Method and apparatus for multi-transmission/reception point power headroom reporting in a wireless communication system

Patent metadata

Field	Value
Publication number	US-2022217653-A1
Application number	US-202117560546-A
Country	US
Kind code	A1
Filing date	Dec 23, 2021
Priority date	Dec 24, 2020
Publication date	Jul 7, 2022
Grant date	—

Abstract

A method and apparatus are disclosed. In an example from the perspective of a User Equipment (UE), the UE receives an uplink (UL) grant. The UL grant is indicative of a first Physical Uplink Shared Channel (PUSCH) transmission on a first Transmission/Reception Point (TRP) of a first cell. The UL grant is not indicative of a PUSCH transmission on a second TRP of the first cell. The UE transmits a Power Headroom Reporting (PHR) Medium Access Control (MAC) Control Element (CE). Based on the UL grant, the PHR MAC CE is indicative of a first power headroom (PH), associated with the first TRP, based on a real PUSCH transmission, and is indicative of a second PH, associated with the second TRP, based on a reference PUSCH transmission.

First claim

1 . A method of a User Equipment (UE), the method comprising:
receiving an uplink (UL) grant, wherein:
the UL grant is indicative of a first Physical Uplink Shared Channel (PUSCH) transmission on a first Transmission/Reception Point (TRP) of a first cell; and
the UL grant is not indicative of a second PUSCH transmission on a second TRP of the first cell; and
transmitting a Power Headroom Reporting (PHR) Medium Access Control (MAC) Control Element (CE), wherein based on the UL grant, the PHR MAC CE is indicative of:
a first Type 1 power headroom (PH), associated with the first TRP of the first cell, based on a real PUSCH transmission; and
a second Type 1 PH, associated with the second TRP of the first cell, based on a reference PUSCH transmission.

2 . The method of claim 1 , wherein the PHR MAC CE is indicative of:
a first UE maximum transmit power for the first TRP and a second UE maximum transmit power for the second TRP; or a single UE maximum transmit power for both the first TRP and the second TRP.

3 . The method of claim 1 , wherein:
the UE is configured with a first PUSCH power control adjustment state for the first TRP and a second PUSCH power control adjustment state for the second TRP; and the first PUSCH power control adjustment state is different from the second PUSCH power control adjustment state.

4 . The method of claim 1 , comprising:
determining, based on a configuration from a network, whether to indicate a single Type 1 PH for the first cell in the PHR MAC CE or to indicate two Type 1 PHs for the first cell in the PHR MAC CE, wherein the PHR MAC CE indicates the first Type 1 PH and the second Type 1 PH based on a determination to indicate two Type 1 PHs for the first cell in the PHR MAC CE.

5 . The method of claim 1 , wherein:
the real PUSCH transmission is the first PUSCH transmission.

6 . The method of claim 1 , wherein at least one of:
the first PUSCH transmission is performed before transmitting the PHR MAC CE; or the first PUSCH transmission is performed in a first slot that overlaps with a second slot for transmitting the PHR MAC CE.

7 . The method of claim 1 , wherein:
transmitting the PHR MAC CE comprises transmitting the PHR MAC CE to the first cell or to a second cell.

8 . The method of claim 1 , wherein:
triggering a PHR, associated with the PHR MAC CE, after receiving the UL grant.

9 . The method of claim 1 , comprising:
determining the second Type 1 PH, wherein at least one of:
determining the second Type 1 PH is not based on a PUSCH transmission indicated by the UL grant; or
determining the second Type 1 PH is based on a difference between a reference UE maximum transmit power and a power for the reference PUSCH transmission.

10 . The method of claim 1 , wherein the real PUSCH transmission is the first PUSCH transmission, the method comprising:
determining the first Type 1 PH based on a difference between a UE maximum transmit power and an estimated power for the first PUSCH transmission.

11 . The method of claim 1 , wherein:
the first TRP is associated with a first Sounding Reference Signal (SRS) resource set of the first cell; and the second TRP is associated with a second SRS resource set of the first cell.

12 . A User Equipment (UE), comprising:
a control circuit; a processor installed in the control circuit; and a memory installed in the control circuit and operatively coupled to the processor, wherein the processor is configured to execute a program code stored in the memory to perform operations, the operations comprising:
receiving an uplink (UL) grant, wherein:
the UL grant is indicative of a first Physical Uplink Shared Channel (PUSCH) transmission on a first Transmission/Reception Point (TRP) of a first cell; and
the UL grant is not indicative of a second PUSCH transmission on a second TRP of the first cell; and

transmitting a Power Headroom Reporting (PHR) Medium Access Control (MAC) Control Element (CE), wherein based on the UL grant, the PHR MAC CE is indicative of:
a first power headroom (PH), associated with the first TRP of the first cell, based on a real PUSCH transmission; and
a second PH, associated with the second TRP of the first cell, based on a reference PUSCH transmission.

13 . The UE of claim 12 , wherein the PHR MAC CE is indicative of:
a first UE maximum transmit power for the first TRP and a second UE maximum transmit power for the second TRP; or a single UE maximum transmit power for both the first TRP and the second TRP.

14 . The UE of claim 12 , wherein:
the UE is configured with a first PUSCH power control adjustment state for the first TRP and a second PUSCH power control adjustment state for the second TRP; and the first PUSCH power control adjustment state is different from the second PUSCH power control adjustment state.

15 . The UE of claim 12 , the operations comprising:
determining, based on a configuration from a network, whether to indicate a single PH for the first cell in the PHR MAC CE or to indicate two PHs for the first cell in the PHR MAC CE, wherein the PHR MAC CE indicates the first PH and the second PH based on a determination to indicate two PHs for the first cell in the PHR MAC CE.

16 . The UE of claim 12 , wherein:
the real PUSCH transmission is the first PUSCH transmission.

17 . The UE of claim 12 , wherein at least one of:
the first PUSCH transmission is performed before transmitting the PHR MAC CE; or the first PUSCH transmission is performed in a first slot that overlaps with a second slot for transmitting the PHR MAC CE.

18 . The UE of claim 12 , wherein:
the first TRP is associated with a first Sounding Reference Signal (SRS) resource set of the first cell; and the second TRP is associated with a second SRS resource set of the first cell.

19 . The UE of claim 12 , wherein:
triggering a PHR, associated with the PHR MAC CE, after receiving the UL grant.

20 . A non-transitory computer-readable medium comprising processor-executable instructions that when executed by a User Equipment (UE) cause performance of operations, the operations comprising:
receiving an uplink (UL) grant, wherein:
the UL grant is indicative of a first Physical Uplink Shared Channel (PUSCH) transmission on a first Transmission/Reception Point (TRP) of a first cell; and
the UL grant is not indicative of a second PUSCH transmission on a second TRP of the first cell; and
transmitting a Power Headroom Reporting (PHR) Medium Access Control (MAC) Control Element (CE), wherein based on the UL grant, the PHR MAC CE is indicative of:
a first Type 1 power headroom (PH), associated with the first TRP of the first cell, based on a real PUSCH transmission; and
a second Type 1 PH, associated with the second TRP of the first cell, based on a reference PUSCH transmission.

Assignees

• Asustek Comp Inc

Inventors

• Kung Yi-Hsuan
• Guo Yu-Hsuan
• Huang Chun-Wei

Classifications

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04W52/42

  in systems with time, space, frequency or polarisation diversity · CPC title

• H04W52/365 Primary

  Power headroom reporting · CPC title

• H04B7/0413

  MIMO systems · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title