REFLECTIVE COMMUNICATION USING RADIO-FREQUENCY DEVICES
First Claim
1. A reflective communication system, comprising:
- a plurality of transmitters that operate on the same frequency wherein each of said plurality of transmitters is adapted to transmit communication signals having different spread spectrum codes;
a plurality of wireless communication devices located in the transmission field of said plurality of transmitters that receive said communication signals from said plurality of transmitters wherein said plurality of wireless communication devices reflectively modulate said communication signals with data signals having a second modulation to form reflected data signals; and
a receiver adapted to receive said reflected data signals from said plurality of wireless communication devices and determine said spread spectrum codes in said reflected data signals in order to determine which of said plurality of transmitters originated said communication signals reflected by said plurality of wireless communications device to determine the approximate location of said wireless communication devices.
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Accused Products
Abstract
The present invention relates to a reflective communication system that allows information from wireless communication devices, such as radio-frequency identification devices (RFID), to be reflectively communicated to a receiver in lieu of using a separate communication system. A transmitter transmits a communication signal, having a carrier frequency, to the wireless communication device to provide power. The wireless communication device modulates a data signal onto the communication signal to form a reflected data signal. The wireless communication device reflects the reflected data signal directly to the receiver. In this manner, the process of communicating information from a wireless communication device is accomplished in one communication system rather than two. If the receiver also directly receives the communication signal from the transmitter, the receiver can determine the location of the wireless communication device relative to the transmitters.
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Citations
37 Claims
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1. A reflective communication system, comprising:
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a plurality of transmitters that operate on the same frequency wherein each of said plurality of transmitters is adapted to transmit communication signals having different spread spectrum codes;
a plurality of wireless communication devices located in the transmission field of said plurality of transmitters that receive said communication signals from said plurality of transmitters wherein said plurality of wireless communication devices reflectively modulate said communication signals with data signals having a second modulation to form reflected data signals; and
a receiver adapted to receive said reflected data signals from said plurality of wireless communication devices and determine said spread spectrum codes in said reflected data signals in order to determine which of said plurality of transmitters originated said communication signals reflected by said plurality of wireless communications device to determine the approximate location of said wireless communication devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A reflective communication system, comprising:
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a plurality of transmitters that each transmit communication signals according to different frequency-hopping sequences;
a plurality of wireless communication devices located in the transmission field of said plurality of transmitters that receive said communication signals from said plurality of transmitters wherein said plurality of wireless communication devices reflectively modulate said communication signals with data signals having a second modulation to form reflected data signals; and
a receiver adapted to receive said reflected data signals from said plurality of wireless communication devices and determine said frequency hopping sequence in said reflected data signals in order to determine which of said plurality of transmitters originated said communication signals reflected by said plurality of wireless communications device to determine the approximate location of said wireless communication devices. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method of determining the origination of a data signal reflected by a wireless communication device using a communication signal from a transmitter as a communication medium, comprising:
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transmitting communication signals having modulation at the same frequency and each with different spread spectrum codes at plurality of transmitters;
reflectively modulating said communication signals with data signals to form reflected data signals at wireless communication devices;
receiving said reflected data signals at a receiver; and
determining which particular one transmitter in said plurality of transmitters originated a particular one of said reflected data signals by correlating the spread spectrum code in said one of said reflected data signal. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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25. A method of determining the origination of a data signal reflected by a wireless communication device using a communication signal from a transmitter as a communication medium, the method comprising:
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transmitting communication signals having a first modulation according to different frequency-hopping sequences from a plurality of transmitters;
reflectively modulating said communication signals with data signals having a second modulation to form reflected data signals at wireless communication devices;
receiving said reflected data signals at a receiver; and
determining a particular transmitter in said plurality of transmitters that originated a particular reflected data signal by correlating the frequency hopping sequence in said particular reflected data signal with said particular transmitter. - View Dependent Claims (26, 27, 28, 29, 30, 31)
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32. A method of determining the origination of a data signal reflected from a wireless communication device using communication signals from a plurality of transmitters as a communication medium, the method comprising:
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reflectively modulating said communication signals to form reflected data signals, wherein the communication signals have a first modulation at the same frequency and have different spread spectrum codes, and wherein the communication signals are modulated with data signals having a second modulation frequency to form said reflected data signals; and
correlating the spread spectrum codes to the plurality of transmitters to determine which of the plurality of transmitters originated a particular reflected data signal. - View Dependent Claims (33, 34)
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35. A method of determining the origination of a data signal reflected from a wireless communication device using communication signals from a plurality of transmitters as a communication medium, the method comprising:
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reflectively modulating said communication signals to form reflected data signals, wherein the communication signals have a first modulation according to different frequency-hopping sequences, and wherein the communication signals are modulated with data signals having a second modulation frequency to form said reflected data signals; and
correlating the frequency-hopping sequences to the plurality of transmitters to determine which of the plurality of transmitters originated a particular reflected data signal. - View Dependent Claims (36)
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37. A reflective communication system for determining the origination of a data signal reflected from a wireless communication device using communication signals from a plurality of transmitters as a communication medium, the system comprising:
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means for reflectively modulating said communication signals to form reflected data signals, wherein the communication signals have a first modulation according to different frequency-hopping sequences, and wherein the communication signals are modulated with data signals having a second modulation frequency to form said reflected data signals; and
means for correlating the frequency-hopping sequences to the plurality of transmitters to determine which of the plurality of transmitters originated a particular reflected data signal.
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Specification