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US-12621035-B2 - Method for beam switching in mmWave systems

US12621035B2US 12621035 B2US12621035 B2US 12621035B2US-12621035-B2

Abstract

Some embodiments include a system, method, and computer program product for managing beam switching at a higher subcarrier spacing (SCS) at millimeter wavelength (mmWave) frequencies in a 5G wireless communications system. A user equipment (UE) transmits a beam switching gap (BSG) capability to a 5G Node B (gNB). The UE receives a transmission configuration indicator (TCI) state from the gNB, and performs a beam switch to the TCI state corresponding to a first beam. The UE can receive a first control resource set (CORESET) on the first beam and a second CORESET on a second beam where the BSG occurs between the first CORESET and a second CORESET. The UE can perform beam switching within the BSG from the first beam to a second beam, and receive the second CORESET on the second beam. The UE can determine and transmit modified candidate values of beam switching parameters to the gNB.

Inventors

  • Oghenekome Oteri
  • Dawei Zhang
  • Wei Zeng
  • Chunxuan Ye
  • Haitong Sun
  • Hong He
  • Yushu Zhang

Assignees

  • APPLE INC.

Dates

Publication Date
20260505
Application Date
20201016

Claims (20)

  1. 1 . A user equipment (UE) system comprising: a transceiver configured to perform wireless communications at millimeter wavelength (mmWave) frequencies; and a processor coupled to the transceiver, configured to: determine a modified candidate value of a beam switching parameter based at least on operation at an mmWave frequency of the mmWave frequencies; transmit, via the transceiver, the modified candidate value of the beam switching parameter to a base station (BS); receive via the transceiver, a first control resource set (CORESET) on a first beam and a second CORESET on a second beam, wherein a beam switching gap (BSG) occurs between the first CORESET and the second CORESET; and perform beam switching within the BSG from the first beam to the second beam based at least on the beam switching parameter.
  2. 2 . The UE system of claim 1 , wherein a time to perform the beam switching within the BSG is greater than a length of a cyclic prefix (CP) of a symbol of the first CORESET.
  3. 3 . The UE system of claim 1 , wherein the processor is further configured to: transmit, via the transceiver, a BSG capability; in response to the transmission, receive via the transceiver, a first transmission configuration indicator (TCI) state; and perform a beam switch to the first beam corresponding to the first TCI state.
  4. 4 . The UE system of claim 1 , wherein the beam switching parameter is associated with a capability including: Aperiodic-Channel State Information-Reference Signal (A-CSI-RS) beam switching timing, Physical Downlink Shared Channel (PDSCH) beam switching, beam reporting timing, a CSI computation delay requirement, beam switching, or more than one Downlink (DL)/Uplink (UL) switch point in a slot.
  5. 5 . The UE system of claim 1 , wherein the beam switching parameter is associated with Physical Uplink Shared Channel (PUSCH) beam switching.
  6. 6 . The UE system of claim 1 , wherein the modified candidate value includes additional symbols to accommodate a smaller symbol duration of the mmWave frequency, or symbol-level beam switching.
  7. 7 . The UE system of claim 1 , wherein to determine the modified candidate value, the processor is configured to: determine a time constant proportional to a candidate value at a subcarrier spacing below the mmWave frequency.
  8. 8 . The UE system of claim 7 , wherein to determine the modified candidate value, the processor is configured to: add a symbol to accommodate symbol-level beam switching.
  9. 9 . The UE system of claim 7 , wherein the modified candidate value is a function of the time constant proportional to the candidate value at the subcarrier spacing below the mmWave frequency.
  10. 10 . The UE system of claim 1 , wherein the beam switching parameter comprises maxNumberRxTxBeamSwitchDL, the determined modified candidate value comprises: a maximum of one receive (Rx) transmit (Tx) switch per slot of the first CORESET; a single Rx Tx switch over multiple slots of the first CORESET; or a minimum number of symbols within a slot of the first CORESET before a Rx Tx switch.
