DPSK Touch Signal Demodulation Without Loop Filters or VCOs

Solution Overview

Problem

Existing differential phase-shift keying demodulation methods in data processing devices require costly loop filters and voltage-controlled oscillators, leading to high power consumption.

Innovation Solution

A data processing system that omits loop filters and voltage-controlled oscillators by using a stylus with transmitting electrodes and a touch device equipped with an analog-to-digital conversion circuit, spectrum extraction circuit, amplitude and phase extraction circuit, and demodulation circuit to obtain pressure and position data without generating reference waves, thereby reducing cost and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If loop filters and voltage-controlled oscillators are used for differential phase-shift keying demodulation, then demodulation accuracy is improved, but device cost and power consumption increase

Engineering Contradiction:

Improvedemodulation accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts and removes the loop filter and voltage-controlled oscillator components from the traditional differential phase-shift keying demodulation system. By using direct digital synthesis to generate reference waves and performing demodulation through digital signal processing, the system achieves accurate demodulation without the power-hungry analog components, thus resolving the contradiction between demodulation accuracy and power consumption

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the analog mechanical system (loop filters and voltage-controlled oscillators) with a digital system. Digital reference wave generation and digital demodulation algorithms substitute for the analog components, maintaining demodulation precision while dramatically reducing power consumption and eliminating the need for costly analog circuitry

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If loop filters and voltage-controlled oscillators are used for differential phase-shift keying demodulation, then demodulation accuracy is improved, but device cost increases

Engineering Contradiction:

Improvedemodulation accuracyVSAvoiddevice cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts and removes the loop filter and voltage-controlled oscillator components from the traditional differential phase-shift keying demodulation system. By using direct digital synthesis to generate reference waves and performing demodulation through digital signal processing, the system achieves accurate demodulation without the power-hungry analog components, thus resolving the contradiction between demodulation accuracy and power consumption

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the analog mechanical system (loop filters and voltage-controlled oscillators) with a digital system. Digital reference wave generation and digital demodulation algorithms substitute for the analog components, maintaining demodulation precision while dramatically reducing power consumption and eliminating the need for costly analog circuitry

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of information

If traditional differential phase-shift keying demodulation is used, then pressure sensing data can be obtained, but computational complexity and power consumption are high

Engineering Contradiction:

Improvepressure sensing data acquisitionVSAvoidcomputational power consumption

Core Design Contradiction:

Loss of informationVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic action by using direct digital synthesis to generate reference waves at the same frequency as the modulation carrier. This periodic reference wave generation enables efficient correlation-based demodulation, reducing computational complexity compared to traditional methods while maintaining accurate pressure sensing data acquisition

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent replaces the analog mechanical system (loop filters and voltage-controlled oscillators) with a digital system. Digital reference wave generation and digital demodulation algorithms substitute for the analog components, maintaining demodulation precision while dramatically reducing power consumption and eliminating the need for costly analog circuitry

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS20260003458A1Data processing device and system

Publication Date: 2026.01.01 FITIPOWER INTEGRATED TECH SHENZHEN INC

AI summary

A data processing device is provided, including a spectrum extraction circuit configured to receive a first electrode signal and obtain a first component signal having a first preset frequency in the first electrode signal; an amplitude and phase extraction circuit, electrically connected to the spectrum extraction circuit, configured to generate a differential phase-shift keying signal, the differential phase-shift keying signal includes a real part of phase and an imaginary part of phase of the first component signal; a demodulation circuit, electrically connected to the amplitude and phase extraction circuit, configured to demodulate the differential phase-shift keying signal according to a phase angle to obtain data information in the first electrode signal, the phase angle is an arctangent value of a ratio of the real part of phase to the imaginary part of phase.