Coherent GPS Receiver Multi-Satellite Signal Acquisition

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Solution Overview

Problem

Conventional GPS user receivers face challenges in rapidly and reliably acquiring satellite ranging signals, especially in environments with signal power attenuation or interference, such as indoors or under foliage, due to the fragile nature of signal acquisition processes.

Innovation Solution

A method and GPS receiver design that enables simultaneous acquisition of satellite ranging signals from multiple satellites using a coherent PRN code signal processing scheme, incorporating initialization data, base-station location data, and time aiding to synchronize the user receiver clock, and searching within a predetermined geographic area to combine power outputs and determine the user receiver's location.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional GPS signal acquisition methods are used, then the receiver can acquire satellite signals under normal conditions, but the acquisition process becomes fragile and unreliable in environments with signal power attenuation or interference

Engineering Contradiction:
Improvesignal acquisition reliabilityVSAvoidsignal power attenuation and interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines power outputs from multiple satellites simultaneously in view to determine user receiver location. This merging of multiple signal sources increases the signal-to-noise ratio by 10 dB or more, making acquisition reliable even when individual signals are attenuated or interfered with. The coherent PRN code signal processing scheme integrates signals from all visible satellites rather than acquiring them separately.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses initialization data, base-station location data, and time aiding to synchronize the user receiver clock before signal acquisition. This preliminary synchronization prepares the receiver in advance, allowing it to quickly and reliably acquire signals even in challenging environments. The predetermined geographic area search is also prepared in advance based on base station data.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If simultaneous acquisition of multiple satellite signals is implemented, then the signal-to-noise ratio improves by 10 dB or more, but the processing complexity increases

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses base station data as an intermediary to provide initialization data, location data, and time aiding information. This intermediary preparation reduces the processing burden on the user receiver by pre-synchronizing clocks and pre-defining search areas, enabling simultaneous multi-satellite acquisition without overwhelming complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the processing approach from sequential single-satellite acquisition to simultaneous multi-satellite coherent processing. By modifying the acquisition parameters to process all satellites in view at once using synchronized timing and predetermined search areas, the system achieves 10 dB or more signal-to-noise ratio improvement while managing complexity through structured parameter control.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If differential GPS correction is applied to reduce ranging errors, then positioning accuracy improves, but the system requires additional ground stations and communication infrastructure

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem infrastructure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the base station serve multiple functions: it provides initialization data, location data, time aiding for synchronization, and error correction information. This multi-functionality reduces the need for separate infrastructure components while achieving both differential GPS accuracy and simplified system architecture.

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

Data Source

PatentEP2049915B1A global position system ( GPS) user receiver and geometric surface processing for all-in-view coherent GPS signal pseudo-random noise (PRN) codes acquisition and navigation solution determination
Publication Date: 2010.04.07 THE BOEING CO
  • EP2049915B1 patent drawingFigure 1~2
  • EP2049915B1 patent drawingFigure 3
  • EP2049915B1 patent drawingFigure 4

AI summary

A method and system for enabling a more robust detection, acquisition and positioning solution capability for a GPS device. The system and method uses GPS satellite ranging signals based on a simultaneous, all-in-view coherent PRN code signal processing scheme, rather than acquisition of GPS signals one at a time, in order to predict a location of a GPS user receiver. Additionally, image processing techniques, ultra-tight coupling processing techniques, or a combination thereof, are used to further enhance accuracy in determining the location of the user receiver. Signal processing techniques are used to determine the location of the GPS user receiver when no GPS satellite ranging signals can be individually detected, or when only one or two strong GPS satellite ranging signals can be individually detected in weak signal environments, jamming conditions, and a combination thereof.