Method and apparatus for indicating time gap for device-to-device communication in a wireless communication system

Patent metadata

Field	Value
Publication number	US-2021007096-A1
Application number	US-202016905500-A
Country	US
Kind code	A1
Filing date	Jun 18, 2020
Priority date	Jul 5, 2019
Publication date	Jan 7, 2021
Grant date	—

Abstract

A method and apparatus are disclosed from the perspective of a first User Equipment (UE). In one embodiment, the method includes the first UE being configured or pre-configured with a sidelink resource pool for sidelink transmission. The method also includes the first UE being triggered to select resources for a TB (Transport Block). The method further includes the first UE selecting a first resource for transmission of the TB. In addition, the method includes the first UE selecting a second resource for HARQ-ACK (Hybrid Automatic Repeat Request-Acknowledgement) based retransmission of the TB, wherein the second resource is later than the first resource, and a time gap between the first resource and the second resource is larger than or equal to a first time duration. Furthermore, the method includes the first UE transmitting a SCI (Sidelink Control Information) and the TB on the first resource in a slot to a second UE, wherein the SCI indicates the first resource and the second resource.

First claim

1 . A method for a first User Equipment (UE) in a wireless communication system, comprising:
the first UE is configured or pre-configured with a sidelink resource pool for sidelink transmission; the first UE is triggered to select resources for a TB (Transport Block); the first UE selects a first resource for transmission of the TB; the first UE selects a second resource for HARQ-ACK (Hybrid Automatic Repeat Request-Acknowledgement) based retransmission of the TB, wherein the second resource is later than the first resource, and a time gap between the first resource and the second resource is larger than or equal to a first time duration; and the first UE transmits a SCI (Sidelink Control Information) and the TB on the first resource in a slot to a second UE, wherein the SCI indicates the first resource and the second resource.

2 . The method of claim 1 , wherein the first resource is earlier than a HARQ-ACK occasion associated with the first resource in time domain, and the second resource is later than the HARQ-ACK occasion in time domain.

3 . The method of claim 2 , wherein the second resource is only later than the HARQ-ACK occasion associated with the first resource, and a time gap between the HARQ-ACK occasion and the second resource is larger than or equal to a second time duration.

4 . The method of claim 3 , wherein for HARQ-ACK based retransmission for the TB, the first UE only selects the second resource or the first resource, wherein a time gap between the HARQ-ACK occasion and the second resource is larger than or equal to the second time duration, and/or
wherein for blind retransmission for the TB, the first UE selects a third resource or the first resource, wherein a time gap between the HARQ-ACK occasion and the third resource is allowed to be smaller than the second time duration, or the third resource is allowed to be earlier than the HARQ-ACK occasion associated with the first resource.

5 . The method of claim 3 , wherein the first time duration comprises the second time duration, or the first time duration comprises the second time duration and the time gap between the HARQ-ACK occasion and the first resource.

6 . The method of claim 3 , wherein the second time duration includes at least decoding and/or receiving time for a HARQ-ACK feedback received on the HARQ-ACK occasion associated with the first resource, and/or a generation or processing time for retransmitting the TB on the second resource in responsive to the HARQ-ACK feedback.

7 . The method of claim 3 , wherein for selecting the second resource, the first UE excludes a candidate resource or occasion, wherein time gap between the HARQ-ACK occasion and the candidate resource or occasion is smaller than the second time duration, and/or
wherein for selecting the second resource, the first UE prevents from selecting a candidate resource, wherein time gap between the HARQ-ACK occasion and the candidate resource is smaller than the second time duration, and/or wherein for selecting the second resource, the first UE is not allowed to select a candidate resource, wherein time gap between the HARQ-ACK occasion and the candidate resource is smaller than the second time duration, and/or wherein for selecting the first resource, the first UE excludes a candidate resource or occasion, wherein time gap between the second resource and a HARQ-ACK occasion associated to the candidate resource or occasion is smaller than the second time duration, and/or wherein for selecting the first resource, the first UE prevents from selecting a candidate resource, wherein time gap between the second resource and a HARQ-ACK occasion associated to the candidate resource or occasion is smaller than the second time duration, and/or wherein for selecting the first resource, the first UE is not allowed to select a candidate resource, wherein time gap between the second resource and a HARQ-ACK occasion associated to the candidate resource or occasion is smaller than the second time duration.

8 . The method of claim 2 , wherein the first UE receives a HARQ-ACK feedback on the HARQ-ACK occasion associated with the first resource, and
if the HARQ-ACK feedback is an ACK, the first UE does not retransmit the TB on the second resource, or if the HARQ-ACK feedback is a NACK (Negative Acknowledgement) or the first UE does not receive the HARQ-ACK feedback, the first UE retransmits the TB on the second resource.

9 . The method of claim 8 , wherein the HARQ-ACK feedback is transmitted via a PSFCH (Physical Sidelink Feedback Channel) from the second UE.

10 . The method of claim 1 , wherein for HARQ-ACK based retransmission for the TB, the first UE only selects the second resource or the first resource, wherein a time gap between the first resource and the second resource is larger than or equal to the first time duration, and/or
wherein for blind retransmission for the TB, the first UE selects a third resource or the first resource, wherein a time gap between the first resource and the third resource is allowed to be smaller than the first time duration.

11 . The method of claim 1 , wherein the first UE derives or sets a time gap field in the SCI for indicating the time gap between the first resource and the second resource.

12 . The method of claim 11 , wherein for indicating HARQ-ACK based retransmission for the TB, a time gap indicated by the time gap field cannot be smaller than the first time duration, and/or wherein for indicating blind retransmission for the TB, the time gap field is set without limitation.

13 . The method of claim 11 , wherein if the time gap field is set to a time gap smaller than the first time duration, the HARQ-ACK based retransmission for the TB is not supported, and/or the first UE does not receive a HARQ-ACK feedback from the second UE on a HARQ-ACK occasion associated with the first resource.

14 . The method of claim 1 , wherein for selecting the second resource, the first UE excludes a candidate resource or occasion, wherein time gap between the first resource and the candidate resource or occasion is smaller than the first time duration, and/or
wherein for selecting the second resource, the first UE prevents from selecting a candidate resource, wherein time gap between the first resource and the candidate resource is smaller than the first time duration, and/or wherein for selecting the second resource, the first UE is not allowed to select a candidate resource, wherein time gap between the first resource and the candidate resource is smaller than the first time duration, and/or wherein for selecting the first resource, the first UE excludes a candidate resource or occasion, wherein time gap between the second resource and the candidate resource or occasion is smaller than the first time duration, and/or wherein for selecting the first resource, the first UE prevents from selecting a candidate resource, wherein time gap between the second resource and the candidate resource is smaller than the first time duration, and/or wherein for selecting the first resource, the first UE is not allowed to select a candidate resource, wherein time gap between the second resource and the candidate resource is smaller than the first time duration.

15 . The method of claim 1 , wherein the first resource and the second resource are in different slots in the sidelink resource pool.

Assignees

• Asustek Comp Inc

Inventors

• Huang Chun-Wei
• Li Ming-Che

Classifications

• H04W72/20 Primary

  Control channels or signalling for resource management · CPC title

• H04L1/1887 Primary

  Scheduling and prioritising arrangements · CPC title

• H04L1/1854

  Scheduling and prioritising arrangements · CPC title

• H04W72/25

  between terminals via a wireless link, e.g. sidelink · CPC title

• H04W92/18

  between terminal devices · CPC title