Satellite Positioning Using TDOA-DOA Ambiguity Resolution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing positioning technologies using pulse radar waves suffer from ambiguity in TDOA and FDOA, leading to reduced positioning accuracy when multiple satellites are involved.

Innovation Solution

A positioning device that utilizes a combination of TDOA and FDOA calculations, along with DOA estimation, to resolve ambiguities through iterative numerical solutions and centroid calculations, ensuring high accuracy even with pulse radar waves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a positioning device is integrated into a surgical instrument, then positioning accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The positioning device is divided into separate functional modules: a positioning transducer integrated into the surgical instrument, a positioning coil integrated into the needle driver, and a separate processor. This segmentation allows each component to be optimized independently while maintaining overall positioning accuracy without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A positioning coil acts as an intermediary between the positioning transducer and the processor. The coil receives signals from the transducer and transmits them to the processor, enabling wireless communication and reducing the complexity of direct electrical connections while maintaining positioning accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a positioning transducer and coil are integrated into the surgical instrument, then positioning accuracy is improved, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmanufacturing precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The positioning system is segmented into modular components (transducer, coil, processor) that can be manufactured separately using standard precision manufacturing processes, then assembled together. This reduces the overall manufacturing precision requirements compared to creating a fully integrated monolithic device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positioning coil serves multiple functions: it acts as a wireless communication interface, a positioning sensor, and a signal transmitter. This multi-functionality reduces the number of separate components needed, thereby reducing the cumulative manufacturing precision requirements.

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

3Device complexity

If the positioning device uses wireless communication between components, then the device complexity is reduced, but the use of energy increases

Engineering Contradiction:
Improvedevice complexityVSAvoiduse of energy
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The wireless communication between the positioning coil and processor uses periodic signal transmission rather than continuous communication. The system transmits positioning data at discrete intervals during surgical procedures, reducing energy consumption while maintaining positioning accuracy and reducing device complexity.

Inventive Principle:
Principle #19Periodic action

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

The device achieves precise positioning by resolving TDOA and FDOA ambiguities, resulting in accurate determination of the radio wave source's location.

Implementation Method 1

a positioning transducer integrated into the surgical instrument to detect the position of the surgical instrument tip relative to the bone

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a positioning coil integrated into the needle driver and a processor, wherein the positioning coil and the positioning transducer are in wireless communication with one another

Methodology Applied
Scientific EffectElectromagnetic wave transmission: Electromagnetic Induction

Data Source

PatentEP4336207B1Positioning device
Publication Date: 2026.04.29 MITSUBISHI ELECTRIC CORP
  • EP4336207B1 patent drawingFigure 1~2
  • EP4336207B1 patent drawingFigure 3
  • EP4336207B1 patent drawingFigure 4

AI summary

A positioning device according to the present disclosure technology includes a TDOA calculating unit (4) to calculate a TDOA on the basis of a peak of cross-correlation, a TDOA positioning processing unit (5) to perform TDOA positioning on the basis of the TDOA, a DOA estimation processing unit (6) to estimate a DOA from a reception signal received by an array antenna of at least one satellite, a DOA positioning processing unit (7) to perform DOA positioning on the basis of the DOA, and an ambiguity handling unit (8) to select one closest to a result calculated by the DOA positioning processing unit (7) from a plurality of positioning results calculated by the TDOA positioning processing unit (5).