Search

US-12621861-B2 - Methods and apparatus for sidelink communications on unlicensed frequency bands

US12621861B2US 12621861 B2US12621861 B2US 12621861B2US-12621861-B2

Abstract

Apparatus and methods are provided for sidelink resource selection in unlicensed frequency bands. In one novel aspect, a combination of SL resource selection procedure and a listen-before-talk (LBT) procedure are used for resource selection in unlicensed frequency bands. In one embodiment, the LBT procedure is performed after the SL resource selection procedure. In one embodiment, the candidate resource selected by the SL resource selection procedure has an overbooking resource size larger than or equal to a resource size required for the SL data transceiving. In another embodiment, the overbooking resource size is dynamically determined based on one or more preconfigured conditions comprising an LBT failure probability, channel loading status information, and channel congestion control information. In yet another embodiment, the candidate resources are multi-consecutive-slot (MCSt) resources with configured multiple consecutive resource blocks. In one embodiment, one or more configuration parameters are dynamically configured.

Inventors

  • Jun-Qiang Cheng
  • Tao Chen
  • Min Lei

Assignees

  • MEDIATEK SINGAPORE PTE. LTD.

Dates

Publication Date
20260505
Application Date
20230207
Priority Date
20230109

Claims (20)

  1. 1 . A method, comprising: performing, by a user equipment (UE), a sidelink (SL) resource selection procedure in a wireless network, wherein the SL resource selection procedure selects candidate resources in unlicensed frequency bands for an SL transceiving for the UE based on one or more configuration parameters, and wherein the one or more configuration parameters are dynamically configured, and wherein the configuration parameters comprising a maximum number of resources to be configured, a maximum number of resources indicated in a 1 st -stage sidelink channel information (SCI); performing a listen-before-talk (LBT) procedure before the SL transceiving, wherein the LBT procedure determines channel selection with other coexisting wireless system in the unlicensed frequency bands; and transceiving SL packets on the selected candidate resources when both the SL resource selection procedure and the LBT procedure succeed.
  2. 2 . The method of claim 1 , wherein the LBT procedure is performed after the SL resource selection procedure.
  3. 3 . The method of claim 1 , wherein the candidate resource selected by the SL resource selection procedure has an overbooking resource size larger than or equal to a resource size required for the SL data transceiving.
  4. 4 . The method of claim 3 , wherein the overbooking resource size is dynamically determined based on one or more preconfigured conditions comprising an LBT failure probability, channel loading status information, and channel congestion control information.
  5. 5 . The method of claim 3 , wherein the overbooking resource size is preconfigured.
  6. 6 . The method of claim 1 , wherein the candidate resources are multi-consecutive-slot (MCSt) resources with configured multiple consecutive resource blocks.
  7. 7 . The method of claim 1 , wherein a Type-1 LBT is configured when the LBT procedure is performed outside a channel occupancy time (COT) or when the LBT procedure initiates a COT.
  8. 8 . The method of claim 7 , wherein a sensing period of the Type-1 LBT is determined by a channel access priority class (CAPC) of the SL transceiving.
  9. 9 . The method of claim 7 , wherein a duration of the COT is determined by a CAPC of the SL transceiving.
  10. 10 . The method of claim 7 , wherein a Type-2A, a Type-2B or a Type-2C LBT is configured when the LBT procedure is performed inside the COT.
  11. 11 . The method of claim 1 , wherein the configuration parameters further comprising a LBT trigger time.
  12. 12 . The method of claim 1 , further comprising: configuring a selection window, wherein the SL resource selection procedure is performed within the selection window, and the LBT procedure is performed before the selected candidate resource for the SL transceiving is triggered at a starting slot n, and wherein a starting slot for the selection window is slot n plus a processing time T1, and a sending slot for the selection window is before the slot n plus a packet delay budget (PDB).
  13. 13 . The method of claim 12 , wherein a new selection window is dynamically configured upon detecting a failure of the LBT procedure before an end of the selection window.
  14. 14 . The method of claim 12 , wherein the SL resource selection procedure excludes one or more candidate resources in the selection window based on predefined rules.
  15. 15 . A user equipment (UE), comprising: a transceiver that transmits and receives radio frequency (RF) signal in a wireless network; a memory, and a processor coupled to the memory, the processor configured to perform sidelink (SL) resource selection procedure, wherein the SL resource selection procedure selects candidate resources in unlicensed frequency bands for an SL transceiving for the UE based on one or more configuration parameters, and wherein the one or more configuration parameters are dynamically configured, and wherein the configuration parameters comprising a maximum number of resources to be configured, a maximum number of resources indicated in a 1 st -stage sidelink channel information (SCI); perform a LBT procedure before the SL transceiving, wherein the LBT procedure determines channel selection with other coexisting wireless system in the unlicensed frequency bands; and transmit and receive SL packets on the selected candidate resources when both the SL resource selection procedure and the LBT procedure succeed.
