US-12621094-B2 - Temporary reference signal for fast secondary cell activation

US12621094B2US 12621094 B2US12621094 B2US 12621094B2US-12621094-B2

Abstract

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.

Inventors

Kazuki Takeda
Changhwan Park
Jae Ho Ryu

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260505
Application Date: 20220127

Claims (20)

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.

Description

CROSS REFERENCE The present Application for Patent claims the benefit of U.S. Provisional Patent Application No. 63/143,662 by TAKEDA et al., entitled “TEMPORARY REFERENCE SIGNAL FOR FAST SECONDARY CELL,” filed Jan. 29, 2021, assigned to the assignee hereof, and expressly incorporated by reference herein. FIELD OF TECHNOLOGY The following relates to wireless communications, including temporary reference signal for fast secondary cell activation. BACKGROUND Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support temporary reference signal for fast secondary cell (SCell) activation. Generally, the described techniques provide for improving activation of SCell(s) for a user equipment (UE) more quickly and efficiently. For example, a UE may receive a SCell activation message indicating that the SCell is being activated. The SCell activation message may be received from a primary cell (PCell), which may be associated with the same base station and/or a different base station than the to-be activated SCell(s). The UE may identify, e.g., based on the SCell(s) activation message and/or other configurations, a non-consecutive slot arrangement for aperiodic reference signals (e.g., a slot location of a slot n and the location of slot n+k based on the slot offset between slot n and slot n+k). That is, the UE may use the activation message to identify the slot location of slot n for a first portion of the aperiodic reference signals as well as the slot offset identifying slot n+k where a second portion of the aperiodic reference signals are transmitted by the to-be activated SCell(s). The UE may then measure the aperiodic reference signals from the SCell(s) using the associated resources, e.g., in the first portion of aperiodic reference signal in slot n and the slot offset identifying slot n+k where the second portion of aperiodic reference signals are, which constitutes non-consecutive slots. This may enable to the UE to synchronize with the SCell in order to perform wireless communications more quickly and efficiently. A method for wireless communication at a UE is described. The method may include receiving, from a base station, a SCell activation message that indicates a SCell is to be activated at the UE in addition to a PCell, identifying, based on the SCell 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 including non-consecutive slots with respect to the slot location, and measuring one or more characteristics of the SCell based on the aperiodic reference signals. In some examples, the slot location may be for a first plurality of slots carrying the first portion of aperiodic reference signals and the slot offset may be between the first plurality of slots and a second plurality of slots carrying the second portion of the aperiodic reference signals, such as illustrated in FIG. 3. In some examples, the timing domain pattern (e.g., symbols) used for the first portion of the aperiodic reference signals carried in the first plurality of slots may be reused (e.g., the same) for the second portion of the aperiodic reference signals carried in the second plurality of slots. An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, a SCell activation message that indicates a SCell is to be activated at the UE in addition to a PCell, identify, based on the SCell activation message, a slot location of a first portion of ape