Pseudolite Signal Generation for Shielded Space Positioning

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Solution Overview

Problem

Satellite-based positioning systems, such as GPS, face challenges in shielded environments like elongated buildings, covered platforms, underground transport routes, tunnels, and mountains, where a clear line of sight to satellites is obstructed, leading to unreliable positioning.

Innovation Solution

Generating imitating radio signals that mimic satellite signals from fictitious satellites with fictitious data, and modifying real satellite signals by adding fictitious trajectory and position data, allowing mobile devices to receive continuous positioning data even in shielded areas by using infrastructure components like directional antennas and computational units to process and transmit these signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If satellite-based positioning systems are used in shielded environments, then positioning can be provided in open areas, but positioning reliability deteriorates in shielded spaces due to obstructed line of sight to satellites

Engineering Contradiction:
Improvepositioning reliabilityVSAvoidobstruction of satellite signal
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces ground-based pseudolite transceivers as intermediary devices that receive real satellite signals and re-transmit them as pseudo-satellite signals within the shielded environment. These pseudolites act as mediators between the external satellite system and the internal shielded space, enabling positioning without direct satellite visibility. The pseudolites are strategically positioned to provide signal coverage throughout the shielded area, effectively bridging the gap caused by signal obstruction.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates artificial copies of satellite signals by generating pseudo-satellite signals that mimic the structure, format, and characteristics of real GPS satellite signals. Each pseudolite transceiver generates signals that appear to originate from fictional satellite positions, copying the essential features of authentic satellite transmissions. This allows standard GPS receivers to process the signals without modification, maintaining compatibility while providing positioning capability in shielded environments.

Inventive Principle:
Principle #26Copying

2Area of stationary object

If ground-based pseudolite transceivers are deployed to provide positioning in shielded areas, then positioning coverage is improved indoors, but system complexity increases due to additional infrastructure components

Engineering Contradiction:
Improvepositioning coverage areaVSAvoidinfrastructure complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent designs the pseudolite transceivers to perform multiple functions: they receive real satellite signals, process and generate pseudo-satellite signals, provide positioning coverage for shielded areas, and maintain compatibility with standard GPS receivers. This multi-functionality reduces the need for separate systems for different environments, as the same infrastructure can serve both open and shielded areas simultaneously.

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

Solution Approach 2:

The patent divides the positioning coverage area into multiple zones, each served by individual pseudolite transceivers positioned at strategic locations. This segmentation allows the system to cover large or complex shielded environments by distributing multiple smaller transmission points rather than requiring a single comprehensive solution, thereby managing infrastructure complexity through modular deployment.

Inventive Principle:
Principle #1Segmentation

3Duration of action of stationary object

If pseudo-satellite signals are generated and transmitted, then continuous positioning is achieved in shielded spaces, but signal interference and confusion may occur between real and artificial satellite signals

Engineering Contradiction:
Improvecontinuous positioning durationVSAvoidsignal accuracy
Core Design Contradiction:
Duration of action of stationary objectVSLoss of information

Solution Approach 1:

The patent implements frequency differentiation where pseudolite transmitters operate on different frequencies or code sequences than real satellites, allowing receivers to distinguish between authentic and artificial signals. This local quality differentiation ensures that while both signal types are present in the environment, their distinct characteristics prevent confusion and maintain signal accuracy for positioning calculations.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3871010B1Locating method and location arrangement for shielded spaces
Publication Date: 2023.09.06 SIEMENS MOBILITY GMBH DE
  • EP3871010B1 patent drawingFigure 1
  • EP3871010B1 patent drawingFigure 2
  • EP3871010B1 patent drawingFigure 3

AI summary

The invention relates, inter alia, to a method for generating signals which allow a mobile navigation device situated within a shielded space to perform location. According to the invention: at least one imitative radio signal (Sf, Sf1, Sf2, Sf3) is generated which contains fictitious satellite data from at least one fictitious satellite (TS, TS1, TS2, TS3); at least one modified radio signal (Sm1, Sm2) is generated by modification of a received satellite signal from a real satellite (CS1, CS2, CS3, CS4, CS5, CS6) of a real satellite system (50), the modification including adding fictitious trajectory data and/or position data of the at least one fictitious satellite (TS, TS1, TS2, TS3) to satellite data of the received satellite signal; and the at least one imitative radio signal (Sf, Sf1, Sf2, Sf3) and the at least one modified radio signal (Sm1, Sm2) are fed into the shielded space.