WET-Assisted Ambient IoT Backscatter Without Downlink Interference

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Solution Overview

Problem

Existing wireless communication systems for IoT devices face challenges in efficiently managing interference between downlink transmissions and wireless power transfer signals, which affects the reliability and efficiency of IoT device communication.

Innovation Solution

A wireless energy transmitter (WET) device configures a continuous wave (CW) signal to avoid interference with downlink transmissions by transmitting the CW signal in a different frequency band or using time-division multiplexing, and the IoT device backscatters and modulates the CW signal for uplink transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a network entity transmits both downlink signals and wireless power transfer signals, then the IoT device can receive power and data, but self-interference occurs between the transmitted signals

Engineering Contradiction:

Improvewireless power transfer to IoT deviceVSAvoidself-interference between downlink and power transfer signals

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent divides the transmission functions by introducing a separate WET device dedicated to wireless power transfer, while the network entity focuses on downlink communications. This segmentation eliminates self-interference by separating the power transmission function from the communication function into different physical devices.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The WET device acts as an intermediary between the network entity and the IoT device for power transfer operations. The WET device receives configuration information from the network entity and independently manages CW signal transmission, serving as a mediator that handles power transfer without creating interference with downlink signals.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the network entity processes both downlink transmissions and backscattered uplink signals, then communication is enabled, but processing requirements and complexity increase

Engineering Contradiction:

Improvesignal processing capabilityVSAvoidprocessing requirements for network entity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent segments the signal processing functions by having the WET device handle CW signal transmission and the network entity handle only downlink communications and backscattered signal reception. This division reduces the processing burden on the network entity, as it no longer needs to manage both power transmission and signal processing simultaneously.

Inventive Principle:

Principle #1Segmentation

3Use of energy by moving object

If CW signal transmission is used for wireless power transfer, then power can be transmitted to ambient IoT devices, but interference with downlink transmissions occurs

Engineering Contradiction:

Improvewireless power transferVSAvoidinterference with downlink transmission

Core Design Contradiction:

Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The WET device serves as an intermediary that transmits CW signals for power transfer while being coordinated by the network entity. The WET device receives configuration information including time-frequency resource allocations from the network entity, allowing it to transmit power signals without interfering with downlink communications.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically allocates time-frequency resources for CW signal transmission based on downlink communication requirements. The WET device adjusts its transmission timing and frequency according to configuration information received from the network entity, enabling dynamic avoidance of interference with downlink signals.

Inventive Principle:

Principle #15Dynamics

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

This solution reduces the processing requirements for network entities, minimizes self-interference, and enhances the separation between transmit and receive antennas, thereby improving the decoding capability and reducing costs associated with deploying additional network entities.

Implementation Method 1

transmit the CW signal for wireless power transfer to at least one ambient Internet of Things (IoT) device

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

backscatter and modulate at least the CW signal to produce a modulated CW signal

Methodology Applied

Scientific EffectBackscattering: Reflection

Data Source

PatentUS20250192929A1Enhancing communication in ambient IoT with wireless energy transmitters

Publication Date: 2025.06.12 QUALCOMM INC

AI summary

Aspects relate to enhancing communication between ambient IoT devices and network entities using wireless energy transmitter (WET) devices. A WET device may be configured to provide a continuous wave (CW) signal to an ambient IoT device to both power the ambient IoT device and facilitate backscattering and modulation of the CW signal by the IoT device. The IoT device may then transmit the backscattered and modulated CW signal as an uplink transmission to a network entity for processing of the modulated CW signal. The WET device may further avoid interference with a downlink transmission from the network entity by avoiding transmission of the CW signal within downlink slots, transmitting the CW signal within a different frequency band than the downlink transmission, and/or transmit the CW signal on a helper tone separated in frequency from a data tone of the downlink transmission.