GNSS Positioning Device TTFF Reduction via Core Service

Solution Overview

Problem

Current Global Navigation Satellite System (GNSS) positioning devices often experience prolonged Time To First Fix (TTFF) and reduced accuracy due to weak satellite signal strength and lack of line of sight, especially in urban areas and indoors, which negatively impacts user experience.

Innovation Solution

A method where a Core Service in User Equipment communicates with a GNSS positioning device to initiate position determination based on user data, such as power detection or acceleration changes, and uses WWAN/WLAN transceivers to access assistance solutions for faster satellite signal acquisition and improved accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the GNSS positioning device operates in autonomous mode without assistance solutions, then the device can work independently without WWAN/WLAN transceiver, but the Time To First Fix (TTFF) is prolonged and sensitivity is reduced

Engineering Contradiction:

Improveindependent operation capabilityVSAvoidTime To First Fix (TTFF)

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-acquiring and storing ephemeris data, almanac data, and other satellite navigation information in the device's memory before actual positioning is needed. This pre-prepared data is then rapidly loaded and used when positioning is required, significantly reducing the TTFF without requiring continuous network connectivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mechanism in the form of a data processing unit that mediates between the GNSS receiver and the autonomous positioning algorithm. This intermediary pre-processes raw satellite signals, extracts relevant parameters, and prepares optimized data structures for the positioning calculation, enabling faster autonomous positioning.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If the GNSS positioning device operates in autonomous mode without assistance solutions, then the device structure is simpler, but the positioning accuracy is reduced due to lack of valid broadcast ephemeris and timing data

Engineering Contradiction:

Improvedevice structureVSAvoidpositioning accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-acquiring and storing ephemeris data, almanac data, and other satellite navigation information in the device's memory before actual positioning is needed. This pre-prepared data is then rapidly loaded and used when positioning is required, significantly reducing the TTFF without requiring continuous network connectivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements self-service by enabling the GNSS device to autonomously acquire satellite signals, extract navigation data, and compute position without external assistance. The device independently manages its own positioning process, including signal acquisition, data decoding, and position calculation, maintaining simplicity while improving accuracy through optimized autonomous algorithms.

Inventive Principle:

Principle #25Self-service

3Use of energy by moving object

If the GNSS positioning device is activated only when needed, then power consumption is reduced, but the TTFF increases because the device must search from scratch each time

Engineering Contradiction:

Improvepower consumptionVSAvoidTime To First Fix (TTFF)

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-acquiring and storing ephemeris data, almanac data, and other satellite navigation information in the device's memory before actual positioning is needed. This pre-prepared data is then rapidly loaded and used when positioning is required, significantly reducing the TTFF without requiring continuous network connectivity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action by activating the GNSS receiver at regular intervals or based on predefined triggers (such as location changes or time-based schedules) rather than continuously. Between activations, the device maintains positioning capability through stored data and can quickly resume operation, balancing power savings with responsive positioning performance.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9903955B2Time to first fix, TTFF, sensitivity and accuracy for a global navigation satellite system positioning device

Publication Date: 2018.02.27 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

The present invention relates to a method for improving Time To First Fix, TTFF, sensitivity and accuracy, wherein a Global Navigation Satellite System, GNSS, positioning device (15), communicates with a Core Service (11) in a User Equipment (16), U—the GNSS positioning device acquires (23) GNSS satellite signals and navigation data and based on said signals/data determines a position within TTFF,—the Core Service detects (24) user data indicating specific user behaviors and initiates said determination of position based on said user data. The present invention also relates to a Core Service, a Global Navigation Satellite System, GNSS, positioning device, a Radio Module and a User Equipment, UE, adapted for the same purpose.