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EP-3857762-B1 - METHOD AND APPARATUS FOR DEVICE-TO-DEVICE COMMUNICATION

EP3857762B1EP 3857762 B1EP3857762 B1EP 3857762B1EP-3857762-B1

Inventors

  • SUN, Zhennian
  • YU, XIAODONG
  • LEI, HAIPENG
  • WU, Lianhai
  • HAN, Jing

Dates

Publication Date
20260506
Application Date
20180927

Claims (13)

  1. A method performed by a user equipment, UE, the method comprising: transmitting (201) a first signal toward a group of UEs, wherein the UE and the group of UEs are configured to perform groupcast transmission; detecting (202), on a shared hybrid automatic repeat request, HARQ, feedback resource which is shared by some or all UEs of the group of UEs, a first HARQ feedback signal from one or more UEs of the group of UEs; and transmitting (203) a second signal toward the group of UEs, wherein the shared HARQ feedback resource only carries Negative Acknowledgement, NACK, feedback signals from one or more UEs within the group of UEs and does not carry Positive Acknowledgement, ACK, from any UEs within the group of UEs; and wherein the second signal is a retransmission of the first signal in response to the received first HARQ feedback signal containing a NACK for the first signal transmitted toward the group of UEs, and the second signal is a new signal in response to the received first HARQ feedback signal containing no NACK for the first signal transmitted toward the group of UEs.
  2. The method of Claim 1, wherein each of the first signal and the second signal comprises scheduling assignment, SA, and groupcast data.
  3. The method of Claim 1, wherein the second signal comprises the same data in the first signal in the case that the second signal is a retransmission of the first signal.
  4. The method of Claim 1, wherein the second signal is transmitted toward one or more UEs within coverage of a first beam of the group of UEs.
  5. The method of Claim 4, wherein the first HARQ feedback signal comprises an accumulation of signal(s) from the one or more UEs within coverage of the first beam of the group of UEs.
  6. The method of Claim 1, further comprising: detecting a second HARQ feedback signal accumulated by signal(s) from one or more UEs within the group of UEs; transmitting the second signal based on the second HARQ feedback signal.
  7. The method of Claim 6, wherein the second HARQ feedback signal is an accumulation of signal(s) from one or more UEs within coverage of a second beam of the group of UEs.
  8. The method of claim 1, wherein the first HARQ feedback signal is a HARQ feedback signal of a single UE of the group of UEs.
  9. The method of claim 1, wherein the first HARQ feedback signal is a HARQ feedback signal accumulated by signals from two or more UEs of the group of UEs.
  10. A processor (1006) for wireless communication by a user equipment, UE, (1000), the processor (1006) being configured to cause the UE (1000) to: transmit (201) a first signal toward a group of UEs, wherein the UE and the group of UEs are configured to perform groupcast transmission; detect (202), on a shared hybrid automatic repeat request, HARQ, feedback resource which is shared by some or all UEs of the group of UEs, a first HARQ feedback signal from one or more UEs of the group of UEs; and transmit (203) a second signal toward the group of UEs, wherein the shared HARQ feedback resource only carries Negative Acknowledgement, NACK, feedback signals from one or more UEs within the group of UEs and does not carry Positive Acknowledgement, ACK, from any UEs within the group of UEs; and wherein the second signal is a retransmission of the first signal in response to the received first HARQ feedback signal containing a NACK for the first signal transmitted toward the group of UEs, and the second signal is a new signal in response to the received first HARQ feedback signal containing no NACK for the first signal transmitted toward the group of UEs.
  11. The processor (1006) of claim 10, wherein the first HARQ feedback signal is a HARQ feedback signal of a single UE of the group of UEs.
  12. The processor (1006) of claim 10, wherein the first HARQ feedback signal is a HARQ feedback signal accumulated by signals from two or more UEs of the group of UEs.
  13. A user equipment, UE, (1000) for wireless communication, the UE (1000) comprising a processor (1006) according to any of claims 10 to 12.

