US 7,734,298 B2Granted

Estimating the location of a wireless terminal based on signal path impairment

AssigneePolaris Wireless, Inc.

InventorsTarun Kumar Bhattacharya, Martin Feuerstein, Scot Douglas Gordon, David Stevenson Spain, Jr.

Life of this patent

Estimating the term…

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Abstract

A technique for estimating the location of a wireless terminal at an unknown location in a geographic region is disclosed. The technique is based on the recognition that there are traits of electromagnetic signals that are dependent on topography, the receiver, the location of the transmitter, and other factors. For example, if a particular radio station is known to be received strongly at a first location and weakly at a second location, and a given wireless terminal at an unknown location is receiving the radio station weakly, it is more likely that the wireless terminal is at the second location than at the first location.

Claims3

Dependent claims

A method comprising:

(1) receiving (i) a first measured pathloss for a signal that is processed by a wireless terminal at a first time T1 and (ii) a second measured pathloss for the signal at a second time T2, wherein the first time does not equal the second time;
(2) estimating a first location of the wireless terminal at the second time based on (i) the first measured pathloss, (ii) the second measured pathloss, and (iii) an estimate of the probability that the wireless terminal at a second location at the first time T1 will still be at the second location at the second time T2;
wherein (2) comprises:
(2.1) comparing the first measured pathloss to:
(i) a first expected pathloss of the signal when the wireless terminal is at a third location at the first time T1, and
(ii) a second expected pathloss of the signal when the wireless terminal is at a fourth location at the first time T1;
and
(2.2) comparing the second measured pathloss to:
(i) a first expected pathloss of the signal when the wireless terminal is at a fifth location at the second time T2, and
(ii) a second expected pathloss of the signal when the wireless terminal is at a sixth location at the second time T2.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/419,657Filed 22 May 2006 · continuation in part
Priority: 22 Sep 1998
Published: US 2006/0240846 A126 Oct 2006
Granted: 8 Jun 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G01S 5/02521
Radio frequency fingerprinting: using a radio-map
G01S 5/021
Details: calibration, monitoring or correction
G01S 19/06
Providing aiding data: employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
G01S 19/252
Involving aiding data received from a cooperating element, e.g. assisted GPS: employing an initial estimate of location in generating assistance data

Family

Application09/158,296Parent of this continuation-in-part · filed 22 Sep 1998
Application09/532,418Parent of this continuation · filed 22 Mar 2000
Application10/128,128Parent of this continuation · filed 22 Apr 2002
Application10/910,511Parent of this continuation-in-part · filed 3 Aug 2004
Application60/700,771Us provisional application · filed 20 Jul 2005
Application60/757,066Us provisional application · filed 6 Jan 2006
US 2006/0240846 A1Pre-grant publication · published 26 Oct 2006
US 7,167,714 B2Parent of this continuation-in-part
US 6,782,265 B2Parent of this continuation
Application10/910,511Parent of this continuation
US 6,393,294 B1Parent of this continuation
US 6,269,246 B1Parent of this continuation-in-part
Application09/532,418Parent of this continuation-in-part
US 2003/0008668 A1Published application
US 2004/0259575 A1Published application
US 7,734,298 B2This patent

From the US filing history. Foreign family members aren’t listed.