Temporary reference signal for fast secondary cell activation
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a base station, a secondary cell activation message that indicates a secondary cell is to be activated at the UE in addition to a primary cell. The UE may identify, based at least in part on the secondary cell activation message, a slot location of a first portion of aperiodic reference signals for cell activation measurements and a slot offset between the first portion of the aperiodic reference signals and a second portion of the aperiodic reference signals, the slot offset comprising non-consecutive slots with respect to the slot location. The UE may measure one or more characteristics of the secondary cell based at least in part on the aperiodic reference signals.
1 . A method for wireless communication at a user equipment (UE), comprising:
receiving a secondary cell activation message that indicates a secondary cell is to be activated at the UE, and wherein the secondary cell activation message further indicates a slot location for a first plurality of slots, a slot offset which indicates a quantity of slots between the first plurality of slots and a second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for aperiodic reference signals of the secondary cell for cell activation measurements of the secondary cell;
identifying, based at least in part on the secondary cell activation message, the slot location for the first plurality of slots carrying a first portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell and the slot offset between the first plurality of slots and the second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, and the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
measuring one or more characteristics of the secondary cell based at least in part on the aperiodic reference signals received via the set of non-zero power reference signal resources.
2 . The method of claim 1 , wherein the secondary cell activation message is received in a medium access control (MAC) control element (CE), a downlink control information (DCI) message, or both.
3 . The method of claim 1 , further comprising:
identifying the slot offset based at least in part on one or more of: a frequency range of the secondary cell, a frequency band of the secondary cell, a frequency band combination of the secondary cell, a subcarrier spacing of the secondary cell, a bandwidth part configuration of the secondary cell, a time-domain duplexing configuration of the secondary cell, or a combination thereof.
4 . The method of claim 1 , further comprising:
receiving a configuration signal indicating the slot offset.
5 . The method of claim 4 , wherein the configuration signal comprises downlink control information including a field indicating the slot offset, the slot location, or both.
6 . The method of claim 1 , further comprising:
transmitting a UE capability message indicating a minimum slot offset value of the UE, wherein the slot offset is based at least in part on the UE capability message.
7 . The method of claim 6 , further comprising:
identifying the minimum slot offset value of the UE for at least one of a frequency range, a frequency band, a frequency band combination, a subcarrier spacing, a bandwidth part configuration, or a time domain duplexing configuration.
8 . A method for wireless communication at a primary cell, comprising:
identifying, for a user equipment (UE), a slot location for a first plurality of slots carrying a first portion of aperiodic reference signals of a secondary cell for cell activation measurements of the secondary cell and a slot offset between the first plurality of slots and a second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
transmitting, to the UE, a secondary cell activation message that indicates the secondary cell is to be activated at the UE in addition to the primary cell and triggers transmission of the aperiodic reference signals at the secondary cell according to the slot location and the slot offset, wherein the secondary cell activation message further indicates the slot location for the first plurality of slots, the slot offset which indicates a quantity of slots between the first plurality of slots and the second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell.
9 . The method of claim 8 , wherein the secondary cell activation message is transmitted in a medium access control (MAC) control element (CE), a downlink control information (DCI) message, or both.
10 . The method of claim 8 , further comprising:
identifying the slot offset based at least in part on one or more of: a frequency range of the secondary cell, a frequency band of the secondary cell, a frequency band combination of the secondary cell, a subcarrier spacing of the secondary cell, a bandwidth part configuration of the secondary cell, a time-domain duplexing configuration of the secondary cell, or a combination thereof.
11 . The method of claim 8 , further comprising:
transmitting a configuration signal indicating the slot offset.
12 . The method of claim 11 , wherein the configuration signal comprises downlink control information including a field indicating the slot offset, the slot location, or both.
13 . The method of claim 8 , further comprising:
receiving a UE capability message indicating a minimum slot offset value of the UE, wherein the slot offset is based at least in part on the UE capability message.
