Crystal Oscillator Frequency Compensation for Thermal GPS Drift

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Solution Overview

Problem

The accuracy of GPS in mobile devices is compromised due to the sensitivity of crystal oscillators to heat conduction, particularly in complex hardware environments like 5G terminals, leading to deteriorated frequency characteristics and GPS performance.

Innovation Solution

A method and circuit for frequency compensation that involves determining speed information, converting it into acceleration values, and compensating the crystal oscillator frequency based on these values to correct for thermal transient jitter effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple frequency multi-mode wireless modules are added to enhance terminal functionality, then the adaptability and versatility of the terminal device is improved, but the heat generation from additional components deteriorates the stability of the crystal oscillator and GPS measurement accuracy

Engineering Contradiction:

Improvefunctionality of terminal deviceVSAvoidGPS measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the parameter of crystal oscillator frequency by introducing a compensation value based on acceleration data. The frequency compensation module adjusts the oscillator frequency dynamically according to the calculated compensation value, which is derived from acceleration information and predetermined coefficients, thereby maintaining GPS accuracy despite thermal variations from additional wireless modules

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where acceleration information is continuously obtained, processed to generate compensation values, and used to adjust the crystal oscillator frequency in real-time. This closed-loop feedback system compensates for thermal effects caused by multiple wireless modules, ensuring sustained GPS measurement accuracy

Inventive Principle:

Principle #23Feedback

2Device complexity

If the crystal oscillator is positioned close to other heat-generating components to save space, then the device complexity is reduced, but the thermal protection and stability of the crystal oscillator deteriorate

Engineering Contradiction:

Improvecircuit layout complexityVSAvoidheat conduction effect on crystal oscillator

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/physical solution of spatial separation with a software-based compensation approach. Instead of physically isolating the crystal oscillator from heat-generating components, the system uses acceleration sensors and algorithmic compensation to counteract thermal effects, thereby maintaining GPS accuracy without increasing hardware complexity or changing physical layout

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If software-based frequency compensation is implemented to correct thermal effects, then the GPS measurement accuracy is improved, but the device complexity increases due to additional processing requirements

Engineering Contradiction:

ImproveGPS measurement accuracyVSAvoidprocessing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies partial compensation by using only the necessary acceleration data and predetermined coefficients to calculate compensation values. The frequency compensation module implements selective adjustment of the crystal oscillator frequency based on calculated compensation values, avoiding full-system reconfiguration and reducing processing complexity while maintaining measurement precision

Inventive Principle:

Principle #16Partial or excessive 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

Improves GPS performance by correcting acceleration errors caused by thermal transient jitter, ensuring accurate frequency synthesis and enhanced GPS accuracy.

Implementation Method 1

a speed sensor, configured to obtain speed information of a terminal device relative to a predetermined device, wherein the speed information includes acceleration information and vector information

Methodology Applied

Scientific EffectAcceleration detection: Accelerometer

Implementation Method 2

a variable capacitance control unit, configured to compensate a frequency of a crystal oscillator in the terminal device based on the first acceleration value and a second acceleration value

Methodology Applied

Scientific EffectFrequency compensation:

Data Source

PatentUS12474485B2Method and circuit for frequency compensation, storage medium, and electronic device

Publication Date: 2025.11.18 ZTE CORP

AI summary

A method and circuit for frequency compensation, a storage medium, and an electronic device, the method including: determining speed information of a terminal device relative to a predetermined device, where the speed information includes acceleration information and vector information; converting the speed information into a first acceleration value corresponding to a Global Positioning System (GPS) device; and compensating a frequency of a crystal oscillator in the terminal device based on the first acceleration value and a second acceleration value, where the second acceleration value is an actual acceleration value of the GPS device determined by the terminal device.