Wi-Fi Backscatter Communication with Low-Power Wake-Up Receiver
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Solution Overview
Problem
Conventional Wi-Fi transceivers require high power levels, conflicting with the low power ideals of IoT devices, and existing backscatter communication solutions are not cost-effective or scalable for widespread deployment using commodity Wi-Fi hardware.
Innovation Solution
A method and integrated device for communicating with commodity Wi-Fi transceivers via backscatter modulation, using a low-power wake-up receiver and modulator to reflect incident Wi-Fi signals with encoded data, enabling Wi-Fi standard compliance and decoding by other Wi-Fi devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional Wi-Fi transceivers are used for communication, then communication capability is achieved, but power consumption increases to 10s to 100s of mW
Solution Approach 1:
The patent introduces a wake-up receiver as an intermediary component that operates in a low-power state to detect incident Wi-Fi signals and trigger the main transceiver only when necessary. This mediator approach allows the system to maintain communication capability while dramatically reducing average power consumption to the μW range during standby periods.
Solution Approach 2:
The system employs periodic wake-up cycles where the low-power wake-up receiver intermittently monitors for incident signals rather than continuously operating the full transceiver. This periodic operation pattern enables the IoT device to achieve communication capability on demand while maintaining extremely low average power consumption during non-communication periods.
2Use of energy by moving object
If backscatter communication is implemented with custom tone generators, then low power consumption is achieved, but deployment cost and complexity increase
Solution Approach 1:
The patent makes the backscatter tag universally compatible with existing commodity Wi-Fi infrastructure by using standard Wi-Fi transceivers and protocols rather than custom tone generators. This universality allows the low-power backscatter communication to be deployed using off-the-shelf Wi-Fi devices, dramatically reducing manufacturing and deployment costs while maintaining μW-level power consumption.
Solution Approach 2:
The system enables self-service deployment by allowing any commodity Wi-Fi device to function as both transmitter and receiver for backscatter communication. This eliminates the need for specialized infrastructure or custom hardware, enabling easy manufacturing and deployment of low-power backscatter tags using only standard Wi-Fi components.
3Ease of manufacture
If Wi-Fi backscatter is implemented with commodity transceivers, then deployment cost is reduced, but communication range is limited to 6-8 meters
Solution Approach 1:
The patent uses preliminary action by employing a wake-up receiver that pre-detects the presence and strength of incident Wi-Fi signals before activating the full backscatter communication function. This preliminary detection allows the system to optimize transmission parameters and select appropriate incident signals, thereby extending the effective communication range beyond the initial 6-8 meter limitation while keeping deployment costs low.
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
The solution achieves low power consumption, enabling IoT devices to operate for extended periods, and allows for communication over substantial distances using commodity Wi-Fi hardware, with a demonstrated range of up to 21 meters and power consumption as low as 2.8 μW during standby.
Implementation Method 1
sensing an incident Wi-Fi-compliant wake-up signal
Implementation Method 2
reflects the incident Wi-Fi-compliant wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant
Implementation Method 3
operating an integrated IQ mixer driving multi-phase-terminated backscatter switches to generate a single-sideband QPSK modulation backscatter tag response
Implementation Method 4
generate a single-sideband QPSK modulation backscatter tag response
Data Source
AI summary
A method for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device is provided. The method includes sensing an incident Wi-Fi? compliant wake-up signal. The method than reflects the incident Wi-Fi-complaint wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant and can be decoded by another WiFi-device. An integrated device includes a downlink Wi-Fi compatible wake-up receiver that checks timing of Wi-Fi compatible signals for a wake-up packet. The device has a modulator that is turned on in response to the wake-up packet and a mixer in the modulator hat mixes tag data with a payload packet from received Wi-Fi payload. Backscatter switches backscatter the response.