14 . The method of claim 13 , further comprising:
identifying the minimum slot offset value of the UE for at least one of a frequency range, a frequency band, a frequency band combination, a subcarrier spacing, a bandwidth part configuration, or a time domain duplexing configuration.
15 . An apparatus for wireless communication at a user equipment (UE), comprising:
at least one processor;
at least one memory coupled with the at least one processor; and
instructions stored in the at least one memory and executable by the at least one processor to cause the UE to:
receive a secondary cell activation message that indicates a secondary cell is to be activated at the UE, and wherein the secondary cell activation message further indicates a slot location for a first plurality of slots, a slot offset which indicates a quantity of slots between the first plurality of slots and a second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for aperiodic reference signals of the secondary cell for cell activation measurements of the secondary cell;
identify, based at least in part on the secondary cell activation message, the slot location for the first plurality of slots carrying a first portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell and the slot offset between the first plurality of slots and the second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
measure one or more characteristics of the secondary cell based at least in part on the aperiodic reference signals received via the set of non-zero power reference signal resources.
16 . The apparatus of claim 15 , wherein the secondary cell activation message is received in a medium access control (MAC) control element (CE), a downlink control information (DCI) message, or both.
17 . The apparatus of claim 15 , wherein the instructions are further executable by the at least one processor to cause the UE to:
identify the slot offset based at least in part on one or more of: a frequency range of the secondary cell, a frequency band of the secondary cell, a frequency band combination of the secondary cell, a subcarrier spacing of the secondary cell, a bandwidth part configuration of the secondary cell, a time-domain duplexing configuration of the secondary cell, or a combination thereof.
18 . The apparatus of claim 15 , wherein the instructions are further executable by the at least one processor to cause the UE to:
receive a configuration signal indicating the slot offset.
19 . The apparatus of claim 18 , wherein the configuration signal comprises downlink control information including a field indicating the slot offset, the slot location, or both.
20 . The apparatus of claim 15 , wherein the instructions are further executable by the at least one processor to cause the UE to:
transmit a UE capability message indicating a minimum slot offset value of the UE, wherein the slot offset is based at least in part on the UE capability message.
21 . The apparatus of claim 20 , wherein the instructions are further executable by the at least one processor to cause the UE to:
identify the minimum slot offset value of the UE for at least one of a frequency range, a frequency band, a frequency band combination, a subcarrier spacing, a bandwidth part configuration, or a time domain duplexing configuration.
22 . An apparatus for wireless communication at a primary cell, comprising:
at least one processor;
at least one memory coupled with the at least one processor; and
instructions stored in the at least one memory and executable by the at least one processor to cause the primary cell to:
identify, for a user equipment (UE), a slot location for a first plurality of slots carrying a first portion of aperiodic reference signals of a secondary cell for cell activation measurements of the secondary cell and a slot offset between the first plurality of slots and a second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
transmit, to the UE, a secondary cell activation message that indicates the secondary cell is to be activated at the UE in addition to the primary cell and triggers transmission of the aperiodic reference signals at the secondary cell according to the slot location and the slot offset, and wherein the secondary cell activation message further indicates the slot location for the first plurality of slots and the slot offset indicates a quantity of slots between the first plurality of slots and the second plurality of slots, the slot offset which indicates a quantity of slots between the first plurality of slots and the second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell.
23 . The apparatus of claim 22 , wherein the secondary cell activation message is transmitted in a medium access control (MAC) control element (CE), a downlink control information (DCI) message, or both.
24 . The apparatus of claim 22 , wherein the instructions are further executable by the at least one processor to cause the primary cell to:
identify the slot offset based at least in part on one or more of: a frequency range of the secondary cell, a frequency band of the secondary cell, a frequency band combination of the secondary cell, a subcarrier spacing of the secondary cell, a bandwidth part configuration of the secondary cell, a time-domain duplexing configuration of the secondary cell, or a combination thereof.
