising: attempting to decode each CBG included in the plurality of CBGs from the initial physical downlink shared channel transmission; as well as HARQ feedback is sent in response to the initial physical downlink shared channel transmission, wherein the HARQ feedback sent in response to the initial physical downlink shared channel transmission includes a corresponding HARQ feedback bit for each of the first plurality of CBGs in the TB.

5. The method according to claim 1, wherein The configuration information is received in a Radio Resource Control (RRC) message.

6. The method according to claim 1, further comprising: A dynamic preemption indication is received, wherein the dynamic preemption indication is used to indicate that a portion of resources corresponding to the initial physical downlink shared channel transmission is preempted.

7. A wireless transmit / receive unit (WTRU), the WTRU comprising: transceiver; as well as A processor configured to: receiving, via the transceiver, configuration information indicating a maximum number of code block group (CBG) hybrid automatic repeat request (HARQ) feedback for CBG; receiving, via the transceiver, an initial physical downlink shared channel transmission, the initial physical downlink shared channel transmission comprising a plurality of CBGs; determining that at least a first CBG of the plurality of CBGs included in the initial physical downlink shared channel transmission is successfully received, at least a second CBG of the plurality of CBGs is not successfully received, and at least a third CBG of the plurality of CBGs is not successfully received; sending, via the transceiver, first HARQ feedback comprising a HARQ acknowledgement (HARQ-ACK) bit for the first CBG, a HARQ negative acknowledgement (HARQ-NACK) bit for the second CBG, and a HARQ-NACK bit for the third CBG; receiving, via the transceiver, a retransmission including the second of the plurality of CBGs, wherein the first CBG is not included in the retransmission; determining that at least the second CBG is successfully received; determining that the third CBG is not included in the retransmission; as well as and sending, via the transceiver, a second HARQ feedback in response to the retransmission, wherein the second HARQ feedback sent in response to the retransmission includes a HARQ-ACK bit for the first CBG not included in the retransmission, a HARQ-ACK bit for the second CBG included in the retransmission, and a HARQ-NACK bit for the third CBG.

8. The WTRU of claim 7, wherein the number of bits included in each of the first HARQ feedback and the second HARQ feedback is equal to the maximum number of CBGs for the CBG-based HARQ feedback indicated in the configuration information.

9. The WTRU of claim 7, wherein the plurality of CBGs correspond to transport blocks (TBs), the processor being further configured to: receiving a retransmission of the TB via the transceiver; Determining that the TB is not successfully received; In response to determining that the TB is not successfully received, sending a third HARQ feedback via the transceiver, wherein: Based on determining that the TB is not successfully received, repeating the HARQ-NACK bit a number of times corresponding to the maximum number of CBGs based on the HARQ feedback of the CBG.

10. The WTRU of claim 7, wherein the plurality of CBGs correspond to transport blocks (TBs), the processor being further configured to: attempting to decode each of the CBGs included in the plurality of CBGs from the initial physical downlink shared channel transmission; and HARQ feedback is sent, via the transceiver, in response to the initial physical downlink shared channel transmission, wherein the HARQ feedback sent in response to the initial physical downlink shared channel transmission includes a corresponding HARQ feedback bit for each of the first plurality of CBGs in the TB.

11. The WTRU of claim 7, wherein the configuration information is received in a radio resource control (RRC) message.

12. The WTRU of claim 7, wherein the processor is further configured to receive a dynamic preemption indication via the transceiver, wherein the dynamic preemption indication indicates that a portion of resources corresponding to the initial physical downlink shared channel transmission is preempted.

