US-20260129488-A1 - TECHNIQUES FOR EARLY CSI ACQUISITION IN LOWER LAYER TRIGGERED MOBILITY

US20260129488A1US 20260129488 A1US20260129488 A1US 20260129488A1US-20260129488-A1

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a first cell, a message that triggers early channel state information (CSI) reporting for a second cell, and perform measurements for a CSI reference signal (CSI-RS) received from the second cell based on message, where the CSI-RS is received subsequent to the message in a time domain. The UE may transmit, to the first cell, the second cell, or both, a CSI report that is based on the measurements performed for the CSI-RS received from the second cell. The UE may then receive, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based on the CSI report.

Inventors

Changhwan Park
Jelena Damnjanovic
Wooseok Nam

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260507
Application Date: 20241106

Claims (20)

1 . A user equipment (UE), comprising: one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to: receive, from a first cell, a message that triggers early channel state information reporting for a second cell; perform measurements for a channel state information reference signal received from the second cell based at least in part on receiving the message, wherein the channel state information reference signal is received subsequent to the message in a time domain; transmit, to the first cell, the second cell, or both, a channel state information report that is based at least in part on the measurements performed for the channel state information reference signal received from the second cell; and receive, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based at least in part on the channel state information report.
2 . The UE of claim 1 , wherein a time interval between reception of the channel state information reference signal and transmission of the channel state information report is based at least in part on a time interval between reception of a downlink message via the first cell and transmission of an additional channel state information report to the first cell.
3 . The UE of claim 1 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, from the first cell, a medium access control-control element message that activates one or more transmission configuration indicator states associated with the second cell, wherein the channel state information reference signal is associated with the one or more transmission configuration indicator states.
4 . The UE of claim 3 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, via the medium access control-control element message, an indication of at least one transmission configuration indicator state from the one or more transmission configuration indicator states that is to be used for early channel state information reporting for the second cell, wherein the channel state information reference signal is associated with the at least one transmission configuration indicator state.
5 . The UE of claim 3 , wherein the channel state information reference signal is configured for semi-persistent or aperiodic transmission, and the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, via the medium access control-control element message, an indication that transmission of the channel state information reference signal by the second cell is activated or triggered.
6 . The UE of claim 3 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive, from the first cell, a second medium access control-control element message, a downlink control information message, or both, that indicates at least one transmission configuration indicator state from the one or more transmission configuration indicator states that is to be used for early channel state information reporting for the second cell, wherein the channel state information reference signal is associated with the at least one transmission configuration indicator state.
7 . The UE of claim 1 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to: receive a synchronization signal block from the second cell based at least in part on receiving the message that triggers early channel state information reporting for the second cell, wherein the synchronization signal block is quasi co-located with the channel state information reference signal, wherein the channel state information reference signal is received based at least in part on receiving the synchronization signal block.
8 . The UE of claim 7 , wherein the synchronization signal block is received during a time interval following reception of the message that triggers early channel state information reporting, and wherein the channel state information reference signal is received after an expiration of the time interval, wherein the time interval is associated with a processing time for the synchronization signal block at the UE.
9 . The UE of claim 1 , wherein the channel state information reference signal is one of a plurality of periodic channel state information reference signals transmitted by the second cell.
10 . The UE of claim 1 , wherein a time interval between reception of the channel state information reference signal and transmission of the channel state information report is based at least in part on one or more capabilities associated with the UE.
11 . The UE of claim 1 , wherein a time interval between reception of the channel state information reference signal and transmission of the channel state information report is based at least in part on a reference signal type associated with the channel state information reference signal, the reference signal type comprising one of a periodic reference signal, an aperiodic reference signal, or a semi-persistent reference signal.
12 . The UE of claim 1 , wherein a time interval between reception of the channel state information reference signal and transmission of the channel state information report is based at least in part on whether the UE has received an activation command for one or more transmission configuration indicator states associated with the second cell.
13 . A first cell, comprising: one or more memories storing processor-executable code; and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the first cell to: transmit, to a user equipment (UE), a message that triggers early channel state information reporting for a second cell; transmit, to a second cell, an indication for the second cell to transmit one or more channel state information reference signals; receive, from the UE, a channel state information report that is based at least in part on a channel state information reference signal of the one or more channel state information reference signals that is transmitted subsequent to the message in a time domain; and transmit, to the UE, a cell switch command to perform a cell switching procedure from the first cell to the second cell based at least in part on the channel state information report.
14 . The first cell of claim 13 , wherein a time interval between the channel state information reference signal and the channel state information report is based at least in part on a time interval between transmission of a downlink message via the first cell and reception of an additional channel state information report from the UE.
15 . The first cell of claim 13 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the first cell to: transmit, to the UE, a medium access control-control element message that activates one or more transmission configuration indicator states associated with the second cell, wherein the channel state information reference signal is associated with the one or more transmission configuration indicator states.
16 . The first cell of claim 15 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the first cell to: transmit, via the medium access control-control element message, an indication of at least one transmission configuration indicator state from the one or more transmission configuration indicator states that is to be used for early channel state information reporting for the second cell, wherein the channel state information reference signal is associated with the at least one transmission configuration indicator state.
17 . The first cell of claim 15 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the first cell to: transmit, to the UE, a second medium access control-control element message, a downlink control information message, or both, that indicates at least one transmission configuration indicator state from the one or more transmission configuration indicator states that is to be used for early channel state information reporting for the second cell, wherein the channel state information reference signal is associated with the at least one transmission configuration indicator state.
18 . The first cell of claim 13 , wherein the one or more processors are individually or collectively further operable to execute the code to cause the first cell to: receive, from the UE, a capability message indicating one or more capabilities associated with the UE; and transmit an indication of the one or more capabilities of the UE, wherein a first time interval between the message that triggers early channels state information reporting and the channel state information reference signal, or a second time interval between the channel state information reference signal and the channel state information report, is based at least in part on the one or more capabilities.
19 . The first cell of claim 13 , wherein a time interval between the channel state information reference signal and the channel state information report is based at least in part on a reference signal type associated with the channel state information reference signal, the reference signal type comprising one of a periodic reference signal, an aperiodic reference signal, or a semi-persistent reference signal.
20 . A method for wireless communications at a user equipment (UE), comprising: receiving, from a first cell, a message that triggers early channel state information reporting for a second cell; performing measurements for a channel state information reference signal received from the second cell based at least in part on receiving the message, wherein the channel state information reference signal is received subsequent to the message in a time domain; transmitting, to the first cell, the second cell, or both, a channel state information report that is based at least in part on the measurements performed for the channel state information reference signal received from the second cell; and receiving, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based at least in part on the channel state information report.