  11. 11 . The UE system of claim 1 , wherein the beam switching parameter comprises a tdd-MultiDL-UL-SwitchPerSlot, the determined modified candidate value comprises: more than one switch point within X slots, where X is an integer, and wherein a minimum number of symbols occur between a switch point of the more than one switch point.
  12. 12 . The UE system of claim 11 , wherein to support the determined modified candidate value of the tdd-MultiDL-UL-SwitchPerSlot, a slot format indicator pattern comprises a flexible symbol between an uplink symbol and a downlink symbol.
  13. 13 . The UE system of claim 1 , wherein the BSG is greater than a time needed by the UE system to perform the beam switching.
  14. 14 . A method for a user equipment (UE) system performing wireless communications at millimeter wavelength (mmWave) frequencies, comprising: determining a modified candidate value of a beam switching parameter based at least on operations at an mmWave frequency of the mmWave frequencies; and transmitting the modified candidate value of the beam switching parameter to a base station (BS); receiving a first control resource set (CORESET) on a first beam and a second CORESET on a second beam, wherein a beam switching gap (BSG) occurs between the first CORESET and the second CORESET; and performing beam switching within the BSG from the first beam to the second beam based at least on the beam switching parameter.
  15. 15 . The method of claim 14 , wherein a time to perform the beam switching within the BSG is greater than a length of a cyclic prefix (CP) of a symbol of the first CORESET, or the BSG is greater than a time needed by the UE system to perform the beam switching.
  16. 16 . The method of claim 14 , wherein the beam switching parameter is associated with a capability including: Aperiodic-Channel State Information-Reference Signal (A-CSI-RS) beam switching timing, Physical Downlink Shared Channel (PDSCH) beam switching, Physical Uplink Shared Channel (PUSCH) beam switching, a CSI computation delay requirement, beam reporting timing, beam switching, or more than one Downlink (DL)/Uplink (UL) switch point in a slot.
  17. 17 . The method of claim 14 , wherein the determining the modified candidate value comprises: determining a time constant proportional to a candidate value at a subcarrier spacing below the mmWave frequency; and adding a symbol to accommodate symbol-level beam switching.
  18. 18 . The method of claim 14 , wherein the beam switching parameter comprises maxNumberRxTxBeamSwitchDL, the determined modified candidate value comprises: a maximum of one receive (Rx) transmit (Tx) switch per slot of the first CORESET; a single Rx Tx switch over multiple slots of the first CORESET; or a minimum number of symbols within a slot of the first CORESET before a Rx Tx switch.
  19. 19 . The method of claim 14 , wherein the beam switching parameter comprises a tdd-MultiDL-UL-SwitchPerSlot, the determined modified candidate value comprises: more than one switch point within X slots, where X is an integer, and wherein a minimum number of symbols occur between a switch point of the more than one switch point.
  20. 20 . A base station (BS) system comprising: a transceiver configured to operate in millimeter wavelength (mmWave) frequencies; and a processor coupled to the transceiver, configured to: receive via the transceiver, a beam switching gap (BSG) capability corresponding to a user equipment (UE) including a modified candidate value of a beam switching parameter based at least on operations at an mmWave frequency of the mmWave frequencies; in response to the reception, transmit via the transceiver, a first transmission configuration indicator (TCI) state for the UE to receive a first beam; and transmit via the transceiver, a first control resource set (CORESET) on the first beam and a second CORESET on a second beam, wherein a BSG occurs between the first CORESET and the second CORESET, wherein the first CORESET identifies a second TCI state for the UE to receive the second beam.

