Method and system for radio-frequency proximity detection using received signal strength variance
First Claim
1. A method for determining proximity between a first wireless device and a second wireless device, said method comprising:
- receiving a first signal from said first wireless device at said second wireless device;
in response to said receiving, determining a signal strength of said received signal;
computing a variance of said signal strength over time; and
determining whether or not said first wireless device is within a proximity range of said second wireless device in conformity with said computed variance.
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Accused Products
Abstract
A method and system for radio-frequency proximity detection uses received signal strength variance to determine proximity distance. A signal is received from a transmitting device by a receiving device and the variance of the signal computed over time. One or more ranges can be established to determine whether or not the variance falls within the expected range. A lower variance indicates a shorter proximity distance and therefore signals from devices within a variance range are established as being within a particular distance range. Denial/granting of service, or restricting of services can be performed in response to determining that a transmitting device is outside of a variance range. Variance computations can be performed at both ends of a transceiver link and results communicated and compared at both transceivers to further improve the accuracy of the proximity determination.
114 Citations
20 Claims
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1. A method for determining proximity between a first wireless device and a second wireless device, said method comprising:
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receiving a first signal from said first wireless device at said second wireless device;
in response to said receiving, determining a signal strength of said received signal;
computing a variance of said signal strength over time; and
determining whether or not said first wireless device is within a proximity range of said second wireless device in conformity with said computed variance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A wireless receiver, comprising:
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an antenna;
a receiver subsystem coupled to said antenna for detecting signals received from said antenna;
an amplitude detector coupled to said receiver subsystem for detecting an amplitude of said received signals; and
a processing subsystem coupled to said amplitude detector for computing a variance of said received signals and determining a proximity level of a transmitting source of said signal in conformity with said variance. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. A wireless communication system, comprising:
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a first transceiver, including a first amplitude detector coupled to a first receiver subsystem of said first transceiver for detecting an amplitude of first signals received by said first transceiver, and a first processing subsystem coupled to said first amplitude detector for computing a first variance of said first received signals; and
a second transceiver, including a second amplitude detector coupled to a second receiver subsystem of said second transceiver for detecting an amplitude of second signals received by said second transceiver, and a second processing subsystem coupled to said second amplitude detector for computing a second variance of said second received signals, and wherein said second transceiver transmits a second variance indication in conformity with said second variance to said first transceiver. - View Dependent Claims (19, 20)
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Specification