Multi-Frequency Positioning Signal Bias Conversion for Error Correction

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Solution Overview

Problem

Existing positioning systems face reduced accuracy due to the inability to correct errors in ranging signals when the signal type of the ranging signal and the signal type of the error information do not match, preventing effective use in positioning calculations.

Innovation Solution

A positioning apparatus that converts error information to a usable signal type by utilizing conversion formulas and tables to align error information with the signal type of the ranging signal, enabling accurate positioning calculations even when signal types mismatch.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If error information is provided for specific signal types (e.g., L1C/A, L2P, L2C), then correction accuracy for matching signals is improved, but the flexibility and usability of error information for different signal types deteriorates

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal type compatibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by converting error information between different signal types using conversion formulas. The conversion unit changes the signal type parameter of error information (e.g., converting from L1C/A to L2P) while maintaining the essential correction capability, allowing error information to be adapted to different signal types without losing its corrective function

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The conversion unit acts as an intermediary between error information and ranging signals with mismatched signal types. It transforms the error information into a compatible signal type, enabling the error correction function to bridge the gap between incompatible signal types and maintain positioning accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If multiple pieces of error information are provided for different signal types, then correction capability for each signal type is improved, but the complexity of managing and matching error information deteriorates

Engineering Contradiction:
Improveerror correction capabilityVSAvoiderror information management
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements universality by enabling error information to serve multiple signal types through conversion. Instead of requiring separate error information for each signal type, the system can convert a single set of error information to match different ranging signal types, reducing the overall quantity of error information needed while maintaining comprehensive correction capability

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

Solution Approach 2:

The conversion unit dynamically changes the signal type parameter of error information based on the received ranging signal type. This parameter transformation allows the system to adapt existing error information to different signal types on-demand, simplifying the management structure by reducing the need to maintain separate error information for each signal type

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4075167B1Positioning device and augmentation information generation apparatus
Publication Date: 2025.08.13 MITSUBISHI ELECTRIC CORP
  • EP4075167B1 patent drawingFigure 1
  • EP4075167B1 patent drawingFigure 2
  • EP4075167B1 patent drawingFigure 3

AI summary

A first bias conversion unit (26) converts, based on a first frequency and a second frequency, a signal bias (PBi) related to carrier phase for correcting a carrier phase (ϕi) contained in a first ranging signal having the first frequency, to a signal bias (PBj) related to carrier phase for correcting a carrier phase (ϕj) contained in a second ranging signal having the second frequency. A first correction unit (28) corrects the carrier phase (ϕj) using the converted signal bias (PBj). A second bias conversion unit (27) converts the signal bias (PBi) related to pseudorange to the signal bias (PBj) related to pseudorange by making reference to a conversion table (41) indicating values for use in conversion of the signal bias (PBi) related to pseudorange to the signal bias (PBj) related to pseudorange. A second correction unit (29) corrects a pseudorange (Pj) using the converted signal bias (CBj).