Signal masking for secure backscattered communication

Patent metadata

Field	Value
Publication number	US-12284028-B2
Application number	US-202318303124-A
Country	US
Kind code	B2
Filing date	Apr 19, 2023
Priority date	Apr 19, 2023
Publication date	Apr 22, 2025
Grant date	Apr 22, 2025

Abstract

Examples are disclosed that relate to improving security of radio frequency (RF) backscattered communication. In one example, a RF device includes a primary RF signal receiver, a secondary signal receiver, a signal mixer, and a transmitter. The primary RF signal receiver is configured to receive a RF carrier signal sent from a base station. The secondary signal receiver is configured to receive a masking signal from the base station. The signal mixer is configured to generate a response signal based at least on the RF carrier signal and generate a mixed signal by mixing the response signal and the masking signal. The transmitter is configured to broadcast the mixed signal, via backscattering, as a masked backscattered signal.

First claim

The invention claimed is:

1. A radio frequency (RF) device, comprising:
a primary RF signal receiver configured to receive a RF carrier signal sent from a base station;
a secondary signal receiver configured to receive a masking audio signal from the base station;
a signal mixer configured to generate a response signal based at least on the RF carrier signal and generate a mixed signal by mixing the response signal and the masking audio signal; and
a transmitter configured to broadcast the mixed signal, via backscattering, as a masked backscattered signal.

2. The RF device of claim 1 , further comprising:
a sensor configured to sense a signal, and wherein the signal mixer is configured to generate the response signal based at least on the sensed signal.

3. The RF device of claim 2 , wherein the sensed signal is an audio signal.

4. The RF device of claim 2 , wherein the sensed signal is a resistive or capacitive signal.

5. The RF device of claim 1 , wherein the RF device and the base station are positioned on a shared substrate, and wherein the masking audio signal is transmitted through the shared substrate.

6. The RF device of claim 1 , further comprising:
an energy harvester configured to harvest energy from the RF carrier signal, wherein the harvested energy is supplied to the transmitter to broadcast the masked backscattered signal.

7. The RF device of claim 1 , wherein a shape of a noise profile of the masking audio signal is based at least on a frequency or temporal characteristic of the response signal.

8. The RF device of claim 1 , wherein the masking audio signal is configured to obfuscate a part of interest of the response signal.

9. The RF device of claim 1 , wherein the masking audio signal encodes an individualized identifier associated with the RF device.

10. A method comprising:
receiving, via a primary RF signal receiver of an RF device, a RF carrier signal sent from a base station;
receiving, via a secondary signal receiver of the RF device, a masking audio signal from the base station;
generating, via a signal mixer of the RF device, a response signal based at least on the RF carrier signal;
generating, via the signal mixer of the RF device, a mixed signal by mixing the response signal and the masking audio signal; and
broadcasting the mixed signal via a transmitter of the RF device, via backscattering, as a masked backscattered signal.

11. The method of claim 10 , further comprising:
sensing, via a sensor, a signal, and wherein the response signal is generated based at least on the sensed signal.

12. The method of claim 10 , further comprising:
harvesting energy from the RF carrier signal via an energy harvester, and wherein the harvested energy is supplied to the transmitter to broadcast the masked backscattered signal.

13. The method of claim 10 , wherein the RF device and the base station are positioned on a shared substrate, and wherein the masking audio signal is transmitted through the shared substrate.

14. The method of claim 10 , wherein a shape of a noise profile of the masking audio signal is based at least on a frequency or temporal characteristic of the response signal.

15. The method of claim 10 , wherein the masking audio signal is configured to obfuscate a part of interest of the response signal.

16. The method of claim 10 , wherein the masking audio signal encodes an individualized identifier associated with the RF device.

17. A battery-free RF device, comprising:
a primary RF signal receiver configured to receive a RF carrier signal sent from a base station positioned on a shared substrate with the battery-free RF device;
an energy harvester configured to harvest energy from the RF carrier signal;
a secondary signal receiver configured to receive a masking audio signal from the base station through the shared substrate;
a signal mixer configured to generate a response signal based at least on the RF carrier signal and generate a mixed signal by mixing the response signal and the masking audio signal; and
a transmitter configured to broadcast the mixed signal, via backscattering, as a masked backscattered signal using the energy harvested from the RF carrier signal.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Nattar Ranganathan Vaishnavi
• Priyantha Nissanka Arachchige Bodhi
• Nakahara Mike
• Iyer Vikram Subramaniam
• Desai Harsh Sandesh

Classifications

• H04B13/00

  Transmission systems characterised by the medium used for transmission, not provided for in groups H04B3/00 - H04B11/00 · CPC title

• H04B11/00

  Transmission systems employing ultrasonic, sonic or infrasonic waves · CPC title

• H04B10/1149

  Arrangements for indoor wireless networking of information · CPC title

• H04B1/18

  Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) · CPC title

• H04K3/827

  using characteristics of target signal or of transmission (as countermeasure against jamming H04K3/25), e.g. using direct sequence spread spectrum or fast frequency hopping (spread spectrum techniques H04B1/69) · CPC title