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CN-122029922-A - Determining TCI status of default indication of PDSCH reception

CN122029922ACN 122029922 ACN122029922 ACN 122029922ACN-122029922-A

Abstract

Methods and apparatus for determining a default TCI state for PDSCH reception when configuring a plurality of indicated TCI states. The method includes receiving scheduling information for a PDSCH via PDCCH DCI before a predetermined time threshold. The PDCCH DCI format includes a scheduling offset between a last symbol of the PDCCH and a first symbol of the PDSCH. The method also includes determining whether the UE (302) is capable of processing a single default beam in frequency range 1 (FR 1) or frequency range 2 (FR 2). The method further includes determining whether at least one of an intra-cell multiple reception point (Multi-Transmission Reception Point, MTRP) multiple DCI mode and an intra-cell MTRP single DCI mode is a joint TCI mode or a separate TCI mode based on the two indicated TCI states, where the UE (302) can only process a single default beam in FR 2.

Inventors

  • D. D.R. Murgonkar
  • K. Mulalidar
  • D. SHARMA
  • S. Montar
  • ZHANG YONGLU

Assignees

  • 三星电子株式会社

Dates

Publication Date
20260512
Application Date
20241010
Priority Date
20231010

Claims (15)

  1. 1. A method performed by a User Equipment (UE) (302) when a plurality of indicated TCI states are configured, the method comprising: Receiving scheduling information for a Physical Downlink Shared Channel (PDSCH) via a Physical Downlink Control Channel (PDCCH) Downlink Control Information (DCI) format before a predetermined time threshold, wherein the PDCCH DCI format includes a scheduling offset between a last symbol of the PDCCH and a first symbol of the PDSCH; determining whether the UE (302) is capable of processing a single default beam in frequency range 1 (FR 1) or frequency range 2 (FR 2), and In the case where the UE (302) can only process a single default beam in FR2, it is determined whether at least one of an intra-cell multiple-reception-point (MTRP) multiple-DCI mode and an intra-cell MTRP single-DCI mode is a joint TCI mode or a separate TCI mode based on the two indicated TCI states.
  2. 2. The method of claim 1, wherein determining an MTRP multi-DCI mode as a joint TCI mode or a separate TCI mode based on the two indicated TCI states comprises: determining whether the MTRP multi-DCI mode is set to a joint TCI mode or a separate TCI mode and whether the two indicated TCI states are configured to a first joint or Downlink (DL) TCI state and a second joint or DL TCI state, and In the case that the MTRP multi-DCI mode is set to the joint TCI mode or the individual TCI mode and the two indicated TCI states are configured to a first joint or DL TCI state and a second joint or DL TCI state, the indicated TCI state of CORESET pool index 0 is selected as the default indicated TCI state for PDSCH reception.
  3. 3. The method according to claim 1, comprising: in the case that the MTRP multi-DCI mode is set to the joint TCI mode or the individual TCI mode and the two indicated TCI states are configured to a first joint or DL TCI state and a second joint or DL TCI state, the first joint or DL TCI state is selected as the TCI state for the default indication of PDSCH reception.
  4. 4. The method according to claim 1, comprising: In the case where the MTRP mode is set to either the joint TCI mode or the individual TCI mode and the two indicated TCI states are configured as a first joint or DL TCI state and a second joint or DL TCI state, the second joint or DCI TCI state is selected as the TCI state for the default indication of PDSCH reception.
  5. 5. The method according to claim 1, comprising: Configuring a TCI state for a default indication of reception of a PDSCH via Radio Resource Control (RRC) signaling or medium access control element (MAC-CE) signaling, and The default indicated TCI state is selected per Component Carrier (CC) or per bandwidth part (BWP) by RRC signaling or MAC-CE signaling based on CORESET in which the PDCCH is transmitted to the UE (302).
  6. 6. The method of claim 1, wherein the TCI state of the default indication is selected based on a lowest CORESET ID among a plurality CORESET of the plurality CORESET configured to the UE (302).