  16. 16 . The UE of claim 15 , wherein the LBT procedure is performed after the SL resource selection procedure.
  17. 17 . The UE of claim 15 , wherein the candidate resource selected by the SL resource selection procedure has an overbooking resource size larger than or equal to a resource size required for the SL data transceiving.
  18. 18 . The UE of claim 15 , wherein the candidate resources are multi-consecutive-slot (MCSt) resources with configured multiple consecutive resource blocks.
  19. 19 . The UE of claim 17 , wherein a Type-1 LBT is configured when the LBT is performed outside a channel occupancy time (COT) or when the LBT initiates a COT, and a Type-2A, a Type-2B or a Type-2C LBT is configured when the LBT is performed inside the COT.
  20. 20 . The UE of claim 15 , wherein the configuration parameters further comprising a LBT trigger time.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is filed under 35 U.S.C. § 111(a) and is based on and hereby claims priority under 35 U.S.C. § 120 and § 365(c) from International Application No. PCT/CN2022/075404, titled “Methods and apparatus for Sidelink Communications on Unlicensed Frequency Bands,” with an international filing date of Feb. 7, 2022. This application claims priority under 35 U.S.C. § 119 from Chinese Application Number CN 202310025110.2 titled “METHODS AND APPARATUS FOR SIDELINK COMMUNICATIONS ON UNLICENSED FREQUENCY BANDS” filed on Jan. 9, 2023. The disclosure of each of the foregoing documents is incorporated herein by reference. TECHNICAL FIELD The disclosed embodiments relate generally to wireless communication, and, more particularly, to sidelink communication on unlicensed frequency bands. BACKGROUND Sidelink (SL) communication was introduced to enable direct transmission between two user equipments (UEs), which is also known as the device-to-device (D2D) communications. With the development of 3GPP normative works, the scenarios of sidelink are extended to UE-to-network relay, public safety, vehicle-to-everything (V2X) communications and so on. The critical role of sidelink in long term evolution (LTE) and the new radio (NR) has made it an inevitable remedy to support diverse use cases of future wireless communications. To meet the increased demands of wireless data traffic, using unlicensed frequency bands has drawn a lot of attention in the wireless industry to improve the capacity of future wireless communication systems. The utilization of unlicensed spectrum for sidelink communications is regarded as the most promising direction for further development of sidelink communication. However, some radio access technologies (RATs), such as NR-U communications, Wi-Fi, etc., have already operated in the unlicensed frequency bands. One of the most critical issues of allowing sidelink communications to operate in the unlicensed frequency bands is to ensure the fair and harmonious coexistence with other RATs. Improvements and enhancements are required for sidelink resource allocation in unlicensed frequency bands to ensure harmonious coexistence with other RATs. SUMMARY Apparatus and methods are provided for sidelink resource selection in unlicensed frequency bands. In one novel aspect, a combination of SL resource selection procedure and a listen-before-talk (LBT) procedure are used for resource selection in unlicensed frequency bands. In one embodiment, the LBT procedure is performed after the SL resource selection procedure. In one embodiment, the candidate resource selected by the SL resource selection procedure has an overbooking resource size larger than or equal to a resource size required for the SL data transceiving. In another embodiment, the overbooking resource size is dynamically determined based on one or more preconfigured conditions comprising an LBT failure probability, channel loading status information, and channel congestion control information. In yet another embodiment, the candidate resources are multi-consecutive-slot (MCSt) resources with configured multiple consecutive resource blocks. In one embodiment, a Type-1 LBT is configured when the LBT is performed outside a channel occupancy time (COT) or when the LBT initiates a COT, and a Type-2A, a Type-2B or a Type-2C LBT is configured when the LBT is performed inside the COT. In another embodiment, the one or more configuration parameters are dynamically configured, and wherein the configuration parameters comprising a maximum number of resources to be configured, a maximum number of resources indicated in a 1st-stage sidelink channel information (SCI), and a LBT trigger time. In one embodiment, a selection window is configured, wherein the SL resource selection procedure is performed within the selection window, and the LBT procedure is performed before the selected resource for a SL transceiving is triggered at a starting slot n, and wherein a starting slot for the selection window is slot n plus a processing time T1, and a sending slot for the selection window is before n plus a packet delay budget (PDB). In yet another embodiment, a new selection window is dynamically configured upon detecting a failure of the LBT procedure before an end of the selection window. In one embodiment, the SL resource selection procedure in the selection window excludes one or more candidate resources based on predefined rules. This summary does not purport to define the invention. The invention is defined by the claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention. FIG. 1A illustrates a schematic system diagram illustrating an exemplary wireless network for sidelink data communication in unlicensed frequency bands with other coexistence RATs in accordance with embodiments of the current invention. FIG. 1B illustrates exemp