UE Positioning via Signal Strength Ratios to Resolve Satellite Mirroring

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Solution Overview

Problem

Time-difference based positioning methods in cellular communication networks using non-terrestrial cells result in ambiguous location estimates due to mirroring of possible areas on either side of a satellite's orbital plane, leading to suboptimal position determination and verification.

Innovation Solution

The method involves measuring and reporting signal strength ratios between cells on different sides of the orbital plane, allowing the network to differentiate between actual and mirrored areas, thereby revising the initial location estimate to obtain a corrected, unambiguous position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If time-difference based positioning methods are used with satellite-based non-terrestrial cells, then positioning coverage is extended to remote areas, but location estimate accuracy deteriorates due to ambiguous mirrored areas

Engineering Contradiction:
Improvepositioning coverageVSAvoidlocation estimate accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies asymmetry by comparing signal strength ratios between different cell sets (terrestrial vs. non-terrestrial, or different non-terrestrial cells) to break the symmetry of mirrored location estimates. The UE measures and reports signal strength ratios that are asymmetric with respect to the orbital plane, allowing the network to distinguish between mirrored areas and select the correct location estimate.

Inventive Principle:
Principle #4Asymmetry

2Measurement precision

If signal strength measurements from multiple cells are performed to resolve ambiguity, then positioning accuracy is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmeasurement processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements partial action by having the UE measure signal strengths only from specific cell sets defined by the network (e.g., terrestrial cells or specific non-terrestrial cells), rather than all available cells. The network configures the UE with specific cell sets to measure, reducing the measurement burden while still providing sufficient information to resolve location ambiguity.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent uses an intermediary approach by having the UE report processed signal strength ratio values to the network, rather than raw measurement data. The network then uses these ratios as intermediary information to resolve the ambiguous location estimates, reducing the processing burden on the UE while maintaining positioning accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If detailed signal strength reporting is performed to eliminate mirrored areas, then location determination precision is improved, but latency and resource consumption increase

Engineering Contradiction:
Improvelocation determination precisionVSAvoidpositioning latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by having the network pre-configure the UE with specific cell sets to measure before the positioning event. This preparation reduces the real-time processing burden during the actual positioning measurement, allowing for faster resolution of location ambiguity without sacrificing precision.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4357816A1Device positioning
Publication Date: 2024.04.24 NOKIA TECHNOLOGIES OY
  • EP4357816A1 patent drawingFigure 1
  • EP4357816A1 patent drawingFigure 2a~2b
  • EP4357816A1 patent drawingFigure 3

AI summary

According to an example aspect of the present invention, there is provided an apparatus, such as a user equipment, configured at least to process a measurement instruction received in the apparatus from a cellular communication system, based on the measurement instruction, measure a received signal strength of a signal from each cell of a first cell set and each cell of a second cell set, the first cell set and the second cell set comprising cells of the cellular communication system, and determine a first signal strength value for the first cell set and a second signal strength value for the second cell set, and report to the cellular communication system a value obtained from the first signal strength value and the second signal strength value.