Apparatuses, systems, and methods for communicating using MIMO and spread spectrum coding in backscatter of ambient signals
First Claim
1. A system comprising:
- an ambient RF backscatter transceiver comprising;
a first antenna configured to receive a backscattered ambient radio frequency (RF) signal;
a second antenna configured to receive the backscattered ambient radio frequency (RF) signal; and
a receiver coupled to the first antenna and the second antenna, wherein the receiver is configured to demodulate the backscattered ambient RF signal to provide output bits using at least one of;
multiple input, multiple output multiplexing demodulation based on a ratio of a magnitude of the backscattered ambient radio frequency signal received via the first antenna to a magnitude of the backscattered ambient radio frequency signal received via the second antenna or spread spectrum code demodulation based on a chip duration;
wherein the backscattered ambient RF signal is generated by backscattering an ambient RF signal at a first frequency, the ambient RF signal configured to provide additional data at a second frequency.
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Accused Products
Abstract
Apparatuses, systems, ambient RF backscatter transceivers, and methods for communicating using MIMO and spread spectrum coding of backscattered ambient RF signals are described. An example system may include an ambient RF backscatter transceiver that include an antenna configured to receive a backscattered ambient radio frequency (RF) signal, and a receiver coupled to the antenna. The receiver may be configured to demodulate the backscattered ambient RF signal using one of multiple input, multiple output multiplexing demodulation or spread spectrum code demodulation to retrieve the first data. The backscattered ambient RF signal may be generated by backscattering an ambient RF signal at a first frequency. The ambient RF signal may be configured to provide other data at a second frequency.
110 Citations
34 Claims
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1. A system comprising:
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an ambient RF backscatter transceiver comprising; a first antenna configured to receive a backscattered ambient radio frequency (RF) signal; a second antenna configured to receive the backscattered ambient radio frequency (RF) signal; and a receiver coupled to the first antenna and the second antenna, wherein the receiver is configured to demodulate the backscattered ambient RF signal to provide output bits using at least one of;
multiple input, multiple output multiplexing demodulation based on a ratio of a magnitude of the backscattered ambient radio frequency signal received via the first antenna to a magnitude of the backscattered ambient radio frequency signal received via the second antenna or spread spectrum code demodulation based on a chip duration;wherein the backscattered ambient RF signal is generated by backscattering an ambient RF signal at a first frequency, the ambient RF signal configured to provide additional data at a second frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An ambient RF backscatter transceiver comprising:
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a first antenna configured to receive a backscattered ambient radio frequency (RF) signal and to provide a first backscattered signal, the backscattered ambient RF signal encoded with first data via backscatter modulation of an ambient RF signal at a first frequency, the ambient RF signal modulated to provide second data at a second frequency; a second antenna configured to receive the backscattered ambient radio frequency (RF) signal and to provide a second backscattered signal having a phase offset relative to the first backscattered signal, a receiver coupled to the first antenna and the second antenna, wherein the receiver is configured to demodulate the backscattered ambient RF signal using multiple input, multiple output multiplexing demodulation based on a ratio of a magnitude of the first backscattered signal to a magnitude of the second backscattered signal to provide output bits; and a microcontroller coupled to the receiver and configured to decode the output bits to retrieve data that is transmitted via the backscattered ambient RF signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21)
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22. An ambient RF backscatter transceiver comprising:
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an antenna configured to receive a backscattered ambient radio frequency (RF) signal, the backscattered ambient RF signal encoded with using spread spectrum coding of data bits via chips via backscatter modulation of an ambient RF signal at a first frequency, the ambient RF signal modulated to provide second data at a second frequency; a receiver coupled to the antenna, wherein the receiver is configured to demodulate the backscattered ambient RF signal using a spread spectrum code demodulation circuit based partly on a chip length to provide output bits, wherein a chip of the backscattered ambient RF signal having a first value is alternative ones and zeroes, and a chip of the backscattered ambient RF signal having a second value is all zeroes, wherein the spread spectrum code demodulation circuit comprises; a first switch configured to be modulated between the backscattered ambient RF signal and an inverted backscattered ambient RF signal at a period equal to the chip length multiplied by a chip rate; and a second switch configured to be modulated with a ninety degree offset from the first switch between the backscattered ambient RF signal and the inverted backscattered ambient RF signal at a period equal to the chip length multiplied by the chip rate; and a microcontroller coupled to the receiver and configured to decode the output bits to retrieve data that is transmitted via the backscattered ambient RF signal. - View Dependent Claims (23, 24, 25, 26)
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27. A method, comprising:
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receiving a backscattered ambient radio frequency (RF) signal at a first antenna, the backscattered ambient RF signal encoded with first data via backscatter modulation of an ambient RF signal at a first frequency, the ambient RF signal modulated to provide second data at a second frequency; receiving the backscattered ambient RF signal at a second antenna; demodulating the backscattered ambient RF signal using at least one of multiple input, multiple output multiplexing demodulation based on a ratio of a magnitude of the backscattered ambient radio frequency signal received via the first antenna to a magnitude of the backscattered ambient radio frequency signal received via the second antenna or spread spectrum code demodulation based on a chip duration; and retrieving the first data based on a demodulated backscattered ambient RF signal. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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Specification