Wireless UE Positioning Using RIS Reflectors With Mobile TPs

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Solution Overview

Problem

Existing wireless network positioning systems face challenges in accurately locating user equipment (UE) due to the introduction of mobile transmit points (TPs) like drones and UAVs, which increase the number of unknown locations and synchronization errors, making it difficult to determine UE location without sufficient fixed reference points.

Innovation Solution

The use of reconfigurable intelligent surfaces (RIS) as smart reflectors that manipulate and tag reflected signals with unique signatures, allowing UE to identify nearby reflectors with known locations, enabling precise location determination even with mobile TPs, by processing a combination of direct and reflected signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If GPS-based location services are used, then location accuracy is improved, but power consumption increases and indoor coverage is lost

Engineering Contradiction:
Improvelocation accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system segments the location determination process into multiple independent measurement techniques (TOA, TDOA, AOA, fingerprinting) that can be selectively applied. Different segmentation strategies are used: dividing the network into base stations with different capabilities, separating indoor and outdoor location methods, and breaking down the location calculation into multiple signal measurement components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system employs composite location determination by combining multiple signal measurement techniques (time of arrival, time difference of arrival, angle of arrival) and multiple identification methods (fingerprinting, trilateration, triangulation) to create a robust hybrid location system that maintains accuracy across diverse environments while optimizing power consumption.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If GPS is used for location tracking, then outdoor location accuracy is improved, but indoor location coverage deteriorates

Engineering Contradiction:
Improvelocation accuracyVSAvoidindoor coverage
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system achieves universality by designing a location determination framework that functions across multiple environments (indoor, outdoor, urban, rural) using the same core infrastructure of base stations and wireless signals. The system adapts its measurement techniques based on environment type, providing consistent location service quality universally.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically selects and adjusts location determination methods based on real-time conditions such as signal availability, environment type, and base station configuration. The location server dynamically chooses between TOA, TDOA, AOA, and fingerprinting methods, and adjusts measurement parameters adaptively to maintain performance across varying conditions.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If multiple base stations are deployed for location triangulation, then location accuracy is improved, but network infrastructure complexity increases

Engineering Contradiction:
Improvelocation accuracyVSAvoidnetwork infrastructure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The location server acts as an intermediary that centralizes the complex computations for location determination. Base stations perform only signal measurement and forward data to the location server, which handles the sophisticated algorithms for TOA, TDOA, AOA calculations and fingerprinting matching. This distribution of complexity reduces individual base station requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses signal copying and replication techniques where location measurement data is collected from multiple base stations and copied to the location server for centralized processing. Fingerprinting templates are pre-computed and stored as copies for rapid matching during location determination, reducing real-time computational complexity.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method reduces synchronization errors and improves positioning accuracy by using RIS to provide additional reference points, allowing UE to determine its location without needing prior knowledge of the reflector, even in environments with mobile TPs.

Implementation Method 1

a base station 102 transmits a positioning reference signal 104 to a user equipment (UE) 106

Methodology Applied
Scientific EffectElectromagnetic wave transmission: Electromagnetic Induction

Implementation Method 2

the UE 106 measures a time of arrival (TOA) 108 of the positioning reference signal 104

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Implementation Method 3

wireless communication and positioning systems rely on the air interface between a base station and a UE

Methodology Applied
Scientific EffectRadio wave propagation: Electromagnetic Induction

Data Source

PatentEP4111225B1Systems and methods for locating user equipment in a wireless network
Publication Date: 2026.05.06 HUAWEI TECH CO LTD
  • EP4111225B1 patent drawingFigure 1
  • EP4111225B1 patent drawingFigure 2A~2B
  • EP4111225B1 patent drawingFigure 3

AI summary

Methods and apparatus are provided that may simplify and enhance the location of nodes in a network, including ED and mobile TPs, even if all or many of the nodes are mobile. The methods may be used to enable single TP positioning, and may be used to reduce synchronization error. The provided methods make use of smart reflectors having known location. By processing a combination of signals, which may include an original transmitted signal, and/or one or more reflected signals, the location of a receiving node can be determined. Media tagging may be employed to allow a receiver to detect the identity of the nearby reflectors (with known locations) and based on the identity determine the locations of the reflectors. Using this information, the receiving node can detect its location regardless of knowing the transmission source and/or location.