LTE CRS Tracking Loop Update for NR UE Power Savings

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Solution Overview

Problem

Current New Radio (NR) user equipment (UE) systems face challenges in efficiently updating tracking loops, particularly in idle/inactive modes, due to limited reference signals and higher power consumption.

Innovation Solution

The method involves configuring NR UE to use Long Term Evolution (LTE) cell-specific reference signals (CRS) for updating tracking loops, allowing NR UE to receive and utilize LTE CRS for tracking loop updates, even in idle/inactive modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If NR UE uses limited NR reference signals for tracking loop updates, then device complexity is reduced, but power consumption increases and tracking precision deteriorates

Engineering Contradiction:

Improvereference signal processing complexityVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The NR UE is configured to use LTE cell-specific reference signals (CRS) in addition to NR reference signals for tracking loop updates. This multi-functionality allows the UE to leverage always-on LTE CRS signals that provide higher density update opportunities, reducing power consumption while maintaining tracking precision without significantly increasing device complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If NR UE uses LTE CRS for tracking loop updates, then tracking precision and update opportunities increase, but device complexity and configuration requirements increase

Engineering Contradiction:

Improvetracking loop update precisionVSAvoidconfiguration complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The base station pre-configures the NR UE with LTE CRS parameters including resource configurations, frequency offsets, and antenna port information before the UE needs to perform tracking loop updates. This preliminary configuration reduces the complexity during actual tracking operations by having all necessary parameters readily available

Inventive Principle:

Principle #10Preliminary action

3Use of energy by moving object

If NR UE operates in idle/inactive modes with limited reference signals, then power consumption is reduced, but tracking loop update opportunities are limited

Engineering Contradiction:

Improvepower consumptionVSAvoidtracking loop update delay

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The LTE CRS signals provide continuous tracking loop update opportunities even when the NR UE is in idle or inactive modes. The always-on nature of LTE CRS ensures that tracking loops can be continuously updated without requiring the UE to transition to connected mode, maintaining both low power consumption and continuous tracking capability

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS12212519B2Cell-specific reference signal for tracking loop update

Publication Date: 2025.01.28 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a New Radio (NR) user equipment (UE) may receive a configuration that configures the NR UE with a capability to use a Long Term Evolution (LTE) cell-specific reference signal (CRS) for updating a tracking loop. The NR UE may receive an LTE CRS. The NR UE may update the tracking loop based at least in part on the LTE CRS. Numerous other aspects are described.