Description

TECHNICAL FIELD The subject application generally relates to NR sidelink communication, and more specifically to NR sidelink communication through groupcast transmission. BACKGROUND As relatively new and more demanding applications arise and a subscriber base increases exponentially, there is an urgent requirement to boost data rates and reduce latency. D2D communication is expected to play a prominent role in upcoming cellular networks as it provides ultra-low latency for communication among users. Such communication mode may operate in licensed or unlicensed spectrum. D2D communication allows user equipments (UEs) in close proximity to communicate using a direct link rather than having their radio signal travel all the way through a base station (BS) or core network. UEs can communicate via direct D2D links. In terms of channel structure, the direct link between two UEs is called a sidelink, which can operate by frequency division duplex or time division duplex. V2X (vehicle to everything) will be introduced into 5G wireless communication technique. Sidelink is an LTE feature introduced in 3GPP (3rd Generation Partnership Project) Release 12 aiming at enabling D2D communication within legacy cellular-based LTE (Long Term Evolution) radio access networks. D2D is applicable to public safety and commercial communication use-cases, and also to V2X scenario. Sidelink enables a direct communication between proximal UEs, and data does not need to go through the BS. In order to meet the requirements of providing relatively good performance on D2D communication, sidelink, or NR sidelink (e.g. advanced 3GPP NR (New radio) V2X service), communication techniques, e.g. sidelink unicast transmission, sidelink groupcast transmission, sidelink broadcast transmission, or the like are developed. Samsung, "Discussion on support of unicast, groupcast and broadcast for NR V2X", R1-1808775, 3GPP TSG RAN WG1 #94, Gothenburg, Sweden, August 20th - 24th, 2018, provides views on the support of unicast, groupcast and broadcast for NR sidelink, with various observations being made. CATT, "Support of unicast, groupcast and broadcast in NR sidelink", R1-1808399, 3GPP TSG RAN WG1 #94, Gothenburg, Sweden, August 20th - 24th, 2018, discusses the design aspects on unicast, groupcast and broadcast in NR sidelink. Samsung, "Discussion on physical layer structures and procedures for NR V2X", R1-1808776, 3GPP TSG RAN WG1 #94, Gothenburg, Sweden, August 20th - 24th, 2018, provides our views on sidelink physical layer structures and procedure(s). SUMMARY The invention is defined by the appended independent claims. Preferred embodiments are provided by the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS In order to describe the manner in which advantages and features of the subject application can be obtained, a description of the subject application is rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict only example embodiments of the subject application and are not therefore to be considered as limiting of its scope. FIG. 1 illustrates an exemplary sidelink groupcast system in accordance with some embodiments of the subject application;FIG. 2 illustrates operations to perform sidelink groupcast transmission in accordance with some embodiments of the subject application;FIG. 3 illustrates operations to perform sidelink groupcast transmission in accordance with some embodiments of the subject application;FIG. 4 illustrates an exemplary sidelink groupcast transmission in accordance with some embodiments of the subject application;FIG. 5 illustrates another exemplary sidelink groupcast transmission in accordance with some embodiments of the subject application;FIG. 6 illustrates another exemplary sidelink groupcast transmission in accordance with some embodiments of the subject application;FIG. 7 illustrates another exemplary sidelink groupcast system in accordance with some embodiments of the subject application;FIGS. 8A and 8B illustrate another exemplary sidelink groupcast transmissions in accordance with some embodiments of the subject application;FIGS. 9A and 9B illustrate another exemplary sidelink groupcast transmissions in accordance with some embodiments of the subject application; andFIG. 10 illustrates an exemplary apparatus in accordance with some embodiments of the subject application. DETAILED DESCRIPTION The detailed description of the appended drawings is intended as a description of the currently preferred embodiments of the subject application, and is not intended to represent the only form in which the subject application may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the scope of the subject application. Groupcast transmission, which may provide a relatively good performance (e.g. relatively good reliability), may be used to achieve a