Description

FIELD OF TECHNOLOGY The following relates to wireless communications, including techniques for early channel state information (CSI) acquisition in lower layer triggered mobility (LTM). BACKGROUND Wireless communications 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, each supporting wireless communication for communication devices, which may be known as user equipment (UE). Wireless devices, such as UEs, may be configured to perform cell switching/reselection procedures to switch between different cells as the wireless devices move throughout a network. When evaluating whether or not to perform a cell switching procedure from one cell to another, a UE may perform measurements (e.g., RSRP, RSRQ) on synchronization signal blocks (SSBs) received from neighboring cells, and may transmit Layer 1 (L1) measurement reports back to the serving cell to assist with cell switching decisions. SUMMARY The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. A method by a user equipment (UE) is described. The method may include receiving, from a first cell, a message that triggers early channel state information (CSI) reporting for a second cell, performing measurements for a CSI reference signal (CSI-RS) received from the second cell based on receiving the message, where the CSI-RS is received subsequent to the message in a time domain, transmitting, to the first cell, the second cell, or both, a CSI report that is based on the measurements performed for the CSI-RS received from the second cell, and receiving, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based on the CSI report. A UE is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively be operable to execute the code to cause the UE to receive, from a first cell, a message that triggers early CSI reporting for a second cell, perform measurements for a CSI-RS received from the second cell based on receiving the message, where the CSI-RS is received subsequent to the message in a time domain, transmit, to the first cell, the second cell, or both, a CSI report that is based on the measurements performed for the CSI-RS received from the second cell, and receive, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based on the CSI report. Another UE is described. The UE may include means for receiving, from a first cell, a message that triggers early CSI reporting for a second cell, means for performing measurements for a CSI-RS received from the second cell based on receiving the message, where the CSI-RS is received subsequent to the message in a time domain, means for transmitting, to the first cell, the second cell, or both, a CSI report that is based on the measurements performed for the CSI-RS received from the second cell, and means for receiving, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based on the CSI report. A non-transitory computer-readable medium storing code is described. The code may include instructions executable by one or more processors to receive, from a first cell, a message that triggers early CSI reporting for a second cell, perform measurements for a CSI-RS received from the second cell based on receiving the message, where the CSI-RS is received subsequent to the message in a time domain, transmit, to the first cell, the second cell, or both, a CSI report that is based on the measurements performed for the CSI-RS received from the second cell, and receive, from the first cell, a cell switch command to perform a cell switching procedure from the first cell to the second cell based on the CSI report. In some examples of the method, UEs, and non-transitory computer-readable medium de