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US-12628187-B2 - Mechanism of scheduling for broadcast and groupcast on new radio UU interface

US12628187B2US 12628187 B2US12628187 B2US 12628187B2US-12628187-B2

Abstract

Methods, systems, and apparatuses may assist scheduling for broadcast and groupcast on new radio Uu interface. In an example, there may be broadcast and groupcast transmission scheduling mechanism with: group based scheduling, UE specific based scheduling, or sub-group based scheduling. In another example, there may be a serving cell configuration for broadcast and groupcast transmission with dedicated cell for broadcast and groupcast, or broadcast and groupcast cell which is shared with the cell for unicast. In another example, there may be downlink control related configuration for broadcast and groupcast transmission with details of the BWP configuration, the CORESET configuration, or the search space configuration.

Inventors

  • Yifan Li
  • Rocco Di Girolamo
  • Patrick Svedman
  • Mohamed M. AWADIN
  • Guodong Zhang
  • Pascal Adjakple
  • Allan Tsai
  • Kyle Pan
  • Zhuo Chen
  • Jerome Vogedes

Assignees

  • INTERDIGITAL PATENT HOLDINGS, INC.

Dates

Publication Date
20260512
Application Date
20210514

Claims (18)

  1. 1 . A method implemented by a wireless transmit/receive unit (WTRU) comprising: receiving a radio resource control (RRC) message, the RRC message indicating a group radio network temporary identifier for semi-persistent scheduling (G-SPS-RNTI) and a group radio network temporary identifier (G-RNTI) for dynamic scheduling, wherein the RRC message comprises an indication of a data scrambling identity for receiving groupcast transmissions via a physical downlink shared channel (PDSCH); receiving first downlink control information (DCI), wherein the first DCI comprises semi-persistent scheduling information for one or more groupcast transmissions, the first DCI being associated with a first cyclic redundancy check (CRC) scrambled with the G-SPS-RNTI; receiving, via the PDSCH, the one or more groupcast transmissions in accordance with the first DCI associated with the first CRC scrambled with the G-SPS-RNTI; receiving second DCI, wherein the second DCI comprises dynamic scheduling information for a dynamic groupcast transmission, the second DCI being associated with a second CRC scrambled with G-RNTI; and receiving, via the PDSCH, the dynamic groupcast transmission in accordance with the second DCI associated with the second CRC scrambled with the G-RNTI, wherein the dynamic groupcast transmission was scrambled using the data scrambling identity.
  2. 2 . The method of claim 1 , wherein the RRC message comprises an indication of a value for initializing a PDSCH demodulation reference signal (DM-RS) sequence for one or more DM-RSs of the one or more groupcast transmissions received via the PDSCH.
  3. 3 . The method of claim 1 , further comprising: receiving second DCI, wherein the second DCI comprises dynamic scheduling information for a dynamic groupcast transmission, the second DCI being associated with a second CRC scrambled with a group radio network temporary identifier, G-RNTI.
  4. 4 . The method of claim 1 , wherein the first DCI comprises an indication of a physical uplink control channel (PUCCH) resource for sending hybrid automatic repeat request (HARQ) feedback for the one or more groupcast transmissions.
  5. 5 . The method of claim 1 , further comprising: receiving a system information block (SIB), the SIB comprising control information for receiving one or more broadcast transmissions.
  6. 6 . The method of claim 1 , wherein the RRC message indicates a bandwidth part for receiving the one or more groupcast transmissions.
  7. 7 . The method of claim 5 , wherein the control information comprises an indication of a data scrambling identity for receiving the one or more broadcast transmissions and an indication of a value for initializing a PDSCH demodulation reference signal (DM-RS) sequence for the one or more broadcast transmissions.
  8. 8 . The method of claim 1 , wherein the one or more groupcast transmissions that were semi-persistently scheduled were scrambled using the data scrambling identity.
  9. 9 . The method of claim 2 , wherein the value for initializing the PDSCH DM-RS sequence for one or more DM-RSs applies to the dynamic groupcast transmission received via the PDSCH.
  10. 10 . A wireless transmit/receive unit (WTRU) comprising: a processor, the processor configured to: receive a radio resource control (RRC) message, the RRC message indicating a group radio network temporary identifier for semi-persistent scheduling (G-SPS-RNTI) and a group radio network temporary identifier (G-RNTI) for dynamic scheduling, wherein the RRC message comprises an indication of a data scrambling identity for receiving groupcast transmissions via a physical downlink shared channel (PDSCH); receive first downlink control information (DCI), wherein the first DCI comprises semi-persistent scheduling information for one or more groupcast transmissions, the first DCI being associated with a first cyclic redundancy check (CRC) scrambled with the G-SPS-RNTI; receive, via the PDSCH, the one or more groupcast transmissions in accordance with the first DCI associated with the first CRC scrambled with the G-SPS-RNTI; receive second DCI, wherein the second DCI comprises dynamic scheduling information for a dynamic groupcast transmission, the second DCI being associated with a second CRC scrambled with G-RNTI; and receive, via the PDSCH, the dynamic groupcast transmission in accordance with the second DCI associated with the second CRC scrambled with the G-RNTI, wherein the dynamic groupcast transmission was scrambled using the data scrambling identity.
  11. 11 . The WTRU of claim 10 , wherein the RRC message comprises an indication of a value for initializing a PDSCH demodulation reference signal (DM-RS) sequence for one or more DM-RSs of the one or more groupcast transmissions received via the PDSCH.
  12. 12 . The WTRU of claim 10 , the processor configured to: receive second DCI, wherein the second DCI comprises dynamic scheduling information for a dynamic groupcast transmission, the second DCI being associated with a second CRC scrambled with a group radio network temporary identifier (G-RNTI).
