Passive UE Position Estimation Through Network RF Sensing

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Solution Overview

Problem

Current wireless communication systems lack support for passive and semi-passive position estimation of user equipment (UE) using radio frequency (RF) sensing, which is essential for power-efficient and accurate localization, particularly for RedCap UEs.

Innovation Solution

Implementing a method for UE position estimation based on RF signals transmitted and measured by wireless nodes other than the UE, involving a location management function (LMF), sensing management function (SnMF), and network components to facilitate passive and semi-passive positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the UE actively transmits and measures RF signals for position estimation, then positioning functionality is achieved, but power consumption increases

Engineering Contradiction:

Improvepositioning accuracyVSAvoidUE power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent inverts the traditional active positioning approach by implementing passive positioning where the UE does not transmit signals but instead measures RF signals transmitted by other wireless nodes (gNBs, LMF, SnMF). This inversion allows the UE to obtain position estimation without the energy expenditure of signal transmission, thereby reducing power consumption while maintaining positioning capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces intermediary wireless nodes (gNBs, LMF, SnMF) that transmit RF sensing signals specifically for positioning purposes. These intermediaries perform the signal transmission function, allowing the UE to passively receive and measure the signals without needing to transmit, thus achieving positioning with reduced energy consumption at the UE

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If passive position estimation using RF sensing is implemented, then power consumption is reduced, but system complexity increases

Engineering Contradiction:

ImproveUE power consumptionVSAvoidnetwork system complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent segments the positioning system into distinct functional components: the LMF responsible for position estimation calculations, the SnMF responsible for RF sensing signal management, and the gNBs responsible for signal transmission. This segmentation distributes the complexity across multiple specialized network elements rather than concentrating it in the UE, making the overall system more manageable despite the increased complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements multi-functionality by having network components (gNBs, LMF, SnMF) serve both traditional communication functions and new RF sensing-based positioning functions. This allows the system to leverage existing infrastructure for dual purposes, reducing the need for entirely new dedicated hardware and thereby managing complexity more effectively

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If position estimation sessions are initiated by UE, then positioning requests are processed, but estimation latency increases

Engineering Contradiction:

Improveposition estimation accuracyVSAvoidposition estimation latency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements preliminary action by having the network (LMF, SnMF, gNBs) pre-configured and ready to perform position estimation calculations and signal transmissions. When a positioning request is received, the network can immediately initiate the RF sensing process and calculations without waiting for UE preparation, thereby reducing the overall estimation latency while maintaining accurate position estimation

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20250287335A1Sensing-based position estimation of a user equipment

Publication Date: 2025.09.11 QUALCOMM INC

AI summary

Aspects of the disclosure are directed to passive UE position estimation (e.g., the target UE does not transmit or measure any signal associated with the position estimation) and semi-passive position estimation (e.g., some signals relied upon for position estimation are neither transmitted nor measured by the target UE, while other signals relied upon for the position estimation may be transmitted and/or measured by the target UE). Such aspects may provide various technical advantages, such as reducing power consumption at the target UE (e.g., particularly advantageous for RedCap UEs), more accurate IE position estimation, reduced UE position estimation latency, and so on.