Description

This application is a U.S. National Phase of International Application No. PCT/CN2020/121488, filed Oct. 16, 2020, which is hereby incorporated by reference in its entirety. BACKGROUND Field The described embodiments relate generally to 5G wireless communications. Related Art 5G wireless communications systems include user equipment (UE) communicating with a 5G node B (gNB) using beam switching. SUMMARY 5G systems that operate with high subcarrier spacing (SCS) in millimeter wavelength (mmWave) frequencies can be mmWave systems. 5G systems operating below mmWave frequencies can perform cyclic prefix (CP)-level beam switching during a CP of a symbol. In mmWave systems, the length of a CP is reduced and may be shorter than the time needed for an mmWave system to perform a beam switch. Thus, after a beam switch, the mmWave system may not receive critical information resulting in poor performance and negative user experience. Some embodiments include a system, method, and computer program product, and/or combination(s) or sub-combination(s) thereof, for beam switching in mmWave systems. Some embodiments include a user equipment (UE) that can operate in mmWave frequencies. The UE transmits a beam switching gap (BSG) capability to a 5G Node B (gNB). In response to the transmission, the UE receives a first transmission configuration indicator (TCI) state and the UE performs a beam switch to the first beam corresponding to the first TCI state. The UE receives from the gNB a first control resource set (CORESET) on the first beam and a second CORESET on a second beam, where the BSG occurs between the first CORESET and a second CORESET. The UE performs beam switching within the BSG from the first beam to a second beam, and receives the second CORESET on the second beam. The time to perform the beam switching within the BSG is greater than a length of a cyclic prefix (CP) of a symbol of the first CORESET, and/or the BSG is greater than the time needed by the UE to perform the beam switching. Further, the UE may not transmit or receive signals during the BSG. In some embodiments the UE determines a modified candidate value of a beam switching parameter based at least on the operation at an mmWave frequency of the mmWave frequencies, and transmits the modified candidate value of the beam switching parameter to the gNB. The beam switching parameter is associated with: beam switching, Aperiodic-Channel State Information-Reference Signal (A-CSI-RS) beam switching timing, Physical Downlink Shared Channel (PDSCH) beam switching, beam reporting timing, more than one Downlink (DL)/Uplink (UL) switch point in a slot, or a CSI computation delay requirement. The beam switching parameter can be associated with Physical Uplink Shared Channel (PUSCH) beam switching. The modified candidate value includes additional symbols to accommodate a smaller symbol duration of the mmWave frequency, or symbol-level beam switching. To determine the modified candidate value, the UE can determine a time constant proportional to a candidate value at a subcarrier spacing below the mm Wave frequency. In some embodiments the UE can add one or more symbols to accommodate symbol-level beam switching. The modified candidate value can be a function of the time constant proportional to the candidate value at the subcarrier spacing below the mmWave frequency. In some embodiments the beam switching parameter is maxNumberRxTxBeamSwitchDL, and the determined modified candidate value includes: a maximum of one receive (Rx) transmit (Tx) switch per slot of the first CORESET; a single Rx Tx switch over multiple slots of the first CORESET; or a minimum number of symbols within a slot of the first CORESET before a Rx Tx switch. In some embodiments the beam switching parameter comprises tdd-MultiDL-UL-SwitchPerSlot, and the determined modified candidate value includes: more than one switch point within X slots, where X is an integer, and wherein a minimum number of symbols occur between a switch point of the more than one switch point. In some embodiments, to support the determined modified candidate value of the tdd-MultiDL-UL-SwitchPerSlot, a slot format indicator pattern comprises a flexible symbol between an uplink symbol and a downlink symbol. In some embodiments the mmWave system is a gNB operating mmWave frequencies. The gNB can receive a BSG capability corresponding to a UE, and in response, transmit a first TCI state for the UE to receive a first beam. The gNB transmits a first CORESET on the first beam and a second CORESET on the second beam, where the BSG occurs between the first CORESET and a second CORESET, and where the first CORESET identifies a second TCI state for the UE to receive a second beam. BRIEF DESCRIPTION OF THE FIGURES The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the presented disclosure and, together with the description, further serve to explain the principles of the disclosure and