13. A base station, comprising: transceiver; as well as A processor configured to: transmitting, via the transceiver, configuration information indicating a maximum number of code block groups (CBGs) for hybrid automatic repeat request (HARQ) feedback based on the CBGs; sending, via the transceiver, an initial physical downlink shared channel transmission, the initial physical downlink shared channel transmission comprising a plurality of CBGs; receiving, via the transceiver, first HARQ feedback comprising a HARQ acknowledgement (HARQ-ACK) bit for the first CBG, a HARQ negative acknowledgement (HARQ-NACK) bit for the second CBG, and a HARQ-NACK bit for a third CBG; sending, via the transceiver, a retransmission including the second CBG of the plurality of CBGs, wherein the first CBG is not included in the retransmission; as well as A second HARQ feedback is received via the transceiver in response to the retransmission, wherein the second HARQ feedback received in response to the retransmission includes a HARQ-ACK bit for the first CBG not included in the retransmission, a HARQ-ACK bit for the second CBG included in the retransmission, and a HARQ-NACK bit for the third CBG.

14. The base station according to claim 13, wherein: The number of bits included in each of the first HARQ feedback and the second HARQ feedback is equal to the maximum number of CBGs of the CBG-based HARQ feedback indicated in the configuration information.

15. The base station according to claim 13, wherein: The plurality of CBGs correspond to transport blocks (TBs), and the processor is further configured to: sending a retransmission of the TB via the transceiver; as well as A third HARQ feedback is received via the transceiver indicating that the TB was not successfully received, wherein, based on determining that the TB was not successfully received, a HARQ-NACK bit is repeated a number of times corresponding to the maximum number of CBGs of the CBG-based HARQ feedback.

16. The base station according to claim 13, wherein: The configuration information is sent in a radio resource control RRC message or in downlink control information DCI.

17. A method performed by a base station, the method comprising: Sending configuration information indicating a maximum number of code block group (CBG) for hybrid automatic repeat request (HARQ) feedback based on CBG; Sending an initial physical downlink shared channel transmission, where the initial physical downlink shared channel transmission includes multiple CBGs; receiving first HARQ feedback, the first HARQ feedback comprising a HARQ acknowledgement (HARQ-ACK) bit for the first CBG, a HARQ negative acknowledgement (HARQ-NACK) bit for the second CBG, and a HARQ-NACK bit for the third CBG; sending a retransmission including the second CBG among the plurality of CBGs, wherein the first CBG is not included in the retransmission; as well as Receive second HARQ feedback in response to the retransmission, wherein the second HARQ feedback received in response to the retransmission includes a HARQ-ACK bit for the first CBG not included in the retransmission, a HARQ-ACK bit for the second CBG included in the retransmission, and a HARQ-NACK bit for the third CBG.

18. The method according to claim 17, wherein the plurality of CBGs correspond to transport blocks (TBs), the method further comprising: Sending a retransmission of the TB; as well as A third HARQ feedback is received indicating that the TB is not successfully received, wherein, based on determining that the TB is not successfully received, the HARQ-NACK bit is repeated a number of times corresponding to a maximum number of CBGs of the CBG-based HARQ feedback.

19. A wireless transmit / receive unit (WTRU), the WTRU comprising a processor configured to: receiving a physical downlink shared channel (PDSCH) transmission, wherein the PDSCH transmission includes a plurality of CBGs, wherein the plurality of CBGs includes a first CBG and a second CBG; Determining that at least the first CBG among the multiple CBGs is successfully received; determining that at least the second CBG among the plurality of CBGs is not successfully received; receiving a retransmission including at least the second CBG among the plurality of CBGs, wherein the first CBG is not included in the retransmission; In response to the retransmission, generating multi-bit HARQ feedback, the multi-bit HARQ feedback comprising a first HARQ feedback bit for a first CBG not included in the retransmission and a second HARQ feedback bit for the second CBG included in the retransmission; and The multi-bit HARQ feedback is sent.

20. The WTRU of claim 19, wherein the PDSCH transmission includes a third CBG, the third CBG not included in the retransmission, and the multi-bit HARQ feedback includes a third HARQ feedback bit for the third CBG.

21. The WTRU of claim 19, wherein the processor is configured to: generating a HARQ-ACK for the third HARQ feedback bit on the condition that the third CBG has been successfully received when sending the multi-bit HARQ feedback; and On the condition that the third CBG has not been successfully received when the multi-bit HARQ feedback is transmitted, a HARQ-NACK for the third HARQ feedback bit is generated.

