Power headroom reporting for short transmission time interval (tti)

Patent metadata

Field	Value
Publication number	US-2019141644-A1
Application number	US-201816175052-A
Country	US
Kind code	A1
Filing date	Oct 30, 2018
Priority date	Nov 3, 2017
Publication date	May 9, 2019
Grant date	—

Abstract

Certain aspects of the present disclosure relate to methods and apparatus for PHR reporting by UEs that support both normal and shortened Transmission Time Interval (sTTI) configurations.

First claim

What is claimed is:

1 . A method for wireless communication by a User Equipment (UE), comprising:
receiving scheduling for at least one of first uplink transmissions according to a first Transmission Time Interval (TTI) or second uplink transmissions according to a second TTI, wherein the second TTI has a shortened duration relative to the first TTI; determining a configuration for performing power headroom (PHR) reporting for the first TTI and for performing PHR reporting for the second TTI; and performing PHR reporting according to the determination.

2 . The method of claim 1 , wherein performing PHR reporting according to the determination comprises:
canceling a PHR transmission for the first TTI due to a collision with transmission for the second TTI; and sending the canceled PHR transmission in the second TTI.

3 . The method of claim 2 , wherein the PHR reported for the first TTI is computed either:
based on fixed parameters instead of parameters for the dropped PHR transmission; or based on the earlier allocation as if the PHR transmission was not cancelled.

4 . The method of claim 1 , wherein the configuration involves separate periodic and prohibit timers for PHR reporting for the first and second TTIs.

5 . The method of claim 4 , wherein performing PHR reporting according to the determination comprises stopping a prohibit timer for PHR for the first TTI if an earlier PHR transmission for the first TTI is dropped due to a collision with transmission for the second TTI.

6 . The method of claim 1 , wherein performing PHR reporting according to the determination comprises triggering PHR reporting for the first TTI if an earlier PHR transmission for the first TTI is dropped due to a collision with transmission for the second TTI.

7 . The method of claim 1 , wherein:
the UE is configured to wait until a next available transmit opportunity corresponding to the first TTI to transmit PHR for the first TTI; and the UE is configured to wait until a next available transmit opportunity corresponding to the second TTI to transmit PHR for the second TTI.

8 . The method of claim 1 , wherein the UE is configured to send the PHR for a first or second TTI in a first available transmission opportunity, whether on a first uplink transmission or a second uplink transmission.

9 . The method of claim 1 , wherein the configuration configures the UE to report PHR for both the first and second TTIs in a single media access control (MAC) control element (CE).

10 . The method of claim 1 , wherein the configuration configures the UE to report PHR for the first and second TTIs in separate media access control (MAC) control elements (CEs).

11 . The method of claim 1 , wherein performing PHR reporting according to the determination comprises:
giving higher priority to a MAC CE which includes PHR for the second TTI if PHR for the first TTI and PHR for the second TTI are both reported in the second TTI; giving higher priority to a MAC CE which includes PHR for the first TTI if PHR for the first TTI and PHR for the second TTI are both reported in the first TTI; or giving higher priority to a MAC CE which includes PHR for the second TTI if PHR for the first TTI and PHR for the second TTI are both reported in the first TTI.

12 . The method of claim 1 , wherein performing PHR reporting according to the determination comprises triggering PHR reporting for the second TTI upon at least one of a radio resource control (RRC) configuration or an activation of the second TTI.

13 . A method for wireless communication by a network entity, comprising:
configuring a user equipment (UE) for performing power headroom (PHR) reporting for uplink transmissions according to a first transmission time interval (TTI) and according to a second TTI, wherein the second TTI has a shortened duration relative to the first TTI; receiving, from the UE, a PHR report according to the configuration.

14 . The method of claim 13 , wherein the configuration involves separate periodic and prohibit timers for PHR reporting for the first and second TTIs.

15 . The method of claim 13 , further comprising triggering the UE for PHR reporting for the second TTI via at least one of an radio resource control (RRC) configuration or an activation of the second TTI.

16 . The method of claim 13 , wherein the PHR report for both the first and second TTIs is received in a single media access control (MAC) control element (CE).

17 . The method of claim 13 , wherein the configuration calls for the UE to report PHR for the first and second TTIs in separate media access control (MAC) control elements (CEs).

18 . An apparatus for wireless communication by a User Equipment (UE), comprising:
at least one processor configured to receive scheduling for at least one of first uplink transmissions according to a first Transmission Time Interval (TTI) or second uplink transmissions according to a second TTI, wherein the second TTI has a shortened duration relative to the first TTI, determine a configuration for performing power headroom (PHR) reporting for the first TTI and for performing PHR reporting for the second TTI, and perform PHR reporting according to the determination; and a memory coupled with the at least one processor.

19 . The apparatus of claim 18 , wherein performing PHR reporting according to the determination comprises:
canceling a PHR transmission for the first TTI due to a collision with transmission for the second TTI; and sending the canceled PHR transmission in the second TTI.

20 . The apparatus of claim 19 , wherein the PHR reported for the first TTI is computed either:
based on fixed parameters instead of parameters for the dropped PHR transmission; or based on the earlier allocation as if the PHR transmission was not cancelled.

21 . The apparatus of claim 18 , wherein the configuration involves separate periodic and prohibit timers for PHR reporting for the first and second TTIs.

22 . The apparatus of claim 21 , wherein performing PHR reporting according to the determination comprises stopping a prohibit timer for PHR for the first TTI if an earlier PHR transmission for the first TTI is dropped due to a collision with transmission for the second TTI.

23 . The apparatus of claim 18 , wherein performing PHR reporting according to the determination comprises triggering PHR reporting for the first TTI if an earlier PHR transmission for the first TTI is dropped due to a collision with transmission for the second TTI.

24 . The apparatus of claim 18 , wherein:
the UE is configured to wait until a next available transmit opportunity corresponding to the first TTI to transmit PHR for the first TTI; and the UE is configured to wait until a next available transmit opportunity corresponding to the second TTI to transmit PHR for the second TTI.

25 . The apparatus of claim 18 , wherein the UE is configured to send the PHR for a first or second TTI in a first available transmission opportunity, whether on a first uplink transmission or a second uplink transmission.

26 . The apparatus of claim 18 , wherein the configuration configures the UE to report PHR for both the first and second TTIs in a single media access control (MAC) control element (CE).

27 . The apparatus of claim 18 , wherein the configuration configures the UE to report PHR for the first and second TTIs in separ

Assignees

• Qualcomm Inc

Inventors

• Ozturk Ozcan
• Hosseini Seyedkianoush
• Rico Alvarino Alberto

Classifications

• H04W72/23

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

• H04W24/10

  Scheduling measurement reports {; Arrangements for measurement reports} · CPC title

• H04L5/00

  Arrangements affording multiple use of the transmission path · CPC title

• H04W52/365 Primary

  Power headroom reporting · CPC title

• H04W52/34

  TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading · CPC title