US-12628168-B2 - Coordinated sidelink resource allocation

Abstract

Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may transmit, to a base station, a buffer status report for a first sidelink transmission to a device. The first UE may receive, from a second UE, sidelink control information scheduling the first UE for a time resource for a second sidelink transmission from the second UE, the sidelink control information including an indication of a serving cell identifier of the second UE. The first UE may detect a half-duplex scheduling conflict, or a possible half-duplex scheduling conflict, based on the serving cell identifier and transmit an indication of the conflict to a serving base station. The base station may then assign, or re-assign, resources for the first sidelink transmission to avoid the scheduling conflict.

Inventors

• Hui Guo
• Kapil Gulati
• Sudhir Kumar Baghel
• Tien Viet Nguyen
• Sourjya DUTTA

Assignees

• QUALCOMM INCORPORATED

Dates

Publication Date

20260512

Application Date

20200417

Claims (20)

1. 1 . A method for wireless communications at a first user equipment (UE), comprising: transmitting, to a network entity, a buffer status report for a first sidelink transmission to a device; and receiving, from a second UE and based at least in part on transmitting the buffer status report, sidelink control information scheduling the first UE for a time resource for a second sidelink transmission from the second UE, the sidelink control information comprising an indication of a serving cell identifier of the second UE, wherein the serving cell identifier corresponds to one of the network entity or a second network entity associated with the second UE.
2. 2 . A first user equipment (UE) for wireless communications, comprising: one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and operable to execute the code to cause the first UE to: transmit, to a network entity, a buffer status report for a first sidelink transmission to a device; and receive, from a second UE and based at least in part on transmission of the buffer status report, sidelink control information scheduling the first UE for a time resource for a second sidelink transmission from the second UE, the sidelink control information comprising an indication of a serving cell identifier of the second UE, wherein the serving cell identifier corresponds to one of the network entity or a second network entity associated with the second UE.
3. 3 . The first UE of claim 2 , wherein the one or more processors are further operable to execute the code to cause the first UE to: receive, from the network entity, a grant scheduling the time resource for the first sidelink transmission, wherein the first sidelink transmission and the second sidelink transmission both being scheduled for the time resource corresponds to a half-duplex scheduling conflict for the first UE; transmit, to the network entity, a request to reconfigure the grant for the first sidelink transmission of the first UE based at least in part on the half-duplex scheduling conflict; and receive, from the network entity, a reconfigured grant scheduling the first UE for a different time resource than the second sidelink transmission.
4. 4 . The first UE of claim 3 , wherein the one or more processors are further operable to execute the code to cause the first UE to: determine the serving cell identifier for the second UE does not match the serving cell identifier for the first UE, wherein the request to reconfigure the grant is transmitted based at least in part on the determination.
5. 5 . The first UE of claim 3 , wherein the request to reconfigure the grant comprises a bitmap of slots corresponding to a set of half-duplex scheduling conflicts comprising at least the half-duplex scheduling conflict.
6. 6 . The first UE of claim 3 , wherein the request to reconfigure the grant is transmitted with feedback for the grant scheduling the time resource for the first sidelink transmission.
7. 7 . The first UE of claim 3 , wherein the request to reconfigure the grant is transmitted based at least in part on receiving the sidelink control information, receiving the grant scheduling the first sidelink transmission, or both.
8. 8 . The first UE of claim 3 , wherein the request to reconfigure the grant is based at least in part on a priority of the first sidelink transmission, the second sidelink transmission, or both.
9. 9 . The first UE of claim 3 , wherein the one or more processors are further operable to execute the code to cause the first UE to: determine the serving cell identifier for the second UE does match the serving cell identifier for the first UE.
10. 10 . The first UE of claim 2 , wherein the one or more processors are further operable to execute the code to cause the first UE to: determine the serving cell identifier for the second UE matches the serving cell identifier for the first UE; transmit an indicator of destination identifiers to the network entity based at least in part on the serving cell identifier for the second UE matching the serving cell identifier for the first UE; and receive, from the network entity, a grant for the first sidelink transmission scheduling the first UE for a different time resource than the second sidelink transmission.
11. 11 . The first UE of claim 10 , wherein the one or more processors are further operable to execute the code to cause the first UE to: receive the second sidelink transmission from the second UE during the time resource; and transmit the first sidelink transmission during the different time resource.
12. 12 . The first UE of claim 2 , wherein the one or more processors are further operable to execute the code to cause the first UE to: determine the first sidelink transmission is scheduled for the time resource with the second sidelink transmission; determine the first sidelink transmission has a higher priority than the second sidelink transmission; drop the second sidelink transmission based at least in part on the higher priority; and receive the first sidelink transmission.
13. 13 . The first UE of claim 2 , wherein the one or more processors are further operable to execute the code to cause the first UE to: receive a configuration for avoiding half-duplex scheduling conflicts, wherein the first sidelink transmission and the second sidelink transmission are scheduled for a half-duplex scheduling conflict.
14. 14 . The first UE of claim 13 , wherein the configuration for avoiding half-duplex scheduling conflicts is received by higher layer signaling, the sidelink control information, downlink control information comprising a sidelink grant, or a combination thereof.
15. 15 . The first UE of claim 13 , wherein the configuration for avoiding half-duplex scheduling conflicts is based at least in part on a first priority of the first sidelink transmission, a second priority of the second sidelink transmission, or both.
16. 16 . The first UE of claim 2 , wherein the first sidelink transmission, the second sidelink transmission, or both, are transmitted via a PC5 interface.
17. 17 . The first UE of claim 2 , wherein the indication of the serving cell identifier corresponds to one or more least significant bits of the serving cell identifier of the second UE.
18. 18 . A second user equipment (UE) for wireless communications, comprising: one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and operable to execute the code to cause the second UE to: transmit, to a network entity, a buffer status report for a sidelink transmission to a first UE; receive, from the network entity, a grant for the sidelink transmission during a time resource based at least in part on transmitting the buffer status report; and transmit, to the first UE based at least in part on receiving the grant, sidelink control information comprising an indication of the sidelink transmission during the time resource and an indication of a serving cell identifier corresponding to the network entity.
19. 19 . The second UE of claim 18 , wherein the one or more processors are further operable to execute the code to cause the second UE to: receive, from the network entity, a reconfigured grant for the sidelink transmission, wherein the reconfigured grant schedules the sidelink transmission for a different time resource based at least in part on transmitting the sidelink control information comprising the indication of the serving cell identifier.
20. 20 . The second UE of claim 18 , wherein the one or more processors are further operable to execute the code to cause the second UE to: transmit the sidelink transmission to the first UE during the time resource.