  7. 7. The method according to claim 1, comprising: The TCI state of the default indication associated with the CORESET pool index value set to 1 is selected for reception of PDSCH.
  8. 8. A method performed by a User Equipment (UE) (302) when a plurality of TCI states are indicated, the method comprising: In the case that the UE (302) can only process a single default beam in frequency range 2 (FR 2), determining whether at least one of an inter-cell MTRP multi-DCI mode and an inter-cell MTRP single-DCI mode is a joint TCI mode or a separate TCI mode based on the two indicated TCI states; One of the following is performed: In the case where the first indicated TCI state belongs to the serving cell and the second indicated TCI state contains QCL information having a Physical Cell ID (PCID) different from the PCID of the serving cell, selecting the first indicated TCI state as a default indicated TCI state, and In case the second indicated TCI state belongs to the serving cell and the first indicated TCI state contains QCL information having a PCID different from the PCID of the serving cell, the second indicated TCI state is selected as the default indicated TCI state.
  9. 9. The method of claim 8, wherein the default indicated TCI state is an indicated TCI state belonging to a serving cell or an indicated TCI state not including a PCID in QCL information.
  10. 10. The method of claim 8, comprising: Configuring a TCI state for a default indication of reception of a PDSCH via Radio Resource Control (RRC) signaling or medium access control element (MAC-CE) signaling, and The default indicated TCI state is selected as the first indicated TCI state or the second indicated TCI state per Component Carrier (CC) or per bandwidth part (BWP) by RRC signaling or MAC-CE signaling based on CORESET associated with the serving cell in which the PDCCH is transmitted to the UE (302).
  11. 11. The method according to claim 9, wherein the method comprises, Wherein the TCI status of the default indication associated with the serving cell in the inter-cell MTRP MDCI has a CORESET pool index value of 0, and Wherein the TCI state for the default indication associated with the serving cell for PDSCH reception has a CORESET pool index value of 1.
  12. 12. The method of claim 8, comprising: Determining whether the TCI state with default indication of CORESET pool index value 0 is associated with a PCI different from the PCI of the serving cell, and Rel-15 default QCL assumptions are applied for both non-UE specific PDSCH and UE specific PDSCH.
  13. 13. The method of claim 12, wherein determining whether the TCI state with a default indication of CORESET pool index value 0 is associated with a PCI different from a PCI of a serving cell comprises: determining whether QCL attributes of default beams in slots of CCs in FR1 are different, and The TCI state of the default indication is selected based on a lowest CORESET ID in a most recent slot of a lowest CC ID among a plurality of CCs configured to the UE (302).
  14. 14. The method of claim 8, comprising: determining whether the TCI status of the default indication belongs to the serving cell, and The indicated TCI state is selected for both the non-UE-specific PDSCH and the UE-specific PDSCH.
  15. 15. A User Equipment (UE) (302) for determining a default Transmission Configuration Indicator (TCI) state for Physical Downlink Shared Channel (PDSCH) reception when a plurality of TCI states are configured, the UE (302) comprising: A processor (304); A memory (306); A first controller (310) communicatively coupled to the processor (304) and the memory (306), wherein the first controller (310): Receiving scheduling information for a Physical Downlink Shared Channel (PDSCH) via a Physical Downlink Control Channel (PDCCH) Downlink Control Information (DCI) format before a predetermined time threshold (duration of QCL), wherein the PDCCH DCI format includes a scheduling offset between a last symbol of the PDCCH and a first symbol of the PDSCH; determining whether the UE (302) is capable of processing a single default beam in frequency range 1 (FR 1) or frequency range 2 (FR 2), and In the case where the UE (302) can only process a single default beam in FR2, it is determined whether at least one of an intra-cell multiple-reception-point (MTRP) multiple-DCI mode and an intra-cell MTRP single-DCI mode is a joint TCI mode or a separate TCI mode based on the two indicated TCI states.

