System and method for locating wireless devices in an unsynchronized wireless environment
First Claim
1. A method for determining a location of a target device capable of transmitting a wireless radio signal based on a first time difference between arrival of a first signal at a first known location and arrival a second signal transmitted by the target device at the first known location, and at least a second time difference between arrival of the first signal at a second known location and arrival of the second signal at the second known location.
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0 Petitions
Accused Products
Abstract
A system and method for determining the location of a device (target device) in a wireless radio environment. The method involves transmitting a first signal. The target device transmits a second signal. The first signal and second signal are received at two or more known locations in the general proximity of the target device. The location of the target device is computed from the time difference of arrival of the first signal and arrival of the second signal at the two or more known locations. This technique does not require the measurements made at the known locations to be time-synchronized and, can be performed completely in software, if desired, using non-real-time post-processing.
226 Citations
97 Claims
- 1. A method for determining a location of a target device capable of transmitting a wireless radio signal based on a first time difference between arrival of a first signal at a first known location and arrival a second signal transmitted by the target device at the first known location, and at least a second time difference between arrival of the first signal at a second known location and arrival of the second signal at the second known location.
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45. A system for determining the location of a target device capable of transmitting a wireless radio signal, comprising:
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a. first and second radio receivers that receive wireless radio signals at first and second known locations, respectively; and
b. a computing device that computes the location of the target device from a first time difference between arrival of a first signal at the first known location and arrival of a second signal transmitted by the target device at the first known location and at least a second time difference between arrival of the first signal at the second known location and arrival of the second signal at the second known location. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63)
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- 64. A processor readable medium that stores instructions, which when executed, cause the processor to perform the step of computing a location of a target device capable of transmitting a wireless radio signal based on a first time difference between arrival of a first signal received at a first known location and arrival of a second signal transmitted by the target device at the first known location, and at least a second time difference between arrival of the first signal at a second known location and arrival of the second signal at the second known location.
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74. A wireless radio device comprising:
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a. a radio receiver that receives wireless radio signals;
b. an analog-to-digital converter (ADC) coupled to the radio receiver that converts analog receive signals output by the radio receiver to digital signals;
c. a memory coupled to the ADC that, in response to a memory store signal, stores digital signals output by the ADC; and
d. a processor coupled to the memory and to the ADC, that generates the memory store signal to cause the memory to store data output by the ADC associated with at least one of two signals received by the radio receiver that are associated with a location measurement operation to locate a target device. - View Dependent Claims (75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93)
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94. A method for detecting an unauthorized wireless radio device, comprising steps of:
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a. detecting a location of a wireless radio device;
b. determining whether the location of the wireless radio device is within a predetermined region; and
c. declaring the wireless radio device an unauthorized device if its location is outside of the predetermined region. - View Dependent Claims (95, 96, 97)
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Specification