Description

CROSS REFERENCE The present Application is a 371 national stage filing of International PCT Application No. PCT/CN2020/085317 by Guo et al. entitled “COORDINATED SIDELINK RESOURCE ALLOCATION,” filed Apr. 17, 2020, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. FIELD OF TECHNOLOGY The following relates generally to wireless communications and more specifically to coordinated sidelink resource allocation. BACKGROUND Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). Some wireless communications systems support a sidelink for communications between devices. For example, device-to-device (D2D) and vehicle-to-everything (V2X) systems may support communication between UEs on a sidelink. In some cases, a base station may select resources for the UEs on the sidelink. Some techniques of allocating resources on a sidelink while observing certain network constraints, such as half-duplex communicating constraints, can be improved. SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support coordinated sidelink resource allocation. A wireless communications system may support devices, such as user equipment (UEs), communicating via a sidelink. In some cases, a base station may allocate resources for sidelink communications between UEs, but the base station may not be aware of the intended receiver of the granted sidelink resource, which may lead to a half-duplex scheduling conflict at one of the UEs. UEs and base stations described herein may implement techniques for coordinated sidelink resource allocation to avoid half duplex scheduling conflicts. A first UE scheduled for both transmitting and receiving sidelink communications may detect the scheduling conflict, or a possibility of a scheduling conflict, and alert a serving cell of the conflict. The first UE may then be rescheduled for its sidelink transmission to avoid the scheduling conflict. In some cases, the first UE may receive sidelink control information from a second UE (e.g., with the pending sidelink transmission to the first UE), where the sidelink control information includes an indicator of a serving cell. The first UE may then apply a technique to avoid a half-duplex scheduling conflict based on whether the second UE has the same or different serving cell. For example, the first UE may either request a grant reconfiguration, or the first UE may report destination identifiers to the serving cell to avoid a scheduling conflict. A method of wireless communications at a first UE is described. The method may include transmitting, to a base station, a buffer status report for a first sidelink transmission to a device and receiving, from a second UE, sidelink control information scheduling the first UE for a time resource for a second sidelink transmission from the second UE, the sidelink control information including an indication of a serving cell identifier of the second UE. An apparatus for wireless communications at a first UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, to a base station, a buffer status report for a first sidelink transmission to a device and receive, from a second UE, sidelink control information scheduling the first UE for a time resource for a second sidelink transmission from the second UE, the sidelink control information including an indication of a serving cell identifier of the second UE. Another apparatus for wireless communications at a first UE is described. The apparatus may include means for transmitting, to a base station, a buffer status report for a first sidelink transmission to a device and receiving, from a second UE, sidelink control information sched