Description

Determining TCI status of default indication of PDSCH reception Technical Field The present application is based on and obtains the rights of indian provisional application 202341067888 filed on 10th year 2023, indian provisional application 202341071559 filed on 19 th 10th year 2023, indian provisional application 202341073875 filed on 30 th year 2023, indian provisional application 202341085972 filed on 15 th 12 th year 2023, and indian full application 202341067888 filed on 5 th 10th year 2024, the contents of which are incorporated herein by reference. The present disclosure relates to wireless communications. More particularly, the present disclosure relates to a method and system for determining a default transmission configuration indicator (Transmission Configuration Indicator, TCI) state received by a physical downlink shared channel (Physical Downlink SHARED CHANNEL, PDSCH) in a User Equipment (UE) when the TCI states are indicated. Background In release 17, a unified TCI is introduced as a way to reduce the overhead signaling of the TCI per physical channel and Reference Signal (RS). It is observed that multiple physical channels follow the same TCI state in multiple time slots, so it is superfluous to configure a new TCI state for each channel in each time slot. Furthermore, in order to measure and configure the TCI state of the neighboring cells, a common type of signaling is required. This problem is solved in release 17 using the unified TCI state. In release 17, the maximum number of defined release 17 unified TCI states is downlink m=1 and uplink n=1. For a multi-TRP scenario, the number of unified TCI states required for operation is greater than 1. This item is previously discussed in Rel-18 to increase the TCI state of multi-TRP operations. The unified TCI defined in release 17 contains one common TCI state for all physical channels and RSs. Early in version 15/16, the TCI framework was unnecessarily modular. A TCI is defined for each control resource set (CORESET). Thus, the Physical Downlink Control Channel (PDCCH) transmitted in a particular CORESET will be received with the TCI state defined for that CORESET. Each PDCCH will then configure a TCI state for the Physical Downlink Shared Channel (PDSCH). The signaling of the TCI state is also modified in release 17, as little redundant signaling is required. In release 15/16, the TCI state of the PDCCH is configured for each CORESET by the MAC-CE. Radio Resource Control (RRC) signaling is used to configure several TCI states in all the TCI state pools. For PDSCH, the MAC-CE will then configure a maximum of 8 TCI code points for each TCI state. The TCI of the PDSCH is indicated in Downlink Control Information (DCI) pointing to one of the TCI code points. In release 17, the signaling of TCI state is changed to MAC CE or MAC ce+dci with format 1_1/1_2 with/without Downlink (DL) allocation. In version 17, a new type of TCI state is introduced as a joint TCI state. Thus, any common unified TCI state may be a joint TCI state or an individual DL/UL TCI state. Version 15/16 TCI state is based on CORESET, so it is straightforward to configure 2 TCI states. For the scenario where the UE receives 2 DCIs from 2 different TRPs, they are sent from 2 different CORESET and CORESETPOOLINDEX is set to be different for this CORESET to identify the multiple DCIs of the UE. Each DCI configures a separate PDSCH to be received from multiple TRPs. In single DCI multi-TRP, a single DCI is sent from any one TRP to the UE, which schedules 2 different PDSCH to the UE. The DCI contains a TCI field pointing to a single TCI code point, which also contains a pair of TCI states for each TRP. During the Rel-18 discussion of MTRP unified TCI, default beam behavior is discussed for S-DCI and M-DCI. The default beam behavior is that when there are two indicated TCIs, the time of PDSCH scheduling by PDCCH DCI format 1_0/1_1/1_2 is before a threshold (timeDurationForQCL). In M-DCI and S-DCI, when the UE capability can only handle a single default beam in FR1 or FR2, then it is required to define which of the 2 indicated TCIs should be regarded as the TCI state of the default indication of PDSCH reception. In addition, the network energy conservation (NES) Work Item (WI) is considering the spatial domain and power domain techniques of Rel-18. RP-223540 according to the agreed WID RAN-1 should specify the following technique in the spatial domain and in the power domain -Signaling [ RAN1, RAN2] specifying the necessary enhancements to CSI and beam management related procedures including measurements and reporting, and enabling efficient adaptation of spatial elements (e.g. antenna ports, active transceiver chains); -signaling to specify the necessary enhancements to CSI related procedures including measurements and reporting, and to enable efficient adaptation of power offset values between PDSCH and CSI-RS RAN1, RAN 2. It is noted that the above-described targets are only for