22. The WTRU of claim 19, wherein the processor being configured to generate the multi-bit HARQ feedback comprises: The processor is configured to generate a HARQ-ACK for the first HARQ feedback bit and a HARQ-NACK for the second HARQ feedback bit.

23. The WTRU of claim 19, wherein the processor is configured to receive configuration information indicating a maximum number of CBGs for CBG-based HARQ feedback.

24. The WTRU of claim 23, wherein the configuration information is received in a radio resource control (RRC) message.

25. The WTRU of claim 19, wherein the processor is further configured to attempt to decode each CBG included in the plurality of CBGs from the PDSCH.

26. The WTRU of claim 25, wherein the plurality of CBGs corresponds to a transport block.

27. The WTRU of claim 19, wherein the processor is configured to receive a dynamic preemption indication indicating that a portion of resources corresponding to the PDSCH transmission is preempted.

28. The WTRU of claim 19, wherein the plurality of CBGs are scheduled for initial transmission and a subset of the plurality of CBGs is scheduled for the retransmission.

29. A method performed by a wireless transmit / receive unit (WTRU), the method comprising: receiving a physical downlink shared channel (PDSCH) transmission, wherein the PDSCH transmission includes a plurality of CBGs, wherein the plurality of CBGs includes a first CBG and a second CBG; Determining that at least the first CBG among the multiple CBGs is successfully received; determining that at least the second CBG among the plurality of CBGs is not successfully received; receiving a retransmission including at least the second CBG among the plurality of CBGs, wherein the first CBG is not included in the retransmission; In response to the retransmission, generating multi-bit HARQ feedback, the multi-bit HARQ feedback comprising a first HARQ feedback bit for a first CBG not included in the retransmission and a second HARQ feedback bit for the second CBG included in the retransmission; and The multi-bit HARQ feedback is sent.

30. The method according to claim 29, wherein The PDSCH transmission includes a third CBG, the third CBG is not included in the retransmission, and the multi-bit HARQ feedback includes a third HARQ feedback bit for the third CBG.

31. The method of claim 29, the processor further comprising: generating a HARQ-ACK for the third HARQ feedback bit, on the condition that the third CBG has been successfully received when sending the multi-bit HARQ feedback; as well as On the condition that the third CBG is not successfully received when sending the multi-bit HARQ feedback, a HARQ-NACK for the third HARQ feedback bit is generated.

32. The method of claim 29, wherein generating the multi-bit HARQ feedback comprises: Generate a HARQ-ACK for the first HARQ feedback bit and a HARQ-NACK for the second HARQ feedback bit.

33. The method of claim 29, further comprising: receiving configuration information indicating a maximum number of CBGs for CBG-based HARQ feedback.

34. The method according to claim 33, wherein The configuration information is received in a Radio Resource Control (RRC) message.

35. The method of claim 29, wherein the plurality of CBGs corresponds to a transport block.

36. The method of claim 29, further comprising: A dynamic preemption indication is received, where the dynamic preemption indication is used to indicate that a portion of resources corresponding to the PDSCH transmission is preempted.

37. A base station, comprising: transceiver; as well as A processor configured to: transmitting, via the transceiver, a physical downlink shared channel (PDSCH) transmission, wherein the PDSCH transmission comprises a plurality of CBGs, wherein the plurality of CBGs comprises a first CBG and a second CBG; sending, via the transceiver, a retransmission including at least the second CBG of the plurality of CBGs, wherein the first CBG is not included in the retransmission; as well as Multi-bit HARQ feedback is received via the transceiver, the multi-bit HARQ feedback including a first HARQ feedback bit for the first CBG not included in the retransmission and a second HARQ feedback bit for the second CBG included in the retransmission.

38. The base station according to claim 37, wherein The configuration information is sent in a Radio Resource Control (RRC) message.

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