25 . The apparatus of claim 22 , wherein the instructions are further executable by the at least one processor to cause the primary cell to:
transmit a configuration signal indicating the slot offset.
26 . The apparatus of claim 25 , wherein the configuration signal comprises downlink control information including a field indicating the slot offset, the slot location, or both.
27 . The apparatus of claim 22 , wherein the instructions are further executable by the at least one processor to cause the primary cell to:
receive a UE capability message indicating a minimum slot offset value of the UE, wherein the slot offset is based at least in part on the UE capability message.
28 . The apparatus of claim 27 , wherein the instructions are further executable by the at least one processor to cause the primary cell to:
identify the minimum slot offset value of the UE for at least one of a frequency range, a frequency band, a frequency band combination, a subcarrier spacing, a bandwidth part configuration, or a time domain duplexing configuration.
29 . An apparatus for wireless communication at a user equipment (UE), comprising:
means for receiving a secondary cell activation message that indicates a secondary cell is to be activated at the UE, and wherein the secondary cell activation message further indicates a slot location for a first plurality of slots, a slot offset which indicates a quantity of slots between the first plurality of slots and a second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for aperiodic reference signals of the secondary cell for cell activation measurements of the secondary cell;
means for identifying, based at least in part on the secondary cell activation message, the slot location for the first plurality of slots carrying a first portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell and the slot offset between the first plurality of slots and the second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
means for measuring one or more characteristics of the secondary cell based at least in part on the aperiodic reference signals received via the set of non-zero power reference signal resources.
30 . An apparatus for wireless communication at a primary cell, comprising:
means for identifying, for a user equipment (UE), a slot location for a first plurality of slots carrying a first portion of aperiodic reference signals of a secondary cell for cell activation measurements of the secondary cell and a slot offset between the first plurality of slots and a second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
means for transmitting, to the UE, a secondary cell activation message that indicates the secondary cell is to be activated at the UE in addition to the primary cell and triggers transmission of the aperiodic reference signals at the secondary cell according to the slot location and the slot offset, and wherein the secondary cell activation message further indicates the slot location for the first plurality of slots, the slot offset which indicates a quantity of slots between the first plurality of slots and the second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell.
31 . A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by at least one processor to:
receive a secondary cell activation message that indicates a secondary cell is to be activated at the UE, and wherein the secondary cell activation message further indicates a slot location for a first plurality of slots, a slot offset which indicates a quantity of slots between the first plurality of slots and a second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for aperiodic reference signals of the secondary cell for cell activation measurements of the secondary cell;
identify, based at least in part on the secondary cell activation message, the slot location for the first plurality of slots carrying a first portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell and the slot offset between the first plurality of slots and the second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
measure one or more characteristics of the secondary cell based at least in part on the aperiodic reference signals received via the set of non-zero power reference signal resources.
32 . A non-transitory computer-readable medium storing code for wireless communication at a primary cell, the code comprising instructions executable by at least one processor to:
identify, for a user equipment (UE), a slot location for a first plurality of slots carrying a first portion of aperiodic reference signals of a secondary cell for cell activation measurements of the secondary cell and a slot offset between the first plurality of slots and a second plurality of slots, the second plurality of slots carrying a second portion of the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell, the slot offset comprising an indication of non-consecutive slots and the second portion of the aperiodic reference signals using a same symbol pattern as the first portion of the aperiodic reference signals; and
transmit, to the UE, a secondary cell activation message that indicates the secondary cell is to be activated at the UE in addition to the primary cell and triggers transmission of the aperiodic reference signals at the secondary cell according to the slot location and the slot offset, and wherein the secondary cell activation message further indicates the slot location for the first plurality of slots, the slot offset which indicates a quantity of slots between the first plurality of slots and the second plurality of slots, and a set of non-zero power reference signal resources indicated by a tracking reference signal (TRS) information parameter, the set of non-zero power reference signal resources configured for the aperiodic reference signals of the secondary cell for the cell activation measurements of the secondary cell.