Backscatter Positioning Using Phase Signals in Indoor Shadow Zones

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Solution Overview

Problem

In indoor environments and areas with deep shadow effects, satellite and cellular signals are vulnerable to interference, making accurate positioning challenging for mobile terminals.

Innovation Solution

Utilizing zero-power consumption devices with backscatter communication to determine distance and location information through phase information of backscatter signals transmitted by anchor devices with different frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If GPS and cellular systems are used for positioning, then positioning accuracy is improved in outdoor environments, but positioning fails in indoor environments and areas with deep shadow effects

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning availability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces backscatter signals from anchor devices as an intermediary mechanism to enable positioning in environments where GPS and cellular signals fail. These backscatter signals reflect off zero-power consumption devices and provide alternative measurement data for determining position, thus mediating between the unavailable satellite/cellular signals and the positioning requirement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the fundamental parameter of signal transmission by using backscatter communication instead of active transmission. Zero-power consumption devices modulate reflected signals to carry positioning information, transforming the communication paradigm from active signal generation to passive signal reflection, enabling operation in power-constrained indoor environments.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If zero-power consumption devices are used for assisted positioning, then positioning availability is improved in indoor environments, but device complexity increases

Engineering Contradiction:
Improvepositioning availabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Zero-power consumption devices perform self-service by automatically modulating and reflecting backscatter signals without requiring active power consumption or complex processing. The devices simply reflect incoming signals with modulation based on their state, eliminating the need for batteries, power management circuits, and complex communication protocols.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses simplified copies of communication functionality through backscatter modulation rather than full-featured transceivers. The zero-power devices create simplified signal copies by modulating reflected signals, providing sufficient positioning information without the complexity of complete communication stacks.

Inventive Principle:
Principle #26Copying

3Measurement precision

If multiple backscatter signals with different frequencies are transmitted, then positioning accuracy is improved through phase information, but signal processing complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the positioning measurement process into multiple frequency components, where each backscatter signal at a different frequency provides independent phase information. This segmentation allows the system to process each frequency separately and combine results, improving accuracy while maintaining manageable processing complexity through modular measurement approaches.

Inventive Principle:
Principle #1Segmentation

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

Enables accurate assisted positioning without power consumption, leveraging low-complexity and low-cost devices for improved positioning accuracy in indoor environments.

Implementation Method 1

transmitting, by an anchor device, a plurality of backscatter signals to a target device

Methodology Applied
Scientific EffectBackscatter communication:

Implementation Method 2

phase information of the plurality of backscatter signals transmitted by the anchor device is used to determine distance information

Methodology Applied
Scientific EffectPhase information:

Data Source

PatentEP4629572A1Wireless communication method, and device
Publication Date: 2025.10.08 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP4629572A1 patent drawingFigure 1~3
  • EP4629572A1 patent drawingFigure 4~6
  • EP4629572A1 patent drawingFigure 7~8

AI summary

A wireless communication method, and a device. The method comprises: a target device receiving a plurality of backscatter signals, which are sent by each anchor device of a plurality of anchor devices, wherein the frequencies of the plurality of backscatter signals are different; and determining distance information between the target device and each anchor device according to phase information of the plurality of backscatter signals, which are sent by each anchor point device, wherein distance information between the target device and the plurality of anchor devices is used for determining position information of the target device.