Frequency-Translated Backscatter for AMP Tag Self-Interference
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Solution Overview
Problem
Existing UE hardware architectures face challenges in supporting ambient power tags due to self-interference from high-power excitation signals overpowering tag responses, making it costly to integrate AMP readers without modifying the receiver architecture.
Innovation Solution
Implement frequency-translated backscatter modulation where the UE transmits an excitation waveform in a first subchannel and the AMP tag backscatters the response in a separate subchannel, applying a frequency shift to reduce interference and enable decoding without modifying the UE's receiver architecture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the UE transmits high-power excitation signals to power ambient power tags, then the tags can be powered wirelessly, but the excitation signals overpower the tag responses causing self-interference at the UE receiver
Solution Approach 1:
The channel bandwidth is divided into multiple subchannels, with the first subchannel dedicated to receiving excitation waveforms and the second subchannel dedicated to transmitting backscattered response waveforms. This frequency division separates the high-power excitation signals from the weak tag responses, allowing the UE to transmit and receive simultaneously without self-interference overpowering the receiver.
2Device complexity
If the UE integrates AMP reader functionality without modifying receiver architecture, then hardware complexity is reduced, but self-interference from excitation signals cannot be adequately handled
Solution Approach 1:
The solution moves from time-division or code-division separation to frequency-division separation by assigning excitation and response communications to different subchannels. This frequency domain approach enables the UE to simultaneously transmit high-power excitation signals and receive weak tag responses without requiring complex receiver architecture modifications like self-interference cancellation circuits.
3Device complexity
If the tag backscatters responses in the same subchannel as the excitation signal, then the system is simpler, but the response signal cannot be distinguished from the excitation signal
Solution Approach 1:
The channel bandwidth is segmented into multiple subchannels, with the first subchannel for excitation waveforms and the second subchannel for backscattered response waveforms. This frequency segmentation allows the tag to backscatter responses that are clearly distinguishable from the excitation signals, enabling reliable information extraction without increasing system complexity.
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 approach reduces interference and complexity at the UE, allowing integration of AMP readers without hardware modifications, thereby enhancing data rate and accessibility of ambient power tag communications.
Implementation Method 1
the backscattered response waveform is based on a frequency translation of signal energy of the excitation waveform from the first subchannel to the second subchannel
Data Source
AI summary
This disclosure provides methods, components, devices and systems for frequency-translated backscatter modulation for ambient power (AMP) tags. In some examples, a user equipment (UE) may transmit an excitation signal to an AMP tag via a first subchannel of a channel bandwidth. The AMP tag may transmit a backscattered tag response to the UE via a second subchannel of the channel bandwidth based on receiving the excitation waveform. In some examples, the AMP tag may modulate information with the backscattered tag response by translating the excitation signal to the second subchannel such that the backscattered tag response does not interfere with the excitation waveform. The second subchannel that includes the backscattered tag response may indicate one or more information bits associated with the backscattered tag response. The UE may decode information bits from the backscattered tag response using an energy detection operation.