Tagging objects in indoor spaces using ambient, distributed backscatter
AssigneeNEC Corporation
InventorsKarthikeyan Sundaresan, Eugene Chai, Sampath Rangarajan
Life of this patent
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Abstract
A product tagging system is provided. The product tagging system includes at least one RF backscatter transmitter configured to emit a Radio Frequency (RF) signal on a frequency. The product tagging system further includes a passive RF backscatter tag associated with a product and configured to reflect and frequency shift the RF signal to a different frequency. The product tagging system also includes at least one RF backscatter receiver configured to read the product on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag.
Claims18
A product tagging system, comprising:
- at least one RF backscatter transmitter configured to emit a Radio Frequency (RF) signal on a frequency;
- a passive RF backscatter tag associated with a product and configured to reflect and frequency shift the RF signal to a different frequency;
- and
- at least one RF backscatter receiver configured to read the product on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag, wherein the passive RF backscatter tag generates the distributed ambient backscatter signal as multiple signals comprising a fundamental frequency and at least one harmonic frequency;
- and
- a tuning circuit, coupled to an antenna, configured to amplify the at least one harmonic frequency.
A method for product tagging, comprising:
- emitting, by at least one RF backscatter transmitter, a Radio Frequency (RF) signal on a frequency;
- reflecting and frequency shifting, by a passive RF backscatter tag associated with a product, the RF signal to a different frequency;
- reading, by at least one RF backscatter receiver, the product on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag;
- carrying, by a first transmission channel, the desired RF carrier signal;
- carrying, by a second transmission channel, two carrier tones needed to generate the distributed ambient backscatter signal.
Dependencies are inferred from the claim text.