  13. 13 . The WTRU of claim 10 , wherein the first DCI comprises an indication of a physical uplink control channel (PUCCH) resource for sending hybrid automatic repeat request (HARQ) feedback for the one or more groupcast transmissions.
  14. 14 . The WTRU of claim 10 , the processor configured to: receive a system information block (SIB), the SIB comprising control information for receiving one or more broadcast transmissions.
  15. 15 . The WTRU of claim 10 , wherein the RRC message indicates a bandwidth part for receiving the one or more groupcast transmissions.
  16. 16 . The WTRU of claim 14 , wherein the control information comprises an indication of a data scrambling identity for receiving the one or more broadcast transmissions and an indication of a value for initializing a PDSCH demodulation reference signal (DM-RS) sequence for the one or more broadcast transmissions.
  17. 17 . The WTRU of claim 10 , wherein the one or more groupcast transmissions that were semi-persistently scheduled were scrambled using the data scrambling identity.
  18. 18 . The WTRU of claim 11 , wherein the value for initializing the PDSCH DM-RS sequence for one or more DM-RSs applies to the dynamic groupcast transmission received via the PDSCH.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is the National Stage Application of International Patent Application No. PCT/US2021/032407, filed May 14, 2021, which claims the benefit of U.S. Provisional Patent Application No. 63/024,720, filed on May 14, 2020, entitled “Mechanism of Scheduling for Broadcast and Groupcast on New Radio Uu Interface,” and U.S. Provisional Patent Application No. 63/170,735, filed on Apr. 5, 2021, entitled “Mechanism of Scheduling for Broadcast and Groupcast on New Radio Uu Interface,” the contents of which are hereby incorporated by reference herein. BACKGROUND LTE MBMS LTE MBMS (Multimedia broadcast multicast services) supports broadcast/multicast services in a cellular system, where the same content is simultaneously transmitted to the UEs located in an area. In LTE, MBMS service area is defined as the area that all the UEs receive the same broadcast/multicast services. An MBMS service area may comprise one or multiple cells. Two types of mechanism are supported in LTE for broadcast/multicast services: MBSFN (Multicast-Broadcast Single Frequency Network), and SC-PTM (Single-Cell Point to Multipoint). LTE MBSFN MBSFN is introduced to LTE in Rel-9, which targets the use case when the MBMS service is of interest over a larger area, e.g., for TV broadcasting. Different cells within the same MBSFN area are mutually time aligned and broadcast the identical information. Therefore, from a UE perspective, the transmissions received from multiple cells can be seen as a single transmission received from one cell subject to severe multi-path propagation as long as the cyclic prefix is large enough. The UE doesn't need to know which cell are actually involved in the transmission. In LTE MBSFN, broadcast/multicast services are transmitted on the dedicated physical channel PMCH (Physical Multicast Channel) in the dedicated MBSFN subframes. An MBSFN subframe consists of two parts: a control region which is used for transmission of regular unicast L1/L2 control signaling, and an MBSFN region which is used for transmission of the multicast channel. Within one MBSFN subframe, all the MBSFN transmissions correspond to the same MBSFN area. However, the MBSFN transmissions in different subframes may correspond to different MBSFN areas. To support coherent demodulation for the received MBSFN transmission, MBSFN area specific MBSFN reference signals are transmitted in the MBSFN subframe. All the cells within the same MBSFN area transmit the MBSFN reference signals at the same time-frequency location and with the same reference-symbol values. Since only one single MBSFN reference signal is transmitted in the MBSFN subframe, MIMO scheme is not supported in LTE MBSFN. LTE SC-PTM SC-PTM is introduced to LTE in release 13 in order to support MBMS services when it is of interest in a single cell or in a small area consisting of a few cells. Different from the MBSFN, SC-PTM transmissions reuse the PDSCH (Physical Downlink Shared Channel). Similar to the unicast transmission, the SC-PTM transmission is dynamically scheduled by the DCI. G-RNTI (Group Radio Network Temporary Identifier) is used to scramble the DCI scheduling the SC-PTM transmission. For different MBMS services, different G-RNTIs are used for UE to receive the SC-PTM transmission that it is interested in. In LTE SC-PTM, HARQ (Hybrid Automatic Repeat Request) feedback and CSI (Channel State Information) reports are not supported. Consequently, only the transmission modes 1-3, which do not rely on feedback, are supported. a. NR Uu Broadcast/Groupcast Use Cases In NR (New Radio), Uu broadcast/groupcast is identified to be beneficial in many use cases, such as V2X (Vehicle-to-everything) communication, public safety, video and audio distribution, IIoT (Industrial Internet of Things), media streams, various types of content distribution etc. Comparing to the LTE, the NR Uu broadcast/groupcast use cases usually have a smaller communication range and require higher reliability and lower latency in many scenarios. b. NR Downlink Scheduling Mechanism In NR, DCI (Downlink Control Information) format 1_1 is used for the scheduling of PDSCH (Physical Downlink Share Channel) for unicast transmission in one cell. The scheduling DCI carries the information such as time and frequency resource assignments, HARQ related information, feedback resource assignment, etc. For a UE, the transmission of DL scheduling is a priori unknown to it. The UE need to blindly detect the DCI from the gNB. To reduce the effort of blind decoding and therefore save the power consumed on it, the UE is configured with the BWP (Bandwidth Part), CORESET (Control Resource Set), search space information by the gNB. So, the UE only need to perform blind decoding within the configured time and frequency region and does not need to search the whole spectrum. c. Feedback Mechanism for NR V2X Groupcast In NR V2X groupcast scenario, two types of HARQ feedback mechanism are supporte