OFDM Backscatter Signal Packet Segmentation for Interference Mitigation
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Solution Overview
Problem
Backscatter devices using an illuminating node for RF carrier generation face interference issues due to the higher power illuminating signal, which affects the reception of backscatter transmission in both monostatic and bistatic scenarios.
Innovation Solution
A method involving an OFDM transmitter that sends a signal packet with an initial portion to trigger and energize the backscatter device, followed by data carrying and illuminating portions to control and facilitate backscatter transmission, allowing for non-overlapping frequency and timing to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an illuminating node is used to generate the RF carrier for backscatter transmission, then power consumption of the backscatter device is significantly reduced, but the backscatter transmission is interfered by the higher power illuminating signal
Solution Approach 1:
The signal packet is segmented into distinct portions: an initial portion for triggering and energy transfer, data carrying portions for control information, and illuminating portions for causing backscatter transmission. This segmentation allows the system to separate the harmful illuminating signal from the useful backscatter transmission in time and frequency domains, reducing interference while maintaining power efficiency
Solution Approach 2:
The patent introduces frequency domain separation by allocating different frequency resources for data carrying and illuminating portions. The frequency indicator for backscatter transmission is configured to cause non-overlapping frequency resources between backscatter transmission and illuminating signal, effectively moving the interference problem from the time domain to the frequency domain where it can be managed through resource allocation
2Power
If the illuminating signal is transmitted with higher power, then the backscatter device can be triggered and energized, but the reception of backscatter transmission is interfered
Solution Approach 1:
The initial portion of the signal packet is designed to trigger the backscatter device circuitry and transfer energy before the illuminating portions are transmitted. This preliminary action ensures the backscatter device is fully activated and ready to operate at optimal power levels before exposure to the high-power illuminating signal, preventing interference during the critical activation phase
Solution Approach 2:
The signal packet uses periodic structure with alternating data carrying portions and illuminating portions. The frequency indicator configures the backscatter transmission to occur during specific time periods when illuminating portions are not transmitted, creating a periodic pattern that allows reliable reception during designated time windows while still providing sufficient illuminating power during other periods
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 enables efficient backscatter transmission without the need for dedicated illumination or reading devices, allowing for coexistence with legacy systems and reuse of existing OFDM transceiver units.
Implementation Method 1
A device comprising a backscatter radio may be referred to as a backscatter device... the backscatter transmission is performed in accordance with the control information
Data Source
AI summary
Methods, signal packets, orthogonal frequency division multiplexing (OFDM) transmitters, backscattering devices and corresponding computer program products are disclosed. According to one aspect, a signal packet is provided for transmission by an OFDM transmitter of to illuminate a backscatter device. The signal packet includes an initial portion to trigger circuitry of the backscatter device for operation, and to transfer energy to the backscatter device. The signal packet includes a data carrying portion providing control information. The data carrying portion includes to the backscatter device regarding backscatter transmission, and an illuminating portion to cause backscatter transmission within a duration of the illuminating portion in accordance with the control information. Also disclosed are a method for an OFDM transmitter and a method for a backscatter device.