Full duplex modulated backscatter system
First Claim
1. A radio communication system comprisingan interrogator includingmeans for generating a first modulated signal by modulating a first information signal onto a radio carrier signal;
- means for transmitting said first modulated signal to at least one tag,said at least one tag includingmeans for receiving said first modulated signal at an antenna,backscatter modulator means for modulating the reflection of said first modulated signal from the antenna using a second information signal, thereby forming a second modulated signal which is the reflected first modulated signal which has been further modulated by the second information signal during a period of time when the first information signal is present on the first modulated signal;
said interrogator further includingmeans for demodulating a received second modulated signal, to obtain said second information signal.
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Accused Products
Abstract
A duplex radio communication system includes an Interrogator which generates a first modulated signal by modulating a first information signal onto a radio carrier signal. The Interrogator transmits the first modulated signal to at least one remote Tag of the system. The remote Tag receives and processes the first modulated signal received at its Antenna. A Backscatter Modulator uses a second information signal to modulate the reflection of the first modulated signal from the Antenna, the reflected signal being a second modulated signal. The Interrogator receives and demodulates the second modulated signal to obtain the second information signal.
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Citations
22 Claims
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1. A radio communication system comprising
an interrogator including means for generating a first modulated signal by modulating a first information signal onto a radio carrier signal; -
means for transmitting said first modulated signal to at least one tag, said at least one tag including means for receiving said first modulated signal at an antenna, backscatter modulator means for modulating the reflection of said first modulated signal from the antenna using a second information signal, thereby forming a second modulated signal which is the reflected first modulated signal which has been further modulated by the second information signal during a period of time when the first information signal is present on the first modulated signal; said interrogator further including means for demodulating a received second modulated signal, to obtain said second information signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A tag for use in a radio communication system, comprising
means for receiving a first modulated signal at an antenna, and backscatter modulator means for modulating the reflection of said first modulated signal from the antenna using a second information signal, thereby forming a second modulated signal which is the reflected first modulated signal which has been further modulated by the second information signal during a period of time when the first information signal is present on the first modulated signal.
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21. A method of operating a radio communication system comprising the steps of
generating, at an interrogator, a first modulated signal by modulating a first information signal onto a radio carrier signal; -
transmitting said first modulated signal to at least one tag; at said at least one tag receiving said first modulated signal at an antenna, modulating, using a backscatter modulator, the reflection of said first modulated signal from the antenna using a second information signal, thereby forming a second modulated signal which is the reflected first modulated signal which has been further modulated by the second information signal during a period of time when the first information signal is present on the first modulated signal; demodulating, at said interrogator, a received second modulated signal, to obtain said second information signal.
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22. A method of operating a tag for use in a radio communication system, comprising the steps of
receiving a first modulated signal at an antenna, and modulating, using a backscatter modulator, the reflection of said first modulated signal from the antenna using a second information signal, thereby forming a second modulated signal which is the reflected first modulated signal which has been further modulated by the second information signal during a period of time when the first information signal is present on the first modulated signal.
Specification